A gas field dosing system and method capable of calibrating dosing amount on site

Abstract

The invention discloses a gas field dosing system capable of calibrating the dosing amount on site, comprising a pump inlet pipe, a pump, a drug delivery pipe, a flow meter, a calibration cylinder, a pressure inlet, a tee, and a drug delivery valve; the pump inlet pipe is connected and communicated with the pump; the pump is connected and communicated with the drug delivery pipe, and the drug delivery pipe is provided with a flow meter; the upper part of the calibration cylinder is provided with a pressure inlet, and the lower part is connected and communicated with the drug delivery pipe and the drug delivery valve through a tee. The invention can effectively solve the problems of dosing flow metering, adjustment, control, and bias flow in the dosing system, and can save the dosing amount; it has the advantages of easy implementation, safety and reliability, wide application, and easy promotion.

Description

Technical Field

[0001] The present invention relates to the field of adding chemicals to natural gas pipelines and gas wells, and in particular to a gas field adding chemical system and method capable of calibrating the amount of added chemical on site, which can be applied to gas wells and natural gas pipelines that require the addition of chemical agents. Background Art

[0002] In order to ensure the normal production and operation of natural gas channels such as gas wells, natural gas pipelines and their pipe fittings and instruments (collectively referred to as natural gas flow channels), it is usually necessary to add functional chemicals (also known as reagents) that are liquid at normal temperature and pressure into the natural gas flow channels, collectively referred to as dosing.

[0003] When adding medicine, it is generally necessary to control, adjust and measure the dosage of the medicine (i.e. the amount of medicine added) or the flow rate of the medicine (i.e. the flow rate of the medicine added).

[0004] At present, the domestic main method is to use metering pumps to control, adjust and measure the dosage or flow rate of the medicine. This method has the following defects:

[0005] 1. This method cannot accurately control, adjust, and measure the dosing flow rate, but can only roughly control, adjust, and measure the dosing flow rate.

[0006] It is known from common knowledge in the art that a metering pump uses a cam mechanism to control the length of the plunger stroke to control the percentage of the rated displacement (or theoretical displacement) of the metering pump, thereby achieving the purpose of controlling the displacement of the metering pump; for example, if the rated displacement of the metering pump is 60 liters / hour, the displacement of the metering pump can be adjusted to 50% of the rated displacement by using its cam mechanism to control the plunger stroke at 50% of the maximum stroke, thereby adjusting the displacement of the metering pump to 30 liters / hour; since the metering pump itself does not have a flow meter, its plunger has leakage and the leakage will increase with the continuous wear of the plunger sealing box and the continuous wear of the discharge valve and the inlet valve, so it is impossible to accurately control, adjust, and meter the dosing flow rate using a metering pump.

[0007] 2. This method cannot effectively control, adjust, and measure the dosing flow rate of a 1-pump multi-tube dosing system, cannot solve the dosing flow deviation problem of a 1-pump multi-tube dosing system, and cannot meet the dosing flow control, adjustment, and metering requirements of this type of dosing system.

[0008] Take the Qinghai gas field as an example.

[0009] The gas field uses high-pressure gas lift production technology. Generally, 2 to 50 high-pressure natural gas injection pipelines are set up in one gas distribution valve group to distribute 10MPa high-pressure natural gas to the casings of 2 to 50 gas wells for gas lift production.

[0010] Take the gas distribution valve group with three high-pressure natural gas injection pipelines in the gas field as an example.Figure 1 As shown, the process can be briefly described as follows: the gas distribution valve group is provided with gas injection pipeline 110, gas injection pipeline 111, and gas injection pipeline 112, and 10MPa natural gas is distributed to three gas wells respectively; in order to prevent the formation of hydrate blockage in the gas injection pipeline 110, gas injection pipeline 111, and gas injection pipeline 112, methanol is respectively injected into the gas injection pipeline 110, gas injection pipeline 111, and gas injection pipeline 112 by a metering pump 102 to prevent freezing and unblocking, and the flow rate of the injected methanol is adjusted, controlled, and metered at any time according to the constantly changing gas injection volume of the gas injection pipeline 110, gas injection pipeline 111, and gas injection pipeline 112 and different anti-freezing and unblocking requirements; The process of adding methanol can be further summarized as follows: 30 to 60 liters / day (or 1.25 to 2.5 liters / hour) of methanol is sucked into the metering pump 102 through the pump inlet pipeline 101, and then 30 to 60 liters / day (or 1.25 to 2.5 liters / hour) of methanol is distributed to the dosing pipe 107, the dosing pipe 108, and the dosing pipe 109 through the manifold 103, and the methanol injection flow rate of the dosing pipe 107 is controlled and adjusted by the valve 104, the methanol injection flow rate of the dosing pipe 108 is controlled and adjusted by the valve 106, and the methanol injection flow rate of the dosing pipe 107 is controlled and adjusted by the valve 105, and the methanol injection flow rate of the dosing pipe 108 is controlled and adjusted by the valve 106 according to the freezing and blocking conditions of the gas injection pipeline 110, the gas injection pipeline 111, and the gas injection pipeline 112. 109 of methanol filling flow; thus, it can be known that although the dosing system of the gas distribution valve group can determine the total methanol flow of the manifold 103 to be 30 to 60 liters / day (or 1.25 to 2.5 liters / hour) through the displacement of the metering pump 102, it is unable to determine the methanol flow of each of the dosing pipes 107, 108, and 109, and therefore it is unable to use valves 104, 105, and 106 to control and adjust the methanol flow of the dosing pipes 107, 108, and 109 to the methanol flow required for antifreeze and unblocking of the gas injection lines 110, 111, and 112; the production of the gas distribution valve group The operation status shows that during the winter period from December to March, the operators can only rely on their personal feelings to adjust the opening of valves 104, 105, and 106 to control the methanol flow entering gas injection pipelines 110, 111, and 112. They are unable to determine the specific methanol flow values ​​and the degree of deviation in gas injection pipelines 110, 111, and 112, and are even more unable to adjust and solve the existing methanol deviation problem, which leads to frequent freezing and blockage of one or two gas injection pipelines, seriously affecting the production of gas wells. Therefore, the current 1-pump multi-tube dosing system cannot meet the production requirements of the Qinghai gas field.

[0011] At present, the flow meter is generally used to measure the liquid flow in China, such as using a gear flow meter to measure the instantaneous water flow and cumulative water flow in the water pipe; this method is used to measure the dosage or flow of the agent, which has the following defects:

[0012] 1. Gear flowmeter has leakage. When the dosing flow is small and the viscosity of the agent is low, the metering error caused by the leakage can reach 57%, which is hundreds of times the metering error of the gear flowmeter calibrated at the factory. It is difficult to effectively measure the dosing flow and cannot meet the actual production requirements.

[0013] It is known from common knowledge in the art that the viscosity of different reagents varies greatly. For example, the viscosity of ethylene glycol used as a natural gas hydrate inhibitor is several times that of clean water. The viscosity of polyacrylamide aqueous solution and polyvinyl pyrrolidone aqueous solution used as natural gas hydrate inhibitors is hundreds of times that of clean water. However, the viscosity of methanol, also used as a natural gas hydrate inhibitor, is lower than that of clean water. The lower the viscosity of the reagent, the greater the leakage of the gear flowmeter and the greater its metering error.

[0014] It is known from common knowledge in this field that gear flow meters are generally used when leaving the factory. Figure 2 The calibration device shown and its measurement error when calibrated with clean water.

[0015] Tests show that: Figure 2 The calibration device and methanol shown in the figure are used to calibrate the gear flowmeter. The results show that when the pressure gauge 202 (accuracy 1.6 level) reads 0.03 MPa, the methanol outflow from the DN15 outlet 206 remains unchanged after being adjusted by the DN15 stop valve 204. If the cumulative flow of the gear flowmeter 203 (accuracy 0.5 level, range 0.3-60 liters / hour) in 10 minutes is 0.2 liters, then the methanol outflow taken from the outlet 206 by the glass measuring cylinder 207 is 0.46 liters. It can be seen that the leakage of the gear flowmeter 203 is 1.56 liters / hour. Further calculation shows that when the methanol flow measured by the gear flowmeter 203 is 1.2 liters / hour, the average methanol flow obtained by calibration is 2.76 liters / hour. It can be seen that when the gear flowmeter 203 measures a small flow of methanol, its measurement error can reach 57%, which is 114 times its factory calibration measurement error.

[0016] It is known from common knowledge in the art that the national standard requires that the maximum error of industrial instruments is 4%. The maximum allowable value of the measurement error of existing industrial flow meters when leaving the factory or being calibrated by an authoritative measurement agency is ±4%. When users use industrial flow meters, the maximum allowable value of the measurement error calibrated indoors is also ±4%. The dosing flow rate of gas fields is generally very small. Taking the gas distribution valve group with three gas injection pipelines in the Qinghai gas field as an example, the total methanol filling amount of the three gas injection pipelines is 30 to 60 liters / day (or 1.25 to 2.5 liters / hour), and the average methanol filling amount of a single gas injection pipeline is only 10 to 20 liters / day (or 0.4 to 0.8 liters / hour). Therefore, when the error of the flow meter reaches 57%, it is impossible to obtain the real and effective dosing amount (or dosing flow) based on the flow meter, and it is impossible to meet the production requirements of the gas field.

[0017] 2. The leakage of the gear flowmeter belongs to the mechanical gap leakage, and its leakage amount will inevitably change with the change of the pressure difference before and after the flowmeter; due to the inevitable complexity, volatility and randomness of the fluid in actual production conditions, the pressure difference before and after the gear flowmeter in actual production applications is bound to vary greatly and change randomly at any time, so its actual leakage amount is also very different and changes randomly at any time; therefore, the measurement error calibrated by the gear flowmeter before leaving the factory or under other indoor conditions is very different from the measurement error in actual production applications, which makes it difficult to accurately measure the dosing flow and cannot meet actual production requirements.

[0018] It is known from common knowledge and fluid mechanics in this field that: when the geometric size of the gap is constant, the flow rate of the fluid through the gap varies with the pressure difference before and after the gap; the flow resistance of the fluid through a small hole with an aperture of 1mm and a large hole with an aperture of 10mm are different; when the fluid passes through a small hole with an aperture of 1mm and a large hole with an aperture of 10mm at the same time, if the flow rate of the fluid through the large hole with an aperture of 10mm is changed, the flow rate through the small hole with an aperture of 1mm will inevitably change; it can be seen that even if the pressure difference before and after the gear flowmeter is constant, the leakage of the gear flowmeter at instantaneous flow rates of 10 liters / hour and 1 liter / hour is different; that is, even if the pressure difference before and after the same gear flowmeter is constant, the leakage of the gear flowmeter when measuring different instantaneous flow rates is different.

[0019] In short, the above-mentioned methods of controlling, adjusting and measuring the dosage (or dosage flow rate) cannot effectively measure the dosage and dosage flow rate when the dosage is small. Summary of the invention

[0020] The "medicine" in the present invention is also called a functional chemical agent, sometimes referred to as medicine, and is liquid at room temperature and pressure.

[0021] The term "dosing" in the present invention is a general term for adding functional chemicals, and sometimes specifically refers to the process of adding liquid chemicals into oil, gas, water wells, and pipelines.

[0022] The "dosage" in the present invention refers to the volume or weight of the added functional chemical agent, and sometimes also refers to the dosing flow rate.

[0023] The "dosing flow rate" in the present invention is sometimes referred to as the dosage, which is an abbreviation for the flow rate of adding functional chemicals, and generally refers to the volume flow rate of functional chemicals.

[0024] The first technical problem to be solved by the present invention is to provide a dosing system that can calibrate the dosing amount on site; the dosing system overcomes the defects of the existing dosing system (or device), can calibrate the dosing flow (or dosing amount) on site at the production site, can effectively solve the dosing flow metering, adjustment, control, and deviation problems of the existing dosing system, can save the dosing amount, and can meet the dosing requirements required for production; it has the advantages of easy implementation, safety and reliability, wide application, and easy promotion.

[0025] The second technical problem to be solved by the present invention is to provide a method for on-site calibration of the dosing flow metering and regulation control of the above-mentioned dosing system; this method overcomes the defects of the dosing flow metering, regulation and control of the existing dosing system (or device), can effectively solve the dosing amount metering, regulation, control and deviation problems existing in the dosing system, can save the dosing amount, and can meet the dosing requirements required for production; it has the advantages of easy implementation, safety and reliability, wide application, and easy promotion.

[0026] In order to solve the above-mentioned first technical problem, the first technical solution adopted by the present invention is:

[0027] A gas field dosing system capable of calibrating the dosing amount on site, comprising a pump inlet pipe, a pump, a drug delivery pipe, a flow meter, a calibration cylinder, a pressure inlet, a tee, and a drug outlet valve;

[0028] The pump inlet pipe is connected to the pump;

[0029] The pump is connected to a medicine delivery tube, and a flow meter is arranged on the medicine delivery tube;

[0030] The upper part of the calibration cylinder is provided with a pressure inlet, and the lower part is connected to the drug delivery tube and the drug outlet valve respectively through a three-way connection.

[0031] The calibration cylinder should be able to meet the production needs of on-site rapid observation (including but not limited to visual inspection) or measurement of the volume of medicine entering the calibration cylinder under pressure conditions, and be able to meet the production requirements of calibration and calibration flow meters; technical personnel in this field can determine the specific form and shape, pressure resistance grade, inner diameter, outer diameter, and installation method of the calibration cylinder based on existing technical means.

[0032] Preferably, in order to facilitate the addition of medicine, the pump is any one of a volumetric pump, a metering pump, a plunger pump, a gear pump, and a centrifugal pump.

[0033] It is known from common knowledge in the art that the displacement of plunger pumps, gear pumps and centrifugal pumps can be adjusted and controlled by variable frequency speed regulation, and thus can be used to adjust and control the dosage.

[0034] Preferably, in order to facilitate flame-free installation, the drug delivery tube is a high-pressure hose reinforced with steel wire or other high-strength fibers.

[0035] Preferably, for the convenience of measurement, the flowmeter is any one of a gear flowmeter, a rotor flowmeter, an ultrasonic flowmeter, an external clamp-on ultrasonic flowmeter, a portable ultrasonic flowmeter, an electromagnetic flowmeter, a float flowmeter, a water meter, an Annubar flowmeter, a elbow flowmeter, a balanced flowmeter, a wedge flowmeter, a target flowmeter, a vortex flowmeter, a turbine flowmeter, an orifice flowmeter, a vortex flowmeter, and a differential pressure flowmeter.

[0036] Preferably, for convenient or fast calibration, measurement and correction, the calibration cylinder is any one of a magnetic flap level gauge, a magnetic float level gauge, a magnetically sensitive electronic two-color level gauge, a glass tube level gauge, a glass plate level gauge, a color quartz tube level gauge, a sight glass level gauge and an ultrasonic level gauge.

[0037] Preferably, in order to realize remote transmission of liquid level measurement signals, the calibration cylinder is a remote transmission type magnetic float type liquid level gauge made by utilizing the buoyancy principle, magnetic coupling effect, and sensors, transmitters, and displays.

[0038] Preferably, in order to realize remote transmission of liquid level measurement signals, the calibration cylinder includes a housing with a flange, a magnetic float liquid level transmitter with a flange, an upper interface and a bottom interface; the lower end of the magnetic float liquid level transmitter extends to the lower part of the housing, and the upper end of the magnetic float liquid level transmitter is connected to the top flange of the housing;

[0039] The magnetic float liquid level transmitter can convert the liquid level into a standard electrical signal and transmit it remotely.

[0040] Preferably, in order to realize remote transmission of liquid level measurement signals, the calibration cylinder includes a threaded shell, a threaded hydrostatic liquid level transmitter, an upper interface and a bottom interface, the lower end of the hydrostatic liquid level transmitter extends to the lower part of the shell, and the upper part of the hydrostatic liquid level transmitter is threadedly connected to the top of the shell; more preferably, the hydrostatic liquid level transmitter is a magnetostrictive liquid level transmitter.

[0041] It can be known from the common knowledge in the art that the static pressure type liquid level transmitter can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the static pressure type liquid level transmitter can effectively measure the liquid level.

[0042] Preferably, in order to realize remote transmission of liquid level measurement signals, the calibration cylinder includes a shell, a pressure transmitter, an upper interface and a bottom interface, and the pressure transmitter is arranged at the lower part of the shell.

[0043] It is known from common knowledge in the art that the pressure transmitter can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the pressure transmitter can effectively measure the liquid level.

[0044] Preferably, in order to reduce costs, the calibration cylinder comprises a shell, a pressure gauge, a top interface and a bottom interface, and the pressure gauge is arranged at the lower part of the shell;

[0045] The pressure gauge is a precision pressure gauge with a 0.1 grade accuracy.

[0046] It is known from common knowledge in the art that after the pressure value generated by the liquid column and the liquid density are known, the pressure value can be quickly converted into the corresponding liquid level; therefore, when the liquid level changes, the precision pressure gauge can effectively measure the liquid level.

[0047] Preferably, in order to reduce costs, the calibration cylinder includes a shell, a magnetic float, a top interface, non-ferrous iron powder and a bottom interface, the magnetic float is arranged in the shell, and the non-ferrous iron powder is arranged outside the shell at a position corresponding to the magnetic float;

[0048] The working principle is: when the magnetic float rises or falls with the liquid level, the colored iron powder on the outer wall of the shell rises or falls accordingly, which can indicate the liquid level.

[0049] Preferably, in order to facilitate management and maintenance, a pressure inlet switch valve is provided on the pressure inlet.

[0050] Furthermore, for ease of installation, a dosing system capable of calibrating the dosing amount on site includes a pump inlet pipe, a pump, a drug delivery pipe, a flow meter, a calibration cylinder, a pressure inlet port, and a drug outlet valve;

[0051] The pump inlet pipe is connected to the pump;

[0052] The pump is connected to a medicine delivery tube, and a flow meter is arranged on the medicine delivery tube;

[0053] The upper side of the calibration tube is provided with a pressure inlet, the lower side is connected to the drug delivery tube, and the bottom is connected to the drug outlet valve. Preferably, in order to facilitate management and maintenance, a pressure inlet switch valve is provided on the pressure inlet.

[0054] Furthermore, in order to solve the problems of dosing flow control, adjustment, metering and calibration of a 1-pump multi-tube dosing system, a dosing system capable of calibrating the dosing amount on site includes a pump inlet pipe, a pump, a manifold tee, a first drug delivery pipe, a first flow meter, a first calibration cylinder, a first pressure inlet, a first tee, a first drug outlet valve, a second drug delivery pipe, a second flow meter, a second calibration cylinder, a second pressure inlet, a second tee and a second drug outlet valve;

[0055] The pump inlet pipe is connected to the pump;

[0056] The pump is connected to one interface of the manifold tee, another interface of the manifold tee is connected to the first drug delivery tube, and the third interface of the manifold tee is connected to the second drug delivery tube;

[0057] A first flow meter is provided on the first drug delivery tube, and a second flow meter is provided on the second drug delivery tube;

[0058] The first-path calibration cylinder has a first-path pressure inlet at the upper portion, and the lower portion is connected to the first-path drug delivery tube and the first-path drug outlet valve respectively through a first-path tee.

[0059] The second-path calibration cylinder has a second-path pressure-introducing port at the upper portion, and the lower portion is connected to the second-path drug delivery tube and the second-path drug outlet valve respectively through a second-path tee.

[0060] The first-path calibration cylinder and the second-path calibration cylinder should be able to meet the production requirements of on-site rapid observation (including but not limited to visual inspection) or measurement of the volume of the medicine entering therein under pressure conditions, and be able to meet the production requirements of calibrating the first-path flowmeter and the second-path flowmeter; technical personnel in this field can determine the specific form, shape, pressure resistance grade, inner diameter, outer diameter, and installation method of the first-path calibration cylinder and the second-path calibration cylinder based on existing technical means.

[0061] Preferably, the first drug delivery tube and the second drug delivery tube are identical except for the length, the first flow meter and the second flow meter are exactly the same, the first calibration cylinder and the second calibration cylinder are exactly the same, the first tee and the second tee are exactly the same, and the first drug outlet valve and the second drug outlet valve are exactly the same.

[0062] Preferably, in order to facilitate management and maintenance, a pressure inlet switch valve is provided on the pressure inlet.

[0063] Furthermore, for safety management, a safety valve, a pressure gauge (or a pressure transmitter), a vent valve, a drain valve, and a reflux regulating valve are provided on the pump or the drug delivery tube.

[0064] It is known from common knowledge that the displacement of the pump can be adjusted by using a reflux regulating valve.

[0065] In order to solve the above-mentioned first technical problem, the second technical solution adopted by the present invention is:

[0066] A gas field dosing system capable of calibrating the dosing amount on site, comprising a drip tank, a bracket, a flow meter, a drug delivery pipe, a manifold, a regulating valve, a main switch valve, a drug tee, a calibration switch valve, a calibration cylinder, a calibration cylinder pressure-inducing pipe, a pressure-inducing tee, a pressure-inducing valve, and a drip tank pressure-inducing pipe;

[0067] A bracket is arranged at the lower part (or bottom) of the drip tank;

[0068] The bottom of the drip tank is connected to the drug delivery tube;

[0069] The drug delivery tube is provided with a flow meter and a main switch valve;

[0070] One end of the drug delivery tube is connected to the side interface of the medicine three-way, and the other end is connected to the bottom (or lower part) of the drip tank;

[0071] The lower interface of the medicine three-way is connected to the regulating valve, the upper interface is connected to the calibration switch valve, and the side interface is connected to the medicine delivery tube;

[0072] The upper part of the calibration switch valve is connected to the calibration cylinder, and the lower part is connected to the reagent three-way valve;

[0073] The upper part of the calibration cylinder is connected to the calibration cylinder pressure-inducing pipe, and the lower part is connected to the calibration switch valve;

[0074] One end of the calibration cylinder pressure-inducing pipe is connected to the upper part of the calibration cylinder, and the other end is connected to the upper interface of the pressure-inducing tee.

[0075] The side interface of the pressure-inducing three-way is connected to the pressure-inducing pipe of the drip tank, the lower part is connected to the pressure-inducing valve, and the upper part is connected to the pressure-inducing pipe of the calibration cylinder;

[0076] One end of the pressure-inducing tube of the drip tank is connected to the upper part (or top) of the drip tank, and the other end is connected to the side interface of the pressure-inducing tee;

[0077] The lower part of the pressure-inducing valve is communicated with the upper part (or top) of the manifold, and the upper part is connected and communicated with the lower part of the pressure-inducing tee;

[0078] The lower part of the regulating valve is communicated with the upper part (or top) of the manifold, and the upper part is connected and communicated with the lower interface of the tee of the medicine;

[0079] The top elevation of the calibration cylinder is equal to or higher than the top elevation of the drip tank;

[0080] The bottom elevation of the calibration cylinder is equal to or lower than the bottom elevation of the drip tank.

[0081] The calibration cylinder should be able to meet the production needs of on-site rapid observation (including but not limited to visual inspection) or measurement of the volume of medicine entering the calibration cylinder under pressure conditions, and be able to meet the production requirements of calibration and calibration flow meters; technical personnel in this field can determine the specific form and shape, pressure resistance grade, inner diameter, outer diameter, and installation method of the calibration cylinder based on existing technical means.

[0082] Furthermore, for the convenience of operation, a flow meter is installed behind the main switch valve on the drug delivery tube.

[0083] Furthermore, in order to keep the dosage unchanged, an auxiliary switch valve is provided between the regulating valve and the reagent three-way;

[0084] The upper end of the auxiliary switch valve is connected and communicated with the lower interface of the medicament three-way, and the lower end is connected and communicated with the regulating valve.

[0085] Furthermore: in order to facilitate installation and observation, the top elevation of the calibration cylinder is lower than the top elevation of the drip tank; the bottom elevation of the calibration cylinder is higher than the bottom elevation of the drip tank.

[0086] Further: In order to facilitate maintenance and management, an auxiliary pressure-leading valve is provided on the pressure-leading pipe of the calibration cylinder.

[0087] Furthermore: the drip tank, bracket, medicine tee, and pressure tee are made of carbon steel or other metals; the regulating valve, main switch valve, calibration switch valve, and pressure valve are steel valves or other metal valves; the drug delivery tube, junction tube, calibration cylinder pressure tube, and drip tank pressure tube are steel pipes or other metal pipes; the flow meter and calibration cylinder are made of steel or other metals.

[0088] Further: the drug delivery tube is any one of a non-metallic tube and a rubber tube; more preferably, the drug delivery tube is a high-pressure hose reinforced with steel wire or other high-strength fibers; the bracket is made of non-metal.

[0089] Further: the flowmeter is any one of a gear flowmeter, a rotor flowmeter, an ultrasonic flowmeter, an external clamp-on ultrasonic flowmeter, a portable ultrasonic flowmeter, an electromagnetic flowmeter, a float flowmeter, a water meter, an Annubar flowmeter, a elbow flowmeter, a balanced flowmeter, a wedge flowmeter, a target flowmeter, a vortex flowmeter, a turbine flowmeter, an orifice flowmeter, a vortex flowmeter, and a differential pressure flowmeter.

[0090] Further: the calibration cylinder is any one of a magnetic flap level gauge, a magnetic float level gauge, a magnetic sensitive electronic two-color level gauge, a glass tube level gauge, a glass plate level gauge, a color quartz tube level gauge, a sight glass level gauge, and an ultrasonic level gauge.

[0091] Furthermore: the calibration cylinder is a remote transmission magnetic float type liquid level gauge made by utilizing the buoyancy principle, magnetic coupling effect and sensors, transmitters and displays.

[0092] Further: the calibration cylinder includes a housing with a flange, a magnetic float liquid level transmitter with a flange, an upper interface and a bottom interface; the lower end of the magnetic float liquid level transmitter extends to the lower part of the housing, and the upper end of the magnetic float liquid level transmitter is connected to the top flange of the housing;

[0093] The magnetic float liquid level transmitter can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the static pressure liquid level transmitter can effectively measure the liquid level.

[0094] Further: the calibration cylinder includes a threaded shell, a threaded hydrostatic level transmitter, an upper interface and a bottom interface, the lower end of the hydrostatic level transmitter extends to the lower part of the shell, and the upper part of the hydrostatic level transmitter is threadedly connected to the top of the shell;

[0095] The static pressure liquid level transmitter is a magnetostrictive liquid level transmitter;

[0096] The static pressure type liquid level transmitter can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the static pressure type liquid level transmitter can effectively measure the liquid level.

[0097] Further: the calibration cylinder includes a shell, a pressure transmitter, an upper interface and a bottom interface, and the pressure transmitter is arranged at the lower part of the shell;

[0098] The pressure transmitter can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the pressure transmitter can effectively measure the liquid level.

[0099] Further: the calibration cylinder includes a shell, a pressure gauge, a top interface and a bottom interface, and the pressure gauge is arranged at the lower part of the shell;

[0100] The pressure gauge is a precision pressure gauge with a 0.1 grade accuracy.

[0101] Furthermore: the calibration cylinder includes a shell, a magnetic float, a top interface, non-ferrous iron powder and a bottom interface, the magnetic float is arranged in the shell, and the non-ferrous iron powder is arranged outside the shell at a position corresponding to the magnetic float.

[0102] Furthermore, for safety management, a liquid level meter, a safety valve, a pressure gauge (or a pressure transmitter), a vent valve, and a drain valve are provided on the drip tank.

[0103] Furthermore, in order to facilitate the replenishment of medicine, a medicine replenishment valve is provided on the drip tank.

[0104] Furthermore, in order to maintain pressure, the drip tank is a closed container and / or a pressure container.

[0105] To solve the above-mentioned first technical problem, the third technical solution adopted by the present invention is:

[0106] A gas field dosing system capable of calibrating the dosing amount on site, comprising a drip tank, a bracket, a drug delivery pipe, a manifold, a regulating valve, a flow meter, a main switch valve, a drug tee, a calibration cylinder, a calibration cylinder pressure-inducing pipe, a pressure-inducing tee, a pressure-inducing valve, and a drip tank pressure-inducing pipe;

[0107] A bracket is arranged at the lower part (or bottom) of the drip tank;

[0108] The bottom of the drip tank is connected to the drug delivery tube;

[0109] A main switch valve is arranged on the drug delivery tube;

[0110] One end of the drug delivery tube is connected to the side interface of the medicine three-way, and the other end is connected to the bottom (or lower part) of the drip tank;

[0111] The lower interface of the medicine tee is connected to the flow meter, the upper interface is connected to the lower or bottom interface of the calibration cylinder, and the side interface is connected to the medicine delivery tube;

[0112] The upper or top interface of the calibration cylinder is connected to the calibration cylinder pressure-inducing tube, and the lower part is connected to the upper interface of the medicine three-way;

[0113] One end of the calibration cylinder pressure-inducing pipe is connected to the upper or top interface of the calibration cylinder, and the other end is connected to the upper interface of the pressure-inducing tee.

[0114] The side interface of the pressure-inducing three-way is connected to the pressure-inducing pipe of the drip tank, the lower part is connected to the pressure-inducing valve, and the upper part is connected to the pressure-inducing pipe of the calibration cylinder;

[0115] One end of the pressure-inducing tube of the drip tank is connected to the upper part (or top) of the drip tank, and the other end is connected to the side interface of the pressure-inducing tee;

[0116] The lower part of the pressure-inducing valve is communicated with the upper part (or top) of the manifold, and the upper part is connected and communicated with the lower part of the pressure-inducing tee;

[0117] The lower interface of the flow meter is connected to the pressure regulating valve, and the upper part is connected to the lower interface of the three-way connection of the medicine;

[0118] The lower part of the pressure regulating valve is connected to the upper part (or top) of the manifold, and the upper part is connected to the lower interface of the flow meter;

[0119] The top elevation of the calibration cylinder is equal to or higher than the top elevation of the drip tank;

[0120] The bottom elevation of the calibration cylinder is equal to or lower than the bottom elevation of the drip tank.

[0121] The calibration cylinder should be able to meet the production needs of on-site rapid observation (including but not limited to visual inspection) or measurement of the volume of medicine entering the calibration cylinder under pressure conditions, and be able to meet the production requirements of calibration and calibration flow meters; technical personnel in this field can determine the specific form and shape, pressure resistance grade, inner diameter, outer diameter, and installation method of the calibration cylinder based on existing technical means.

[0122] Further: in order to facilitate calibration observation, a calibration switch valve is provided between the calibration cylinder and the reagent tee;

[0123] The upper end of the calibration switch valve is connected and communicated with the lower interface of the calibration cylinder, and the lower end is connected and communicated with the upper interface of the tee of the medicine.

[0124] Furthermore: in order to facilitate installation and observation, the top elevation of the calibration cylinder is lower than the top elevation of the drip tank; the bottom elevation of the calibration cylinder is higher than the bottom elevation of the drip tank.

[0125] Further: In order to facilitate maintenance and management, an auxiliary pressure-leading valve is provided on the pressure-leading pipe of the calibration cylinder.

[0126] Furthermore: the drip tank, bracket, medicine tee, and pressure tee are made of carbon steel or other metals; the regulating valve, main switch valve, calibration switch valve, and pressure valve are steel valves or other metal valves; the drug delivery tube, junction tube, calibration cylinder pressure tube, and drip tank pressure tube are steel pipes or other metal pipes; the flow meter and calibration cylinder are made of steel or other metals.

[0127] Further: the drug delivery tube is any one of a non-metallic tube and a rubber hose, and the bracket is made of non-metal; more preferably, the drug delivery tube is a high-pressure hose reinforced with steel wire or other high-strength fibers.

[0128] Further: the flowmeter is any one of a gear flowmeter, a rotor flowmeter, an ultrasonic flowmeter, an external clamp-on ultrasonic flowmeter, a portable ultrasonic flowmeter, an electromagnetic flowmeter, a float flowmeter, a water meter, an Annubar flowmeter, a elbow flowmeter, a balanced flowmeter, a wedge flowmeter, a target flowmeter, a vortex flowmeter, a turbine flowmeter, an orifice flowmeter, a vortex flowmeter, and a differential pressure flowmeter.

[0129] Further: the calibration cylinder is any one of a magnetic flap level gauge, a magnetic float level gauge, a magnetic sensitive electronic two-color level gauge, a glass tube level gauge, a glass plate level gauge, a color quartz tube level gauge, a sight glass level gauge, and an ultrasonic level gauge.

[0130] Furthermore: the calibration cylinder is a remote transmission magnetic float type liquid level gauge made by utilizing the buoyancy principle, magnetic coupling effect and sensors, transmitters and displays.

[0131] Further: the calibration cylinder includes a housing with a flange, a magnetic float liquid level transmitter with a flange, an upper interface and a bottom interface; the lower end of the magnetic float liquid level transmitter extends to the lower part of the housing, and the upper end of the magnetic float liquid level transmitter is connected to the top flange of the housing;

[0132] The magnetic float liquid level transmitter can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the static pressure liquid level transmitter can effectively measure the liquid level.

[0133] Further: the calibration cylinder includes a threaded shell, a threaded hydrostatic level transmitter, an upper interface and a bottom interface, the lower end of the hydrostatic level transmitter extends to the lower part of the shell, and the upper part of the hydrostatic level transmitter is threadedly connected to the top of the shell;

[0134] The static pressure liquid level transmitter is a magnetostrictive liquid level transmitter;

[0135] The static pressure type liquid level transmitter can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the static pressure type liquid level transmitter can effectively measure the liquid level.

[0136] Further: the calibration cylinder includes a shell, a pressure transmitter, an upper interface and a bottom interface, and the pressure transmitter is arranged at the lower part of the shell;

[0137] The pressure transmitter can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the pressure transmitter can effectively measure the liquid level.

[0138] Further: the calibration cylinder includes a shell, a pressure gauge, a top interface and a bottom interface, and the pressure gauge is arranged at the lower part of the shell;

[0139] The pressure gauge is a precision pressure gauge with a 0.1 grade accuracy.

[0140] Furthermore: the calibration cylinder includes a shell, a magnetic float, a top interface, non-ferrous iron powder and a bottom interface, the magnetic float is arranged in the shell, and the non-ferrous iron powder is arranged outside the shell at a position corresponding to the magnetic float.

[0141] Furthermore: for safety management, the drip tank is provided with a liquid level meter, a safety valve, a pressure gauge (or a pressure transmitter), a vent valve, and a drain valve.

[0142] Furthermore, in order to facilitate the replenishment of medicine, a medicine replenishment valve is provided on the drip tank.

[0143] Furthermore, in order to maintain pressure, the drip tank is a closed container and / or a pressure container.

[0144] In order to solve the second technical problem, the method for on-site calibration of dosing flow metering and regulation control of the dosing system of the present invention adopts a first technical solution: comprising the following steps:

[0145] 1) Connection balance pressure:

[0146] At the top of the natural gas pipeline, first use the medicine outlet pipeline to vertically connect the medicine outlet valve to the top of the natural gas pipeline, and then use the pressure inlet pipeline to connect the pressure inlet and the natural gas pipeline, so that the pressure in the calibration cylinder is automatically balanced with the pressure in the natural gas pipeline and the medicine outlet valve;

[0147] 2) Dosing:

[0148] Open the medicine outlet valve and start the pump. The medicine will flow into the natural gas pipeline through the pump inlet pipe, pump, medicine delivery pipe, flow meter, tee, medicine outlet valve and medicine outlet pipeline in sequence under the action of gravity.

[0149] 3) Flow meter measurement:

[0150] Keep the flow state of the reagent entering the natural gas pipeline in sequence through the pump inlet pipe, pump, drug delivery pipe, flow meter, tee, drug outlet valve, and drug outlet pipeline under the action of gravity; read and record the instantaneous flow and cumulative flow of the flow meter to obtain the average dosing flow of the reagent entering the natural gas pipeline;

[0151] 4) Calibrate the flow meter measurement error

[0152] Close the medicine outlet valve, let the medicine flow upward into the calibration cylinder, read the increase in the liquid level of the calibration cylinder per unit time, calculate the volume of the medicine entering the calibration cylinder per unit time, and obtain the medicine flow rate of the medicine entering the calibration cylinder; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder - average dosing flow rate entering the natural gas pipeline) ÷ medicine flow rate entering the calibration cylinder × 100%, obtain the calibration measurement error of the flow meter;

[0153] 5) Calibrate and correct the dosing flow rate

[0154] First, open the medicine outlet valve, and let the medicine enter the natural gas pipeline through the pump inlet pipe, pump, medicine delivery pipe, flow meter, tee, and medicine outlet valve in sequence under the action of gravity; then, according to the flow meter calibration measurement error obtained in step 4), calibrate and correct the instantaneous flow and cumulative flow of the flow meter that are read and recorded again;

[0155] 6) Adjust the dosing flow rate to the required dosing amount

[0156] According to the flow meter calibration measurement error obtained in step 4), the instantaneous flow rate and the cumulative flow rate of the flow meter recorded are calibrated and corrected; then, according to the calibrated and corrected instantaneous flow rate and the cumulative flow rate readings of the flow meter, the displacement of the pump is gradually adjusted to the required dosing flow rate.

[0157] Preferably, in order to facilitate inspection and management of the calibration cylinder, a valve is provided on the pressure-conducting pipeline.

[0158] Furthermore, in order to solve the problem of calibration of the dosing flow rate of gas well dosing, the method for on-site calibration of dosing flow metering and regulation control of the dosing system of the present invention adopts a first technical solution: comprising the following steps:

[0159] 1) Connection balance pressure:

[0160] Use the medicine outlet pipeline to vertically connect the medicine outlet valve and the casing joint, and then use the pressure inlet pipeline to connect the pressure inlet and the casing joint, so that the pressure in the calibration cylinder and the pressure in the gas well casing are automatically balanced;

[0161] It is known from the common knowledge in this field that the casing joint is a commonly used product in this field, which is generally connected to the casing valve with a pipe thread and the other end is closed.

[0162] 2) Dosing:

[0163] Open the medicine outlet valve and start the pump. Under the action of gravity, the medicine passes through the pump inlet pipe, pump, medicine delivery pipe, flow meter, tee, medicine outlet valve, medicine outlet pipeline, casing joint, and gas well casing valve in sequence and enters the gas well casing;

[0164] 3) Flow meter measurement:

[0165] Keep the flow state of the reagent entering the gas well casing unchanged through the pump inlet pipe, pump, drug delivery pipe, flow meter, tee, drug outlet valve, drug outlet pipeline, casing joint, and gas well casing valve in sequence; read and record the instantaneous flow and cumulative flow of the flow meter to obtain the average dosing flow of the reagent entering the gas well casing;

[0166] 4) Calibrate the flow meter measurement error

[0167] Close the medicine outlet valve, let the medicine flow upward into the calibration cylinder, read the increase in the calibration cylinder liquid level per unit time, calculate the volume of the medicine entering the calibration cylinder per unit time, and obtain the medicine flow rate entering the calibration cylinder; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder - average dosing flow rate entering the gas well casing) ÷ medicine flow rate entering the calibration cylinder × 100%, obtain the calibration measurement error of the flow meter;

[0168] 5) Calibrate and correct the dosing flow rate

[0169] First, open the medicine outlet valve, and let the medicine pass through the pump inlet pipe, pump, medicine delivery pipe, flow meter 4, tee, medicine outlet valve, medicine outlet pipeline, casing joint, and gas well casing valve in sequence into the gas well casing; then, according to the flow meter calibration measurement error obtained in step 4), calibrate and correct the instantaneous flow and cumulative flow of the flow meter that are read and recorded again;

[0170] 6) Adjust the dosing flow rate to the required dosing amount

[0171] According to the flow meter calibration measurement error obtained in step 4), calibrate and correct the instantaneous flow rate and 10-minute cumulative flow rate of the flow meter that are read and recorded; then, according to the calibrated and corrected instantaneous flow rate and cumulative flow rate readings of the flow meter, gradually adjust the pump displacement to the required dosing flow rate.

[0172] Preferably, in order to facilitate inspection and management of the calibration cylinder, a valve is provided on the pressure-conducting pipeline.

[0173] Further, in order to solve the problems of dosing flow control, adjustment, metering and calibration of a 1-pump multi-tube dosing system, the method for on-site calibration of dosing flow metering and regulating control of the dosing system of the present invention adopts the first technical solution: comprising the following steps:

[0174] 1) Connection balance pressure:

[0175] At the top of the first natural gas pipeline, first use the first medicine outlet pipeline to vertically connect the first medicine outlet valve to the top of the first natural gas pipeline, and then use the first pressure inlet pipeline to connect the first pressure inlet and the first natural gas pipeline, so that the pressure in the first calibration cylinder is automatically balanced with the pressure in the first natural gas pipeline and the first medicine outlet valve;

[0176] At the top of the second natural gas pipeline, first use the second medicine outlet pipeline to vertically connect the second medicine outlet valve to the top of the second natural gas pipeline, and then use the second pressure-intake pipeline to connect the second pressure-intake port and the second natural gas pipeline, so that the pressure in the second calibration cylinder is automatically balanced with the pressure in the second natural gas pipeline and the second medicine outlet valve;

[0177] 2) Dosing:

[0178] Open the first medicine outlet valve and start the pump. The medicine will flow into the first natural gas pipeline in sequence through the pump inlet pipe, the pump, the manifold tee, the first medicine delivery pipe, the first flow meter, the first tee, the first medicine outlet valve, and the first medicine outlet pipeline under the action of gravity.

[0179] Open the second medicine outlet valve, and the medicine will enter the natural gas pipeline through the pump inlet pipe, pump, manifold tee, second medicine delivery pipe, second flow meter, second tee, second medicine outlet valve, and second medicine outlet pipeline in sequence under the action of gravity;

[0180] 3) Flow meter measurement:

[0181] Keep the medicine under the action of gravity, passing through the pump inlet pipe, pump, manifold tee, first medicine delivery pipe, first flow meter, first tee, first medicine outlet valve, first medicine outlet pipeline into the first natural gas pipeline in sequence;

[0182] Keep the medicine under gravity and pass through the pump inlet pipe, pump, manifold tee, second medicine delivery pipe, second flow meter, second tee, second medicine outlet valve, second medicine outlet pipeline 2 in sequence into the natural gas pipeline;

[0183] 4) Calibrate the flow meter measurement error

[0184] Close the first medicine outlet valve, let the medicine flow upward into the calibration cylinder, read the increase in the calibration cylinder liquid level per unit time, calculate the volume of the medicine entering the calibration cylinder per unit time, and obtain the medicine flow rate entering the calibration cylinder; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder - average dosing flow rate entering the natural gas pipeline) ÷ medicine flow rate entering the calibration cylinder × 100%, obtain the calibration measurement error of the first flow meter;

[0185] Close the second medicine outlet valve, let the medicine flow upward into the calibration cylinder, read the increase in the calibration cylinder liquid level per unit time, calculate the volume of the medicine entering the calibration cylinder per unit time, and obtain the medicine flow rate entering the calibration cylinder; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder - average dosing flow rate entering the natural gas pipeline) ÷ medicine flow rate entering the calibration cylinder × 100%, obtain the calibration measurement error of the second flow meter;

[0186] 5) Calibrate and correct the dosing flow rate

[0187] Open the first medicine outlet valve, and allow the medicine to enter the first natural gas pipeline through the pump inlet pipe, the pump, the manifold tee, the first medicine delivery pipe, the first flow meter, the first tee, the first medicine outlet valve, and the first medicine outlet pipeline in sequence under the action of gravity; then, according to the calibration measurement error of the first flow meter obtained in step 4), calibrate and correct the instantaneous flow and cumulative flow of the first flow meter that are read and recorded again;

[0188] Open the second medicine outlet valve, and allow the medicine to enter the natural gas pipeline in sequence through the pump inlet pipe, the pump, the manifold tee, the second medicine delivery pipe, the second flow meter, the second tee, the second medicine outlet valve, and the second medicine outlet pipeline under the action of gravity; then calibrate and correct the instantaneous flow and cumulative flow of the second flow meter that are read and recorded again according to the calibration measurement error of the second flow meter obtained in step 4);

[0189] 6) Adjust the dosing flow rate to the required dosing amount

[0190] According to the calibration measurement error of the first flow meter obtained in step 4), calibrate and correct the instantaneous flow and cumulative flow of the first flow meter read and recorded;

[0191] According to the calibration measurement error of the second flow meter obtained in step 4), calibrate and correct the instantaneous flow and cumulative flow of the second flow meter read and recorded;

[0192] Then, according to the instantaneous flow rate and the accumulated flow rate readings of the first and second flow meters after calibration, the displacement of the pump is gradually adjusted to the required dosing flow rate.

[0193] Preferably, in order to facilitate the inspection and management of the calibration cylinder, a valve is respectively provided on the first pressure-conducting pipeline and the second pressure-conducting pipeline.

[0194] In order to solve the second technical problem, the second technical solution adopted by the method for on-site calibration of dosing flow metering and regulation control of the dosing system of the present invention is: comprising the following steps:

[0195] 1) Wiring and elevation:

[0196] Connect the manifold with one end closed to the gas well casing valve horizontally, so that the center line of the manifold is at the same level as the center line of the gas well casing valve, or the center line of the manifold is higher than the center line of the gas well casing valve;

[0197] Using existing methods, the bottom of the drip tank is made higher than the valve of the gas well casing and the center line of the gas well casing;

[0198] The bracket should be able to ensure that the bottom of the drip tank is higher than the gas well casing valve and the center line of the gas well casing, and should be able to meet the production requirements of liquid medicine flowing from the drip tank into the gas well casing valve and the gas well casing; technical personnel in this field can use existing methods to determine the specific form, shape, material, and installation method of the bracket, and can determine the maximum height, minimum height, and optimal height of the bracket 2.

[0199] 2) Balance pressure

[0200] Open the gas well casing valve, the pressure guide valve, the calibration switch valve, and the main switch valve to allow the natural gas in the gas well casing to enter the calibration cylinder and the drip tank, thereby balancing the pressure in the calibration cylinder, the drip tank, and the gas well casing, and balancing the liquid level in the calibration cylinder and the drip tank;

[0201] 3) Dosing:

[0202] Open the regulating valve, and the medicine in the drip tank will flow into the gas well casing by gravity through the flow meter, medicine delivery pipe, main switch valve, medicine tee, regulating valve, manifold, gas well casing valve in sequence;

[0203] 4) Flow meter measurement:

[0204] Keep the medicine in the drip tank flowing into the gas well casing through the flow meter, medicine delivery pipe, main switch valve, medicine tee, regulating valve, manifold, and gas well casing valve in sequence; read and record the instantaneous flow and cumulative flow of the flow meter to obtain the average dosing flow of the medicine entering the gas well casing;

[0205] 5) Calibrate the flow meter measurement error

[0206] Keep the opening of the regulating valve and the calibration switch valve unchanged, close the main switch valve, and the reagent in the calibration cylinder will flow into the gas well casing by gravity through the calibration switch valve, the reagent tee, the regulating valve, the junction pipe, and the gas well casing valve in sequence; read the value of the calibration cylinder liquid level reduction per unit time, calculate the volume of the reagent flowing out of the calibration cylinder per unit time, and obtain the reagent flow rate of the reagent flowing out of the calibration cylinder; then, according to the formula of flow meter calibration measurement error = (medicine flow rate out of the calibration cylinder - average dosing flow rate into the gas well casing) ÷ reagent flow rate out of the calibration cylinder × 100%, obtain the calibration measurement error of the flow meter;

[0207] Tests show that the metering error of the gear flowmeter calibrated with the calibration cylinder does not exceed 4%, which meets the national standard for the maximum allowable metering error of industrial instruments and flowmeters and can meet the production requirements of gas fields.

[0208] 6) Calibrate and correct the dosing flow rate

[0209] Using the flow meter calibration measurement error obtained in step 5), the average dosing flow rate of the reagent entering the gas well casing obtained in step 4) is calibrated and corrected;

[0210] 7) Adjust the dosing flow rate to the required dosing amount

[0211] Open the main switch valve, and the medicine in the drip tank will flow into the gas well casing by gravity through the flow meter, medicine delivery pipe, main switch valve, medicine tee, regulating valve, manifold, gas well casing valve, and part of the medicine will automatically flow into the calibration cylinder to restore the balance between the liquid level of the calibration cylinder and the liquid level in the drip tank.

[0212] Adjust the opening of the regulating valve and repeat steps 4) and 6) to adjust the dosing flow rate to the required flow rate.

[0213] Furthermore, in order to facilitate maintenance, the following steps are also included:

[0214] After the flow meter metering error calibration is completed, close the auxiliary pressure valve and calibration switch valve, remove the calibration cylinder, and use it again for the flow meter metering error calibration of other gas wells.

[0215] In order to solve the second technical problem, the third technical solution adopted by the method for on-site calibration of dosing flow metering and regulation control of the dosing system of the present invention is: comprising the following steps:

[0216] 1) Wiring and elevation:

[0217] Connect the manifold with one end closed to the gas well casing valve horizontally, so that the center line of the manifold is at the same level as the center line of the gas well casing valve, or the center line of the manifold is higher than the center line of the gas well casing valve;

[0218] Using existing methods, the bottom of the drip tank is made higher than the valve of the gas well casing and the center line of the gas well casing;

[0219] The bracket should be able to ensure that the bottom of the drip tank is higher than the gas well casing valve and the center line of the gas well casing, and should be able to meet the production requirements of liquid medicine flowing from the drip tank into the gas well casing valve and the gas well casing; technical personnel in this field can use existing methods to determine the specific form, shape, material, and installation method of the bracket, and can determine the maximum height, minimum height, and optimal height of the bracket.

[0220] 2) Balance pressure

[0221] Open the gas well casing valve, the pressure-inducing valve, and the main switch valve to allow the natural gas in the gas well casing to enter the calibration cylinder and the drip tank, thereby balancing the pressure in the calibration cylinder, the drip tank, and the gas well casing, and balancing the liquid level in the calibration cylinder and the drip tank;

[0222] 3) Dosing:

[0223] When the regulating valve is opened, the medicine in the drip tank will flow into the gas well casing by gravity through the medicine delivery pipe, main switch valve, medicine tee, flow meter, regulating valve, manifold, and gas well casing valve in sequence;

[0224] 4) Flow meter measurement:

[0225] Keep the medicine in the drip tank flowing into the gas well casing through the medicine delivery pipe, main switch valve, medicine tee, flow meter, regulating valve, manifold, and gas well casing valve in sequence; read and record the instantaneous flow and cumulative flow of the flow meter to obtain the average dosing flow of the medicine entering the gas well casing;

[0226] 5) Calibrate the flow meter measurement error

[0227] Keep the opening of the regulating valve unchanged, close the main switch valve, and the reagent in the calibration cylinder will flow into the gas well casing by gravity through the reagent tee, flow meter, regulating valve, manifold, and gas well casing valve in sequence; read the calibration cylinder liquid level reduction value per unit time, calculate the volume of the reagent flowing out of the calibration cylinder per unit time, and obtain the reagent flow rate of the reagent flowing out of the calibration cylinder; then, according to the formula of flow meter calibration measurement error = (medicine flow rate out of the calibration cylinder - average dosing flow rate into the gas well casing) ÷ reagent flow rate out of the calibration cylinder × 100%, obtain the calibration measurement error of the flow meter;

[0228] 6) Calibrate and correct the dosing flow rate

[0229] Using the flow meter calibration measurement error obtained in step 5), the average dosing flow rate of the reagent entering the gas well casing obtained in step 4) is calibrated and corrected;

[0230] 7) Adjust the dosing flow rate to the required dosing amount

[0231] Open the main switch valve, and the medicine in the drip tank will flow into the gas well casing by gravity through the medicine delivery pipe, the main switch valve, the medicine tee, the flow meter, the regulating valve, the manifold, and the gas well casing valve. At the same time, part of the medicine will automatically flow into the calibration cylinder to restore the balance between the liquid level of the calibration cylinder and the liquid level in the drip tank.

[0232] Adjust the opening of the regulating valve and repeat steps 4) and 6) to adjust the dosing flow rate to the required flow rate.

[0233] Alternatively, the steps include:

[0234] 1) Wiring and elevation:

[0235] Connect the manifold with one end closed to the gas well casing valve horizontally, so that the center line of the manifold is at the same level as the center line of the gas well casing valve, or the center line of the manifold is higher than the center line of the gas well casing valve;

[0236] Using existing methods, the bottom of the drip tank is made higher than the valve of the gas well casing and the center line of the gas well casing;

[0237] The bracket should be able to ensure that the bottom of the drip tank is higher than the gas well casing valve and the center line of the gas well casing, and should be able to meet the production requirements of liquid medicine flowing from the drip tank into the gas well casing valve and the gas well casing; technical personnel in this field can use existing methods to determine the specific form, shape, material, and installation method of the bracket, and can determine the maximum height, minimum height, and optimal height of the bracket.

[0238] 2) Balance pressure

[0239] Open the gas well casing valve, the pressure-inducing valve, and the main switch valve to allow the natural gas in the gas well casing to enter the calibration cylinder and the drip tank, thereby balancing the pressure in the calibration cylinder, the drip tank, and the gas well casing, and balancing the liquid level in the calibration cylinder and the drip tank;

[0240] 3) Dosing:

[0241] When the regulating valve is opened, the medicine in the drip tank will flow into the gas well casing by gravity through the medicine delivery pipe, main switch valve, medicine tee, flow meter, regulating valve, manifold, and gas well casing valve in sequence;

[0242] It is known from common knowledge in the art that a gear flow meter, for example, is allowed to be installed and used on a vertical or vertical pipeline.

[0243] 4) Calibrate the flow meter measurement error

[0244] When the main switch valve is closed, the reagent in the calibration cylinder will flow into the gas well casing by gravity through the reagent tee, flow meter, regulating valve, manifold, and gas well casing valve in sequence; read the calibration cylinder liquid level drop value per unit time, calculate the volume of the reagent flowing out of the calibration cylinder per unit time, and obtain the reagent flow rate of the reagent flowing out of the calibration cylinder;

[0245] At the same time, read and record the instantaneous flow and cumulative flow of the flow meter to obtain the average flow value of the flow meter;

[0246] Then, according to the formula of flow meter calibration measurement error = (flow rate of medicine flowing out of calibration cylinder - average flow value of flow meter) ÷ flow rate of medicine flowing out of calibration cylinder × 100%, the calibration measurement error of flow meter is obtained;

[0247] 5) Calibrate and correct the dosing flow rate

[0248] Using the flow meter calibration measurement error obtained in step 4), calibrate and correct the average flow value of the flow meter obtained in step 4);

[0249] 6) Adjust the dosing flow rate to the required dosing amount

[0250] Open the main switch valve, and the medicine in the drip tank will flow into the gas well casing by gravity through the medicine delivery pipe, the main switch valve, the medicine tee, the flow meter, the regulating valve, the manifold, and the gas well casing valve. At the same time, part of the medicine will automatically flow into the calibration cylinder to restore the balance between the liquid level of the calibration cylinder and the liquid level in the drip tank.

[0251] Adjust the opening of the regulating valve and repeat steps 4) and 5) to adjust the dosing flow rate to the required flow rate.

[0252] Furthermore, in order to facilitate maintenance, the following steps are also included:

[0253] After the flow meter metering error calibration is completed, close the auxiliary pressure valve and calibration switch valve, remove the calibration cylinder, and use it again for the flow meter metering error calibration of other gas wells.

[0254] The beneficial effects of the present invention are as follows: the present invention overcomes the defects of the existing dosing system in metering, adjusting and controlling the dosing flow, can perform on-site calibration of the dosing flow (or dosing amount) at the production site, can effectively solve the dosing flow metering, adjustment, control and deviation problems of the dosing system, can save the dosing amount, and can meet the dosing requirements required for production; it has the advantages of easy implementation, safety and reliability, wide application, and easy promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0255] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0256] Figure 1This is a schematic diagram of the existing 1 pump 3 pipe dosing system;

[0257] Figure 2 It is a schematic diagram of the existing flow meter calibration device in Example 36;

[0258] Figure 3 This is a schematic diagram of the dosing system in Example 1;

[0259] Figure 4 This is a schematic diagram of the dosing system in Example 2;

[0260] Figure 5 This is a schematic diagram of the dosing system in Example 3;

[0261] Figure 6 This is a schematic diagram of the calibration cylinder structure in Example 9;

[0262] Figure 7 This is a schematic diagram of the calibration cylinder structure in Example 10;

[0263] Figure 8 Schematic diagram of the calibration cylinder structure in Example 11;

[0264] Fig. 9 This is a schematic diagram of the calibration cylinder structure in Example 12;

[0265] Fig.10 This is a schematic diagram of the calibration cylinder structure in Example 13;

[0266] Fig.11 This is a schematic diagram of the dosing system in Example 14;

[0267] Fig.12 This is a schematic diagram of the dosing system in Example 16;

[0268] Fig.13 Schematic diagram of the flow meter normal pressure calibration test device in Examples 16 and 21;

[0269] Fig.14 This is a schematic diagram of the dosing system in Example 18;

[0270] Fig.15 This is a schematic diagram of the dosing system in Example 19;

[0271] Fig.16 This is a schematic diagram of the dosing system in Example 20;

[0272] Fig.17 This is a schematic diagram of the method for calibrating the on-site dosing flow rate of a natural gas pipeline in Example 36;

[0273] Fig.18 It is a schematic diagram of the method for in-situ calibration of gas well drug addition flow rate in Example 38;

[0274] Fig.19 A schematic diagram of the method for calibrating the on-site dosing flow rate of a natural gas pipeline in Example 40;

[0275] Fig. 20 A schematic diagram of the method for calibrating the on-site dosing flow rate of a natural gas pipeline in Example 42;

[0276] Fig.21 A schematic diagram of the method for calibrating the on-site dosing flow rate of a natural gas pipeline in Example 44;

[0277] Fig. 22 It is a schematic diagram of the method for in-situ calibration of gas well drug addition flow rate in Example 46;

[0278] Fig.23 It is a schematic diagram of the method for in-situ calibration of gas well drug addition flow rate in Example 47;

[0279] Fig.24 It is a schematic diagram of the method for in-situ calibration of gas well drug addition flow rate in Example 48;

[0280] Fig.25 It is a schematic diagram of the method for in-situ calibration of gas well drug addition flow rate in Example 49;

[0281] Fig.26 It is a schematic diagram of the method for in-situ calibration of gas well drug addition flow rate in Example 50;

[0282] Fig. 27 It is a schematic diagram of the method for in-situ calibration of gas well drug addition flow rate in Example 51; DETAILED DESCRIPTION

[0283] Example 1

[0284] See also Figure 3 As shown, a dosing system capable of calibrating the dosing amount on site includes a pump inlet pipe 301, a pump 302, a drug delivery pipe 303, a flow meter 304, a calibration cylinder 305, a pressure inlet port 306, a tee 307, and a drug outlet valve 308;

[0285] The pump inlet pipe 301 is connected to the pump 302;

[0286] The pump 302 is connected to a medicine delivery tube 303, and a flow meter 304 is provided on the medicine delivery tube 303;

[0287] The top of the calibration cylinder 305 is provided with a pressure inlet 306, and the bottom is connected to the drug delivery tube 303 and the drug outlet valve 308 through a three-way 307;

[0288] The calibration cylinder 305 is a stainless steel magnetic flap level gauge with a pressure resistance of 25 MPa (minimum graduation value 1 mm), with an inner diameter of 50 mm and a length of 1000 mm. A DN15 stainless steel pressure inlet 306 with a pressure resistance of 25 MPa is welded on the top, and a DN25 stainless steel tee 307 with a pressure resistance of 25 MPa is welded on the bottom; the lower part of the tee 307 is connected to a DN25 stainless steel medicine outlet valve 308 with a pressure resistance of 25 MPa by a pipe thread, and the side is connected to a DN25 stainless steel pressure inlet 308 with a pressure resistance of 25 MPa by a pipe thread. Medicine tube 303; a DN15 stainless steel gear flowmeter 304 with a pressure resistance of 40MPa and a measuring range of 0.3-60 liters / hour is connected to the stainless steel medicine delivery tube 303 by a reducer and a pipe thread; one end of the stainless steel medicine delivery tube 303 is connected to the side of a stainless steel tee 307 by a pipe thread, and the other end is connected to the outlet of a stainless steel metering pump 302 with a maximum rated output pressure of 20MPa and a maximum rated displacement of 60 liters / hour by a pipe fitting; the stainless steel metering pump 302 is connected to a DN25 stainless steel pump inlet pipe 301 by a pipe fitting.

[0289] It can be known from the common knowledge in this field that the stainless steel magnetic flap level gauge is a mature technology, which is made by utilizing the buoyancy principle and magnetic coupling. Its structure can be summarized as follows: a magnetic float is arranged in a metal straight tube, and a corresponding scale and a two-color metal cylinder are arranged outside the metal straight tube; its working principle can be summarized as follows: when the liquid enters the metal straight tube, the magnetic float floats up, and the two-color metal cylinder is driven to rotate by magnetic force, and corresponds to the value on the scale, thereby accurately displaying the liquid level in the metal straight tube under high pressure; under the condition that its inner diameter is known (based on which the inner cross-sectional area can be accurately calculated), the liquid or its volume in the metal straight tube can be quickly calculated based on the liquid level reading; the interface or opening position and form of the stainless steel magnetic flap level gauge are various, and the interface or opening position and form do not affect the function of the stainless steel magnetic flap level gauge. Those skilled in the art can determine the specific interface or opening position and form of the stainless steel magnetic flap level gauge based on existing methods.

[0290] According to the above example data, the volume of the calibration cylinder at a height of 1 mm is 2 ml, and the volume at a height of 10 mm is 20 ml; therefore, the amount of medicine and the flow rate of medicine entering the calibration cylinder can be quickly calculated and calibrated by visually observing the change in the height of the medicine entering the calibration cylinder per unit time (i.e., the change in the liquid level of the calibration cylinder), thereby meeting the production requirement of quickly calibrating the dosing flow rate on-site under pressure conditions using the calibration cylinder.

[0291] Furthermore, a pressure-introducing switch valve is provided on the pressure-introducing port 306 , and the pressure-introducing switch valve is a stainless steel stop valve with a DN25 and a pressure resistance of 25 MPa.

[0292] Example 2

[0293] See also Figure 4As shown, Example 1 is repeated, and the difference is that: a dosing system capable of calibrating the dosing amount on site includes a pump inlet pipe 401, a pump 402, a drug delivery pipe 403, a flow meter 404, a calibration cylinder 405, a pressure inlet port 406, a tee 407, and a drug outlet valve 408;

[0294] The pump inlet pipe 401 is connected to the pump 402;

[0295] The pump 402 is connected to a medicine delivery tube 403, and a flow meter 404 is provided on the medicine delivery tube 403;

[0296] The upper side of the calibration cylinder 405 is provided with a pressure inlet 406, and the bottom is connected to the drug delivery tube 403 and the drug outlet valve 408 through a three-way 407;

[0297] The pressure inlet 406 is welded to the upper side of the calibration cylinder 405, and the tee 407 is welded to the bottom; the lower part of the tee 407 is connected to the medicine outlet valve 408 by a pipe thread, and the side is connected to the medicine delivery tube 403 by a pipe thread; the gear flowmeter 404 is connected to the medicine delivery tube 403 by a reducer and a pipe thread; one end of the medicine delivery tube 403 is connected to the side of the tee 407 by a pipe thread, and the other end is connected to the outlet of the metering pump 402 by a pipe fitting; the metering pump 402 is connected to the pump inlet pipe 401 by a pipe fitting.

[0298] It is known from common knowledge in the art that the interface or opening position and form of the stainless steel magnetic flap level gauge are various, and the interface or opening position and form do not affect the function of the stainless steel magnetic flap level gauge. Those skilled in the art can determine the specific interface or opening position and form of the stainless steel magnetic flap level gauge based on existing methods.

[0299] Furthermore, a pressure-introducing switch valve is provided on the pressure-introducing port 306 , and the pressure-introducing switch valve is a stainless steel stop valve with a DN25 and a pressure resistance of 25 MPa.

[0300] Example 3

[0301] See also Figure 5 As shown, the embodiment 1-2 is repeated, and the difference is that: a dosing system capable of calibrating the dosing amount on site comprises a pump inlet pipe 501, a pump 502, a drug delivery pipe 503, a flow meter 504, a calibration cylinder 505, a pressure inlet port 506, and a drug outlet valve 507;

[0302] The pump inlet pipe 501 is connected to the pump 502;

[0303] The pump 502 is connected to a medicine delivery tube 503, and a flow meter 504 is provided on the medicine delivery tube 503;

[0304] The upper side of the calibration cylinder 505 is provided with a pressure inlet 506, the lower side is connected to the drug delivery tube 503, and the bottom is connected to the drug outlet valve 507;

[0305] The pressure inlet 506 is welded to the upper side of the calibration cylinder 505, the lower side is connected to the drug delivery tube 503 by a pipe thread, and the bottom is connected to the drug outlet valve 507 by a pipe thread; the gear flowmeter 504 is connected to the drug delivery tube 503 by a reducer and a pipe thread; one end of the drug delivery tube 503 is connected to the lower side of the calibration cylinder 505 by a pipe thread, and the other end is connected to the outlet of the metering pump 502 by a pipe fitting; the metering pump 502 is connected to the pump inlet pipe 501 by a pipe fitting.

[0306] Furthermore, a pressure-introducing switch valve is provided on the pressure-introducing port 306, and the pressure-introducing switch valve is a stainless steel stop valve with a DN25 and a pressure resistance of 25 MPa.

[0307] Example 4

[0308] Repeat Examples 1-3, except that the pump 302 is any one of a volumetric pump, a metering pump, a plunger pump, a gear pump, and a centrifugal pump.

[0309] It is known from common knowledge in the art that the metering pump can adjust the pump displacement by adjusting the length of the plunger stroke; positive displacement pumps, plunger pumps, gear pumps, and centrifugal pumps can all adjust the pump displacement by variable frequency speed regulation, and therefore can all be used to adjust and control the dosage.

[0310] Example 5

[0311] Repeat Examples 1-3, with the difference being that the drug delivery tube 303 is any one of a metal tube, a non-metal tube, and a rubber tube; more preferably, the drug delivery tube is a high-pressure hose reinforced with steel wire or other high-strength fibers.

[0312] It is known from common knowledge in the art that metal pipes, high-pressure hoses, etc. can be connected with pipe fittings, threads, joints, etc., and can be connected and installed without flames. High-pressure hoses reinforced with steel wire can withstand pressures of more than 50MPa.

[0313] Example 6

[0314] Repeat Examples 1-3, with the difference being that the flow meter 304 is any one of a gear flow meter, a rotor flow meter, an ultrasonic flow meter, an external clamp-on ultrasonic flow meter, a portable ultrasonic flow meter, an electromagnetic flow meter, a float flow meter, a water meter, an Annubar flow meter, an elbow flow meter, a balanced flow meter, a wedge flow meter, a target flow meter, a vortex flow meter, a turbine flow meter, an orifice flow meter, a vortex flow meter, and a differential pressure flow meter.

[0315] Example 7

[0316] Repeat Examples 1-3, with the difference being that the calibration cylinder is any one of a magnetic flap level gauge, a magnetic float level gauge, a magnetically sensitive electronic two-color level gauge, a glass tube level gauge, a glass plate level gauge, a color quartz tube level gauge, a sight glass level gauge, and an ultrasonic level gauge.

[0317] It is known from the common knowledge in this field that: magnetic flap level gauges, magnetic float level gauges, and magnetically sensitive electronic two-color level gauges are all made using the buoyancy principle and magnetic coupling, and can accurately display the liquid level. They are commonly used liquid level display methods in this field; glass tube level gauges, glass plate level gauges, color quartz tube level gauges, and sight glass level gauges can withstand pressure and are commonly used liquid level display methods for pressure vessels; ultrasonic level gauges are also commonly used liquid level display methods for pressure vessels.

[0318] Example 8

[0319] Repeat Examples 1-3 and Example 7, the difference being that the calibration cylinder is a remote transmission magnetic float level gauge made by utilizing the buoyancy principle, magnetic coupling, and a sensor, a transmitter, and a display.

[0320] Example 9

[0321] See also Figure 6 As shown, Example 2 is repeated, and the difference is that: the calibration cylinder 405 includes a housing 4051 with a flange, a magnetic float liquid level transmitter 4052 with a flange, an upper interface 4053 and a bottom interface 4054; the lower end of the magnetic float liquid level transmitter 4052 extends to the lower part of the housing 4051, and the upper end of the magnetic float liquid level transmitter 4052 is connected to the top flange of the housing 4051;

[0322] The magnetic float liquid level transmitter 4052 can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the static pressure liquid level transmitter can effectively measure the liquid level.

[0323] Example 10

[0324] See also Figure 7 As shown, Example 2 is repeated, and the difference is that: the calibration cylinder 405 includes a threaded shell 4151, a threaded static pressure type liquid level transmitter 4152, an upper interface 4153 and a bottom interface 4154, the lower end of the static pressure type liquid level transmitter 4152 extends to the lower part of the shell 4151, and the upper part of the static pressure type liquid level transmitter 4152 is threadedly connected to the top of the shell 4151;

[0325] The static pressure level transmitter 4152 is a magnetostrictive level transmitter;

[0326] The static pressure type liquid level transmitter 4152 can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the static pressure type liquid level transmitter can effectively measure the liquid level.

[0327] Embodiment 11

[0328] See also Figure 8 As shown, Example 2 is repeated, and the difference is that: the calibration cylinder 405 includes a housing 4251, a pressure transmitter 4252, an upper interface 4253 and a bottom interface 4254, and the pressure transmitter 4252 is arranged at the lower part of the housing 4251;

[0329] The pressure transmitter 4252 can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the pressure transmitter can effectively measure the liquid level.

[0330] Example 12

[0331] See also Fig. 9 As shown, Example 1 is repeated, and the difference is that: the calibration cylinder 305 includes a shell 3051, a pressure gauge 3052, a top interface 3053 and a bottom interface 3054, and the pressure gauge 3052 is arranged at the lower part of the shell 3051;

[0332] The pressure gauge 3052 is a precision pressure gauge with a 0.1 level accuracy.

[0333] It is known from common knowledge in the art that after the pressure value generated by the liquid column and the liquid density are known, the pressure value can be quickly converted into the corresponding liquid level; therefore, when the liquid level changes, the precision pressure gauge can effectively measure the liquid level.

[0334] Embodiment 13

[0335] See also Fig.10 As shown, Example 1 is repeated, and the difference is that: the calibration cylinder 305 includes a shell 3151, a magnetic float 3152, a top interface 3153, a colored iron powder 3154 and a bottom interface 3155, the magnetic float 3152 is arranged in the shell 3151, and the colored iron powder 3154 is arranged outside the shell 3151 at a position corresponding to the magnetic float 3152;

[0336] The working principle is: when the magnetic float 3152 rises or falls with the liquid level, the colored iron powder 3154 on the outer wall of the shell 3151 rises or falls accordingly, which can indicate the liquid level.

[0337] Embodiment 14

[0338] See also Fig.11As shown, embodiments 1-3, 4-8, 9-13 are repeated, and the difference is that: in order to solve the problems of dosing flow control, adjustment, metering and calibration of a 1-pump multi-tube dosing system, a dosing system capable of calibrating the dosing amount on site includes a pump inlet pipe 601, a pump 602, a manifold tee 603, a first drug delivery pipe 604, a first flow meter 605, a first calibration cylinder 606, a first pressure inlet port 607, a first tee 608, a first drug outlet valve 609, a second drug delivery pipe 610, a second flow meter 611, a second calibration cylinder 612, a second pressure inlet port 613, a second tee 614, and a second drug outlet valve 615;

[0339] The pump inlet pipe 601 is connected to the pump 602;

[0340] The pump 602 is connected to one interface of the manifold tee 603, another interface of the manifold tee 603 is connected to the first drug delivery tube 604, and the third interface of the manifold tee 603 is connected to the second drug delivery tube 610;

[0341] The first drug delivery tube 604 is provided with a first flow meter 605, and the second drug delivery tube 610 is provided with a second flow meter 611;

[0342] The first-path calibration cylinder 606 has a first-path pressure inlet 607 at its upper portion, and is connected to the first-path drug delivery tube 604 and the first-path drug outlet valve 609 at its lower portion through a first-path tee 608;

[0343] The second-path calibration cylinder 612 has a second-path pressure-introducing port 613 at its upper portion, and is connected to the second-path drug delivery tube 610 and the second-path drug outlet valve 615 at its lower portion via a second-path tee 614 .

[0344] The first-path calibration cylinder 606 and the second-path calibration cylinder 612 should be able to meet the production requirements of on-site rapid observation (including but not limited to visual inspection) or measurement of the volume of medicine entering therein under pressure conditions, and be able to meet the production requirements of calibrating the first-path flow meter 606 and the second-path flow meter 612; technical personnel in this field can determine the specific form, shape, pressure resistance grade, inner diameter, outer diameter, and installation method of the first-path calibration cylinder 606 and the second-path calibration cylinder 612 based on existing technical means.

[0345] Preferably, the first drug delivery tube 604 and the second drug delivery tube 610 are identical except for the length, the first flow meter 605 and the second flow meter 611 are exactly the same, the first calibration cylinder 606 and the second calibration cylinder 612 are exactly the same, the first tee 608 and the second tee 614 are exactly the same, and the first drug outlet valve 609 and the second drug outlet valve 615 are exactly the same.

[0346] Furthermore, the pressure inlet 607 and the pressure inlet 613 are provided with a pressure switch valve, and the pressure switch valve is a stainless steel stop valve with a DN25 and a pressure resistance of 25 MPa.

[0347] Embodiment 15

[0348] Repeat Examples 1-3 and 14, with the difference that: a safety valve, a pressure gauge (or a pressure transmitter), a vent valve, a drain valve, and a reflux regulating valve are provided on the pump or the drug delivery tube.

[0349] Example 16

[0350] See also Fig.12 As shown, a dosing system capable of calibrating the dosing amount on site includes a drip tank 701, a bracket 702, a flow meter 703, a drug delivery tube 704, a manifold 705, a regulating valve 706, a main switch valve 707, a medicine tee 708, a calibration switch valve 709, a calibration cylinder 710, a calibration cylinder pressure-inducing tube 711, a pressure-inducing tee 712, a pressure-inducing valve 713, and a drip tank pressure-inducing tube 714;

[0351] A bracket 702 is provided at the lower part (or bottom) of the drip tank 701;

[0352] The bottom of the drip tank 701 is connected to the drug delivery tube 704;

[0353] The drug delivery tube 704 is provided with a flow meter 703 and a main switch valve 707;

[0354] One end of the drug delivery tube 704 is connected to the side interface of the medicine tee 708, and the other end is connected to the bottom (or lower part) of the drip tank 701;

[0355] The lower interface of the medicine three-way 708 is connected to the regulating valve 706, the upper interface is connected to the calibration switch valve 709, and the side interface is connected to the medicine delivery tube 704;

[0356] The upper portion of the calibration switch valve 709 is connected to the calibration cylinder 710, and the lower portion is connected to the medicine three-way 708;

[0357] The upper part of the calibration cylinder 710 is connected to the calibration cylinder pressure-inducing pipe 711, and the lower part is connected to the calibration switch valve 709;

[0358] One end of the calibration cylinder pressure-inducing tube 711 is connected to the upper portion of the calibration cylinder 710, and the other end is connected to the upper interface of the pressure-inducing tee 712;

[0359] The side interface of the pressure-inducing tee 712 is connected to the pressure-inducing pipe 714 of the drip tank, the lower part is connected to the pressure-inducing valve 713, and the upper part is connected to the pressure-inducing pipe 711 of the calibration tube;

[0360] One end of the drip tank pressure-inducing tube 714 is connected to the upper part (or top) of the drip tank 701, and the other end is connected to the side interface of the pressure-inducing tee 712;

[0361] The lower part of the pressure-inducing valve 713 is connected to the upper part (or top) of the manifold 705, and the upper part is connected to the lower part of the pressure-inducing tee 712;

[0362] The lower part of the regulating valve 706 is connected to the upper part (or top) of the manifold 705, and the upper part is connected to the lower interface of the reagent tee 708;

[0363] The drip tank 701 is a horizontal pressure tank made of manganese steel, with a length of 2 meters, an inner diameter of 400 mm, a wall thickness of 50 mm, a design pressure of 25 MPa, an effective volume of 250 liters, and a welded foot support at the bottom and bolted to a bracket 702 with a height of 1 meter made of steel;

[0364] The bottom of the drip tank 701 is connected to a DN15, PN250 stainless steel drug delivery tube 704 by a pipe thread;

[0365] The DN15 stainless steel drug delivery tube 704 is first connected with a stainless steel gear flowmeter 703 with a precision of 0.5, a range of 0.3 to 60 liters / hour, and a design pressure of 32 MPa, and then a DN15 stainless steel main switch valve 707 with a design pressure of 32 MPa is connected behind the gear flowmeter with a pipe fitting. The main switch valve 707 is a ball valve.

[0366] One end of the stainless steel drug delivery tube 704 is connected to the side interface of the DN15, PN250 stainless steel medicine tee 708 by pipe thread, and the other end is connected to the bottom (or lower part) of the drip tank 701 by pipe thread;

[0367] The lower interface of the stainless steel medicine tee 708 is connected to the DN15, PN250 stainless steel regulating valve 706 by pipe thread, the upper interface is connected to the DN15, PN250 stainless steel calibrated switch valve 709, and the side interface is connected to the DN15 stainless steel drug delivery tube 704;

[0368] The stainless steel calibration switch valve 709 is a ball valve, the upper part of which is connected to the calibration cylinder 710 by a pipe thread, and the lower part of which is connected to the DN15, PN250 reagent tee 708 by a pipe thread;

[0369] The calibration cylinder 710 is a stainless steel magnetic flap level gauge with a design pressure of 25 MPa, an inner diameter of 50 mm, a length of 1 meter, a graduation value of 1 mm, an upper interface at the top and a lower interface at the bottom. The top is connected to the calibration cylinder pressure pipe 711 by a pipe thread, and the lower part is connected to the calibration switch valve 709 by a pipe thread.

[0370] The calibration tube pressure-inducing pipe 711 is a DN15, PN250 stainless steel pipe, one end of which is connected to the upper part of the calibration tube 710 by a pipe thread, and the other end is connected to the upper interface of the pressure-inducing tee 712 by a pipe thread;

[0371] The pressure-inducing tee 712 is a DN15, PN250 stainless steel pipe fitting, the side interface is connected to the drip tank pressure-inducing pipe 714 by pipe thread, the lower part is connected to the pressure-inducing valve 713 by pipe thread, and the upper part is connected to the calibration tube pressure-inducing pipe 711 by pipe thread;

[0372] The drip tank pressure-inducing pipe 714 is a DN15, PN250 stainless steel pipe, one end of which is connected to the top of the drip tank 701 by a pipe thread, and the other end of which is connected to the side interface of the pressure-inducing tee 712 by a pipe thread;

[0373] The pressure-inducing valve 713 is a DN15, PN250 stainless steel stop valve, the lower part of which is vertically connected to the top of the manifold 705 by pipe threads, and the upper part is connected to the lower part of the pressure-inducing tee 712 by pipe threads;

[0374] The regulating valve 706 is a DN15, PN250 stainless steel stop valve, the lower part of which is vertically connected to the top of the manifold 705 by a pipe thread, and the upper part is connected to the lower interface of the reagent tee 708 by a pipe thread;

[0375] The manifold 705 is made of DN50, PN250 stainless steel pipe, with an open left end and external pipe thread, and a welded right end. Two left and right interfaces with a spacing of 100 mm are arranged on the top. The left interface is vertically connected to the lower interface of the pressure-inducing valve 713 by pipe thread, and the right interface is vertically connected to the lower interface of the regulating valve 706 by pipe thread.

[0376] The top elevation of the calibration cylinder 710 is equal to or higher than the top elevation of the drip tank 701;

[0377] The bottom elevation of the calibration cylinder 710 is equal to or lower than the bottom elevation of the drip tank 701. It is known from the common knowledge in the art that the stainless steel magnetic flap level gauge is a mature technology, which is made by using the buoyancy principle and magnetic coupling. The interface position can be at the top, bottom, upper and lower sides, and can accurately display the liquid level in the metal tube; if the inner diameter of the metal tube of the stainless steel magnetic flap level gauge is known, the liquid volume in the stainless steel magnetic flap level gauge can be accurately calculated according to the liquid level value displayed.

[0378] According to the above example data, the volume of the calibration cylinder at a height of 1 mm is 2 ml, and the volume at a height of 10 mm is 20 ml; therefore, the amount of medicine and the flow rate of medicine entering the calibration cylinder can be quickly calculated and calibrated by visually observing the change in the height of the medicine entering the calibration cylinder per unit time (i.e., the change in the liquid level of the calibration cylinder), thereby meeting the production requirement of quickly calibrating the dosing flow rate on-site under pressure conditions using the calibration cylinder.

[0379] Take the normal pressure calibration test of the gear flowmeter as an example.

[0380] like Fig.13 As shown, the overview of the calibration experimental device is as follows: the left side of the manifold 705 is open to the atmosphere, and a glass measuring cylinder 801 is used to collect water from the left side of the manifold 705; the drip tank 701 has an outer diameter of 500 mm and an inner diameter of 400 mm; the calibration cylinder 710 is a stainless steel magnetic flap level gauge, which is made of a stainless steel pipe, a magnetic float is arranged inside the steel pipe, and a two-color rotor and a scale plate are arranged outside the steel pipe, with an inner diameter of 50 mm, an effective length of 1 meter, and a graduation value of 1 mm; the top of the drip tank 701 and the calibration cylinder 710 are both 1.5 meters above the ground, the bottom of the drip tank 701 is 1 meter above the ground, and the bottom of the calibration cylinder 710 is 0.5 meters above the ground; the drug delivery tube 704 is a stainless steel tube with a diameter of DN15 and a length of 20 meters; the flowmeter 703 is a gear flowmeter with an accuracy of 0.5 level and a range of 0.3 to 60 liters / hour;

[0381] The test steps are summarized as follows:

[0382] 1) The first step is preparation before the test: make the regulating valve 706, the main switch valve 707, and the calibration switch valve 709 all in the closed state, open the pressure valve 713, make the drip tank 701 and the calibration cylinder 710 open to the atmosphere, and add clean water to the drip tank 701 to more than two-thirds of the tank level;

[0383] 2) The second step is to balance the water level: open the main switch valve 707 and the calibration switch valve 709 and wait for 1 to 5 minutes. When the water levels of the drip tank 701 and the calibration cylinder 710 are the same or the instantaneous flow reading of the gear flow meter 703 returns to zero, close the calibration switch valve 709;

[0384] 3) The third step is to calibrate the metering error of the gear flowmeter: close the calibration switch valve 709, open and adjust the opening of the regulating valve 706 until the instantaneous flow of the gear flowmeter 703 is 1.5-2 liters / hour; then use the measuring cylinder 801 to collect water from the left side of the manifold 705, and quickly reset the gear flowmeter's cumulative flow reading to "0", and start timing at the same time; read the gear flowmeter's cumulative flow reading for 10 minutes, and use the measuring cylinder to measure the water output for 10 minutes; then calculate the average flow metering error of the gear flowmeter based on this;

[0385] It is known from common knowledge in this field that existing small-range gear flow meters all have digital display modes, which can quickly reset the accumulated flow to zero. Therefore, the accumulated flow of the gear flow meter can be accurately obtained by using the fast reset zero point method. At present, there are no successful precedents or public information on the application of pointer-type small-range gear flow meters in China.

[0386] 4) The fourth step is to determine the metering error of the calibration cylinder: keep the opening of the regulating valve 706 unchanged and close the main switch valve 707; then open the calibration switch valve 709, use the measuring cylinder 801 to collect the water output for 10 minutes from the left side of the manifold 705, and read the 10-minute liquid level drop reading of the calibration cylinder 710; then calculate the average flow metering error of the calibration cylinder 710 based on this;

[0387] The test results show that: when water flows from the drip tank 701 through the gear flowmeter 703 and enters the regulating valve 706, if the average flow rate of the gear flowmeter for 10 minutes is 1.6 liters / hour, the average actual flow rate of the 10 minutes calibrated by the measuring cylinder is 3.1 liters / hour. From this calculation, it can be known that the measurement error is as high as 48% and the leakage is as high as 1.5 liters / hour; when the opening of the regulating valve 706 is kept unchanged and water flows from the calibration cylinder 710 into the regulating valve 706, the average flow rate out of the calibration cylinder 710 in 10 minutes is 3.1 liters / hour. The average flow rate and the average flow rate collected by the measuring cylinder are both 3 liters / hour (that is, the measurement error of the calibration cylinder 711 itself is "0" or cannot be observed); from this, it can be seen that under the condition that the opening of the regulating valve 706 remains unchanged, the average actual flow rate of water flowing from the drip tank 701 through the gear flowmeter 703 into the regulating valve 706 is 3.1 liters / hour, and the average actual flow rate flowing directly from the calibration cylinder 710 into the regulating valve 706 is 3 liters / hour; therefore, the measurement error of calibrating the gear flowmeter 703 with the calibration cylinder 710 is 3.2%.

[0388] The test results further show that when the gear flowmeter 703 is calibrated with the calibration cylinder 710, although the liquid level reduction value of the calibration cylinder 710 is greater than the liquid level reduction value of the drip tank 701, resulting in a slight change in the liquid column pressure difference, which in turn causes a slight error of less than 4% in the flow rate of the two, it is within the measurement error requirement range of industrial instruments and can meet the gas field production requirements.

[0389] It is known from common knowledge that: national standards stipulate that the maximum allowable measurement error of industrial instruments and flow meters is 4%.

[0390] Further experiments show that when the water is replaced with methanol and the same experiment is carried out, the experimental conclusions are exactly the same;

[0391] Further experiments show that when the metering time is changed from 10 minutes to other times for the same type of test, the experimental conclusions are exactly the same;

[0392] In summary, the above tests show that the gear flowmeter can be accurately calibrated and calibrated using the above example data and calibration cylinder, and fully meets national standards and industrial production requirements.

[0393] Furthermore, an auxiliary pressure-guiding valve is provided on the calibration cylinder pressure-guiding tube 711.

[0394] Embodiment 17

[0395] Example 16 is repeated, with the difference being that the flow meter 703 is installed behind the main switch valve 707 on the drug delivery tube 704 .

[0396] Embodiment 18

[0397] See also Fig.14 As shown, Example 16 is repeated, and the difference is that: in order to facilitate maintenance management and keep the dosage unchanged, a dosing system capable of calibrating the dosage on site is provided with an auxiliary switch valve 901 between the regulating valve 706 and the reagent three-way 708;

[0398] The upper end of the auxiliary switch valve 901 is connected to the lower interface of the medicine three-way 708, and the lower end is connected to the regulating valve 706;

[0399] The auxiliary switch valve 901 is a DN15, PN250 stainless steel ball valve.

[0400] Embodiment 19

[0401] See also Fig.15 As shown, a dosing system capable of calibrating the dosing amount on site includes a drip tank 1001, a bracket 1002, a drug delivery tube 1003, a manifold 1004, a regulating valve 1005, a flow meter 1006, a main switch valve 1007, a medicine tee 1008, a calibration cylinder 1009, a calibration cylinder pressure-inducing tube 1010, a pressure-inducing tee 1011, a pressure-inducing valve 1012, and a drip tank pressure-inducing tube 1013;

[0402] A bracket 1002 is provided at the lower part (or bottom) of the drip tank 1001;

[0403] The bottom of the drip tank 1001 is connected to the drug delivery tube 1003;

[0404] The drug delivery tube 1003 is provided with a main switch valve 1007;

[0405] One end of the drug delivery tube 1003 is connected to the side interface of the medicine three-way 1008, and the other end is connected to the bottom (or lower part) of the drip tank 1001;

[0406] The lower interface of the medicine tee 1008 is connected to the flow meter 1006, the upper interface is connected to the lower or bottom interface of the calibration cylinder 1009, and the side interface is connected to the medicine delivery tube 1003;

[0407] The upper or top interface of the calibration cylinder 1009 is connected to the calibration cylinder pressure-inducing tube 1010, and the lower part is connected to the upper interface of the medicine tee 1008;

[0408] One end of the calibration tube pressure-inducing tube 1010 is connected to the upper or top interface of the calibration tube 1009, and the other end is connected to the upper interface of the pressure-inducing tee 1011;

[0409] The side interface of the pressure-inducing tee 1011 is connected to the pressure-inducing pipe 1013 of the drip tank, the lower part is connected to the pressure-inducing valve 1012, and the upper part is connected to the pressure-inducing pipe 1010 of the calibration cylinder;

[0410] One end of the drip tank pressure-inducing tube 1013 is connected to the upper part (or top) of the drip tank 1001, and the other end is connected to the side interface of the pressure-inducing tee 1011;

[0411] The lower part of the pressure-inducing valve 1012 is connected to the upper part (or top) of the manifold 1004, and the upper part is connected to the lower part of the pressure-inducing tee 1011;

[0412] The lower interface of the flow meter 1006 is connected to the pressure regulating valve 1005, and the upper part is connected to the lower interface of the medicine three-way 1008;

[0413] The lower part of the pressure regulating valve 1005 is connected to the upper part (or top) of the manifold 1004, and the upper part is connected to the lower interface of the flow meter 1006;

[0414] The drip tank 1001 is a horizontal pressure tank made of manganese steel, with a length of 2 meters, an inner diameter of 400 mm, a wall thickness of 50 mm, a design pressure of 25 MPa, an effective volume of 250 liters, and a welded foot support at the bottom and bolted to a bracket 1003 with a height of 1 meter made of steel.

[0415] The bottom of the drip tank 1001 is connected to a DN15, PN250 stainless steel drug delivery tube 1003 by a pipe thread;

[0416] The DN15 stainless steel drug delivery tube 1003 is connected to a DN15 stainless steel main switch valve 1007 with a design pressure of 32 MPa by a pipe fitting. The main switch valve 1007 is a ball valve.

[0417] One end of the stainless steel drug delivery tube 1003 is connected to the side interface of the DN15, PN250 stainless steel medicine tee 1008 by pipe thread, and the other end is connected to the bottom (or lower part) of the drip tank 1001 by pipe thread;

[0418] The lower interface of the stainless steel medicine tee 1008 is connected to a PN320 stainless steel gear flowmeter 1006 with a precision of 0.5 and a range of 0.3 to 60 liters / hour by pipe threads, the upper interface is connected to a calibration cylinder 1009 by pipe threads, and the side interface is connected to a DN15 stainless steel drug delivery tube 1003;

[0419] The calibration cylinder 1009 is a stainless steel magnetic flap level gauge with a design pressure of 25MPa, an inner diameter of 50mm, a length of 1m, a graduation value of 1mm, an upper interface at the top and a lower interface at the bottom. The top is connected to the calibration cylinder pressure pipe 1010 by a pipe thread, and the bottom is connected to the reagent tee 1008 by a pipe thread.

[0420] The calibration tube pressure-inducing pipe 1010 is a DN15, PN250 stainless steel pipe, one end of which is connected to the upper part of the calibration tube 1009 by a pipe thread, and the other end is connected to the upper interface of the pressure-inducing tee 1011 by a pipe thread;

[0421] The pressure-inducing tee 1011 is a DN15, PN250 stainless steel pipe fitting, the side interface is connected to the drip tank pressure-inducing pipe 1013 by pipe thread, the lower part is connected to the pressure-inducing valve 1012 by pipe thread, and the upper part is connected to the calibration tube pressure-inducing pipe 1010 by pipe thread;

[0422] The drip tank pressure-inducing pipe 1013 is a DN15, PN250 stainless steel pipe, one end of which is connected to the top of the drip tank 1001 by a pipe thread, and the other end is connected to the side interface of the pressure-inducing tee 1011 by a pipe thread;

[0423] The pressure-inducing valve 1012 is a DN15, PN250 stainless steel stop valve, the lower part of which is vertically connected to the top of the manifold 1004 by pipe threads, and the upper part is connected to the lower interface of the pressure-inducing tee 1011 by pipe threads;

[0424] The gear flow meter 1006 is connected to the regulating valve 1005 at the bottom by a pipe thread, and is connected to the lower interface of the reagent tee 1008 at the top by a pipe thread;

[0425] The regulating valve 1005 is a DN15, PN250 stainless steel stop valve, the lower part of which is vertically connected to the top of the manifold 1004 by pipe threads, and the upper part is connected to the lower part of the gear flow meter 1006 by pipe threads;

[0426] The manifold 1004 is made of DN50, PN250 stainless steel pipe, with an open left end and external pipe thread, and a welded right end. Two left and right interfaces with a spacing of 100 mm are arranged on the top. The left interface is vertically connected to the lower interface of the pressure-guiding valve 1012 by pipe thread, and the right interface is vertically connected to the lower interface of the regulating valve 1005 by pipe thread.

[0427] The top elevation of the calibration cylinder 1009 is equal to or higher than the top elevation of the drip tank 1001;

[0428] The bottom elevation of the calibration cylinder 1009 is equal to or lower than the bottom elevation of the drip tank 1001 .

[0429] It is known from common knowledge in the field that the diameter of the stainless steel magnetic flap liquid level metal tube can be varied, and the interface position can be at the top, bottom, or on the upper and lower sides, all of which can accurately display the liquid level in the metal tube; if the inner diameter of the metal tube of the stainless steel magnetic flap liquid level gauge is known, the liquid volume in the stainless steel magnetic flap liquid level gauge can be accurately calculated based on the liquid level value displayed.

[0430] According to the above example data, the volume of the calibration cylinder at a height of 1 mm is 0.49 ml, and the volume at a height of 10 mm is 4.9 ml; therefore, the amount of medicine and the flow rate of medicine entering the calibration cylinder can be quickly calculated and calibrated by visually observing the change in the height of the medicine entering the calibration cylinder per unit time (i.e., the change in the liquid level of the calibration cylinder), thereby meeting the production requirement of quickly calibrating the dosing flow rate on-site under pressure conditions using the calibration cylinder.

[0431] Furthermore, an auxiliary pressure-guiding valve is provided on the calibration cylinder pressure-guiding tube 1010 .

[0432] Embodiment 20

[0433] See also Fig.16 As shown, Example 19 is repeated, and the difference is that: for the convenience of maintenance, a dosing system capable of calibrating the dosing amount on site is provided with a calibration switch valve 1101 between the calibration cylinder 1009 and the reagent tee 1008;

[0434] The upper end of the calibration switch valve 1101 is connected to the lower interface of the calibration cylinder 1009, and the lower end is connected to the upper interface of the medicine three-way 1008;

[0435] The calibration switch valve 1101 is a DN15, PN250 stainless steel ball valve.

[0436] Embodiment 21

[0437] Repeat Examples 16-20, with the difference being that: in order to facilitate installation and observation, the top elevation of the calibration cylinder is lower than the top elevation of the drip tank; and the bottom elevation of the calibration cylinder is higher than the bottom elevation of the drip tank.

[0438] Experiments show that: using Fig.13 The results of the calibration test of the calibration experimental device shown in the figure show that: the calibration cylinder liquid level is 0.5 meters lower than the drip tank liquid level, the timing is 10 minutes, and the metering error of the gear flowmeter with a range of 0.3 to 60 liters / day is calibrated by the calibration cylinder. The calibration metering error obtained at different flow rates is 3.2 to 3.4%; the experimental conclusion remains unchanged when the timing is changed; therefore, the metering error caused by the pressure difference change when the calibration cylinder liquid level is 0.5 meters lower than the drip tank liquid level can be ignored, which meets the requirements of industrial instruments for metering errors, and can therefore meet the production requirements of gas fields.

[0439] Further experiments show that when the bottom elevation of the calibration cylinder is higher than the bottom elevation of the drip tank or the top elevation of the calibration cylinder is lower than the top elevation of the drip tank, the calibration cylinder can be used to effectively calibrate the metering error of the gear flowmeter, thereby meeting the production requirements of using the calibration cylinder to quickly calibrate the dosing flow on-site under pressure conditions.

[0440] Embodiment 22

[0441] Repeat Examples 16-18, except that: in order to facilitate maintenance and management, realize the purpose of using one cylinder for multiple purposes and using it in different places, reduce the amount of calibration cylinders used in gas fields, and reduce costs, a dosing system capable of calibrating the dosage on site is provided with an auxiliary pressure-inducing valve on the pressure-inducing pipe 711 of the calibration cylinder;

[0442] The auxiliary pressure-guiding valve is a DN15, PN250 stainless steel ball valve.

[0443] Embodiment 23

[0444] Repeat Examples 19-21, except that: in order to facilitate maintenance and management, realize the purpose of using one cylinder for multiple purposes and using it in different places, reduce the amount of calibration cylinders used in gas fields, and reduce costs, a dosing system capable of calibrating the dosage on site is provided with an auxiliary pressure-inducing valve on the calibration cylinder pressure-inducing pipe 1010;

[0445] The auxiliary pressure-guiding valve is a DN15, PN250 stainless steel ball valve.

[0446] Embodiment 24

[0447] Repeat Examples 16-21, with the following differences: the drip tank, bracket, medicine tee, and pressure tee are made of carbon steel or other metals; the regulating valve, main switch valve, calibration switch valve, and pressure valve are steel valves or other metal valves; the drug delivery tube, junction tube, calibration cylinder pressure tube, and drip tank pressure tube are steel pipes or other metal pipes; the flow meter and calibration cylinder are made of steel or other metals.

[0448] Embodiment 25

[0449] Repeat Examples 16-21, with the difference that: the drug delivery tube is any one of a non-metallic tube and a rubber tube; more preferably, the drug delivery tube is a high-pressure hose reinforced with steel wire or other high-strength fibers; and the bracket is made of non-metal.

[0450] Embodiment 26

[0451] Repeat Examples 16-21, except that the flowmeter is any one of a gear flowmeter, a rotor flowmeter, an ultrasonic flowmeter, an external clamp-on ultrasonic flowmeter, a portable ultrasonic flowmeter, an electromagnetic flowmeter, a float flowmeter, a water meter, an Annubar flowmeter, an elbow flowmeter, a balanced flowmeter, a wedge flowmeter, a target flowmeter, a vortex flowmeter, a turbine flowmeter, an orifice flowmeter, a vortex flowmeter, and a differential pressure flowmeter.

[0452] Embodiment 27

[0453] Repeat Examples 16-21, with the difference being that the calibration cylinder is any one of a magnetic flap level gauge, a magnetic float level gauge, a magnetically sensitive electronic two-color level gauge, a glass tube level gauge, a glass plate level gauge, a color quartz tube level gauge, a sight glass level gauge, and an ultrasonic level gauge.

[0454] Embodiment 28

[0455] Repeat Examples 16-21, with the difference being that the calibration cylinder is a remote transmission type magnetic float level gauge made using the buoyancy principle, magnetic coupling, and a sensor, a transmitter, and a display.

[0456] Embodiment 29

[0457] Repeat Examples 16-21, except that: the calibration cylinder 405 includes a housing 4051 with a flange, a magnetic float liquid level transmitter 4052 with a flange, an upper interface 4053 and a bottom interface 4054; the lower end of the magnetic float liquid level transmitter 4052 extends to the lower part of the housing 4051, and the upper end of the magnetic float liquid level transmitter 4052 is connected to the top flange of the housing 4051;

[0458] The magnetic float liquid level transmitter 4052 can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the static pressure liquid level transmitter can effectively measure the liquid level.

[0459] Embodiment 30

[0460] Repeat Examples 16-21, except that: the calibration cylinder 405 includes a threaded housing 4151, a threaded hydrostatic level transmitter 4152, an upper interface 4153 and a bottom interface 4154, the lower end of the hydrostatic level transmitter 4152 extends to the lower part of the housing 4151, and the upper part of the hydrostatic level transmitter 4152 is threadedly connected to the top of the housing 4151;

[0461] The static pressure level transmitter 4152 is a magnetostrictive level transmitter;

[0462] The static pressure type liquid level transmitter 4152 can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the static pressure type liquid level transmitter can effectively measure the liquid level.

[0463] Embodiment 31

[0464] Repeat Examples 16-21, except that: the calibration cylinder 405 includes a housing 4251, a pressure transmitter 4252, an upper interface 4253 and a bottom interface 4254, and the pressure transmitter 4252 is disposed at the lower part of the housing 4251;

[0465] The pressure transmitter 4252 can convert the liquid level into a standard electrical signal and transmit it remotely; when the liquid level changes, the pressure transmitter can effectively measure the liquid level.

[0466] Embodiment 32

[0467] Repeat Examples 16-21, except that: the calibration cylinder 305 includes a housing 3051, a pressure gauge 3052, a top interface 3053 and a bottom interface 3054, and the pressure gauge 3052 is disposed at the lower portion of the housing 3051;

[0468] The pressure gauge 3052 is a precision pressure gauge with a 0.1 level accuracy.

[0469] Embodiment 33

[0470] Repeat Examples 16-21, except that: the calibration cylinder 305 includes a housing 3151, a magnetic float 3152, a top interface 3153, a colored iron powder 3154 and a bottom interface 3155, the magnetic float 3152 is arranged in the housing 3151, and the colored iron powder 3154 is arranged outside the housing 3151 at a position corresponding to the magnetic float 3152;

[0471] The working principle is: when the magnetic float 3152 rises or falls with the liquid level, the colored iron powder 3154 on the outer wall of the shell 3151 rises or falls accordingly, which can indicate the liquid level.

[0472] Embodiment 34

[0473] Repeat Examples 16-33, except that: for the convenience of management, a liquid level meter, a pressure gauge (or a pressure transmitter), a safety valve, a vent valve, and a drain valve are provided on the drip tank.

[0474] Embodiment 35

[0475] The examples 16-33 were repeated, except that a medicine replenishment valve was provided on the drip tank for convenient replenishment of medicine.

[0476] Embodiment 36

[0477] See also Fig.17 As shown, the method for calibrating the metering and regulating control of the dosing flow rate of the dosing system in the process of dosing in the natural gas pipeline includes the following steps:

[0478] 1) Connection balance pressure:

[0479] At the top of the natural gas pipeline 1201, first use the medicine outlet pipeline 1202 to vertically connect the medicine outlet valve 308 to the top of the natural gas pipeline 1201, and then use the pressure-introducing pipeline 1203 to connect the pressure-introducing port 306 and the natural gas pipeline 1201, so that the pressure in the calibration cylinder 305 is automatically balanced with the pressure in the natural gas pipeline 1201 and the medicine outlet valve 308;

[0480] 2) Dosing:

[0481] Open the medicine outlet valve 308 and start the pump 302. The medicine will flow into the natural gas pipeline 1201 through the pump inlet pipe 301, the pump 302, the medicine delivery pipe 303, the flow meter 304, the tee 307, the medicine outlet valve 308 and the medicine outlet pipeline 1202 in sequence under the action of gravity.

[0482] It is known from common knowledge in the art that since the height of the calibration cylinder 305 is higher than the height of the medicine outlet valve 308, when the medicine outlet valve 308 is opened and connected to the natural gas pipeline 1201, the medicine can only pass downward through the medicine outlet valve 308 and the medicine outlet pipeline 1202 into the natural gas pipeline 1201, and it is impossible to pass upward through the calibration cylinder 305, the pressure inlet port 306, and the pressure inlet pipeline 1203 in sequence into the natural gas pipeline 1201.

[0483] 3) Flow meter measurement:

[0484] Keep the medicine flowing through the pump inlet pipe 301, pump 302, medicine delivery pipe 303, flow meter 304, tee 307, medicine outlet valve 308, medicine outlet pipeline 1202 into the natural gas pipeline 1201 under the action of gravity; read and record the instantaneous flow rate and the accumulated flow rate within 10 minutes of the flow meter 304 to obtain the average dosing flow rate of the medicine entering the natural gas pipeline 1201;

[0485] 4) Calibrate the flow meter measurement error

[0486] Close the medicine outlet valve 308, let the medicine flow upward into the calibration cylinder 305, read the increase in the liquid level of the calibration cylinder 305 in 10 minutes, quickly calculate the volume of the medicine entering the calibration cylinder 305 within 10 minutes, and obtain the medicine flow rate of the medicine entering the calibration cylinder 305; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder 305 - average dosing flow rate entering the natural gas pipeline 1201) ÷ medicine flow rate entering the calibration cylinder 305 × 100%, obtain the calibration measurement error of the flow meter;

[0487] It can be known from common knowledge in this field that: taking pressure gauge calibration as an example, a high-precision pressure gauge is used to calibrate a low-precision pressure gauge, that is, using high-precision to calibrate a low-precision measurement calibration method is a conventional technology; experiments have shown that the measurement error of the calibration cylinder 305 is much smaller than the measurement error of the flow meter, so using the measurement error of the calibration cylinder 305 to calibrate the measurement error of the flow meter belongs to the measurement calibration method of high-precision to calibrate a low-precision measurement calibration method; therefore, the calculation formula "measurement error = (chemical flow entering the calibration cylinder 305 - average dosing flow entering the natural gas pipeline 1201) ÷ chemical flow entering the calibration cylinder 305 × 100%" meets the national standard requirements for the calculation of industrial instrument measurement errors.

[0488] It is known from common knowledge in the art that when the reagent fills up the calibration cylinder 305, it will enter the pressure inlet 306, the pressure pipeline 1203 and then enter the natural gas pipeline 1201, and will not cause a pressure holding accident; when the medicine outlet valve 308 is opened, the reagent in the calibration cylinder 305, the pressure inlet 306 and the pressure pipeline 1203 will quickly fall into the natural gas pipeline 1201 under the action of gravity; therefore, when calibrating with the calibration cylinder 305, even if the operation is not timely, resulting in the calibration cylinder 305, the pressure inlet 306 and the pressure pipeline 1203 being completely filled with reagents, it will not cause a production safety accident and will not affect the re-calibration work.

[0489] 5) Calibrate and correct the dosing flow rate

[0490] First, open the medicine outlet valve 308, and allow the medicine to enter the natural gas pipeline 1201 through the pump inlet pipe 301, the pump 302, the medicine delivery pipe 303, the flow meter 304, the tee 307, and the medicine outlet valve 308 in sequence under the action of gravity; then, according to the flow meter calibration measurement error obtained in step 4), the instantaneous flow rate and the 10-minute cumulative flow rate of the flow meter 304 that are read and recorded again are calibrated and corrected;

[0491] It is known from common knowledge in the art that: since the height of the calibration cylinder 305 is higher than the height of the medicine outlet valve 308, after the medicine outlet valve 308 is opened and connected to the natural gas pipeline 1201, the medicine in the calibration cylinder 305 will flow downward through the medicine outlet valve 308 into the natural gas pipeline 1201 under the action of gravity, thereby automatically emptying the calibration cylinder 305; using a calibrated flow meter to calibrate and correct the metering error is a commonly used technical method in the art.

[0492] 6) Adjust the dosing flow rate to the required dosing amount

[0493] According to the flow meter calibration measurement error obtained in step 4), the instantaneous flow rate and the 10-minute cumulative flow rate of the flow meter 304 recorded are calibrated and corrected; then, according to the calibrated and corrected instantaneous flow rate and cumulative flow rate readings of the flow meter, the pump displacement is gradually adjusted to the required dosing flow rate.

[0494] It is known from the common knowledge in the art that the displacement of a metering pump can be adjusted by adjusting the reciprocating stroke of the plunger, and the displacement of a plunger pump, a gear pump, a centrifugal pump, etc. can be adjusted by frequency conversion speed regulation.

[0495] The application of the present invention to the gas distribution valve group of three gas injection pipelines in Qinghai gas field is taken as an example.

[0496] Public data from the Qinghai gas field shows that the pressure of the gas injection pipeline of the gas distribution valve group of the gas field is 10MPa, and natural gas hydrates are very likely to freeze and block it in winter. A metering pump and three pipelines are used to add methanol to the three gas injection pipelines to prevent freezing and blockage. During the winter period from December to March, operators can only adjust the methanol flow of the three gas injection pipelines based on their personal feelings, resulting in serious deviation of the methanol flow of the three gas injection pipelines, which further leads to frequent freezing and blockage of the gas injection pipelines, seriously affecting the gas lift production of the gas wells.

[0497] Experiments show that: Figure 2 The calibration device shown in the figure was used to carry out a gear flowmeter calibration test with methanol. The results showed that when the gear flowmeter was measuring a small flow of methanol, its metering error could reach 57%, which was 114 times of its factory calibration metering error.

[0498] Analysis and calculations show that methanol viscosity is lower than that of water; the average daily methanol injection volume of the three gas injection pipelines is 60 liters / day or 2.5 liters / hour, and the average daily methanol injection volume of each gas injection pipeline is 20 liters / day or 0.83 liters / hour, and the methanol flow rate is very small; if a gear flowmeter is installed on each alcohol injection pipeline, the flow measurement error can reach more than 50%; according to the average methanol injection of the three gas injection pipelines, the operator adjusts the methanol flow added to each gas injection pipeline to 1.25 liters / hour according to the flowmeter indication value and adjusts the metering pump displacement to 3.75 liters / hour, which means that the antifreeze needs of the gas injection pipeline have been met; however, because the 1.25 liters / hour displayed by the flowmeter has an error of 50%, the operator can adjust the flow rate of each gas injection pipeline to 1.25 liters / hour according to the flowmeter indication value and adjusts the metering pump displacement to 3.75 liters / hour. As mentioned above, the actual methanol flow rate of a certain gas injection pipeline may be 2.5 liters / hour (i.e. increased by 1 time) or 0.625 liters / hour; if the actual methanol flow rate of the gas injection pipeline is 2.5 liters / hour, it will inevitably cause the alcohol injection amount of the other two gas injection pipelines to be lower than 1.25 liters / hour and thus freeze; if the actual methanol flow rate of the gas injection pipeline is 0.625 liters / hour, it will inevitably lead to the gas injection pipeline; therefore, it means that the operator operates according to the indication value of the flowmeter with a metering error of more than 50%, and cannot solve the problem of methanol deviation in the gas injection pipeline, which will inevitably cause the gas injection pipeline to freeze and affect the production of the gas well; it can be seen that the method of setting a flow meter on each alcohol injection pipeline cannot effectively solve the problem of methanol deviation.

[0499] In order to solve the methanol bias problem in the gas distribution valve group, ensure that the gas injection pipeline is not frozen and blocked in winter and does not affect the production of gas wells, the gas distribution valve was tested in December 2018 using the present invention, and its technical solution is as follows:

[0500] 1) Install calibration cylinder, pressure pipeline, flow meter, etc.:

[0501] A DN15, PN250, 100mm long manganese steel drug outlet pipeline 1202 is vertically welded on the top of the gas injection pipeline 1201, and then a DN15, PN250 stainless steel ball valve is vertically installed on the upper part of the drug outlet pipeline 1202 with a threaded joint as a drug outlet valve 308, and then a DN15, PN250 stainless steel tee 307 is vertically installed on the upper part of the drug outlet valve 308 with a threaded joint, and then the upper interface of the tee 307 is vertically connected with a threaded joint to the bottom opening of the magnetic flap level gauge with an inner diameter of 50mm, a length of 1000mm, a liquid level scale division value of 1mm, and an opening at the top and bottom as the calibration cylinder 305, and then the top opening of the magnetic flap level gauge is connected with a threaded joint as the pressure inlet 306. A DN15, PN250 stainless steel pressure-inducing pipeline 1203 is connected, and then the other end of the pressure-inducing pipeline 1203 is welded to the top of the gas injection pipeline 1201 and connected thereto, so that the pressure in the calibration cylinder 305 is automatically balanced with the pressure in the gas injection pipeline 1201 and the medicine outlet valve 308; then a DN15, PN250 stainless steel medicine delivery pipe 303 is connected to the side interface of the tee 307 with a threaded joint, and then a PN250, 0.5-level accuracy, 0.3-60 liter / day gear flowmeter is connected to the medicine delivery pipe 303 with a threaded joint, and then the medicine delivery pipe 303 is connected to the outlet of a metering pump 302 with a maximum outlet pressure of 20MPa and a displacement of 0-10 liters / hour, and then the pump inlet pipe 301 is installed at the inlet of the metering pump 302;

[0502] Further analysis shows that the pressure of the gas injection pipeline 1201 of the gas distribution valve group is as high as 10 MPa, and the length (ie height) of the calibration cylinder 305 used is 1 meter. The increased pressure value of the metering pump 302 is less than 1%, and the impact on the leakage of the metering pump 302 is negligible.

[0503] 2) Add methanol:

[0504] Open the medicine outlet valve 308, start the pump 302, and methanol, under the action of gravity, passes through the pump inlet pipe 301, the pump 302, the medicine delivery pipe 303, the flow meter 304, the three-way 307, the medicine outlet valve 308, and the medicine outlet pipeline 1202 in sequence and enters the gas injection pipeline 1201;

[0505] 3) Flow meter measurement:

[0506] Keep the methanol flowing into the natural gas pipeline 1201 in sequence through the pump inlet pipe 301, the pump 302, the drug delivery pipe 303, the flow meter 304, the tee 307, the drug outlet valve 308, and the drug outlet pipeline 1202 under the action of gravity; read and record the instantaneous flow rate of the flow meter 304 and the cumulative flow rate for 10 minutes to obtain the average flow rate of the methanol entering the gas injection pipeline 1201;

[0507] 4) Calibrate the measurement error of the flow meter

[0508] Close the medicine outlet valve 308 to allow methanol to flow upward into the calibration cylinder 305; then start the timer and read the increase in the methanol liquid level in the calibration cylinder 305 in 10 minutes; then quickly calculate the volume of methanol entering the calibration cylinder 305 within 10 minutes based on the known 50 mm inner diameter of the calibration cylinder 305 (or the volume of 1 mm liquid level is 2 ml), and obtain the flow rate of methanol entering the calibration cylinder 305; then use the formula of flow meter calibration measurement error = (methanol flow rate entering the calibration cylinder 305 - average methanol flow rate entering the gas injection pipeline 1201) ÷ methanol flow rate entering the calibration cylinder 305 × 100% to obtain the calibration measurement error of the flow meter;

[0509] 5) Calibrate and correct methanol flow

[0510] First, open the medicine outlet valve 308, and allow the methanol to enter the injection pipeline 1201 through the pump inlet pipe 301, the pump 302, the medicine delivery pipe 303, the flow meter 304, the three-way 307, and the medicine outlet valve 308 in sequence under the action of gravity, and then read and record the instantaneous flow rate and the cumulative flow rate for 10 minutes of the flow meter 304 again; then, according to the flow meter calibration measurement error obtained in step 4), calibrate and correct the instantaneous flow rate and the cumulative flow rate for 10 minutes of the flow meter 304 read and recorded;

[0511] 6) Adjust the methanol flow rate to the required dosage

[0512] According to the flow meter calibration measurement error obtained in step 4), the instantaneous flow rate and the 10-minute cumulative flow rate of the flow meter 304 recorded are calibrated and corrected; then, according to the calibrated and corrected instantaneous flow rate and cumulative flow rate readings of the flow meter, the pump displacement is gradually adjusted to the required methanol flow rate.

[0513] The production experiment results show that after the gas distribution valve group applies the technical solution of the present invention, the methanol deviation problem of the three gas injection pipelines is effectively solved. During the 90-day test period, the three gas injection pipelines did not experience freezing and blockage problems, ensuring the normal gas lift production of the gas wells in winter.

[0514] Embodiment 37

[0515] Example 36 is repeated, with the difference being that a DN15, PN250 stainless steel pressure switch valve is provided on the pressure pipe 1203 for the convenience of inspection and management of the calibration cylinder.

[0516] Embodiment 38

[0517] See also Fig.18 As shown, Example 36 is repeated, and the difference is that: the method for calibrating the metering and regulating control of the dosing flow rate in situ during the dosing process of the gas well described in the dosing system of Examples 1, 4-8, 12-15 includes the following steps: 1) connecting the balanced pressure:

[0518] The medicine outlet valve is vertically connected to the casing joint 1302 with one end closed by the medicine outlet pipeline 1304, and then the pressure inlet port 306 is connected to the casing joint 1302 by the pressure inlet pipeline 1303, so that the pressure in the calibration cylinder 305 is automatically balanced with the pressure in the gas well casing; 2) Dosing:

[0519] Open the medicine outlet valve 308, start the pump 302, and the medicine, under the action of gravity, passes through the pump inlet pipe 301, the pump 302, the medicine delivery pipe 303, the flow meter 304, the tee 307, the medicine outlet valve 308, the medicine outlet pipeline 1304, the casing joint 1302, and the gas well casing valve 1301 and enters the gas well casing; 3) Flow meter measurement:

[0520] Keep the flow state of the agent entering the gas well casing unchanged by sequentially passing through the pump inlet pipe 301, the pump 302, the drug delivery pipe 303, the flow meter 304, the tee 307, the drug outlet valve 308, the drug outlet pipeline 1304, the casing joint 1302, and the gas well casing valve 1301; read and record the instantaneous flow rate and the 10-minute cumulative flow rate of the flow meter 304 to obtain the average drug addition flow rate of the agent entering the gas well casing;

[0521] 4) Calibrate the flow meter measurement error

[0522] Close the medicine outlet valve 308, let the medicine flow upward into the calibration cylinder 305, read the increase in the liquid level of the calibration cylinder 305 in 10 minutes, quickly calculate the volume of the medicine entering the calibration cylinder 305 within 10 minutes, and obtain the medicine flow rate of the medicine entering the calibration cylinder 305; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder 305 - average dosing flow rate entering the gas well casing) ÷ medicine flow rate entering the calibration cylinder 305 × 100%, obtain the calibration measurement error of the flow meter;

[0523] 5) Calibrate and correct the dosing flow rate

[0524] First, open the medicine outlet valve 308, and let the medicine pass through the pump inlet pipe 301, the pump 302, the medicine delivery pipe 303, the flow meter 304, the tee 307, the medicine outlet valve 308, the medicine outlet pipeline 1304, the casing joint 1302, and the gas well casing valve 1301 to enter the gas well casing; then, according to the flow meter calibration measurement error obtained in step 4), the instantaneous flow rate and the 10-minute cumulative flow rate of the flow meter 304 that are read and recorded again are calibrated and corrected;

[0525] 6) Adjust the dosing flow rate to the required dosing amount

[0526] According to the flow meter calibration measurement error obtained in step 4), the instantaneous flow rate and the 10-minute cumulative flow rate of the flow meter 304 recorded are calibrated and corrected; then, according to the calibrated and corrected instantaneous flow rate and cumulative flow rate readings of the flow meter, the pump displacement is gradually adjusted to the required dosing flow rate.

[0527] Embodiment 39

[0528] Example 38 is repeated, with the difference being that in order to facilitate the inspection and management of the calibration cylinder, a DN15, PN250 stainless steel pressure switch valve is provided on the pressure pipe 1303.

[0529] Embodiment 40

[0530] See also Fig.19 As shown, Example 36 is repeated, except that: the method for calibrating the dosing flow metering and regulating control of the dosing system described in Examples 2, 4-11, and 14-15 during the dosing process of the natural gas pipeline includes the following steps:

[0531] 1) Connection balance pressure

[0532] At the top of the natural gas pipeline 1401, first use the medicine outlet pipeline 1402 to vertically connect the medicine outlet valve 408 to the top of the natural gas pipeline 1401, and then use the pressure-introducing pipeline 1403 to connect the pressure-introducing port 406 and the natural gas pipeline 1401, so that the pressure in the calibration cylinder 405 is automatically balanced with the pressure in the natural gas pipeline 1401 and the medicine outlet valve 408;

[0533] 2) Dosing

[0534] Open the medicine outlet valve 408 and start the pump 402. The medicine will flow into the natural gas pipeline 1401 through the pump inlet pipe 401, the pump 402, the medicine delivery pipe 403, the flow meter 404, the tee 407, the medicine outlet valve 408 and the medicine outlet pipeline 1402 in sequence under the action of gravity.

[0535] 3) Flow meter measurement

[0536] Keep the medicine flowing through the pump inlet pipe 401, pump 402, medicine delivery pipe 403, flow meter 404, tee 407, medicine outlet valve 408, medicine outlet pipeline 1402 into the natural gas pipeline 1401 in sequence under the action of gravity; read and record the instantaneous flow rate and the accumulated flow rate within 10 minutes of the flow meter 404 to obtain the average dosing flow rate of the medicine entering the natural gas pipeline 1401;

[0537] 4) Calibrate the flow meter measurement error

[0538] Close the medicine outlet valve 408, let the medicine flow upward into the calibration cylinder 405, read the increase in the liquid level of the calibration cylinder 405 in 10 minutes, quickly calculate the volume of the medicine entering the calibration cylinder 405 within 10 minutes, and obtain the medicine flow rate of the medicine entering the calibration cylinder 405; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder 405 - average dosing flow rate entering the natural gas pipeline 1401) ÷ medicine flow rate entering the calibration cylinder 405 × 100%, obtain the calibration measurement error of the flow meter;

[0539] 5) Calibrate and correct the dosing flow rate

[0540] First, open the medicine outlet valve 408, and allow the medicine to enter the natural gas pipeline 1401 through the pump inlet pipe 401, the pump 402, the medicine delivery pipe 403, the flow meter 404, the three-way 407, and the medicine outlet valve 408 in sequence under the action of gravity; then, according to the flow meter calibration measurement error obtained in step 4), the instantaneous flow rate and the 10-minute cumulative flow rate of the flow meter 404 that are read and recorded again are calibrated and corrected;

[0541] 6) Adjust the dosing flow rate to the required dosing amount

[0542] According to the flow meter calibration measurement error obtained in step 4), the instantaneous flow rate and the 10-minute cumulative flow rate of the flow meter 404 recorded are calibrated and corrected; then, according to the calibrated and corrected instantaneous flow rate and cumulative flow rate readings of the flow meter, the pump displacement is gradually adjusted to the required dosing flow rate.

[0543] Embodiment 41

[0544] Example 40 is repeated, with the difference being that a DN15, PN250 stainless steel pressure switch valve is provided on the pressure pipe 1403 for the convenience of inspection and management of the calibration cylinder.

[0545] Embodiment 42

[0546] See also Fig. 20 As shown, examples 36, 38, and 40 are repeated, and the difference is that the method for calibrating the dosing flow metering and regulating control of the dosing system in the process of dosing in the natural gas pipeline includes the following steps:

[0547] 1) Connection balance pressure

[0548] At the top of the natural gas pipeline 1501, first use the medicine outlet pipeline 1502 to vertically connect the medicine outlet valve 507 to the top of the natural gas pipeline 1501, and then use the pressure-introducing pipeline 1503 to connect the pressure-introducing port 506 and the natural gas pipeline 1501, so that the pressure in the calibration cylinder 505 is automatically balanced with the pressure in the natural gas pipeline 1501 and the medicine outlet valve 507;

[0549] 2) Dosing

[0550] Open the medicine outlet valve 507 and start the pump 502. The medicine will flow into the natural gas pipeline 1501 through the pump inlet pipe 501, the pump 502, the medicine delivery pipe 503, the flow meter 504, the medicine outlet valve 507 and the medicine outlet pipeline 1502 in sequence under the action of gravity.

[0551] 3) Flow meter measurement

[0552] Keep the medicine flowing through the pump inlet pipe 501, pump 502, medicine delivery pipe 503, flow meter 504, medicine outlet valve 507, medicine outlet pipeline 1502 into the natural gas pipeline 1501 in sequence under the action of gravity; read and record the instantaneous flow rate and the accumulated flow rate in 10 minutes of the flow meter 504 to obtain the average dosing flow rate of the medicine entering the natural gas pipeline 1501;

[0553] 4) Calibrate the flow meter measurement error

[0554] Close the medicine outlet valve 507, let the medicine flow upward into the calibration cylinder 505, read the increase in the liquid level of the calibration cylinder 505 in 10 minutes, quickly calculate the volume of the medicine entering the calibration cylinder 505 within 10 minutes, and obtain the medicine flow rate of the medicine entering the calibration cylinder 505; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder 505 - average dosing flow rate entering the natural gas pipeline 1501) ÷ medicine flow rate entering the calibration cylinder 505 × 100%, obtain the calibration measurement error of the flow meter;

[0555] 5) Calibrate and correct the dosing flow rate

[0556] First, open the medicine outlet valve 507, and allow the medicine to enter the natural gas pipeline 1501 through the pump inlet pipe 501, the pump 502, the medicine delivery pipe 503, the flow meter 504, and the medicine outlet valve 507 in sequence under the action of gravity; then, according to the flow meter calibration measurement error obtained in step 4), the instantaneous flow rate and the 10-minute cumulative flow rate of the flow meter 504 that are read and recorded again are calibrated and corrected;

[0557] 6) Adjust the dosing flow rate to the required dosing amount

[0558] According to the flow meter calibration measurement error obtained in step 4), calibrate and correct the instantaneous flow rate and 10-minute cumulative flow rate of the flow meter 504 read and recorded; then, according to the calibrated and corrected flow meter instantaneous flow rate and cumulative flow rate readings, gradually adjust the pump displacement to the required dosing flow rate.

[0559] Embodiment 43

[0560] Example 42 is repeated, with the difference being that a DN15, PN250 stainless steel pressure switch valve is provided on the pressure pipe 1503 for the convenience of inspection and management of the calibration cylinder.

[0561] Embodiment 44

[0562] See also Fig.21 As shown, examples 36, 38, 40, and 42 are repeated, with the difference that: the method for calibrating the dosing flow metering and regulating control of the dosing system in the process of dosing in the natural gas pipeline in situ comprises the following steps:

[0563] 1) Connection balance pressure:

[0564] At the top of the first natural gas pipeline 1601, firstly use the first medicine outlet pipeline 1602 to vertically connect the first medicine outlet valve 609 to the top of the first natural gas pipeline 1601, and then use the first pressure-introducing pipeline 1603 to connect the first pressure-introducing port 607 and the first natural gas pipeline 1601, so that the pressure in the first calibration cylinder 606 is automatically balanced with the pressure in the first natural gas pipeline 1601 and the first medicine outlet valve 609;

[0565] At the top of the second natural gas pipeline 1701, first use the second medicine outlet pipeline 1702 to vertically connect the second medicine outlet valve 615 to the top of the second natural gas pipeline 1701, and then use the second pressure-introducing pipeline 1703 to connect the second pressure-introducing port 613 and the second natural gas pipeline 1701, so that the pressure in the second calibration cylinder 612 is automatically balanced with the pressure in the second natural gas pipeline 1701 and the second medicine outlet valve 615;

[0566] 2) Dosing:

[0567] Open the first medicine outlet valve 609 and start the pump 602. The medicine will flow into the first natural gas pipeline 1601 through the pump inlet pipe 601, the pump 602, the manifold tee 603, the first medicine delivery pipe 604, the first flow meter 605, the first tee 608, the first medicine outlet valve 609, and the first medicine outlet pipeline 1602 in sequence under the action of gravity.

[0568] When the second medicine outlet valve 615 is opened, the medicine will flow into the natural gas pipeline 1701 through the pump inlet pipe 601, the pump 602, the manifold tee 603, the second medicine delivery pipe 610, the second flow meter 611, the second tee 614, the second medicine outlet valve 615, and the second medicine outlet pipeline 1702 in sequence under the action of gravity;

[0569] 3) Flow meter measurement:

[0570] Keep the medicine under gravity and sequentially pass through the pump inlet pipe 601, pump 602, manifold tee 603, first medicine delivery pipe 604, first flow meter 605, first tee 608, first medicine outlet valve 609, first medicine outlet pipeline 1602 into the first natural gas pipeline 1601;

[0571] Keep the medicine under gravity and sequentially pass through the pump inlet pipe 601, pump 602, manifold tee 603, second medicine delivery pipe 610, second flow meter 611, second tee 614, second medicine outlet valve 615, second medicine outlet pipeline 1702 into the natural gas pipeline 1701;

[0572] 4) Calibrate the flow meter measurement error

[0573] Close the first medicine outlet valve 609, let the medicine flow upward into the calibration cylinder 606, read the 10-minute liquid level increase value of the calibration cylinder 606, quickly calculate the volume of the medicine entering the calibration cylinder 606 within 10 minutes, and obtain the medicine flow rate of the medicine entering the calibration cylinder 606; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder 606 - average dosing flow rate entering the natural gas pipeline 1601) ÷ medicine flow rate entering the calibration cylinder 606 × 100%, obtain the calibration measurement error of the first flow meter 605;

[0574] Close the second medicine outlet valve 615, let the medicine flow upward into the calibration cylinder 612, read the 10-minute liquid level increase value of the calibration cylinder 612, quickly calculate the volume of the medicine entering the calibration cylinder 612 within 10 minutes, and obtain the medicine flow rate of the medicine entering the calibration cylinder 612; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder 612 - average dosing flow rate entering the natural gas pipeline 1701) ÷ medicine flow rate entering the calibration cylinder 612 × 100%, obtain the calibration measurement error of the second flow meter 611;

[0575] 5) Calibrate and correct the dosing flow rate

[0576] Open the first medicine outlet valve 609, and allow the medicine to pass through the pump inlet pipe 601, the pump 602, the manifold tee 603, the first medicine delivery pipe 604, the first flow meter 605, the first tee 608, the first medicine outlet valve 609, the first medicine outlet pipeline 1602 in sequence under the action of gravity and enter the first natural gas pipeline 1601; then calibrate the metering error of the first flow meter 605 obtained in step 4), and calibrate and correct the instantaneous flow and 10-minute cumulative flow of the first flow meter 605 that are read and recorded again;

[0577] Open the second medicine outlet valve 615, and allow the medicine to enter the natural gas pipeline 1701 through the pump inlet pipe 601, the pump 602, the manifold tee 603, the second medicine delivery pipe 610, the second flow meter 611, the second tee 614, the second medicine outlet valve 615, and the second medicine outlet pipeline 1702 in sequence under the action of gravity; then calibrate the metering error of the second flow meter 611 obtained in step 4), and calibrate and correct the instantaneous flow and 10-minute cumulative flow of the second flow meter 611 that are read and recorded again;

[0578] 6) Adjust the dosing flow rate to the required dosing amount

[0579] According to the calibration measurement error of the first flow meter 605 obtained in step 4), calibrate and correct the instantaneous flow and 10-minute cumulative flow of the first flow meter 605 read and recorded;

[0580] According to the calibration measurement error of the second flow meter 611 obtained in step 4), calibrate and correct the instantaneous flow and 10-minute cumulative flow of the second flow meter 611 read and recorded;

[0581] Then, according to the instantaneous flow and the accumulated flow readings of the first flow meter 605 and the second flow meter 611 after calibration and correction, the displacement of the pump is gradually adjusted to the required dosing flow.

[0582] Embodiment 45

[0583] Example 44 is repeated, with the difference being that, in order to facilitate the inspection and management of the calibration cylinder, a DN15, PN250 stainless steel pressure switch valve is provided on the first pressure pipe 1603 and the second pressure pipe 1703, respectively.

[0584] Embodiment 46

[0585] See also Fig. 22 As shown, the method for calibrating the metering and regulating control of the dosing flow rate of the dosing system in the gas well dosing process in situ in the embodiment 16-17, 21-22, 24-35 includes the following steps:

[0586] 1) Wiring and elevation:

[0587] Use pipe threads to horizontally connect the manifold 705 with one end closed to the gas well casing valve 1801, so that the center line of the manifold 705 and the center line of the gas well casing valve 1801 are at the same level, or the center line of the manifold 705 is higher than the center line of the gas well casing valve 1801;

[0588] Use the existing method to make the bottom of the drip tank 701 higher than the center line of the gas well casing valve 1801 and the gas well casing 1802;

[0589] The bracket 702 should be able to ensure that the bottom of the drip tank 701 is higher than the center line of the gas well casing valve 1801 and the gas well casing 1802, and should be able to meet the production requirements of liquid medicine flowing from the drip tank 701 into the gas well casing valve 1801 and the gas well casing 1802; technical personnel in this field can use existing methods to determine the specific form, shape, material, and installation method of the bracket 702, and can determine the maximum height, minimum height, and optimal height of the bracket 702.

[0590] It is known from common knowledge in the art that the center lines of the gas well casing 1802 and the gas well casing valve 1801 are usually on the same horizontal line.

[0591] 2) Balance pressure

[0592] Open the gas well casing valve 1801, the pressure-inducing valve 713, the calibration switch valve 709, and the main switch valve 707, so that the natural gas in the gas well casing 1802 enters the calibration cylinder 710 and the drip tank 701, thereby balancing the pressure in the calibration cylinder 710, the drip tank 701, and the gas well casing 1802, and balancing the liquid levels in the calibration cylinder 710 and the drip tank 701;

[0593] It can be known from the common knowledge in the art and the U-tube principle that when the pressures in the calibration cylinder 710 and the drip tank 701 are equal, the liquid levels in the calibration cylinder 710 and the drip tank 701 can be automatically balanced.

[0594] 3) Dosing:

[0595] When the regulating valve 706 is opened, the medicine in the drip tank 701 will flow into the gas well casing 1802 by gravity through the flow meter 703, the medicine delivery tube 704, the main switch valve 707, the medicine three-way 708, the regulating valve 706, the manifold 705, and the gas well casing valve 1801;

[0596] It is known from common knowledge in the art that since the pressure and liquid level in the calibration cylinder 710 and the drip tank 701 are in a balanced state, the medicine in the drip tank 701 can flow into the gas well casing 1802 by gravity.

[0597] 4) Flow meter measurement:

[0598] Keep the medicine in the drip tank 701 flowing into the gas well casing 1802 by gravity through the flow meter 703, the medicine delivery tube 704, the main switch valve 707, the medicine three-way 708, the regulating valve 706, the manifold 705, and the gas well casing valve 1801 in sequence; read and record the instantaneous flow rate and the 10-minute cumulative flow rate of the flow meter 703 to obtain the average dosing flow rate of the medicine entering the gas well casing 1802;

[0599] 5) Calibrate the flow meter measurement error

[0600] Keep the opening of the regulating valve 706 and the calibration switch valve 709 unchanged, close the main switch valve 707, and the reagent in the calibration cylinder 710 will flow into the gas well casing 1802 by gravity through the calibration switch valve 709, the reagent tee 708, the regulating valve 706, the junction pipe 705, and the gas well casing valve 1801 in sequence; read the 10-minute liquid level reduction value of the calibration cylinder 710, quickly calculate the volume of the reagent flowing out of the calibration cylinder 710 within 10 minutes, and obtain the reagent flow rate of the reagent flowing out of the calibration cylinder 710; then, according to the formula of flow meter calibration measurement error = (medicine flow rate out of the calibration cylinder 710 - average dosing flow rate into the gas well casing 1802) ÷ reagent flow rate out of the calibration cylinder 710 × 100%, obtain the calibration measurement error of the flow meter 703;

[0601] From the test described in Example 16 of the present invention, it can be seen that the metering error of the gear flowmeter 703 calibrated by the calibration tube 710 is 3.2%, which meets the national standard requirements for the maximum allowable metering error of industrial instruments and flowmeters and can meet the production requirements of gas fields.

[0602] 6) Calibrate and correct the dosing flow rate

[0603] The flow meter 703 obtained in step 5) is used to calibrate the metering error, and the average dosing flow rate of the reagent entering the gas well casing 1802 obtained in step 4) is calibrated and corrected;

[0604] It is known from common knowledge in the art that using the calibrated flow meter measurement error to calibrate and correct the dosing flow rate is a commonly used technical method in the art.

[0605] 7) Adjust the dosing flow rate to the required dosing amount

[0606] When the main switch valve 707 is opened, the medicine in the drip tank 701 will flow into the gas well casing 1802 by gravity through the flow meter 703, the medicine delivery tube 704, the main switch valve 707, the medicine tee 708, the regulating valve 706, the manifold 705, and the gas well casing valve 1801. At the same time, part of the medicine will automatically flow into the calibration cylinder 710 to restore the liquid level of the calibration cylinder 710 to the balance with the liquid level in the drip tank 701.

[0607] Adjust the opening of the regulating valve 706, repeat steps 4) and 6) to adjust the dosing flow rate to the required flow rate.

[0608] It is known from common knowledge in the art that the capacity of the calibration cylinder 710 is extremely limited. After the main switch valve 707 is opened, the liquid level in the calibration cylinder 710 and the liquid level in the drip tank 701 can quickly restore balance.

[0609] Take the application of the present invention to the gas wells in the Qinghai gas field as an example.

[0610] Public data from the Qinghai gas field shows that the oil pressure of the gas wells in the gas field is generally above 5MPa. Natural gas hydrates are very likely to freeze and block the oil pipelines and gas gathering pipelines in winter. Methanol is injected into the gas wells to prevent freezing and blockage. The average daily methanol injection volume for a single well is 20-100 liters / day or 0.83 to 4 liters / hour. The flow meter error can reach more than 50%, which seriously affects the operator's judgment on the amount of methanol injection, resulting in frequent freezing and blockage of the gas well pipelines, seriously affecting the production of the gas wells.

[0611] In order to solve the problem of difficulty in judging the amount of alcohol injection due to large flow meter errors and ensure that the gas well pipeline is not frozen and blocked in winter and does not affect gas well production, the gas field applied the present invention to conduct production tests at three wells in January 2019. The technical solution is as follows:

[0612] 1) Wiring and elevation:

[0613] Use pipe threads to connect the manifold with one end closed to the gas well casing valve horizontally, or make the center line of the manifold higher than the center line of the gas well casing valve;

[0614] Use the method of raising the foundation to make the bottom of the drip tank 1.5 meters higher than the valve of the gas well casing and the center line of the gas well casing;

[0615] 2) Balance pressure

[0616] Introduce the natural gas in the gas well casing into the calibration cylinder and the drip tank, so that the pressure in the calibration cylinder, the drip tank and the gas well casing is balanced, and at the same time, the liquid level in the calibration cylinder and the drip tank is balanced;

[0617] 3) Dosing:

[0618] Allow the reagent in the drip tank to flow into the gas well casing under the action of gravity;

[0619] 4) Flow meter measurement:

[0620] Use a flow meter to measure the amount of chemicals entering the gas well casing;

[0621] 5) Calibrate the flow meter measurement error

[0622] According to the formula of flow meter calibration measurement error = (flow rate of reagent out of calibration cylinder - average dosing flow rate into gas well casing) ÷ flow rate of reagent out of calibration cylinder × 100%, the calibration measurement error of the flow meter is obtained;

[0623] 6) Calibrate and correct the dosing flow rate

[0624] The flow meter calibration measurement error obtained in step 5) is used to calibrate and correct the flow rate of the reagent entering the gas well casing in step 4);

[0625] 7) Adjust the dosing flow rate to the required dosing amount

[0626] Adjust the opening of the regulating valve 706, repeat steps 4) and 6) to adjust the dosing flow rate to the required flow rate.

[0627] The production experiment results show that after the three gas wells in the gas field were applied with the technical solution of the present invention, the problem that the flow meter was difficult to accurately measure the amount of injected alcohol was effectively solved. During the 30-day test period, the three gas wells did not experience freezing and blockage, ensuring the normal gas lift production of the gas wells in winter.

[0628] Embodiment 47

[0629] See also Fig.23 As shown, Example 46 is repeated, the difference being that the method for calibrating the metering and regulating control of the dosing flow rate in situ during the dosing process of the gas well described in Examples 18, 21-35 comprises the following steps:

[0630] 1) Wiring and elevation:

[0631] Use pipe threads to horizontally connect the manifold 705 with one end closed to the gas well casing valve 1901, so that the center line of the manifold 705 and the center line of the gas well casing valve 1901 are at the same level, or the center line of the manifold 705 is higher than the center line of the gas well casing valve 1901;

[0632] Use the existing method to make the bottom of the drip tank 701 higher than the center line of the gas well casing valve 1901 and the gas well casing 1902;

[0633] The bracket 702 should be able to ensure that the bottom of the drip tank 701 is higher than the center line of the gas well casing valve 1901 and the gas well casing 1902, and should be able to meet the production requirements of liquid medicine flowing from the drip tank 701 into the gas well casing valve 1901 and the gas well casing 1902; technical personnel in this field can use existing methods to determine the specific form, shape, material, and installation method of the bracket 702, and can determine the maximum height, minimum height, and optimal height of the bracket 702.

[0634] 2) Balance pressure

[0635] Open the gas well casing valve 1901, the pressure-inducing valve 713, the calibration switch valve 709, the auxiliary switch valve 901, and the main switch valve 707, so that the natural gas in the gas well casing 1902 enters the calibration cylinder 710 and the drip tank 701, thereby balancing the pressure in the calibration cylinder 710, the drip tank 701, and the gas well casing 1902, and balancing the liquid levels in the calibration cylinder 710 and the drip tank 701;

[0636] 3) Dosing:

[0637] When the regulating valve 706 is opened, the medicine in the drip tank 701 will flow into the gas well casing 1902 by gravity through the flow meter 703, the medicine delivery tube 704, the main switch valve 707, the medicine three-way 708, the auxiliary switch valve 901, the regulating valve 706, the manifold 705, and the gas well casing valve 1901;

[0638] 4) Flow meter measurement:

[0639] Keep the medicine in the drip tank 701 flowing into the gas well casing 1902 by gravity through the flow meter 703, the medicine delivery tube 704, the main switch valve 707, the medicine three-way 708, the auxiliary switch valve 901, the regulating valve 706, the manifold 705, and the gas well casing valve 1801 in sequence; read and record the instantaneous flow rate and the 10-minute cumulative flow rate of the flow meter 703 to obtain the average dosing flow rate of the medicine entering the gas well casing 1902;

[0640] 5) Calibrate the flow meter measurement error

[0641] Keep the opening of the regulating valve 706 and the calibration switch valve 709 unchanged, close the main switch valve 707, and the reagent in the calibration cylinder 710 will flow into the gas well casing 1902 by gravity through the calibration switch valve 709, the reagent tee 708, the auxiliary switch valve 901, the regulating valve 706, the junction pipe 705, and the gas well casing valve 1901 in sequence; read the 10-minute liquid level reduction value of the calibration cylinder 710, quickly calculate the volume of the reagent flowing out of the calibration cylinder 710 within 10 minutes, and obtain the reagent flow rate of the reagent flowing out of the calibration cylinder 710; then, according to the formula of flow meter calibration measurement error = (medicine flow rate out of the calibration cylinder 710 - average dosing flow rate into the gas well casing 1902) ÷ reagent flow rate out of the calibration cylinder 710 × 100%, obtain the calibration measurement error of the flow meter 703;

[0642] 6) Calibrate and correct the dosing flow rate

[0643] The flow meter 703 obtained in step 5) is used to calibrate the metering error, and the average dosing flow rate of the reagent entering the gas well casing 1902 obtained in step 4) is calibrated and corrected;

[0644] 7) Adjust the dosing flow rate to the required dosing amount

[0645] When the main switch valve 707 is opened, the medicine in the drip tank 701 will flow into the gas well casing 1902 by gravity through the flow meter 703, the medicine delivery tube 704, the main switch valve 707, the medicine three-way 708, the auxiliary switch valve 901, the regulating valve 706, the manifold 705, and the gas well casing valve 1901. At the same time, part of the medicine will automatically flow into the calibration cylinder 710 to restore the balance between the liquid level of the calibration cylinder 710 and the liquid level in the drip tank 701.

[0646] Adjust the opening of the regulating valve 706, repeat steps 4) and 6) to adjust the dosing flow rate to the required flow rate.

[0647] Embodiment 48

[0648] See also Fig.24 As shown, the method for calibrating the metering and regulating control of the dosing flow rate in situ during the dosing process of the dosing system of Examples 19-21 and 23-35 comprises the following steps:

[0649] 1) Wiring and elevation:

[0650] Use pipe threads to horizontally connect the manifold 1004 with one end closed to the gas well casing valve 2001, so that the center line of the manifold 1004 and the center line of the gas well casing valve 2001 are at the same level, or the center line of the manifold 1004 is higher than the center line of the gas well casing valve 2001;

[0651] The bottom of the drip tank 1001 is made higher than the center line of the gas well casing valve 2001 and the gas well casing 2002 by using the existing method;

[0652] The bracket 1002 should be able to ensure that the bottom of the drip tank 1001 is higher than the center line of the gas well casing valve 2001 and the gas well casing 2002, and should be able to meet the production requirements of liquid medicine flowing from the drip tank 1001 into the gas well casing valve 2001 and the gas well casing 2002 by gravity; technical personnel in this field can determine the specific form, shape, material, and installation method of the bracket 1002 using existing methods, and can determine the maximum height, minimum height, and optimal height of the bracket 1002.

[0653] 2) Balance pressure

[0654] Open the gas well casing valve 2001, the pressure-inducing valve 1012, and the main switch valve 1007, so that the natural gas in the gas well casing 2002 enters the calibration cylinder 1009 and the drip tank 1001, thereby balancing the pressure in the calibration cylinder 1009, the drip tank 1001, and the gas well casing 2002, and balancing the liquid levels in the calibration cylinder 1009 and the drip tank 1001;

[0655] 3) Dosing:

[0656] When the regulating valve 1005 is opened, the medicine in the drip tank 1001 will flow into the gas well casing 2002 by gravity through the medicine delivery tube 1003, the main switch valve 1007, the medicine three-way 1008, the flow meter 1006, the regulating valve 1005, the manifold 1004, and the gas well casing valve 2001;

[0657] 4) Flow meter measurement:

[0658] Keep the medicine in the drip tank 1001 flowing into the gas well casing 2002 by gravity through the medicine delivery tube 1003, the main switch valve 1007, the medicine three-way 1008, the flow meter 1006, the regulating valve 1005, the manifold 1004, and the gas well casing valve 2001 in sequence; read and record the instantaneous flow rate and the 5-minute cumulative flow rate of the flow meter 1006 to obtain the average dosing flow rate of the medicine entering the gas well casing 2002;

[0659] 5) Calibrate the flow meter measurement error

[0660] Keep the opening of the regulating valve 1005 unchanged, close the main switch valve 1007, and the reagent in the calibration cylinder 1009 will flow into the gas well casing 2002 by gravity through the reagent tee 1008, the flow meter 1006, the regulating valve 1005, the junction pipe 1004, and the gas well casing valve 2001 in sequence; read the 5-minute liquid level reduction value of the calibration cylinder 1009, quickly calculate the volume of the reagent flowing out of the calibration cylinder 1009 within 5 minutes, and obtain the reagent flow rate of the reagent flowing out of the calibration cylinder 1009; then, according to the formula of flow meter calibration measurement error = (medicine flow rate out of the calibration cylinder 1009 - average dosing flow rate into the gas well casing 2002) ÷ reagent flow rate out of the calibration cylinder 1009 × 100%, obtain the calibration measurement error of the flow meter 1006;

[0661] 6) Calibrate and correct the dosing flow rate

[0662] The flow meter 1006 obtained in step 5) is used to calibrate the metering error, and the average dosing flow rate of the reagent entering the gas well casing 2002 obtained in step 4) is calibrated and corrected;

[0663] 7) Adjust the dosing flow rate to the required dosing amount

[0664] When the main switch valve 1007 is opened, the medicine in the drip tank 1001 will flow into the gas well casing 2002 by gravity through the medicine delivery tube 1003, the main switch valve 1007, the medicine tee 1008, the flow meter 1006, the regulating valve 1005, the manifold 1004, and the gas well casing valve 2001. At the same time, part of the medicine will automatically flow into the calibration cylinder 1009 to restore the liquid level of the calibration cylinder 1009 to the balance with the liquid level in the drip tank 1001.

[0665] Adjust the opening of the regulating valve 1005, repeat steps 4) and 6) to adjust the dosing flow rate to the required flow rate.

[0666] Alternatively, in order to simplify the operation, the method for calibrating the metering and regulating control of the dosing flow rate of the dosing system described in Examples 19-21 and 23-35 during the dosing process of the gas well includes the following steps:

[0667] 1) Wiring and elevation:

[0668] Use pipe threads to horizontally connect the manifold 1004 with one end closed to the gas well casing valve 2001, so that the center line of the manifold 1004 and the center line of the gas well casing valve 2001 are at the same level, or the center line of the manifold 1004 is higher than the center line of the gas well casing valve 2001;

[0669] The bottom of the drip tank 1001 is made higher than the center line of the gas well casing valve 2001 and the gas well casing 2002 by using the existing method;

[0670] The bracket 1002 should be able to ensure that the bottom of the drip tank 1001 is higher than the center line of the gas well casing valve 2001 and the gas well casing 2002, and should be able to meet the production requirements of liquid medicine flowing from the drip tank 1001 into the gas well casing valve 2001 and the gas well casing 2002 by gravity; technical personnel in this field can determine the specific form, shape, material, and installation method of the bracket 1002 using existing methods, and can determine the maximum height, minimum height, and optimal height of the bracket 1002.

[0671] 2) Balance pressure

[0672] Open the gas well casing valve 2001, the pressure-inducing valve 1012, and the main switch valve 1007, so that the natural gas in the gas well casing 2002 enters the calibration cylinder 1009 and the drip tank 1001, thereby balancing the pressure in the calibration cylinder 1009, the drip tank 1001, and the gas well casing 2002, and balancing the liquid levels in the calibration cylinder 1009 and the drip tank 1001;

[0673] 3) Dosing:

[0674] When the regulating valve 1005 is opened, the medicine in the drip tank 1001 will flow into the gas well casing 2002 by gravity through the medicine delivery tube 1003, the main switch valve 1007, the medicine three-way 1008, the flow meter 1006, the regulating valve 1005, the manifold 1004, and the gas well casing valve 2001;

[0675] It is known from common knowledge in the art that a gear flow meter, for example, is allowed to be installed and used on a vertical or vertical pipeline.

[0676] 4) Calibrate the flow meter measurement error

[0677] When the main switch valve 1007 is closed, the reagent in the calibration cylinder 1009 will flow into the gas well casing 2002 by gravity through the reagent tee 1008, the flow meter 1006, the regulating valve 1005, the manifold 1004, and the gas well casing valve 2001 in sequence; read the 5-minute liquid level drop value of the calibration cylinder 1009, quickly calculate the volume of the reagent flowing out of the calibration cylinder 1009 within 5 minutes, and obtain the reagent flow rate of the reagent flowing out of the calibration cylinder 1009;

[0678] At the same time, read and record the instantaneous flow rate and the 5-minute cumulative flow rate of the flow meter 1006 to obtain the average flow rate value of the flow meter 1006;

[0679] Then, according to the formula of flow meter calibration measurement error = (medicine flow rate out of calibration cylinder 1009 - average flow value of flow meter 1006) ÷ medicine flow rate out of calibration cylinder 1009 × 100%, the calibration measurement error of flow meter 1006 is obtained;

[0680] 5) Calibrate and correct the dosing flow rate

[0681] The flow meter 1006 obtained in step 4) is used to calibrate the measurement error, and the average flow value of the flow meter 1006 obtained in step 4) is calibrated and corrected;

[0682] 6) Adjust the dosing flow rate to the required dosing amount

[0683] When the main switch valve 1007 is opened, the medicine in the drip tank 1001 will flow into the gas well casing 2002 by gravity through the medicine delivery tube 1003, the main switch valve 1007, the medicine tee 1008, the flow meter 1006, the regulating valve 1005, the manifold 1004, and the gas well casing valve 2001. At the same time, part of the medicine will automatically flow into the calibration cylinder 1009 to restore the liquid level of the calibration cylinder 1009 to the balance with the liquid level in the drip tank 1001.

[0684] Adjust the opening of the regulating valve 1005, repeat steps 4) and 5) to adjust the dosing flow rate to the required flow rate.

[0685] Embodiment 49

[0686] See also Fig.25 As shown, Example 48 is repeated, the difference being that: for the convenience of maintenance, the method for calibrating the dosing flow metering and regulating control of the dosing system described in Examples 20-21 and 23-35 during the dosing process of the gas well includes the following steps:

[0687] 1) Wiring and elevation:

[0688] Use pipe threads to horizontally connect the manifold 1004 with one end closed to the gas well casing valve 2101, so that the center line of the manifold 1004 and the center line of the gas well casing valve 2101 are at the same level, or the center line of the manifold 1004 is higher than the center line of the gas well casing valve 2101;

[0689] Use the existing method to make the bottom of the drip tank 1001 higher than the center line of the gas well casing valve 2101 and the gas well casing 2102;

[0690] The bracket 1002 should be able to ensure that the bottom of the drip tank 1001 is higher than the center line of the gas well casing valve 2101 and the gas well casing 2102, and should be able to meet the production requirements of liquid medicine flowing from the drip tank 1001 into the gas well casing valve 2101 and the gas well casing 2102; technical personnel in this field can use existing methods to determine the specific form, shape, material, and installation method of the bracket 1002, and can determine the maximum height, minimum height, and optimal height of the bracket 1002.

[0691] 2) Balance pressure

[0692] Open the gas well casing valve 2101, the pressure-inducing valve 1012, the calibration switch valve 1101, and the main switch valve 1007, so that the natural gas in the gas well casing 2102 enters the calibration cylinder 1009 and the drip tank 1001, thereby balancing the pressure in the calibration cylinder 1009, the drip tank 1001, and the gas well casing 2002, and balancing the liquid levels in the calibration cylinder 1009 and the drip tank 1001;

[0693] 3) Dosing:

[0694] When the regulating valve 1005 is opened, the medicine in the drip tank 1001 will flow into the gas well casing 2102 by gravity through the medicine delivery tube 1003, the main switch valve 1007, the medicine three-way 1008, the flow meter 1006, the regulating valve 1005, the manifold 1004, and the gas well casing valve 2101;

[0695] 4) Flow meter measurement:

[0696] Keep the medicine in the drip tank 1001 flowing into the gas well casing 2102 by gravity through the medicine delivery tube 1003, the main switch valve 1007, the medicine three-way 1008, the flow meter 1006, the regulating valve 1005, the manifold 1004, and the gas well casing valve 2101 in sequence; read and record the instantaneous flow rate and the 15-minute cumulative flow rate of the flow meter 1006 to obtain the average dosing flow rate of the medicine entering the gas well casing 2102;

[0697] 5) Calibrate the flow meter measurement error

[0698] Keep the opening of the regulating valve 1005 unchanged, close the main switch valve 1007, and the reagent in the calibration cylinder 1009 will flow into the gas well casing 2102 by gravity through the calibration switch valve 1101, the reagent tee 1008, the flow meter 1006, the regulating valve 1005, the junction pipe 1004, and the gas well casing valve 2101 in sequence; read the 15-minute liquid level reduction value of the calibration cylinder 1009, quickly calculate the volume of the reagent flowing out of the calibration cylinder 1009 within 15 minutes, and obtain the reagent flow rate of the reagent flowing out of the calibration cylinder 1009; then, according to the formula of flow meter calibration measurement error = (medicine flow rate out of the calibration cylinder 1009 - average dosing flow rate into the gas well casing 2102) ÷ reagent flow rate out of the calibration cylinder 1009 × 100%, obtain the calibration measurement error of the flow meter 1006;

[0699] 6) Calibrate and correct the dosing flow rate

[0700] The flow meter 1006 obtained in step 5) is used to calibrate the metering error, and the average dosing flow rate of the reagent entering the gas well casing 2102 obtained in step 4) is calibrated and corrected;

[0701] 7) Adjust the dosing flow rate to the required dosing amount

[0702] When the main switch valve 1007 is opened, the medicine in the drip tank 1001 will flow into the gas well casing 2102 by gravity through the medicine delivery tube 1003, the main switch valve 1007, the medicine tee 1008, the flow meter 1006, the regulating valve 1005, the manifold 1004, and the gas well casing valve 2101. At the same time, part of the medicine will automatically flow into the calibration cylinder 1009 to restore the balance between the liquid level of the calibration cylinder 1009 and the liquid level in the drip tank 1001.

[0703] Adjust the opening of the regulating valve 1005, repeat steps 4) and 6) to adjust the dosing flow rate to the required flow rate.

[0704] Alternatively, in order to simplify the operation, the method for calibrating the metering and regulating control of the dosing flow rate of the dosing system described in Examples 20-21 and 23-35 during the dosing process of the gas well includes the following steps:

[0705] 1) Wiring and elevation:

[0706] Use pipe threads to horizontally connect the manifold 1004 with one end closed to the gas well casing valve 2101, so that the center line of the manifold 1004 and the center line of the gas well casing valve 2101 are at the same level, or the center line of the manifold 1004 is higher than the center line of the gas well casing valve 2101;

[0707] Use the existing method to make the bottom of the drip tank 1001 higher than the center line of the gas well casing valve 2101 and the gas well casing 2102;

[0708] The bracket 1002 should be able to ensure that the bottom of the drip tank 1001 is higher than the center line of the gas well casing valve 2101 and the gas well casing 2102, and should be able to meet the production requirements of liquid medicine flowing from the drip tank 1001 into the gas well casing valve 2101 and the gas well casing 2102; technical personnel in this field can use existing methods to determine the specific form, shape, material, and installation method of the bracket 1002, and can determine the maximum height, minimum height, and optimal height of the bracket 1002.

[0709] 2) Balance pressure

[0710] Open the gas well casing valve 2101, the pressure-inducing valve 1012, the calibration switch valve 1101, and the main switch valve 1007, so that the natural gas in the gas well casing 2102 enters the calibration cylinder 1009 and the drip tank 1001, thereby balancing the pressure in the calibration cylinder 1009, the drip tank 1001, and the gas well casing 2102, and balancing the liquid levels in the calibration cylinder 1009 and the drip tank 1001;

[0711] 3) Dosing:

[0712] When the regulating valve 1005 is opened, the medicine in the drip tank 1001 will flow into the gas well casing 2102 by gravity through the medicine delivery tube 1003, the main switch valve 1007, the medicine three-way 1008, the flow meter 1006, the regulating valve 1005, the manifold 1004, and the gas well casing valve 2101;

[0713] 4) Calibrate the flow meter measurement error

[0714] When the main switch valve 1007 is closed, the reagent in the calibration cylinder 1009 will flow into the gas well casing 2102 by gravity through the calibration switch valve 1101, the reagent tee 1008, the flow meter 1006, the regulating valve 1005, the manifold 1004, and the gas well casing valve 2101; read the 10-minute liquid level drop value of the calibration cylinder 1009, quickly calculate the volume of the reagent flowing out of the calibration cylinder 1009 within 10 minutes, and obtain the reagent flow rate of the reagent flowing out of the calibration cylinder 1009;

[0715] At the same time, read and record the instantaneous flow rate and the 10-minute cumulative flow rate of the flow meter 1006 to obtain the average flow rate value of the flow meter 1006;

[0716] Then, according to the formula of flow meter calibration measurement error = (medicine flow rate out of calibration cylinder 1009 - average flow value of flow meter 1006) ÷ medicine flow rate out of calibration cylinder 1009 × 100%, the calibration measurement error of flow meter 1006 is obtained;

[0717] 5) Calibrate and correct the dosing flow rate

[0718] The flow meter 1006 obtained in step 4) is used to calibrate the measurement error, and the average flow value of the flow meter 1006 obtained in step 4) is calibrated and corrected;

[0719] 6) Adjust the dosing flow rate to the required dosing amount

[0720] When the main switch valve 1007 is opened, the medicine in the drip tank 1001 will flow into the gas well casing 2102 by gravity through the medicine delivery tube 1003, the main switch valve 1007, the medicine tee 1008, the flow meter 1006, the regulating valve 1005, the manifold 1004, and the gas well casing valve 2101. At the same time, part of the medicine will automatically flow into the calibration cylinder 1009 to restore the balance between the liquid level of the calibration cylinder 1009 and the liquid level in the drip tank 1001.

[0721] Adjust the opening of the regulating valve 1005, repeat steps 4) and 5) to adjust the dosing flow rate to the required flow rate.

[0722] Embodiment 50

[0723] See also Fig.26 As shown, Examples 46-47 are repeated, with the difference that: for the convenience of maintenance, the method for calibrating the dosing flow metering and regulating control of the dosing system in the gas well dosing process in situ in Example 22 includes the following steps:

[0724] After the flow meter measurement error calibration is completed, the auxiliary pressure-inducing valve 2201 and the calibration switch valve 709 are closed, and the calibration cylinder 710 is removed and used again for the flow meter measurement error calibration of other gas wells.

[0725] It is known from common knowledge in the art that the dosage of gas wells is usually less than 10 liters / hour, and the change in flow meter leakage caused by the change in dosage can be ignored; before the drip tank 701 is reinstalled, the change in flow meter leakage can be ignored; therefore, after the flow meter is calibrated once, before the dosing system described in the present invention is significantly changed, the flow meter is allowed to no longer be calibrated.

[0726] Embodiment 51

[0727] See also Fig. 27 As shown, Examples 48-49 are repeated, with the difference that: for the convenience of maintenance, the method for calibrating the dosing flow metering and regulating control of the dosing system in the gas well dosing process in situ in Example 23 includes the following steps:

[0728] After the flow meter measurement error calibration is completed, the auxiliary pressure-inducing valve 2301 and the calibration switch valve 1101 are closed, and the calibration cylinder 1009 is removed and used again for the flow meter measurement error calibration of other gas wells.

[0729] Embodiment 52

[0730] Example 1 is repeated, except that a pressure inlet switch valve is provided on the pressure inlet for the convenience of management and maintenance.

[0731] Embodiment 52

[0732] Example 1-35 is repeated: the difference is that in order to add chemicals to the oil well casing, the chemical addition system capable of calibrating the dosage on site is used for adding chemicals to the oil well casing.

[0733] It is known from the common knowledge in this field that the casing of the oil well contains natural gas, which is equivalent to a natural gas pipeline.

[0734] Embodiment 53

[0735] Repeat Examples 36-51: The difference is that in order to add chemicals to the oil well casing, the method of calibrating the dosing flow metering and regulating control on-site during the dosing process is used for dosing the oil well casing.

[0736] The words "up", "down", "left", "right", etc. used in this article to describe the directions are for the convenience of explanation and are based on the directions shown in the drawings. In an actual system, these directions may be different due to the layout of the system.

[0737] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all implementation methods here. Any obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A gas field dosing system that can calibrate the dosing amount on site. Features: It includes a pump inlet pipe, a pump, a manifold tee, a first drug delivery pipe, a first flow meter, a first calibration cylinder, a first pressure inlet, a first tee, a first drug outlet valve, a second drug delivery pipe, a second flow meter, a second calibration cylinder, a second pressure inlet, a second tee, and a second drug outlet valve; The pump inlet pipe is connected to the pump; The pump is connected to one interface of the manifold tee, another interface of the manifold tee is connected to the first drug delivery tube, and the third interface of the manifold tee is connected to the second drug delivery tube; A first flow meter is provided on the first drug delivery tube, and a second flow meter is provided on the second drug delivery tube; The first-path calibration cylinder has a first-path pressure inlet at the upper portion, and the lower portion is connected to the first-path drug delivery tube and the first-path drug outlet valve through a first-path tee. The second-way calibration cylinder is provided with a second-way pressure inlet at the upper part, and the lower part is connected to the second-way drug delivery tube and the second-way drug outlet valve respectively through a second-way tee. The pump is any one of a plunger pump, a gear pump, and a centrifugal pump; a safety valve, a pressure gauge or a pressure transmitter, a vent valve, a drain valve, and a reflux regulating valve are arranged on the pump or the drug delivery tube; and a pressure inlet switch valve is arranged on the pressure inlet.

2. A gas field dosing system that can calibrate the dosing amount on site. Features: Including drip tank, bracket, flow meter, drug delivery tube, manifold, regulating valve, main switch valve, medicine tee, calibration switch valve, calibration cylinder, calibration cylinder pressure pipe, pressure tee, pressure valve, drip tank pressure pipe; A bracket is arranged at the lower part of the drip tank; The bottom of the drip tank is connected to the drug delivery tube; The drug delivery tube is provided with a flow meter and a main switch valve; One end of the drug delivery tube is connected to the side interface of the medicine three-way, and the other end is connected to the lower part of the drip tank; The lower interface of the medicine tee is connected to the regulating valve, the upper interface of the medicine tee is connected to the calibration switch valve, and the side interface of the medicine tee is connected to the medicine delivery tube; The upper part of the calibration switch valve is connected to the calibration cylinder, and the lower part of the calibration switch valve is connected to the reagent three-way connection; The upper part of the calibration cylinder is connected to the calibration cylinder pressure-inducing pipe, and the lower part of the calibration cylinder is connected to the calibration switch valve; One end of the calibration cylinder pressure-inducing tube is connected to the upper part of the calibration cylinder, and the other end is connected to the upper interface of the pressure-inducing tee. The side interface of the pressure-inducing tee is connected to the pressure-inducing pipe of the drip tank, the lower part of the pressure-inducing tee is connected to the pressure-inducing valve, and the upper part of the pressure-inducing tee is connected to the pressure-inducing pipe of the calibration cylinder; One end of the pressure-inducing tube of the drip tank is connected to the upper part of the drip tank, and the other end is connected to the side interface of the pressure-inducing tee; The lower part of the pressure-inducing valve is communicated with the upper part of the manifold, and the upper part of the pressure-inducing valve is connected and communicated with the lower part of the pressure-inducing tee; The lower part of the regulating valve is communicated with the upper part of the manifold, and the upper part of the regulating valve is connected and communicated with the lower interface of the medicine tee; The top elevation of the calibration cylinder is equal to or higher than the top elevation of the drip tank; The bottom elevation of the calibration cylinder is equal to or lower than the bottom elevation of the drip tank; The top elevation of the calibration cylinder is lower than the top elevation of the drip tank; the bottom elevation of the calibration cylinder is higher than the bottom elevation of the drip tank; the drip tank is provided with a liquid level meter, a safety valve, a pressure gauge or a pressure transmitter, a vent valve, and a drain valve.

3. A gas field dosing system capable of calibrating the dosing amount on site according to claim 2, Features: An auxiliary switch valve is arranged between the regulating valve and the medicine three-way valve; the upper end of the auxiliary switch valve is connected and communicated with the lower interface of the medicine three-way valve, and the lower end is connected and communicated with the regulating valve.

4. A gas field dosing system that can calibrate the dosing amount on site. Features: Including drip tank, bracket, drug delivery tube, manifold, regulating valve, flow meter, main switch valve, medicine tee, calibration cylinder, calibration cylinder pressure pipe, pressure tee, pressure valve, drip tank pressure pipe; A bracket is arranged at the lower part of the drip tank; The bottom of the drip tank is connected to the drug delivery tube; A main switch valve is arranged on the drug delivery tube; One end of the drug delivery tube is connected to the side interface of the medicine three-way, and the other end is connected to the lower part of the drip tank; The lower interface of the medicine tee is connected to the flow meter, the upper interface of the medicine tee is connected to the lower interface of the calibration cylinder, and the side interface of the medicine tee is connected to the medicine delivery tube; The upper interface of the calibration cylinder is connected to the calibration cylinder pressure-inducing pipe, and the lower part of the calibration cylinder is connected to the upper interface of the medicine three-way. One end of the calibration cylinder pressure-inducing tube is connected to the upper interface of the calibration cylinder, and the other end is connected to the upper interface of the pressure-inducing tee. The side interface of the pressure-inducing tee is connected to the pressure-inducing pipe of the drip tank, the lower part of the pressure-inducing tee is connected to the pressure-inducing valve, and the upper part of the pressure-inducing tee is connected to the pressure-inducing pipe of the calibration cylinder; One end of the pressure-inducing tube of the drip tank is connected to the upper part of the drip tank, and the other end is connected to the side interface of the pressure-inducing tee; The lower part of the pressure-inducing valve is communicated with the upper part of the manifold, and the upper part of the pressure-inducing valve is connected and communicated with the lower part of the pressure-inducing tee; The lower interface of the flow meter is connected to the pressure regulating valve, and the upper part of the flow meter is connected to the lower interface of the medicine three-way. The lower part of the pressure regulating valve is communicated with the upper part of the manifold, and the upper part of the pressure regulating valve is connected and communicated with the lower interface of the flow meter; The top elevation of the calibration cylinder is equal to or higher than the top elevation of the drip tank; The bottom elevation of the calibration cylinder is equal to or lower than the bottom elevation of the drip tank; The top elevation of the calibration cylinder is lower than the top elevation of the drip tank; the bottom elevation of the calibration cylinder is higher than the bottom elevation of the drip tank; the drip tank is provided with a liquid level meter, a safety valve, a pressure gauge or a pressure transmitter, a vent valve, and a drain valve.

5. A gas field dosing system capable of calibrating the dosing amount on site according to claim 4, Features: A calibration switch valve is arranged between the calibration cylinder and the reagent tee; the upper end of the calibration switch valve is connected and communicated with the lower interface of the calibration cylinder, and the lower end is connected and communicated with the upper interface of the reagent tee.

6. A gas field dosing system capable of calibrating the dosing amount on site according to claim 2 or 4, Features: The drip tank is provided with a medicine replenishing valve.

7. A gas field dosing system capable of calibrating dosing amount on site according to claim 2 or 4, Features: An auxiliary pressure-guiding valve is provided on the pressure-guiding pipe of the calibration cylinder.

8. A gas field dosing system capable of calibrating dosing amount on site according to any one of claims 1, 2 and 4, Features: The flow meter is any one of a rotor flow meter, an ultrasonic flow meter, a vortex flow meter, and a differential pressure flow meter.

9. A gas field dosing system capable of calibrating dosing amount on site according to any one of claims 1, 2 and 4, Features: The calibration cylinder is any one of a magnetic flap level gauge, a magnetic float level gauge, a magnetic sensitive electronic two-color level gauge, a glass tube level gauge, a glass plate level gauge, and an ultrasonic level gauge.

10. A gas field dosing system capable of calibrating dosing amount on site according to any one of claims 1, 2 and 4, Features: The calibration cylinder is a remote transmission type magnetic float type liquid level meter made by utilizing the buoyancy principle, magnetic coupling effect, sensor, transmitter and display instrument.

11. A gas field dosing system capable of calibrating dosing amount on site according to any one of claims 1, 2 and 4, Features: The calibration cylinder includes a shell with a flange, a magnetic float liquid level transmitter with a flange, an upper interface and a bottom interface; the lower end of the magnetic float liquid level transmitter extends to the lower part of the shell, and the upper end of the magnetic float liquid level transmitter is connected to the top flange of the shell.

12. A gas field dosing system capable of calibrating dosing amount on site according to any one of claims 1, 2 and 4, Features: The calibration cylinder includes a threaded shell, a threaded hydrostatic level transmitter, an upper interface and a bottom interface. The lower end of the hydrostatic level transmitter extends to the lower part of the shell, and the upper part of the hydrostatic level transmitter is threadedly connected to the top of the shell.

13. A gas field dosing system capable of calibrating dosing amount on site according to any one of claims 1, 2 and 4, Features: The calibration cylinder comprises a shell, a pressure transmitter, an upper interface and a bottom interface, and the pressure transmitter is arranged at the lower part of the shell.

14. A gas field dosing system capable of calibrating dosing amount on site according to any one of claims 1, 2 and 4, Features: The calibration cylinder comprises a shell, a pressure gauge, a top interface and a bottom interface, and the pressure gauge is arranged at the lower part of the shell.

15. A gas field dosing system capable of calibrating dosing amount on site according to any one of claims 1, 2 and 4, Features: The calibration cylinder comprises a shell, a magnetic float, a top interface, non-ferrous iron powder and a bottom interface. The magnetic float is arranged in the shell, and the non-ferrous iron powder is arranged outside the shell at a position corresponding to the magnetic float.

16. A method for measuring and regulating the flow rate of a dosing system for a gas field according to claim 1, comprising the following steps: 1) Connection balance pressure: At the top of the natural gas pipeline, first use the medicine outlet pipeline to vertically connect the medicine outlet valve to the top of the natural gas pipeline, and then use the pressure inlet pipeline to connect the pressure inlet and the natural gas pipeline, so that the pressure in the calibration cylinder is automatically balanced with the pressure in the natural gas pipeline and the medicine outlet valve; 2) Dosing: Open the medicine outlet valve and start the pump. The medicine will flow into the natural gas pipeline through the pump inlet pipe, pump, medicine delivery pipe, flow meter, tee, medicine outlet valve and medicine outlet pipeline in sequence under the action of gravity. 3) Flow meter measurement: Keep the medicine flowing through the pump inlet pipe, pump, medicine delivery pipe, flow meter, tee, medicine outlet valve, medicine outlet pipeline into the natural gas pipeline under the action of gravity ； Read and record the instantaneous flow and cumulative flow of the flow meter to obtain the average dosing flow of the agent entering the natural gas pipeline; 4) Calibrate the flow meter measurement error Close the medicine outlet valve, let the medicine flow upward into the calibration cylinder, read the increase in the liquid level of the calibration cylinder per unit time, calculate the volume of the medicine entering the calibration cylinder per unit time, and obtain the medicine flow rate of the medicine entering the calibration cylinder; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder - average dosing flow rate entering the natural gas pipeline) ÷ medicine flow rate entering the calibration cylinder × 100%, obtain the calibration measurement error of the flow meter; 5) Calibrate and correct the dosing flow rate First, open the medicine outlet valve and let the medicine enter the natural gas pipeline through the pump inlet pipe, pump, medicine delivery pipe, flow meter, tee, and medicine outlet valve in sequence under the action of gravity; Then, according to the flow meter calibration measurement error obtained in step 4), the instantaneous flow rate and the accumulated flow rate of the flow meter read and recorded again are calibrated and corrected; 6) Adjust the dosing flow rate to the required dosing amount According to the flow meter calibration measurement error obtained in step 4), calibrate and correct the instantaneous flow rate and cumulative flow rate of the flow meter read and recorded; Then, according to the calibrated and corrected instantaneous flow and accumulated flow readings of the flow meter, gradually adjust the pump displacement to the required dosing flow.

17. The on-site calibration dosing flow metering and regulating control method of the dosing system for a gas field according to claim 1 comprises the following steps: 1) Connection balance pressure: At the top of the first natural gas pipeline, first use the first medicine outlet pipeline to vertically connect the first medicine outlet valve to the top of the first natural gas pipeline, and then use the first pressure inlet pipeline to connect the first pressure inlet and the first natural gas pipeline, so that the pressure in the first calibration cylinder is automatically balanced with the pressure in the first natural gas pipeline and the first medicine outlet valve; At the top of the second natural gas pipeline, first use the second medicine outlet pipeline to vertically connect the second medicine outlet valve to the top of the second natural gas pipeline, and then use the second pressure-intake pipeline to connect the second pressure-intake port and the second natural gas pipeline, so that the pressure in the second calibration cylinder is automatically balanced with the pressure in the second natural gas pipeline and the second medicine outlet valve; 2) Dosing: Open the first medicine outlet valve and start the pump. The medicine will flow into the first natural gas pipeline in sequence through the pump inlet pipe, the pump, the manifold tee, the first medicine delivery pipe, the first flow meter, the first tee, the first medicine outlet valve, and the first medicine outlet pipeline under the action of gravity. Open the second medicine outlet valve, and the medicine will enter the natural gas pipeline through the pump inlet pipe, pump, manifold tee, second medicine delivery pipe, second flow meter, second tee, second medicine outlet valve, and second medicine outlet pipeline in sequence under the action of gravity; 3) Flow meter measurement: Keep the medicine under the action of gravity, passing through the pump inlet pipe, pump, manifold tee, first medicine delivery pipe, first flow meter, first tee, first medicine outlet valve, first medicine outlet pipeline into the first natural gas pipeline in sequence; Keep the medicine under gravity and pass through the pump inlet pipe, pump, manifold tee, second medicine delivery pipe, second flow meter, second tee, second medicine outlet valve, second medicine outlet pipeline into the natural gas pipeline in sequence; 4) Calibrate the flow meter measurement error Close the first medicine outlet valve, let the medicine flow upward into the calibration cylinder, read the increase in the calibration cylinder liquid level per unit time, calculate the volume of the medicine entering the calibration cylinder per unit time, and obtain the medicine flow rate entering the calibration cylinder; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder - average dosing flow rate entering the natural gas pipeline) ÷ medicine flow rate entering the calibration cylinder × 100%, obtain the calibration measurement error of the first flow meter; Close the second medicine outlet valve, let the medicine flow upward into the calibration cylinder, read the increase in the calibration cylinder liquid level per unit time, calculate the volume of the medicine entering the calibration cylinder per unit time, and obtain the medicine flow rate entering the calibration cylinder; then, according to the formula of flow meter calibration measurement error = (medicine flow rate entering the calibration cylinder - average dosing flow rate entering the natural gas pipeline) ÷ medicine flow rate entering the calibration cylinder × 100%, obtain the calibration measurement error of the second flow meter; 5) Calibrate and correct the dosing flow rate Open the first medicine outlet valve, and allow the medicine to enter the first natural gas pipeline through the pump inlet pipe, pump, manifold tee, first medicine delivery pipe, first flow meter, first tee, first medicine outlet valve, and first medicine outlet pipeline in sequence under the action of gravity; Then, according to the calibration measurement error of the first flow meter obtained in step 4), the instantaneous flow and the accumulated flow of the first flow meter that are read and recorded again are calibrated and corrected; Open the second medicine outlet valve, and allow the medicine to enter the natural gas pipeline through the pump inlet pipe, pump, manifold tee, second medicine delivery pipe, second flow meter, second tee, second medicine outlet valve, and second medicine outlet pipeline in sequence under the action of gravity; Then, according to the calibration measurement error of the second flow meter obtained in step 4), the instantaneous flow and the accumulated flow of the second flow meter read and recorded again are calibrated and corrected; 6) Adjust the dosing flow rate to the required dosing amount According to the calibration measurement error of the first flow meter obtained in step 4), calibrate and correct the instantaneous flow and cumulative flow of the first flow meter read and recorded; According to the calibration measurement error of the second flow meter obtained in step 4), calibrate and correct the instantaneous flow and cumulative flow of the second flow meter read and recorded; Then, according to the instantaneous flow rate and the accumulated flow rate readings of the first and second flow meters after calibration, the displacement of the pump is gradually adjusted to the required dosing flow rate.

18. The on-site calibration dosing flow metering and regulating control method of the dosing system for a gas field according to claim 2 comprises the following steps: 1) Wiring and elevation: Connect the manifold to the gas well casing valve horizontally, so that the center line of the manifold is at the same level as the center line of the gas well casing valve, or make the center line of the manifold higher than the center line of the gas well casing valve; Using existing methods, the bottom of the drip tank is made higher than the valve of the gas well casing and the center line of the gas well casing; 2) Balance pressure Open the gas well casing valve, the pressure guide valve, the calibration switch valve, and the main switch valve to allow the natural gas in the gas well casing to enter the calibration cylinder and the drip tank, thereby balancing the pressure in the calibration cylinder, the drip tank, and the gas well casing, and balancing the liquid level in the calibration cylinder and the drip tank; 3) Dosing: Open the regulating valve, and the medicine in the drip tank will flow into the gas well casing by gravity through the flow meter, medicine delivery pipe, main switch valve, medicine tee, regulating valve, manifold, gas well casing valve in sequence; 4) Flow meter measurement: Keep the medicine in the drip tank flowing into the gas well casing through the flow meter, medicine delivery pipe, main switch valve, medicine tee, regulating valve, manifold, and gas well casing valve in sequence; read and record the instantaneous flow and cumulative flow of the flow meter to obtain the average dosing flow of the medicine entering the gas well casing; 5) Calibrate the flow meter measurement error Keep the opening of the regulating valve and the calibration switch valve unchanged, close the main switch valve, and the reagent in the calibration cylinder will flow into the gas well casing by gravity through the calibration switch valve, the reagent tee, the regulating valve, the manifold, and the gas well casing valve in sequence; Read the value of the liquid level drop in the calibration cylinder per unit time, calculate the volume of the reagent flowing out of the calibration cylinder per unit time, and obtain the reagent flow rate flowing out of the calibration cylinder; then, according to the formula of flow meter calibration measurement error = (medicine flow rate flowing out of the calibration cylinder - average dosing flow rate entering the gas well casing) ÷ reagent flow rate flowing out of the calibration cylinder × 100%, obtain the calibration measurement error of the flow meter; 6) Calibrate and correct the dosing flow rate Using the flow meter calibration measurement error obtained in step 5), the average dosing flow rate of the reagent entering the gas well casing obtained in step 4) is calibrated and corrected; 7) Adjust the dosing flow rate to the required dosing amount Open the main switch valve, and the medicine in the drip tank will flow into the gas well casing by gravity through the flow meter, medicine delivery pipe, main switch valve, medicine tee, regulating valve, manifold, gas well casing valve, and part of the medicine will automatically flow into the calibration cylinder to restore the balance between the liquid level of the calibration cylinder and the liquid level in the drip tank. Adjust the opening of the regulating valve and repeat steps 4) and 6) to adjust the dosing flow rate to the required flow rate.

19. The on-site calibration dosing flow metering and regulating control method of the dosing system for gas fields according to claim 18, Features: The method also includes the following steps: after the flow meter measurement error is calibrated, the auxiliary pressure-inducing valve and the calibration switch valve are closed, the calibration cylinder is removed, and it is used again for the flow meter measurement error calibration of other gas wells.

20. The on-site calibration dosing flow metering and regulating control method of the dosing system for a gas field according to claim 4 comprises the following steps: 1) Wiring and elevation: Connect the manifold to the gas well casing valve horizontally, so that the center line of the manifold is at the same level as the center line of the gas well casing valve, or make the center line of the manifold higher than the center line of the gas well casing valve; Using existing methods, the bottom of the drip tank is made higher than the valve of the gas well casing and the center line of the gas well casing; 2) Balance pressure Open the gas well casing valve, the pressure-inducing valve, and the main switch valve to allow the natural gas in the gas well casing to enter the calibration cylinder and the drip tank, thereby balancing the pressure in the calibration cylinder, the drip tank, and the gas well casing, and balancing the liquid level in the calibration cylinder and the drip tank; 3) Dosing: When the regulating valve is opened, the medicine in the drip tank will flow into the gas well casing by gravity through the medicine delivery pipe, main switch valve, medicine tee, flow meter, regulating valve, manifold, and gas well casing valve in sequence; 4) Flow meter measurement: Keep the medicine in the drip tank flowing into the gas well casing through the medicine delivery pipe, main switch valve, medicine tee, flow meter, regulating valve, manifold, and gas well casing valve in sequence; read and record the instantaneous flow and cumulative flow of the flow meter to obtain the average dosing flow of the medicine entering the gas well casing; 5) Calibrate the flow meter measurement error Keep the opening of the regulating valve unchanged, close the main switch valve, and the reagent in the calibration cylinder will flow into the gas well casing by gravity through the reagent tee, flow meter, regulating valve, manifold, and gas well casing valve in sequence; read the calibration cylinder liquid level reduction value per unit time, calculate the volume of the reagent flowing out of the calibration cylinder per unit time, and obtain the reagent flow rate of the reagent flowing out of the calibration cylinder; then, according to the formula of flow meter calibration measurement error = (medicine flow rate out of the calibration cylinder - average dosing flow rate into the gas well casing) ÷ reagent flow rate out of the calibration cylinder × 100%, obtain the calibration measurement error of the flow meter; 6) Calibrate and correct the dosing flow rate Using the flow meter calibration measurement error obtained in step 5), the average dosing flow rate of the reagent entering the gas well casing obtained in step 4) is calibrated and corrected; 7) Adjust the dosing flow rate to the required dosing amount Open the main switch valve, and the medicine in the drip tank will flow into the gas well casing by gravity through the medicine delivery pipe, the main switch valve, the medicine tee, the flow meter, the regulating valve, the manifold, and the gas well casing valve. At the same time, part of the medicine will automatically flow into the calibration cylinder to restore the balance between the liquid level of the calibration cylinder and the liquid level in the drip tank. Adjust the opening of the regulating valve and repeat steps 4) and 6) to adjust the dosing flow rate to the required flow rate.

21. The on-site calibration dosing flow metering and regulating control method of the dosing system for a gas field according to claim 4 comprises the following steps: 1) Wiring and elevation: Connect the manifold with one end closed to the gas well casing valve horizontally, so that the center line of the manifold is at the same level as the center line of the gas well casing valve, or the center line of the manifold is higher than the center line of the gas well casing valve; Using existing methods, the bottom of the drip tank is made higher than the valve of the gas well casing and the center line of the gas well casing; 2) Balance pressure Open the gas well casing valve, the pressure-inducing valve, and the main switch valve to allow the natural gas in the gas well casing to enter the calibration cylinder and the drip tank, thereby balancing the pressure in the calibration cylinder, the drip tank, and the gas well casing, and balancing the liquid level in the calibration cylinder and the drip tank; 3) Dosing: When the regulating valve is opened, the medicine in the drip tank will flow into the gas well casing by gravity through the medicine delivery pipe, main switch valve, medicine tee, flow meter, regulating valve, manifold, and gas well casing valve in sequence; 4) Calibrate the flow meter measurement error When the main switch valve is closed, the reagent in the calibration cylinder will flow into the gas well casing by gravity through the reagent tee, flow meter, regulating valve, manifold, and gas well casing valve in sequence; Read the value of the liquid level drop in the calibration cylinder per unit time, calculate the volume of the agent flowing out of the calibration cylinder per unit time, and obtain the agent flow rate of the agent flowing out of the calibration cylinder; At the same time, read and record the instantaneous flow and cumulative flow of the flow meter to obtain the average flow value of the flow meter; Then, according to the formula of flow meter calibration measurement error = (flow rate of medicine flowing out of calibration cylinder - average flow value of flow meter) ÷ flow rate of medicine flowing out of calibration cylinder × 100%, the calibration measurement error of flow meter is obtained; 5) Calibrate and correct the dosing flow rate Using the flow meter calibration measurement error obtained in step 4), calibrate and correct the average flow value of the flow meter obtained in step 4); 6) Adjust the dosing flow rate to the required dosing amount Open the main switch valve, and the medicine in the drip tank will flow into the gas well casing by gravity through the medicine delivery pipe, the main switch valve, the medicine tee, the flow meter, the regulating valve, the manifold, and the gas well casing valve. At the same time, part of the medicine will automatically flow into the calibration cylinder to restore the balance between the liquid level of the calibration cylinder and the liquid level in the drip tank. Adjust the opening of the regulating valve and repeat steps 4) and 5) to adjust the dosing flow rate to the required flow rate.

22. The on-site calibration dosing flow metering and regulating control method of the dosing system for gas fields according to claim 20 or 21, Features: The method also includes the following steps: after the flow meter measurement error is calibrated, the auxiliary pressure-inducing valve and the calibration switch valve are closed, the calibration cylinder is removed, and it is used again for the flow meter measurement error calibration of other gas wells.

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