Automatic sampling and water content detecting device for oil well production fluid and detecting method

Abstract

The application discloses an automatic sampling and water content detecting device and method for oil well production fluid, which comprises a measuring cylinder for containing detecting liquid, an overflow cylinder sleeved on the upper outer periphery of the measuring cylinder and receiving overflow liquid of the measuring cylinder, a detecting tube connected with the lower part of the measuring cylinder through a measuring communication tube to form a communicating vessel and containing indicating liquid, and scale lines corresponding to the liquid level of the indicating liquid and the water content of the detecting liquid are arranged on the outer wall of the detecting tube, and an inner liquid storage bag is arranged in the inner cavity of the measuring cylinder, a tensionless material is used to contain the indicating liquid, the inner liquid storage bag is sealingly connected with the inner port of the measuring communication tube, and the detecting liquid and the indicating liquid are isolated while the liquid column pressure is transmitted. The detecting method comprises the following steps in sequence: the measuring cylinder is reset to discharge residual liquid; the detecting liquid is injected into the measuring cylinder from the bottom; the detecting liquid stops overflowing to stop liquid injection; a digital liquid level meter detects the height of the indicating liquid in the detecting tube and sends the height to a paperless recorder; and the paperless recorder records and converts to obtain the water content of the detecting liquid in the measuring cylinder.

Description

Technical Field

[0001] This invention relates to a sampling and testing device, and more particularly to an automatic sampling and water content testing device for oil well produced fluid. This invention also relates to an automatic sampling and water content testing method for oil well produced fluid, belonging to the field of oil well produced fluid testing technology. Background Technology

[0002] Oil wells typically produce a three-phase mixture of oil, gas, and water. To obtain the oil production of a single well and understand the dynamic changes in water cut, it is necessary to sample and analyze the produced fluid. This work is usually carried out every three to four days for each well. For new wells or wells with significant dynamic changes after treatment, more frequent monitoring is required, and the sampling frequency is increased. Sometimes, individual wells are sampled once or twice a day.

[0003] Currently, the water content testing of oil well produced fluids involves oil workers using sampling gates to collect the fluid into sampling containers (500ml and 1000ml containers depending on monitoring requirements). These containers are then centrally transported to a laboratory for water content analysis, and the resulting waste oil is then collected and sent to a storage facility for recycling. This process not only places a heavy workload on oil workers and lab technicians but also poses a risk of crude oil pollution to the environment.

[0004] Chinese invention application CN 116500097A discloses a device and method for measuring the water cut at the wellhead of a high water-cut oil well. The technical solution includes a sampling unit capable of sampling the produced fluid at the wellhead. The sampling unit includes a sealable measuring container, within which a capacitive measuring unit is installed to detect the dielectric constant of the medium inside the measuring container. It also includes a differential pressure measuring unit capable of detecting the differential pressure of the medium inside the measuring container, and a heating and temperature control unit for heating the medium inside the measuring container. Furthermore, it includes a controller for receiving, processing, and storing signals from the capacitive measuring unit, the differential pressure measuring unit, and the heating and temperature control unit. This technical solution requires determining the dielectric constant of the sampled fluid, as well as heating and recording the differential pressure. It is susceptible to interference, resulting in inaccurate water cut measurements. Moreover, the device is complex, costly, and has low precision. Summary of the Invention

[0005] The primary objective of this invention is to overcome the problems existing in the prior art and provide an automatic sampling and water content detection device for oil well produced fluids, which can replace crude oil sampling and testing, reduce the labor intensity of personnel, and avoid the problem of crude oil contamination during the sampling and testing process.

[0006] To solve the above technical problems, the present invention provides an automatic sampling and water content detection device for oil well produced fluid, comprising:

[0007] Measuring cylinder, used to hold the test liquid;

[0008] An overflow cylinder is fitted around the upper outer periphery of the metering cylinder to receive the overflow liquid from the metering cylinder;

[0009] The detection tube is connected to the lower part of the measuring cylinder through a measuring connecting tube at its bottom to form a communicating vessel, and contains an indicator liquid. The outer wall is provided with scale lines corresponding to the liquid level height of the indicator liquid and the water content of the detection liquid.

[0010] The inner reservoir, located inside the measuring cylinder, is made of tension-free material to hold the indicator liquid and is sealed to the inner opening of the measuring connecting pipe, isolating the detection liquid from the indicator liquid while transmitting the liquid column pressure.

[0011] Furthermore, the middle section of the measuring connecting tube is provided with an outer reservoir to contain the indicator liquid, and the outer reservoir is a rigid container.

[0012] Furthermore, a high-precision digital level gauge is provided at the upper part of the detection tube. The liquid level height of the indicator liquid measured by the high-precision digital level gauge is sent to the intelligent paperless recorder for storage and conversion to calculate the water content of the detection liquid.

[0013] Furthermore, the bottom of the metering cylinder is conical and a metering cylinder drain pipe is connected to the lowest point of the center. A drain solenoid valve is installed in the middle section of the metering cylinder drain pipe, and the outlet of the metering cylinder drain pipe is connected to the sleeve gas through a sleeve port connector.

[0014] Furthermore, the bottom of the side wall of the metering cylinder is provided with a metering cylinder inlet, which is connected to an inlet pipe, and an inlet solenoid valve is installed in the middle section of the inlet pipe.

[0015] Furthermore, the top of the overflow cylinder is provided with an overflow cylinder top cover to seal it, and the bottom of the overflow cylinder is provided with an overflow cylinder cone bottom that is high in the middle and low around the edges. The lowest point of the overflow cylinder cone bottom is connected to an overflow cylinder drain pipe and is equipped with an overflow solenoid valve.

[0016] Furthermore, the lower end of the overflow drain pipe is connected to the metering cylinder inlet at the bottom of the metering cylinder sidewall via an overflow connection pipe.

[0017] Furthermore, the overflow connection pipe is lower than the measuring connection pipe, and a lower magnetic float switch is installed in the middle section of the overflow connection pipe. The bottom outlet of the lower magnetic float switch is connected to the metering cylinder drain pipe.

[0018] Furthermore, the top cover of the overflow cylinder is provided with an overflow cylinder exhaust port, the top of the detection tube is provided with a top-closed detection tube exhaust chamber, the overflow cylinder exhaust port is connected to the detection tube exhaust chamber, the detection tube exhaust chamber is connected to the balance tube, the middle section of the balance tube is provided with a balance solenoid valve, and the outlet of the balance tube is connected to the sleeve gas.

[0019] Furthermore, a pressure gauge valve is connected to the side wall outlet of the sleeve connector, and the outlet of the pressure gauge valve is connected to the outlet of the sleeve pressure gauge via a tee and is connected to the outlet of the balance pipe.

[0020] Furthermore, the casing gas pressure value measured by the casing pressure gauge is sent to the intelligent paperless recorder for storage and recording. The intelligent paperless recorder calculates the casing gas production based on the increment of the casing gas pressure value using the gas state equation, which serves as the basis for casing gas utilization.

[0021] Furthermore, a magnetic float switch for detecting the liquid level in the overflow tank is installed on the top cover of the overflow tank.

[0022] Furthermore, a temperature sensor for detecting the temperature of the indicator liquid is inserted into the outer liquid storage bag, and the temperature of the indicator liquid measured by the temperature sensor is sent to the intelligent paperless recorder for storage and recording.

[0023] Furthermore, the top cover of the overflow cylinder is symmetrically provided with mounting lugs, which are suspended from the center of the triangular bracket by slings. The axes of the mounting lugs, the metering cylinder and the detection tube are located in the same vertical plane.

[0024] Furthermore, it also includes a control system, which includes:

[0025] The metering cylinder reset control circuit consists of a reset button FA, a normally closed contact of relay KA2, a normally closed contact of relay KA3, and a coil of relay KA1 connected in series. The self-holding contact of relay KA1 is connected in parallel with the reset button FA.

[0026] In the liquid inlet control circuit of the measuring cylinder, the normally closed contact of the measurement start button CA and the relay KA3 is connected in series with the coil of the relay KA2, and the relay KA2 is connected in parallel with the measurement start button CA;

[0027] In the metering cylinder discharge control circuit, the normally closed contact of the measurement end button JA and relay KA2 is connected in series with the coil of relay KA3, and the self-holding contact of relay KA3 is connected in parallel with the measurement end button JA.

[0028] The normally open contact of relay KA2 and the normally closed contact of relay KA1 are connected in series in the coil circuit of relay KFA. The normally open contact of relay KFA controls the opening of the liquid inlet solenoid valve.

[0029] The normally open contact of relay KA1 is connected in parallel with the normally open contact of relay KA3, and then connected in series in the coil circuit of relays KFB and KFD. The normally open contact of relay KFB controls the opening of the overflow solenoid valve, and the normally open contact of relay KFD controls the opening of the drain solenoid valve.

[0030] The normally open contacts of relays KA1, KA2, and KA3 are connected in parallel and then connected in series in the coil circuit of relay KFC. The normally open contact of relay KFC controls the opening of the solenoid valve.

[0031] Furthermore, the coil circuit of the relay KA1 is connected in series with the normally open contact of the lower magnetic float switch.

[0032] Furthermore, the coil circuit of the relay KA2 is connected in series with the normally closed contact of the upper magnetic float switch.

[0033] Furthermore, the coil circuit of the relay KA3 is connected in series with the normally open contact of the lower magnetic float switch.

[0034] Furthermore, the power off button TA and the power on button QA are connected in series with the coil of the relay KA, the self-holding contact of the relay KA is connected in parallel with the power on button QA, and the normally open output of the relay KA controls the power supply of the metering cylinder reset control circuit, the metering cylinder liquid inlet control circuit and the metering cylinder liquid outlet control circuit.

[0035] Furthermore, the first normally open contact of the programmable time switch is connected in parallel with the normally open contact of the relay KA3 and then connected in series in the coil circuit of the relay KD; the normally closed contact of the relay KD is connected in series in the coil circuit of the relay KA, the normally open contact of the relay KD is connected in parallel with the power "on" button QA, and the second normally open contact of the programmable time switch is connected in parallel with the normally closed contact of the relay KD.

[0036] Furthermore, the normally open contact of the upper magnetic float switch is connected in series in the coil circuit of the time delay relay KT1, and the time-delayed closing normally open contact of the time delay relay KT1 is connected in parallel with the measurement end button JA.

[0037] Another objective of this invention is to overcome the problems existing in the prior art and provide an automatic sampling and water content detection method for oil well produced fluid, which can replace crude oil sampling and testing, reduce the labor intensity of personnel, and avoid the problem of crude oil contamination during the sampling and testing process.

[0038] To solve the above technical problems, the present invention provides an automatic sampling and water content detection method for oil well produced fluid, employing the automatic sampling and water content detection device for oil well produced fluid as described in claim 9, comprising the following steps in sequence:

[0039] S1. Reset the measuring cylinder and drain the residual liquid.

[0040] S2. Open the inlet solenoid valve and the balance solenoid valve, and close the overflow solenoid valve and the drain solenoid valve. The test liquid is injected into the measuring cylinder from the bottom.

[0041] S3. The test liquid overflows from the upper port of the metering cylinder into the overflow cylinder. Close the inlet solenoid valve and the balance solenoid valve, and the metering cylinder stops feeding liquid.

[0042] S4. The pressure of the liquid column in the metering cylinder is transmitted to the detection tube through the inner liquid storage tank. The high-precision digital level gauge detects the height of the indicator liquid in the detection tube.

[0043] S5. The paperless recorder records the height of the indicator liquid in the detection tube and calculates the water content of the detection liquid in the measuring cylinder.

[0044] Furthermore, the correspondence between the indicator liquid level in the detection tube and the water content of the detection liquid in the measuring cylinder is calibrated according to the following steps:

[0045] B1. Pour pure water into the measuring cylinder until it overflows. After the indicator liquid in the detection tube stabilizes, the corresponding highest liquid level is calibrated as 100% water content.

[0046] B2. Inject crude oil into the measuring cylinder until it overflows. After the indicator liquid in the detection tube stabilizes, the corresponding lowest liquid level is calibrated as 0% water content.

[0047] B3. Divide the scale lines evenly between the highest and lowest liquid levels, which represents the water content of the actual test liquid.

[0048] Compared with the prior art, the present invention has achieved the following beneficial effects: 1. For specific blocks in oil fields, the physical properties of crude oil are specific, that is, the density of crude oil in each oil well is constant, and the water content in the oil well mixture is linearly related to the density of the mixture. The water content of the oil well produced fluid can be accurately measured using a simple device, which is simple, practical and unaffected by interference factors.

[0049] 2. An automatic sampling and water content detection device for oil well produced fluid is installed next to the oil well to enable timed automatic sampling and water content detection of the oil well produced fluid, and the results are recorded in a paperless recorder or uploaded through an information system.

[0050] 3. By setting different time periods for programmable time control switches, multiple sampling and water content testing records can be completed every day without human intervention. This has changed the original manual sampling method of using sampling buckets to collect samples, sending them to the laboratory for testing, and transferring and treating waste liquid, greatly reducing the labor intensity of oilfield workers and laboratory workers.

[0051] 4. The pressure at the top of both ends of the casing gas balance connector is used to make the measurement more accurate; the pressure of the casing gas can also be used to accelerate the drainage and improve the measurement efficiency; in addition, the pressure of the casing gas and its recovery value can be monitored.

[0052] 5. The entire process is conducted in a closed loop, and residual liquid and waste gas are directly returned to the well, completely avoiding environmental pollution. Attached Figure Description

[0053] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The drawings are provided for reference and illustration only and are not intended to limit the present invention.

[0054] Figure 1 This is a diagram showing the composition and pipeline connection of the automatic sampling and water content detection device for oil well produced fluid of the present invention;

[0055] Figure 2 This is a diagram showing the state of the detection device of the present invention after it has been suspended.

[0056] Figure 3 This is a top view of the tripod;

[0057] Figure 4 This is a control circuit diagram of the present invention;

[0058] In the diagram: 1. Measuring cylinder; 2. Overflow cylinder; 3. Inner storage tank; 4. Outer storage tank; 5. Detection tube; 6. Lifting lug; 7. High-precision digital level gauge; 8. Upper magnetic float switch; 9. Lower magnetic float switch; 10. Temperature sensor; 11. Sleeve pressure gauge; 12. Inlet pipe; 13. Measuring cylinder drain pipe; 14. Overflow cylinder drain pipe; 15. Balance pipe; 16. Sleeve connector; 17. Inlet solenoid valve; 18. Overflow solenoid valve; 19. Balance solenoid valve; 20. Drain solenoid valve; 21. Pressure gauge valve; 22. Triangular support; 23. Lifting sling. Detailed Implementation

[0059] In the following description of the present invention, the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not mean that the device must have a specific orientation.

[0060] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention.

[0062] like Figures 1 to 3 As shown, the automatic sampling and water content detection device for oil well produced fluid of the present invention consists of a metering cylinder 1, an overflow cylinder 2, a detection tube 5, a high-precision digital level gauge 7, an inlet solenoid valve 17, an overflow solenoid valve 18, a balance solenoid valve 19, a discharge solenoid valve 20, a casing pressure gauge 11, a temperature sensor 10, etc.

[0063] Measuring cylinder 1 is a key measuring component of the device, with a length of not less than 1 meter, typically ranging from 1 meter to 1.5 meters. The bottom of measuring cylinder 1 is conical, and the lowest point of the center is connected to a measuring cylinder drain pipe 13. A drain solenoid valve 20 is installed in the middle section of the measuring cylinder drain pipe 13, and the outlet of the measuring cylinder drain pipe 13 is connected to the sleeve gas through a sleeve port connector 16.

[0064] The bottom of the side wall of the measuring cylinder 1 is provided with a measuring cylinder inlet, which is connected to the inlet pipe 12. The middle section of the inlet pipe 12 is equipped with an inlet solenoid valve 17.

[0065] The top of the overflow cylinder 2 is provided with an overflow cylinder top cover to seal it, and the bottom of the overflow cylinder 2 is provided with an overflow cylinder cone bottom that is high in the middle and low around the edges. The lowest point of the overflow cylinder cone bottom is connected to the overflow cylinder drain pipe 14 and is equipped with an overflow solenoid valve 18. The top cover of the overflow cylinder is equipped with an upper magnetic float switch 8 for detecting the liquid level in the overflow cylinder 2.

[0066] The lower end of the overflow cylinder drain pipe 14 is connected to the metering cylinder inlet at the bottom of the side wall of the metering cylinder 1 via an overflow connecting pipe. The overflow connecting pipe is lower than the measuring connecting pipe, and a lower magnetic float switch 9 is installed in the middle section of the overflow connecting pipe. The bottom outlet of the lower magnetic float switch 9 is connected to the metering cylinder drain pipe 13.

[0067] The top cover of the overflow cylinder is provided with an overflow cylinder exhaust port, and the top of the detection tube 5 is provided with a top-closed detection tube exhaust chamber. The overflow cylinder exhaust port is connected to the detection tube exhaust chamber. The detection tube exhaust chamber is connected to the balance tube 15. The middle section of the balance tube 15 is provided with a balance solenoid valve 19, and the outlet of the balance tube 15 is connected to the sleeve gas.

[0068] A pressure gauge valve 21 is connected to the side wall outlet of the casing connector 16. The outlet of the pressure gauge valve 21 is connected to the casing pressure gauge via a tee and is also connected to the outlet of the balance pipe 15. The casing gas pressure value measured by the casing pressure gauge is sent to the intelligent paperless recorder for storage and recording. The intelligent paperless recorder calculates the casing gas production based on the increment of the casing gas pressure value using the gas state equation, which serves as the basis for the utilization of the casing gas.

[0069] The inner reservoir 3, outer reservoir 4, and detection tube 5 are filled with pure water or 40% alcohol (for winter antifreeze purposes) as indicator solutions. The inner reservoir 3, made of tension-free material, is located inside the measuring cylinder 1 and has a maximum volume of 350-500 mL. It is sealed to the inner opening of the measuring connecting tube, isolating the indicator solution from the detection solution while transmitting liquid column pressure. The outer reservoir 4 is a rigid shell. The detection tube 5 and measuring cylinder 1 remain connected through the inner reservoir 3, achieving mutual isolation between the detection solution in measuring cylinder 1 and the indicator solution in detection tube 5 while transmitting pressure. The measuring cylinder 1, through the inner reservoir 3 and detection tube 5, constitutes a communicating vessel principle.

[0070] The upper 500mm of the detection tube 5 is marked with millimeter graduations for calibrating the high-precision digital level gauge 7. The high-precision digital level gauge 7 uses an armored straight rod level transmitter with a measurement range of 0-300mm and an accuracy of 0.2%. The liquid level height of the indicated liquid measured by the high-precision digital level gauge 7 is sent to the intelligent paperless recorder for storage and conversion to calculate the water content of the detected liquid.

[0071] In addition, a temperature sensor 10 is inserted into the outer liquid storage tank to detect the temperature of the indicator liquid. The temperature of the indicator liquid measured by the temperature sensor 10 is sent to the intelligent paperless recorder for storage and recording to correct the influence of temperature on the density of the detection liquid. The water content accuracy of the entire device can be controlled within 1%, and it is linear and unaffected by the water content range.

[0072] Two symmetrical mounting lugs 6 are provided on the top cover of the overflow cylinder. The two mounting lugs 6 are suspended from the center of the triangular bracket 22 by the sling 23. The line connecting the two mounting lugs 6 is in the same vertical plane as the axis of the metering cylinder 1, the detection tube 5, and the metering cylinder drain pipe 13, ensuring that the entire device is perpendicular to the ground under the action of the triangular bracket 22, so that no secondary adjustment of horizontality and verticality is required.

[0073] Measuring cylinder 1 is made of polytetrafluoroethylene material, or its inner surface is coated with non-stick oil coating to prevent oil from sticking to the inner wall after measurement and affecting the accuracy of the next measurement.

[0074] The device drains liquid through the balance pipe 15, which connects the top of the device to the sleeve gas via the high-precision digital level gauge 7 connector, the balance solenoid valve 19, the balance pipe 15, and the pressure gauge valve 21. The liquid is drained from the metering cylinder 1 and the overflow cylinder 2 by gravity. The bottom of the metering cylinder 1 is conical, and the bottom of the overflow cylinder 2 is sloped, both to facilitate the complete drainage of liquid from the device.

[0075] The inlet of the metering cylinder 1 is lower than the inner storage tank 3. The upper inlet of the lower magnetic float switch 9 is connected to the bottom of the metering cylinder 1. The lower outlet of the lower magnetic float switch 9 is lower than the inlet of the metering cylinder 1 and is connected to the metering cylinder discharge pipe 13. Its function is to detect whether the metering cylinder 1 has completely discharged the liquid and ensure that the liquid detected next time is the newly introduced oil well production liquid.

[0076] The purpose of the overflow cylinder 2 in the device design is to ensure the accuracy of the liquid height in the metering cylinder 1, prevent the operation error (position, time) of the upper magnetic float switch 8, and avoid affecting the height of the oil well produced fluid that needs to be measured.

[0077] On-site installation: After the device and the triangular support 22 are assembled, connect the inlet of the inlet pipe 12 to the oil well sampling gate, connect the outlet of the outlet pipe 13 to the casing port connector 16, connect the casing port connector 16 to the casing clamp head, and connect the balance pipe 15 to the tee joint of the casing pressure gauge 11.

[0078] The function of temperature sensor 10 is to correct the influence of temperature on the density of the detection liquid, that is, to solve the temperature drift of the device (especially since the density of alcohol is greatly affected by temperature).

[0079] The casing pressure gauge 11 measures the increase in casing gas pressure over a period of time and then estimates the casing gas production of the oil well using the gas state equation formula, which serves as the basis for the utilization of casing gas.

[0080] Working principle: The measuring cylinder 1, through the inner liquid storage bag 3 and the detection tube 5, forms a communicating vessel. According to the communicating vessel principle, the following can be known:

[0081] When the oil well produces entirely water, the liquid level in the detection tube 5 is at its highest point, consistent with the liquid level in the measuring cylinder 1 after equilibrium is reached.

[0082] When the oil well produces fluid that is entirely oil, the liquid level in the detection tube 5 is at its lowest point because the density of crude oil is lower than that of water and remains relatively constant. Furthermore, since the upper and lower diameters of the metering cylinder 1 are the same, the water content of the oil well produced fluid (referred to as water content) is linearly related to the liquid level in the detection tube 5. By measuring the height of the indicated liquid in the detection tube 5 using a high-precision digital level gauge 7, the water content of the oil well produced fluid can be calculated.

[0083] Device calibration: The correspondence between the indicator liquid level in detection tube 5 and the water content of the detection liquid in measuring cylinder 1 shall be calibrated according to the following steps:

[0084] B1. Pour pure water into the measuring cylinder 1 until it overflows. After the indicator liquid in the detection tube 5 stabilizes, the corresponding highest liquid level is calibrated as 100% water content.

[0085] B2. Inject crude oil into metering cylinder 1 until it overflows. After the indicator liquid in detection tube 5 stabilizes, the corresponding lowest liquid level is calibrated as 0% water content.

[0086] B3. Divide the scale lines evenly between the highest and lowest liquid levels, which represents the water content of the actual test liquid.

[0087] If other media with a known density comparable to crude oil are used, their density needs to be compared with that of crude oil, and the corresponding water content can be obtained through linear conversion.

[0088] The detection tube 5 is made of glass, with millimeter graduations at the top 500mm position. This length is within the detection range of the high-precision digital level gauge 7 and is used to calibrate the high-precision digital level gauge 7.

[0089] Work process:

[0090] 1) Metering cylinder reset

[0091] Each time a sample is taken for testing, it is necessary to check whether there is residual liquid in the metering cylinder 1 and the overflow cylinder 2. If there is residual liquid, it needs to be emptied to ensure that the metering cylinder 1 contains newly taken oil well production fluid.

[0092] 2) Metering cylinder liquid inlet

[0093] The inlet pipe 12 is connected to the oil well sampling gate. After the device is put into use, the sampling gate is normally open. When the device is filled with liquid, the inlet solenoid valve 17 and the balance solenoid valve 19 are opened, and the overflow solenoid valve 18 and the drain solenoid valve 20 are closed.

[0094] Liquid enters the inner cavity of the metering cylinder 1 from the bottom through the inlet pipe 12 and the inlet solenoid valve 17. When the metering cylinder 1 is full and reaches the upper edge of the metering cylinder 1, the liquid automatically overflows to the overflow pipe 2 due to gravity, thereby ensuring that the liquid height in the metering cylinder 1 is a constant value.

[0095] When the liquid in the overflow cylinder 2 reaches the detection position of the upper magnetic float switch 8, the upper magnetic float switch 8 sends a signal to close the liquid inlet solenoid valve 17 and the balance solenoid valve 19, and the metering cylinder 1 stops receiving liquid.

[0096] 3) Moisture content test records

[0097] During the liquid injection process, the liquid in the detection tube 5, which is connected to the metering cylinder 1, rises under the pressure of the liquid in the metering cylinder 1. A time delay relay maintains a stable level for a set period. Simultaneously, the high-precision digital level gauge 7 detects the level of the indicator liquid in the detection tube 5 and records it in a paperless recorder. The water content of the detected liquid in the metering cylinder 1 can be obtained from the calibrated scale value. If there is gas in the oil well during this process, it can enter the casing annular space through the balance pipe 15 without affecting the water content test results.

[0098] 4) Device drainage

[0099] When the test is completed, the time delay relay is activated, and the overflow solenoid valve 18, the balance solenoid valve 19, and the drain solenoid valve 20 are opened, while the inlet solenoid valve 17 is closed. The upper part of the device is connected to the sleeve gas through the connector of the high-precision digital level gauge 7, the balance solenoid valve 19, the balance pipe 15, and the pressure gauge valve 21, and the liquid is drained from the metering cylinder 1 and the overflow cylinder 2 by gravity.

[0100] When the liquid level drops to the detection position of the lower magnetic float switch 9, the drainage ends and a signal is sent to close the overflow solenoid valve 18, the balance solenoid valve 19, and the drainage solenoid valve 20, completing one measurement and waiting for the next sampling test.

[0101] The entire process of sampling, testing, and liquid discharge of the device does not involve contact with air, thus solving the environmental pollution problems of sampling tubes, testing instruments, and residual liquid disposal after testing in conventional sampling and testing.

[0102] like Figure 4 As shown, the control system includes a power supply circuit, a metering cylinder reset control circuit, a metering cylinder liquid inlet control circuit, a metering cylinder liquid outlet control circuit, and a solenoid valve control circuit.

[0103] In the metering cylinder reset control circuit: the reset button FA, the normally closed contact KA2-2 of relay KA2, the normally closed contact KA3-2 of relay KA3, the normally open contact 9-1 of the lower magnetic float switch 9 are connected in series with the coil of relay KA1, and the self-holding contact KA1-1 of relay KA1 and the normally open contact KD-3 of relay KD are connected in parallel with the reset button FA.

[0104] In the metering cylinder liquid inlet control circuit: the measurement start button CA, the normally closed contact KA3-3 of relay KA3, the normally closed contact 8-2 of the upper magnetic float switch 8, and the coil of relay KA2 are connected in series. Relay KA2 is connected in parallel with the measurement start button CA. The self-holding contact KA2-1 of relay KA2 is connected in parallel with the measurement start button CA. The normally open contact KD-4 of relay KD and the normally closed contact 9-3 of lower magnetic float switch 9 are connected in series and then in parallel across the measurement start button CA.

[0105] In the metering cylinder discharge control circuit: the measurement end button JA, the normally closed contact KA2-3 of relay KA2, the normally open contact 9-2 of the lower magnetic float switch 9, and the coil of relay KA3 are connected in series. The self-holding contact KA3-1 of relay KA3 is connected in parallel with the measurement end button JA. The normally open contact 8-1 of the upper magnetic float switch 8 is connected in series in the coil circuit of time delay relay KT1. The time-delayed closing normally open contact KT1-1 of time delay relay KT1 is connected in parallel with the measurement end button JA.

[0106] The normally open contact KA2-4 of relay KA2 and the normally closed contact KA1-2 of relay KA1 are connected in series in the coil circuit of relay KFA. The normally open contact of relay KFA controls the opening of the liquid inlet solenoid valve 17.

[0107] The normally open contact KA1-3 of relay KA1 and the normally open contact KA3-4 of relay KA3 are connected in parallel and then connected in series in the coil circuits of relays KFB and KFD. The normally open contact of relay KFB controls the opening of overflow solenoid valve 18, and the normally open contact of relay KFD controls the opening of drain solenoid valve 20.

[0108] The normally open contacts KA1-4 of relay KA1, KA2-5 of relay KA2, and KA3-6 of relay KA3 are connected in parallel and then connected in series in the coil circuit of relay KFC. The normally open contacts of relay KFC control the opening of the solenoid valve 19.

[0109] The power off button TA and the power on button QA are connected in series with the coil of the relay KA. The self-holding contact of the relay KA is connected in parallel with the power on button QA. The normally open output of the relay KA controls the power supply of the metering cylinder reset control circuit, the metering cylinder liquid inlet control circuit, and the metering cylinder liquid outlet control circuit.

[0110] The first normally open contact KS-1 of the programmable time switch is connected in parallel with the normally open contact KA3-5 of the relay KA3 and then connected in series in the coil circuit of the relay KD; the normally closed contact KD-2 of the relay KD is connected in series in the coil circuit of the relay KA; the second normally open contact KS-2 of the programmable time switch is connected in parallel with the normally closed contact KD-2 of the relay KD.

[0111] The control process is as follows:

[0112] 1. The device is powered by a 24V DC power supply. Manual sampling, water content detection and drainage can be achieved by pressing the power "on" button QA, reset button FA, measurement start button CA, measurement end button JA, and power "off" button TA. At the same time, the device can also achieve timed and multiple sampling, water content detection and drainage every day through a programmable timer switch.

[0113] 2. Power supply to the device

[0114] When the programmable time switch reaches the set start time, its first normally open contact KS-1 closes, or the normally open contact KA3-5 of relay KA3 closes, the coil of relay KD is energized, and the normally open contact KD-1 of relay KD closes.

[0115] When the second normally open contact KS-2 of the programmable time switch is closed, press the power "on" button QA, or the normally open contact KD-1 of the relay KD closes, the coil of the relay KA is energized, its normally open contact KA-1 closes to maintain the energization of the coil of the relay KA, the power indicator L1 lights up, and the normally open contact KA-2 of the relay KA closes to connect the power supply to the device.

[0116] Press the power "off" button TA, or when the programmable timer reaches the set end time, its normally open contacts KS-1 and KS-2 will both open, the coil of relay KD will be de-energized, the normally closed contact KD-2 of relay KD will open, the coil of relay KA will also be de-energized, the power indicator L1 will go out, and the normally open contact KA-2 of relay KA will open, disconnecting the power supply to the device.

[0117] 3. The purpose of resetting the metering cylinder is to drain any residual liquid that may be present in the metering cylinder, ensuring that the detected oil well production fluid is the newly added liquid to the metering cylinder.

[0118] When the reset button FA is pressed, or the programmable timer switch reaches the set start time, the normally open contact KD-3 of relay KD closes, the coil of relay KA1 is energized, the normally open contact KA1-1 of relay KA1 closes for self-holding, the reset indicator L2 lights up, the normally closed contact KA1-2 of relay KA1 opens, so that relay KFA cannot be energized, and the liquid inlet solenoid valve 17 is in the closed state.

[0119] When the normally open contact KA1-4 of relay KA1 closes, relay KFC is energized, and the balancing solenoid valve 19 opens.

[0120] When the normally open contact KA1-3 of relay KA1 closes, relays KFB and KFD are energized, and overflow solenoid valve 18 and drain solenoid valve 20 open, allowing the device to drain.

[0121] KA1-2 acts as an interlock to prevent relay KFA from being energized during drainage, thus avoiding the opening of the inlet solenoid valve 17 for inlet drainage. After drainage is completed, the normally open contact 9-1 of the lower magnetic float switch 9 opens, the coil of relay KA1 is de-energized, the normally open contact 9-2 of the lower magnetic float switch 9 opens, the coil of relay KA3 is de-energized, and the reset ends.

[0122] When there is no residual liquid in the measuring cylinder 1, the normally open contact 9-1 of the lower magnetic float switch 9 is in the open state. When the reset switch button is pressed, the coil of the relay KA1 cannot be energized, and the reset indicator light L2 does not light up.

[0123] 4. Liquid is fed into the measuring cylinder.

[0124] Press the measurement start button CA, or the programmable timer switch reaches the set start time. The normally open contact KD-4 of relay KD closes. Because the measuring cylinder 1 has undergone a reset process, the normally closed contact 9-3 of the lower magnetic float switch 9 is in the closed state. The coil of relay KA2 is energized, and its normally open contact KA2-1 closes for self-holding. The liquid inlet indicator L3 lights up. The normally open contact KA2-4 of relay KA2 closes, relay KFA is energized, and the liquid inlet solenoid valve 17 opens, allowing liquid to enter the measuring cylinder 1. The normally closed contact KA2-2 of relay KA2 cuts off the coil circuit of relay KA1.

[0125] When the normally open contact KA2-5 of relay KA2 closes, relay KFC is energized, and the balancing solenoid valve 19 opens, maintaining the pressure balance at the top of the measuring cylinder 1 and the detection tube 5.

[0126] When the normally closed contact KA2-3 of relay KA2 is opened, the drainage circuit is open, causing the coil of relay KA3 to be de-energized. In this case, relays KFB and KFD in the drainage circuit cannot be energized, and the overflow solenoid valve 18 and the drainage solenoid valve 20 are in the closed state.

[0127] When the measuring cylinder 1 is full of test liquid and reaches the upper edge of the measuring cylinder 1, it automatically overflows into the overflow cylinder 2. When the liquid in the overflow cylinder 2 reaches the detection position of the upper magnetic float switch 8, the normally closed contact 8-2 of the upper magnetic float switch 8 opens, the coil of the relay KA2 in the liquid inlet circuit is de-energized, the liquid inlet solenoid valve 17 and the balance solenoid valve 19 are closed, and the liquid inlet ends.

[0128] The normally closed contacts KA2-3 of relay KA2 and KA3-3 of relay KA3 are interlocked to prevent the coils of relay KA2 in the liquid inlet circuit and relay KA3 in the liquid outlet circuit from being energized at the same time.

[0129] 5. Device Detection and Recording. When the liquid in the overflow tank 2 reaches the detection position of the upper magnetic float switch 8, after the liquid inflow is completed, the normally open contact 8-1 of the upper magnetic float switch 8 closes, energizing the coil of the time-delay relay KT1. Considering the impact of fluctuations during the liquid inflow process on the detection data, a detection and recording delay circuit is added. The time-delay relay KT1 can be selected from 0 to 30 minutes. After a certain delay, the normally open contact KT1-1 closes, energizing the coil of relay KA3 and initiating the liquid drainage action. This ensures that the high-precision digital level gauge 7 can detect and record stable liquid level data. When the coil of relay KA3 is energized, its normally closed contact KA3-2 cuts off the coil circuit of relay KA1.

[0130] 6. Measuring cylinder drainage. Press the measurement end button JA, or when the time delay relay KT1 reaches the set time, the normally open contact KT1-1 closes, relay KA3 closes, and its normally open contact KA3-1 closes for self-holding, illuminating the drainage indicator L4; in the drainage solenoid valve control circuit, the normally open contact KA3-4 of relay KA3 closes, connecting the drainage circuit, energizing relays KFB and KFD, opening overflow solenoid valve 18 and drainage solenoid valve 20, and draining the liquid. The normally open contact KA3-6 of relay KA3 closes, energizing relay KFC, opening the balancing solenoid valve 19, using the pressure of the sleeve air to make the drainage smoother.

[0131] When the drainage is finished, the normally open contact 9-1 of the lower magnetic float switch 9 opens, the coil of relay KA3 is de-energized, its normally open contact KA3-4 opens, relays KFB and KFD are de-energized, and overflow solenoid valve 18 and drainage solenoid valve 20 are closed; the normally open contact KA3-6 of relay KA3 opens, relay KFC is de-energized, and balance solenoid valve 19 is closed.

[0132] When the programmable controller switch reaches the set time period, the normally closed contact KD-2 of relay KD opens, the coil of relay KA is de-energized, and the entire device is powered off. Some detection liquids are viscous and drain slowly. To prevent the device from shutting off before drainage is complete, the normally open contact KA3-5 of relay KA3 is connected in parallel with the normally closed contact KD-2 of relay KD to ensure that the device will not shut off before drainage is complete.

[0133] The time period set by the programmable timer switch needs to be slightly longer than the total time required to complete one reset, liquid injection, detection recording, and liquid drainage cycle. After completing the above actions, wait for the next set sampling and detection time, and then begin the next cycle of reset, sampling, detection recording, and liquid drainage.

[0134] The above description is merely a preferred embodiment of the present invention, showing and describing the basic principles, main features, and advantages of the present invention. It is not intended to limit the scope of patent protection of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. In addition to the above embodiments, the present invention may have other implementations without departing from the spirit and scope of the invention. Various changes and modifications to the present invention are possible, and all technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents. Technical features not described in the present invention can be implemented by or using existing technology, and will not be elaborated here.

Claims

1. An automatic sampling water cut measurement device for oil well production fluids, characterized by, include: Measuring cylinder, used to hold the test liquid; An overflow cylinder is fitted around the upper outer periphery of the metering cylinder to receive the overflow liquid from the metering cylinder; The detection tube is connected to the lower part of the measuring cylinder through a measuring connecting tube at its bottom to form a communicating vessel, and contains an indicator liquid. The outer wall is provided with scale lines corresponding to the liquid level height of the indicator liquid and the water content of the detection liquid. The inner liquid storage bag, located inside the metering cylinder, is made of a tension-free flexible material and is sealed with the indicator liquid. The inner liquid storage bag is sealed and connected to the inner tube opening of the measuring connecting tube that extends into the inner cavity of the metering cylinder, thereby isolating the detection liquid from the indicator liquid while achieving balanced transmission of liquid column pressure. The upper part of the detection tube is equipped with a high-precision digital level gauge. The liquid level height of the indicator liquid measured by the high-precision digital level gauge is sent to the intelligent paperless recorder for storage and conversion to calculate the water content of the detection liquid. The top of the overflow cylinder is provided with an overflow cylinder vent, and the top of the detection tube is provided with a top-closed detection tube vent chamber. The overflow cylinder vent is connected to the detection tube vent chamber. The detection tube vent chamber is connected to a balance pipe. A balance solenoid valve is provided in the middle section of the balance pipe. The outlet of the balance pipe is used to communicate with the casing gas of the oil well so as to balance the gas phase pressure in the metering cylinder, overflow cylinder and detection tube with the casing gas pressure.

2. The automatic oil well effluent sampling water cut measurement apparatus of claim 1, wherein: The middle section of the measuring connecting tube is provided with an outer liquid storage bag to contain the indicator liquid, and the outer liquid storage bag is a rigid container.

3. The automatic oil well effluent sampling water cut measurement apparatus of claim 2, wherein: The bottom of the metering cylinder is conical, and a metering cylinder drain pipe is connected to the lowest point of the center. A drain solenoid valve is installed in the middle section of the metering cylinder drain pipe, and the outlet of the metering cylinder drain pipe is connected to the sleeve gas through a sleeve port connector.

4. The automatic oil well effluent sampling water cut measurement apparatus of claim 3, wherein: The metering cylinder has a liquid inlet at the bottom of its side wall. The liquid inlet is connected to a liquid inlet pipe, and a liquid inlet solenoid valve is installed in the middle section of the liquid inlet pipe.

5. The automatic oil well effluent sampling water cut measurement apparatus of claim 4, wherein: The top of the overflow cylinder is provided with an overflow cylinder top cover to seal it, and the bottom of the overflow cylinder is provided with an overflow cylinder cone bottom that is high in the middle and low around the edges. The lowest point of the overflow cylinder cone bottom is connected to an overflow cylinder drain pipe and is equipped with an overflow solenoid valve.

6. The automatic oil well effluent sampling water cut measurement apparatus of claim 5, wherein: The lower end of the overflow cylinder drain pipe is connected to the metering cylinder inlet at the bottom of the side wall of the metering cylinder via an overflow connection pipe.

7. The automatic oil well effluent sampling water cut measurement apparatus of claim 6, wherein: The overflow connection pipe is lower than the measuring connection pipe, and a lower magnetic float switch is installed in the middle section of the overflow connection pipe. The bottom outlet of the lower magnetic float switch is connected to the metering cylinder drain pipe.

8. The automatic oil well effluent sampling water cut measurement apparatus of claim 3, wherein: The side wall outlet of the sleeve connector is connected to a pressure gauge valve, and the outlet of the pressure gauge valve is connected to the outlet of the balance pipe via a tee.

9. The automatic oil well effluent sampling water cut measurement apparatus of claim 8, wherein: The casing gas pressure value measured by the casing pressure gauge is sent to the intelligent paperless recorder for storage and recording. The intelligent paperless recorder calculates the casing gas production based on the increment of the casing gas pressure value using the gas state equation, which serves as the basis for the utilization of casing gas.

10. The automatic oil well effluent sampling water cut measurement apparatus of claim 7, wherein: The top cover of the overflow tank is equipped with an upper magnetic float switch for detecting the liquid level in the overflow tank.

11. The automatic oil well effluent sampling water cut measurement apparatus of claim 5, wherein: A temperature sensor for detecting the temperature of the indicator liquid is inserted into the outer liquid storage tank. The temperature of the indicator liquid measured by the temperature sensor is sent to the intelligent paperless recorder for storage and recording.

12. The automatic oil well effluent sampling water cut measurement apparatus of claim 5, wherein: The top cover of the overflow cylinder is symmetrically provided with mounting lugs, which are suspended from the center of the triangular bracket by slings. The axes of the mounting lugs, the metering cylinder and the detection tube are located in the same vertical plane.

13. The automatic oil well effluent fluid sampling water cut detection apparatus of claim 10, wherein, It also includes a control system, which includes: The metering cylinder reset control circuit consists of a reset button FA, a normally closed contact of relay KA2, a normally closed contact of relay KA3, and a coil of relay KA1 connected in series. The self-holding contact of relay KA1 is connected in parallel with the reset button FA. In the liquid inlet control circuit of the measuring cylinder, the normally closed contact of the measurement start button CA and the relay KA3 is connected in series with the coil of the relay KA2, and the relay KA2 is connected in parallel with the measurement start button CA; In the metering cylinder discharge control circuit, the normally closed contact of the measurement end button JA and relay KA2 is connected in series with the coil of relay KA3, and the self-holding contact of relay KA3 is connected in parallel with the measurement end button JA. The normally open contact of relay KA2 and the normally closed contact of relay KA1 are connected in series in the coil circuit of relay KFA. The normally open contact of relay KFA controls the opening of the liquid inlet solenoid valve. The normally open contact of relay KA1 is connected in parallel with the normally open contact of relay KA3, and then connected in series in the coil circuit of relays KFB and KFD. The normally open contact of relay KFB controls the opening of the overflow solenoid valve, and the normally open contact of relay KFD controls the opening of the drain solenoid valve. The normally open contacts of relays KA1, KA2, and KA3 are connected in parallel and then connected in series in the coil circuit of relay KFC. The normally open contact of relay KFC controls the opening of the balancing solenoid valve.

14. The automatic oil well effluent sampling water cut measurement apparatus of claim 13, wherein, The coil circuit of the relay KA1 has a normally open contact of a lower magnetic float switch connected in series.

15. The automatic oil well effluent sampling water cut measurement apparatus of claim 13, wherein, The coil circuit of the relay KA2 has a normally closed contact of an upper magnetic float switch connected in series.

16. The automatic oil well effluent fluid sampling water cut detection apparatus of claim 13, wherein, The coil circuit of the relay KA3 has a normally open contact of a lower magnetic float switch connected in series.

17. The automatic oil well effluent fluid sampling water cut detection apparatus of claim 13, wherein, The power off button TA and the power on button QA are connected in series with the coil of the relay KA. The self-holding contact of the relay KA is connected in parallel with the power on button QA. The normally open output of the relay KA controls the power supply of the metering cylinder reset control circuit, the metering cylinder liquid inlet control circuit, and the metering cylinder liquid outlet control circuit.

18. The automatic oil well effluent sampling water cut measurement apparatus of claim 17, wherein, The first normally open contact of the programmable time switch is connected in parallel with the normally open contact of the relay KA3 and then connected in series in the coil circuit of the relay KD; the normally closed contact of the relay KD is connected in series in the coil circuit of the relay KA; the normally open contact of the relay KD is connected in parallel with the power "on" button QA; and the second normally open contact of the programmable time switch is connected in parallel with the normally closed contact of the relay KD.

19. The automatic oil well effluent sampling water cut measurement apparatus of claim 13, wherein, The normally open contact of the upper magnetic float switch is connected in series in the coil circuit of the time delay relay KT1, and the normally open contact of the time delay relay KT1 is connected in parallel with the measurement end button JA.

20. An automatic sampling water cut method for oil well production fluid, characterized in that, The automatic sampling and water content detection device for oil well produced fluid as described in claim 13 includes the following steps in sequence: S1. Reset the measuring cylinder and drain the residual liquid. S2. Open the inlet solenoid valve and the balance solenoid valve, and close the overflow solenoid valve and the drain solenoid valve. The test liquid is injected into the measuring cylinder from the bottom. S3. The test liquid overflows from the upper port of the metering cylinder into the overflow cylinder. Close the inlet solenoid valve and the balance solenoid valve, and the metering cylinder stops feeding liquid. S4. The pressure of the liquid column in the metering cylinder is transmitted to the detection tube through the inner liquid storage tank. The high-precision digital level gauge detects the height of the indicator liquid in the detection tube. S5. The paperless recorder records the height of the indicator liquid in the detection tube and calculates the water content of the detection liquid in the measuring cylinder.

21. The method of claim 20, wherein, The correspondence between the indicator liquid level in the detection tube and the water content of the detection liquid in the measuring cylinder is calibrated according to the following steps: B1. Pour pure water into the measuring cylinder until it overflows. After the indicator liquid in the detection tube stabilizes, the corresponding highest liquid level is calibrated as 100% water content. B2. Inject crude oil into the measuring cylinder until it overflows. After the indicator liquid in the detection tube stabilizes, the corresponding lowest liquid level is calibrated as 0% water content. B3. Divide the scale lines evenly between the highest and lowest liquid levels, which represents the water content of the actual test liquid.

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