Device and method for measuring oil-gas-water three-phase flow pipeline section holdup

Abstract

The invention discloses an oil-gas-water three-phase flow pipeline section holdup measuring device and method. An air supply structure is connected to a gas path pipeline; the oil pipeline is connected with an oil supply structure; the waterway pipeline is connected with a water supply structure; a second liquid level sensor is arranged in the water supply structure; the oil-gas-water three-phase separation tank is respectively connected with the oil path pipeline, the gas path pipeline and the water path pipeline; a third liquid level sensor is arranged in the oil-gas-water three-phase separation tank; and one end of the test pipeline is communicated with the oil-way pipeline, the gas-way pipeline and the water-way pipeline, and the other end is connected with the oil-gas-water three-phase separation tank. The method comprises the following steps: acquiring oil, gas and water parameters after three-phase dynamic balance of the device and when oil, gas and water do not pass through a test section; acquiring oil, gas and water parameters after three-phase dynamic balance of the device and when oil, gas and water do not pass through the straight pipe section; and obtaining the oil, gas and water three-phase section holdup of the test section according to the parameters. The invention has the effects of simplifying the structure and reducing the production cost.

Description

Technical Field

[0001] This invention relates to three-phase flow measurement technology for oil, gas and water, and specifically to a device and method for measuring the cross-sectional content of a three-phase flow pipeline. Background Technology

[0002] In oil and gas field development, three-phase metering of oil, gas, and water at the wellhead is crucial throughout the entire development lifecycle. The flow rate measurement of oil, gas, and water is a vital reference indicator for understanding reservoir characteristics and production dynamics, and it also provides a basis for further determining and optimizing development plans and improving recovery rates. To meet the three-phase flow metering needs in the oil and gas industry, corresponding three-phase flow meters have been developed. These flow meters employ single-phase metering instruments such as Venturi tubes or specially designed throttling structures, combined with phase fraction measurement technology. Based on the measured total flow rate and phase fraction, the oil, water, and gas flow rates are obtained. However, because the gas phase in the three-phase flow meter contains a small amount of oil-water mixture, the measured results tend to be higher than when no liquid phase is present. This higher measurement is called a false overestimation. Therefore, it is necessary to correct the three-phase flow meter measurement data by obtaining the three-phase content of oil, gas, and water within the pipeline.

[0003] Currently, measuring the three-phase content of oil, gas, and water using optical and ultrasonic measuring devices requires separate optical and ultrasonic analysis devices, resulting in a complex overall structure, complex supporting systems, high cost, and low practicality in the field. Summary of the Invention

[0004] The technical problem to be solved by this invention is that existing optical and ultrasonic measurement devices require separate optical and ultrasonic analysis devices, resulting in complex overall structures and high costs. The purpose is to provide a device and method for measuring the cross-sectional content of oil, gas and water three-phase flow pipelines. The device obtains the parameters of the device in its initial state and the parameters after the device is in dynamic equilibrium through a liquid level sensor, thereby obtaining the oil, water and gas three-phase content at the test pipeline. This replaces the complex and costly optical and ultrasonic analysis devices, simplifies the structure and reduces production costs.

[0005] This invention is achieved through the following technical solution:

[0006] A device for measuring the cross-sectional content of a three-phase flow pipeline (oil, gas, and water) includes a gas pipeline, an oil pipeline, a water pipeline, and an oil-gas-water three-phase separator. An air supply structure is connected to the gas pipeline; an oil supply structure is connected to the oil pipeline, and a first liquid level sensor is installed within the oil supply structure; a water supply structure is connected to the water pipeline, and a second liquid level sensor is installed within the water supply structure; the oil-gas-water three-phase separator is connected to the oil pipeline, gas pipeline, and water pipeline respectively, and a third liquid level sensor is installed within the oil-gas-water three-phase separator; the inlet end of the test pipeline is connected to the outlet ends of the oil pipeline, gas pipeline, and water pipeline, and the outlet end of the test pipeline is connected to the oil-gas-water three-phase separator.

[0007] The beneficial effects of this invention are that it sets up a closed device with gas pipelines, oil pipelines, water pipelines, test pipelines, and an oil-gas-water three-phase separator. It provides air, oil, and water to the device through air supply, oil supply, and water supply structures. A first liquid level sensor detects the liquid level in the oil supply device, a second liquid level sensor detects the liquid level in the water supply device, and a third liquid level sensor detects the liquid level in the oil-gas-water three-phase separator. By measuring the initial liquid level using these three liquid level sensors, the device operates to allow oil, gas, and water to enter the test pipelines and the oil-gas-water three-phase separator. Once dynamic equilibrium is reached within the device, the three liquid level sensors measure the corresponding liquid level after dynamic equilibrium is achieved. The cross-sectional gas content, cross-sectional oil content, and cross-sectional water content of the test section are then calculated. This eliminates the need for complex and costly optical and ultrasonic analysis devices, simplifying the structure, reducing production costs, and improving the device's practicality in the field.

[0008] In some embodiments, the air supply structure includes a fan and a flow meter, with the fan connected upstream of the flow meter. The fan generates airflow that is then introduced into the gas pipeline, subsequently entering the test pipeline and the three-phase separator.

[0009] In some embodiments, the water supply structure includes a water storage tank, a first piston pump, and a water flow meter, which are connected sequentially from upstream to downstream. A second liquid level sensor is connected inside the water storage tank. The first piston pump pumps water from the storage tank into the water pipeline, which then flows into the test pipeline and the three-phase separator. The second sensor measures the initial liquid level and the liquid level after dynamic equilibrium in the storage tank.

[0010] In some embodiments, the oil supply structure includes an oil storage tank, a second piston pump, and an oil flow meter, which are connected sequentially from upstream to downstream. The first liquid level sensor is connected inside the oil storage tank. The second piston pump adds water from the oil storage tank into the oil pipeline, which then enters the test pipeline and the three-phase separator. The first sensor measures the initial liquid level and the liquid level after dynamic equilibrium in the oil storage tank.

[0011] In some embodiments, check valves are connected to the outlet ends of the oil pipeline, gas pipeline, and water pipeline. These check valves prevent backflow of oil, gas, and water from the oil pipeline, gas pipeline, and water pipeline, and allow them to all enter the test pipeline.

[0012] In some embodiments, the test pipeline includes a straight pipe section and a test section connected in parallel. A first three-way valve is installed at the inlet end of each straight pipe section and test section, and a second three-way valve is installed at the outlet end of each straight pipe section and test section. By installing the first and second three-way valves at both ends of the straight pipe section and test section, it is convenient to control the entry of the three phases (oil, gas, and water) into the straight pipe section or test section.

[0013] In some embodiments, a weighing device is further included, which is used to detect the weight of the oil-gas-water three-phase separator. The mass of the oil-gas-water three-phase separator and the mass of oil, gas, and water within the separator after dynamic equilibrium are obtained by setting up the weighing device.

[0014] This invention also provides a method for detecting the cross-sectional content of an oil-gas-water three-phase flow pipeline, implemented based on the aforementioned oil-gas-water three-phase flow pipeline cross-sectional content measuring device, comprising the following steps:

[0015] S1, obtain the oil, gas and water parameters after the three-phase dynamic balance of the device and before the oil, gas and water have passed through the test section;

[0016] S2, obtain the oil, gas and water parameters after the three-phase dynamic balance of the device and before the oil, gas and water pass through the straight pipe section, and the straight pipe section is sealed with the oil, gas and water medium when step S1 is executed;

[0017] S3, obtain the oil, gas and water parameters after the three-phase dynamic balance of the device and before the oil, gas and water pass through the straight pipe section;

[0018] S4, based on the parameters in S1 and S2 or the parameters in S1 and S3, obtain the cross-sectional content of the three phases of oil, gas and water in the test section;

[0019] Steps S2 and S3 are not performed simultaneously.

[0020] The present invention, employing the above-described scheme, obtains the oil, gas, and water parameters after the device has achieved three-phase dynamic equilibrium and before the oil, gas, and water have passed through the test section, and the oil, gas, and water parameters after the device has achieved three-phase dynamic equilibrium and before the oil, gas, and water have passed through the straight pipe section. Then, the three-phase cross-sectional content of oil, gas, and water in the test section can be calculated using the parameters under the two states, thereby correcting the parameters obtained by the three-phase level gauge.

[0021] In some embodiments, a first calculation formula is set to obtain parameters after three-phase dynamic equilibrium and before the oil, gas and water have passed through the test section. The parameters are the volume of water in the oil-gas-water three-phase separator and the volume of oil in the oil-gas-water three-phase separator.

[0022] In some embodiments, the first calculation formula is:

[0023] v l =(m1-m0-ρ2h3S1) / (ρ1-ρ2);

[0024] v o =(m1-m0-ρ1h3S1) / (ρ2-ρ1);

[0025] Where m0 is the mass of the oil-gas-water three-phase separator, m1 is the mass of the three-phase separator in step S1, h3 is the height of the water-oil mixture in the oil-gas-water three-phase separator in step S1, ρ1 is the density of water, ρ2 is the density of oil, and v l v represents the volume of water in the three-phase oil-gas-water separator in state S1. o Let S be the volume of oil in the oil-gas-water three-phase separator in step S1. The volumes of water and oil in the oil-gas-water three-phase separator are obtained using the first calculation formula described above.

[0026] In some embodiments, a second calculation formula is provided to obtain the volume V of oil in all pipelines except for oil storage tanks, water storage tanks, and oil-gas-water three-phase separators. o And the volume of water V1, the second calculation formula is:

[0027] V o =h2S3-h5S3-v o ;

[0028] V1 = h1S2 - h4S2 - v l ;

[0029] Where S2 is the cross-sectional area of ​​the water tank, S3 is the cross-sectional area of ​​the oil tank, h1 is the initial water height in the water tank, h2 is the initial oil height in the oil tank, h4 is the water level in the water tank in step S1, and h5 is the oil level in the oil tank in step S1. The v obtained from the first calculation formula... l v represents the volume of water in the three-phase oil-gas-water separator in state S1.o The volume of oil in the oil-gas-water three-phase separator in step S1 is used as the basis for the second calculation formula to obtain the volume V of oil in all pipelines except the oil storage tank and the oil-gas-water three-phase separator. o The volume of water is V1.

[0030] In some embodiments, a third calculation formula is set to obtain the volume of water and the volume of oil in the oil-gas-water three-phase separator at state S2. The third calculation formula is:

[0031] v l1 =(m2-m0-ρ2h6S1) / (ρ1-ρ2);

[0032] v o1 =(m2-m0-ρ1h6S1) / (ρ2-ρ1);

[0033] Where m0 is the mass of the oil-gas-water three-phase separator, m2 is the mass of the three-phase separator in step S2, h6 is the height of the water-oil mixture in the oil-gas-water three-phase separator in step S2, ρ1 is the density of water, ρ2 is the density of oil, and v 11 v represents the volume of water in the three-phase oil-gas-water separator in state S2. o1 S1 represents the volume of oil in the oil-gas-water three-phase separator in step S2, and S1 represents the cross-sectional area of ​​the liquid storage container inside the oil-gas-water three-phase separator.

[0034] In some embodiments, a fourth calculation formula is used to obtain the volume V of water in all pipelines except the water storage tank and the oil-gas-water three-phase separator in step S2. 11 Except for the oil storage tank and the oil-gas-water three-phase separator, the volume V of oil in all other pipelines is... o1 The fourth calculation formula is:

[0035] V 11 =h1S2-h7S2-v l1

[0036] V o1 =h2S3-h8S3-v o1

[0037] Wherein, S2 is the cross-sectional area of ​​the water tank, S3 is the cross-sectional area of ​​the oil tank, h1 is the initial height of the water in the water tank, h8 is the height of the oil in the oil tank in step S2, h7 is the water level in the water tank in step S2, and h2 is the initial height of the oil in the oil tank.

[0038] In some embodiments, a fifth calculation formula is set to obtain the cross-sectional oil, gas, and water content of the test section, wherein the fifth calculation formula is:

[0039]

[0040]

[0041]

[0042] Among them, V 12 V is the volume of water in the pipe segment between the test section and the straight pipe section under S2 conditions. o2 S represents the volume of oil in the pipe segment between the test section and the straight pipe section under condition S2. 31 L3 is the cross-sectional area of ​​the pipe in the test section, L3 is the length difference between the test section and the straight pipe section, and F is the cross-sectional area of ​​the pipe in the test section. l F represents the cross-sectional water content of the test section. o F represents the cross-sectional oil content of the test section. g The cross-sectional gas holdup of the test section.

[0043] In some embodiments, a sixth calculation formula is set to obtain the volume of water and the volume of oil in the oil-gas-water three-phase separator at state S3. The sixth calculation formula is:

[0044] v l2 =(m3-m0-ρ2h) 11 S1) / (ρ1-ρ2);

[0045] v o2 =(m3-m0-ρ1h) 11 S1) / (ρ2-ρ1);

[0046] Among them, v l2 v represents the volume of water in the three-phase oil-gas-water separator during step S2. o2 Let m be the volume of oil in the three-phase oil-gas-water separator at state S2, m3 be the mass of the three-phase oil-gas-water separator at state S2, ρ1 be the density of water, ρ2 be the density of oil, and h be the density of water. 11 The height of the water-oil mixture in the three-phase separator during step S2.

[0047] In some embodiments, a seventh calculation formula is set to obtain the volume of water reduced in the water storage tank and the oil-gas-water three-phase separator after directly running from step S1 to step S3, and V. l3 The reduction in oil volume and V in oil storage tanks and oil-gas-water three-phase separators o3 The seventh calculation formula is:

[0048] V l3 =(h4S2+v l )-(h 12 S2+v l2 );

[0049] V o3 =(h5S3+vo )-(h 13 S3+v o2 );

[0050] Where S2 is the cross-sectional area of ​​the water storage tank, S3 is the cross-sectional area of ​​the oil storage tank, and v l v represents the volume of water in the three-phase oil-gas-water separator at state S1. o h1 is the volume of oil in the three-phase oil-gas-water separator in state S1, h4 is the water level in the water tank after dynamic equilibrium in state S1, h5 is the oil level in the oil tank after dynamic equilibrium in state S1, and v is the volume of oil in the oil tank. l2 v represents the volume of water in the oil-gas-water three-phase separator at state S3. o2 Let h be the volume of oil in the oil-gas-water three-phase separator at state S3. 12 h represents the liquid level in the storage tank during step S3. 13 The oil level in the storage tank during step S3.

[0051] In some embodiments, an eighth calculation formula is set to obtain the cross-sectional oil, gas, and water content of the test section. The eighth calculation formula is as follows:

[0052]

[0053]

[0054]

[0055] Among them, F l F represents the cross-sectional water content of the test section. o F represents the cross-sectional oil content of the test section. g S represents the cross-sectional gas holdup of the test section. 31 L1 is the cross-sectional area of ​​the pipe in the test section, L2 is the length of the test section, and V is the cross-sectional area of ​​the pipe in the test section. l3 V represents the sum of the volumes of water reduced in the water storage tank and the oil-gas-water three-phase separator during step S3. o3 The sum of the reduced oil volume in the oil storage tank and the oil-gas-water three-phase separator during step S3.

[0056] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0057] 1. An air supply structure, an oil supply structure, and a water supply structure are set up to provide air, oil, and water to the device. A first liquid level sensor is set up to detect the liquid level in the oil supply device, a second liquid level sensor is set up to detect the liquid level in the water supply device, and a third liquid level sensor is set up to detect the liquid level in the oil-gas-water three-phase separation tank. The initial liquid level is measured by the above three liquid level sensors. The device is operated so that oil, gas, and water enter the test pipeline and the oil-gas-water three-phase separation tank. When the device reaches dynamic equilibrium, the above three liquid level sensors measure the corresponding liquid level after dynamic equilibrium is reached. The cross-sectional gas content, cross-sectional oil content, and cross-sectional water content of the test section are obtained by calculation. There is no need to set up complex and expensive optical analysis devices and ultrasonic analysis devices, simplifying the structure, reducing production costs, and improving the field practicality of the device.

[0058] 2. Install the first three-way valve and the second three-way valve at both ends of the straight pipe section and the test section to facilitate the control of the three phases of oil, gas and water entering the straight pipe section or the test section.

[0059] 3. Set up a weighing device to obtain the mass of the oil-gas-water three-phase separator and the mass of the oil-gas-water three-phase separator after the device is in dynamic equilibrium. Attached Figure Description

[0060] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0061] Figure 1 This is a schematic diagram of the present invention.

[0062] The attached diagram shows the markings and corresponding component names:

[0063] 1-Oil-gas-water three-phase separator, 11-Water pipeline, 12-Water storage tank, 13-First piston pump, 14-Water flow meter, 8-Check valve, 21-Oil pipeline, 22-Oil storage tank, 23-Second piston pump, 24-Oil flow meter, 30-Gas pipeline, 31-Centrifugal fan, 32-Gas flow meter, 40-First three-way valve, 41-Straight pipe section, 42-Second three-way valve, 43-Test section. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0065] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0066] In the description of this invention, the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0067] The terms "first," "second," etc., used in this invention are merely for clarity of description and are not intended to limit any order or emphasize importance. Furthermore, the term "connection" as used herein, unless otherwise specified, can refer to a direct connection or an indirect connection via other components.

[0068] Example 1

[0069] A device for measuring the cross-sectional content of a three-phase flow pipeline (oil, gas, and water) includes a gas pipeline 30, an oil pipeline 21, a water pipeline 11, and an oil-gas-water three-phase separator 1. An air supply structure is connected to the gas pipeline 30; an oil supply structure is connected to the oil pipeline 21, and a first liquid level sensor is installed within the oil supply structure; a water supply structure is connected to the water pipeline 11, and a second liquid level sensor is installed within the water supply structure; the oil-gas-water three-phase separator 1 is connected to the oil pipeline 21, the gas pipeline 30, and the water pipeline 11 respectively, and a third liquid level sensor is installed within the oil-gas-water three-phase separator 1; the inlet end of the test pipeline is connected to the outlet ends of the oil pipeline 21, the gas pipeline 30, and the water pipeline 11, and the outlet end of the test pipeline is connected to the oil-gas-water three-phase separator 1. The device is equipped with a closed system consisting of a gas pipeline 30, an oil pipeline 21, a water pipeline 11, a test pipeline, and an oil-gas-water three-phase separator 1. Air, oil, and water are supplied to the device via air, oil, and water supply structures. A first liquid level sensor detects the liquid level in the oil supply device, a second liquid level sensor detects the liquid level in the water supply device, and a third liquid level sensor detects the liquid level in the oil-gas-water three-phase separator 1. The device operates by measuring the initial liquid level through these three sensors, allowing oil, gas, and water to enter the test pipeline and the oil-gas-water three-phase separator 1. Once dynamic equilibrium is reached, the three liquid level sensors measure the corresponding liquid level after dynamic equilibrium is achieved. The cross-sectional gas content, cross-sectional oil content, and cross-sectional water content of the test section 43 are then calculated. This eliminates the need for complex and costly optical and ultrasonic analysis devices, simplifying the structure, reducing production costs, and improving the device's practicality in the field.

[0070] Specifically, the fan can be a conventional fan or a centrifugal fan 34.

[0071] See Figure 1 The air supply structure includes a fan and a flow meter 32, with the fan connected upstream of the flow meter 32. The fan generates airflow that is then introduced into the air pipeline 30, and subsequently into the test pipeline and the three-phase separator 1.

[0072] See Figure 1 The water supply structure includes a water storage tank 12, a first piston pump 13, and a water flow meter 14. The water storage tank 12, the first piston pump 13, and the water flow meter 14 are connected sequentially from upstream to downstream. A second liquid level sensor is connected inside the water storage tank 12. The first piston pump 13 pumps water from the water storage tank 12 into the water pipeline 11, which then enters the test pipeline and the three-phase separator 1. The second sensor measures the initial liquid level and the liquid level after dynamic equilibrium in the water storage tank 12.

[0073] See Figure 1The oil supply structure includes an oil storage tank 22, a second piston pump 23, and an oil flow meter 24. The oil storage tank 22, the second piston pump 23, and the oil flow meter 24 are connected sequentially from upstream to downstream. The first liquid level sensor is connected inside the oil storage tank 22. Water from the oil storage tank 22 is pumped into the oil pipeline 21 by the second piston pump 23, and then enters the test pipeline and the three-phase separator 1. The first sensor measures the initial liquid level and the liquid level after dynamic equilibrium in the oil storage tank 22.

[0074] See Figure 1 The outlet ends of the oil pipeline, gas pipeline, and water pipeline are all connected to check valves 8. The check valves 8 are installed to prevent backflow of oil, gas, and water in the oil pipeline 21, gas pipeline 30, and water pipeline 11, and to ensure that they all enter the test pipeline.

[0075] See Figure 1 The test pipeline includes a straight pipe section 41 and a test section 43, which are connected in parallel. A first three-way valve 40 is installed at the inlet end of each straight pipe section 41 and test section 43, and a second three-way valve 42 is installed at the outlet end of each straight pipe section 41 and test section 43. By installing the first three-way valve 40 and the second three-way valve 42 at both ends of the straight pipe section 41 and test section 43, it is convenient to control the entry of the three phases (oil, gas, and water) into the straight pipe section 41 and test section 43.

[0076] See Figure 1 The system also includes a weighing device for detecting the weight of the oil-gas-water three-phase separator 1. The mass of the oil-gas-water three-phase separator 1 and the mass of the oil-gas-water three-phase separator 1 after dynamic equilibrium are obtained by setting up the weighing device. The first piston pump 13 and the second piston pump 23 in this invention have adjustable frequencies to control the corresponding liquid flow rates.

[0077] Example 2

[0078] This invention also provides a method for detecting the cross-sectional content of an oil-gas-water three-phase flow pipeline, implemented based on the aforementioned oil-gas-water three-phase flow pipeline cross-sectional content measuring device, comprising the following steps:

[0079] S1, obtain the oil, gas and water parameters after the three-phase dynamic balance of the device and before the oil, gas and water have passed through the test section;

[0080] S2, obtain the oil, gas and water parameters after the three-phase dynamic balance of the device and before the oil, gas and water pass through the straight pipe section, and the oil, gas and water medium in the straight pipe section is the same as that in step S1.

[0081] S3, obtain the oil, gas and water parameters after the three-phase dynamic balance of the device and before the oil, gas and water pass through the straight pipe section;

[0082] S4, based on the parameters in S1 and S2 or the parameters in S1 and S3, obtain the cross-sectional content of the three phases of oil, gas and water in the test section;

[0083] Steps S2 and S3 are not performed simultaneously. The present invention, employing the above scheme, obtains the oil, gas, and water parameters after the device has achieved three-phase dynamic equilibrium and before the oil, gas, and water have passed through the test section, and the oil, gas, and water parameters after the device has achieved three-phase dynamic equilibrium and before the oil, gas, and water have passed through the straight pipe section. Furthermore, the three-phase cross-sectional content of oil, gas, and water in the test section can be calculated using the parameters under these two states, thereby reducing production costs and improving practicality.

[0084] When the device starts operating, all pipelines are filled with a gaseous medium at pressure P, which can be natural gas, nitrogen, or other gases; a certain amount of water is injected into water storage tank 12, which can be pure water or demineralized water, etc., and the water level is measured as h1; a certain amount of oil is injected into oil storage tank 22, which can be kerosene, crude oil, decane, or light hydrocarbons, etc., and the oil level is measured as h2; there is no water or oil in oil-gas-water three-phase separator 1, the weighing device displays the mass as m0, the length of the straight pipe section is L1, the length of the test section is L2, and the length of L2 is greater than the length of L1, which is L3.

[0085] When the device is in operation, the centrifugal fan 31 drives the gas medium in the pipeline to circulate, and the gas flow meter 32 measures the gas volumetric flow rate as q. g The first piston pump 13 is adjusted to inject water into the water storage tank 12, and the water flow meter 14 measures the water flow rate as q. l The second piston pump 23 is adjusted to inject oil from the oil storage tank 22 into the pipeline, and the oil flow meter 24 measures the oil flow rate as q. oThe first three-way valve 40 has its A1 and B1 ends connected and its A1 and C1 ends closed. The second three-way valve 42 has its A2 and B2 ends connected and its A2 and C2 ends closed. After the oil, gas, and water three-phase mixture is formed, it flows into the oil-gas-water three-phase separator 1 through the straight pipe section 41. The oil-gas-water three-phase separator 1 separates the oil, gas, and water. The gas flows into the centrifugal fan 31 from the upper outlet, the oil flows into the oil storage tank 22 from the middle outlet, and the water flows into the water storage tank 12 from the lower outlet. After running for a period of time, the oil, gas, and water three-phase flow in all pipelines will reach a state of equilibrium. The water-oil mixture level in the oil-gas-water three-phase separator 1 will remain constant at h3. The weighing device will show the mass of the oil-gas-water three-phase separator 1 as m1. The water level in the water storage tank 12 will remain constant at h4, and the oil level in the oil storage tank 22 will remain constant at h5. Given that after reaching flow equilibrium, the cross-sectional area of ​​the oil-gas-water three-phase separator 1 is S1, the water-oil mixture level is h3, the weighing device shows the mass of the oil-gas-water three-phase separator 1 as m1, and the density of water is ρ1, while the density of oil is ρ2. Since the densities of water and oil are different, and water will accumulate at the bottom of the oil-gas-water three-phase separator 1, assuming the accumulated water layer height is h6, and the oil layer will be above the water layer, assuming the oil layer height is h7, we can obtain the following information about the oil-gas-water three-phase separator 1.

[0086] In the middle: h3=h6+h7(1)

[0087] ρ1h6S1+ρ2h7S1=m1-m0(2)

[0088] Combining equations (1) and (2), we can obtain the volume of water in the oil-gas-water three-phase separator:

[0089] v l =(m1-m0-ρ2h3S1) / (ρ1-ρ2) (3)

[0090] The volume of oil in the oil-gas-water three-phase separator:

[0091] v o =(m1-m0-ρ1h3S1) / (ρ2-ρ1) (4)

[0092] Therefore: Excluding water storage tank 12 and oil-gas-water three-phase separator 1, the volume V1 of water in all other pipelines is:

[0093] V1 = h1S2 - h4S2 - v l (5)

[0094] Except for oil storage tank 22 and oil-gas-water three-phase separator 1, the volume V of oil in all other pipelines is... o for:

[0095] V o =h2S3-h5S3-v o (6)

[0096] Method 1:

[0097] Shut down the first piston pump 13 and the compound piston pump 2, then keep the centrifugal fan 31 running. The water and oil in the pipeline will return to the oil-gas-water three-phase separator 1, the water storage tank 12, and the oil storage tank 22 along with the gas flow. Switch the first three-way valve 40 to connect ends A1 and C1 and close ends A1 and B1, and connect ends A2 and C2 of the second three-way valve 42 and close ends A2 and B2, maintaining the oil-gas-water three-phase flow rate q. o The flow of the three-phase mixture of oil, gas, and water remains constant, allowing it to flow through test section 43. After a period of operation, the flow of oil, gas, and water in all pipelines will reach equilibrium. The water-oil mixture level in oil-gas-water three-phase separator 1 will remain constant at h6, and the weighing device will show the mass of oil-gas-water three-phase separator 1 as m2. The liquid level in water tank 12 will remain constant at h7, and the oil level in oil tank 22 will remain constant at h8. Given that after reaching flow equilibrium, the cross-sectional area of ​​oil-gas-water three-phase separator 1 is S1, the water-oil mixture level is h6, the weighing device shows the mass of oil-gas-water three-phase separator 1 as m2, and the density of water is ρ1 while the density of oil is ρ2, due to the different densities of water and oil, and the water accumulating at the bottom of oil-gas-water three-phase separator 1 (assuming a water layer height of h9), and the oil layer above the water layer (assuming an oil layer height of h), the flow of the three-phase mixture will reach equilibrium. 10 The oil, gas and water three-phase separator 1 can be used to obtain:

[0098] h6 = h9 + h 10 (7)

[0099] ρ1h9S1+ρ2h 10 S1=m2-m0 (8)

[0100] Combining equations (7) and (8), we can obtain the volume of water in oil-gas-water three-phase separator 1:

[0101] v l1 =h9S1=(m2-m0-ρ2h6S1) / (ρ1-ρ2) (9)

[0102] The volume of oil in the oil-gas-water three-phase separator:

[0103] v o1 =h 10 S1=(m2-m0-ρ1h6S1) / (ρ2-ρ1) (10)

[0104] Then: The volume V of water in all pipelines except for water storage tank 12 and oil-gas-water three-phase separator 1 is... 11 for:

[0105] V 11=h1S2-h7S2-v l1 (11)

[0106] Except for oil storage tank 22 and oil-gas-water three-phase separator 1, the volume V of oil in all other pipelines is... o1 for:

[0107] V o1 =h2S3-h8S3-v o1 (12)

[0108] Because the operating parameters of all pipelines before and after the switching flow of the first three-way valve 40 and the second three-way valve 42 are consistent, the flow state and cross-sectional content of the oil, gas, and water phases are also consistent. Therefore: the volume of water V in the pipeline with the length difference L3 between the test section and the straight pipe section is... 12 For V 11 The difference from V1,

[0109] That is: V 12 =V 11 -V1(13)

[0110] The volume of oil V in the pipeline during the length difference L3 between the test section and the straight section. o2 For V o1 With V o The difference is:

[0111] V o2 =V o1 -V o (14)

[0112] The cross-sectional area of ​​the pipe in the test section is known to be S. 31 If the length difference between the test section and the straight pipe section is L3, then the cross-sectional water content F of the test section is... l for:

[0113]

[0114] Then the cross-sectional oil content F of the test section o for:

[0115]

[0116] Then the cross-sectional gas holdup F of the test section g for:

[0117]

[0118] Method 2: Switch the first three-way valve 40 to connect terminals A1 and C1, and close terminals A1 and B1; connect the second three-way valve 42 to connect terminals A2 and C2, and close terminals A2 and B2; adjust and maintain the gas volumetric flow rate at q. gWithout changing the settings, restart the first piston pump 13 and the compound piston pump 2, and adjust the water flow rate to maintain q. l The oil flow rate remains unchanged at q. o The flow of the three-phase mixture of oil, gas, and water remains unchanged, allowing it to flow through the test section. After a period of operation, the flow of oil, gas, and water in all pipelines will reach equilibrium, and the water-oil mixture level in the three-phase separator 1 will remain at h. 11 The weighing device shows the mass of the oil-gas-water three-phase separator 1 as m3, and the liquid level in the water storage tank 12 will remain at h. 12 The oil level in storage tank 22 will remain unchanged at h. 13 The cross-sectional area of ​​the three-phase oil-gas-water separator 1 is S1, and the height of the water-oil mixture is h, after reaching flow equilibrium. 11 The weighing device shows that the mass of the oil-gas-water three-phase separator 1 is m3, and the density of water is ρ1 and the density of oil is ρ2. Because the densities of water and oil are different, and water will accumulate at the bottom of the oil-gas-water three-phase separator 1, let's assume the height of the accumulated water layer is h. 14 The oil layer will be above the water layer, assuming the oil layer height is h. 15 The oil, gas and water three-phase separator 1 can be used to obtain:

[0119] h 11 =h 14 +h 15 (18)

[0120] ρ1h 14 S1+ρ2h 15 S1=m3-m0 (19)

[0121] Combining equations (18) and (19), we can obtain the volume of water in oil-gas-water three-phase separator 1:

[0122] v l2 =(m3-m0-ρ2h) 11 S1) / (ρ1-ρ2) (20)

[0123] The volume of oil in oil-gas-water three-phase separator 1:

[0124] v o2 =(m3-m0-ρ1h) 11 S1) / (ρ2-ρ1) (21)

[0125] At this point, because the length of L2 is greater than the length of L1, the total water volume in the water storage tank 12 and the oil-gas-water three-phase separator 1 is further reduced, and the reduced volume V l3 for:

[0126] V l3 =(h4S2+v l )-(h12 S2+v l2 ) (twenty two)

[0127] This also leads to a further reduction in the total oil volume in oil storage tank 22 and oil-gas-water three-phase separator 1, with a reduction in volume V. o3

[0128] For: V o3 =(h5S3+v o )-(h 13 S3+v o2 )(twenty three)

[0129] Because the operating parameters of all pipelines before and after the switching flow of the first three-way valve 40 and the second three-way valve 42 are consistent, the flow state and cross-sectional fraction of the oil, gas, and water phases are also consistent. Therefore, the total reduction in water in the water storage tank 12 and the oil, gas, and water three-phase separator 1 flows into the test section 43. Thus, the volume of water in the L2 pipeline is V. l3 Similarly, the volume of oil in the L2 section of the pipeline is V. o3 Given that the cross-sectional area of ​​the pipe in test section 43 is S3 and the length of the test section is L2, then the water content F of the test section is... l for:

[0130]

[0131] Then the oil content F of test section 43 is... o for:

[0132] Then the cross-sectional gas holdup F of test section 43 g for:

[0133] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for measuring the cross-sectional content of an oil-gas-water three-phase flow pipeline, characterized in that, include: Gas pipeline, wherein an air supply structure is connected to the gas pipeline; An oil pipeline is provided, and an oil supply structure is connected to the oil pipeline. A first liquid level sensor is installed inside the oil supply structure. A water pipeline, on which a water supply structure is connected, and a second liquid level sensor is installed inside the water supply structure; An oil-gas-water three-phase separator is provided, which is connected to the oil pipeline, gas pipeline and water pipeline respectively, and a third liquid level sensor is provided inside the oil-gas-water three-phase separator. The test pipeline has its inlet end connected to the outlet ends of the oil pipeline, gas pipeline, and water pipeline, and its outlet end connected to the oil-gas-water three-phase separator.

2. The oil-gas-water three-phase flow pipeline section content measuring device according to claim 1, characterized in that, The air supply structure includes a fan and an air flow meter, with the fan connected upstream of the air flow meter.

3. The oil-gas-water three-phase flow pipeline section content measuring device according to claim 1, characterized in that, The water supply structure includes a water storage tank, a first piston pump, and a water flow meter, which are connected sequentially from upstream to downstream. The second liquid level sensor is connected inside the water storage tank.

4. The oil-gas-water three-phase flow pipeline section content measuring device according to claim 1, characterized in that, The oil supply structure includes an oil storage tank, a second piston pump, and an oil flow meter, which are connected sequentially from upstream to downstream. The first liquid level sensor is connected inside the oil storage tank.

5. The oil-gas-water three-phase flow pipeline section content measuring device according to claim 1, characterized in that, The outlet ends of the oil pipeline, gas pipeline and water pipeline are all connected to check valves.

6. The oil-gas-water three-phase flow pipeline section content measuring device according to claim 1, characterized in that, The test pipeline includes a straight pipe section and a test section, which are connected in parallel. A first three-way valve is installed at the inlet end of the straight pipe section and the test section, and a second three-way valve is installed at the outlet end of the straight pipe section and the test section. It also includes a weighing device for detecting the weight of the oil-gas-water three-phase separator.

7. A method for detecting the cross-sectional content of an oil-gas-water three-phase flow pipeline, characterized in that, The implementation of the cross-sectional content measurement device for three-phase flow pipelines of oil, gas and water as described in claims 1-6 includes the following steps: S1, obtain the oil, gas and water parameters after the three-phase dynamic balance of the device and before the oil, gas and water have passed through the test section; S2, obtain the oil, gas and water parameters after the three-phase dynamic balance of the device and before the oil, gas and water pass through the straight pipe section, and there is no oil and water medium remaining in the straight pipe section when step S1 was executed. S3, obtain the oil, gas and water parameters after the three-phase dynamic balance of the device and before the oil, gas and water pass through the straight pipe section, and the straight pipe section is sealed with the oil, gas and water medium when step S1 is executed; S4, based on the parameters in S1 and S2 or the parameters in S1 and S3, obtain the cross-sectional content of the three phases of oil, gas and water in the test section; Steps S2 and S3 are not performed simultaneously.

8. The method for detecting the cross-sectional content of an oil-gas-water three-phase flow pipeline according to claim 7, characterized in that, The first calculation formula is set to obtain the parameters after the three-phase dynamic equilibrium is reached and before the oil, gas and water have passed through the test section. The parameters are the volume of water in the oil-gas-water three-phase separator and the volume of oil in the oil-gas-water three-phase separator.

9. The method for detecting the cross-sectional content of an oil-gas-water three-phase flow pipeline according to claim 8, characterized in that, The first calculation formula is: v l =(m1-m0-ρ2h3S1) / (ρ1-ρ2); v o =(m1-m0-ρ1h3S1) / (ρ2-ρ1); Where m0 is the mass of the oil-gas-water three-phase separator, m1 is the mass of the three-phase separator in step S1, h3 is the height of the water-oil mixture in the oil-gas-water three-phase separator in step S1, ρ1 is the density of water, ρ2 is the density of oil, and v l v represents the volume of water in the three-phase oil-gas-water separator in state S1. o S1 represents the volume of oil in the oil-gas-water three-phase separator in step S1, where S1 is the cross-sectional area of ​​the liquid storage container inside the oil-gas-water three-phase separator.

10. The method for detecting the cross-sectional content of an oil-gas-water three-phase flow pipeline according to claim 9, characterized in that, The second calculation formula is used to obtain the volume V of oil in all pipelines except for the oil storage tank, water storage tank, and oil-gas-water three-phase separator. o And the volume of water V1, the second calculation formula is: V o =h2S3-h5S3-v o ; V1=h1S2-h4S2-v l ; Wherein, S2 is the cross-sectional area of ​​the water tank, S3 is the cross-sectional area of ​​the oil tank, h1 is the initial height of the water in the water tank, h2 is the initial height of the oil in the oil tank, h4 is the water level in the water tank in step S1, and h5 is the oil level in the oil tank in step S1.

11. The method for detecting the cross-sectional content of an oil-gas-water three-phase flow pipeline according to claim 10, characterized in that, A third calculation formula is set to obtain the volume of water and the volume of oil in the oil-gas-water three-phase separator at state S2. The third calculation formula is: v l1 =(m2-m0-ρ2h6S1) / (ρ1-ρ2); v o1 =(m2-m0-ρ1h6S1) / (ρ2-ρ1); Where m0 is the mass of the oil-gas-water three-phase separator, m2 is the mass of the three-phase separator in step S2, h6 is the height of the water-oil mixture in the oil-gas-water three-phase separator in step S2, ρ1 is the density of water, ρ2 is the density of oil, and v 11 v represents the volume of water in the three-phase oil-gas-water separator in state S2. o1 S1 represents the volume of oil in the oil-gas-water three-phase separator in step S2, and S1 represents the cross-sectional area of ​​the liquid storage container inside the oil-gas-water three-phase separator.

12. The method for detecting the cross-sectional content of an oil-gas-water three-phase flow pipeline according to claim 11, characterized in that, The fourth calculation formula is used to obtain the volume V of water in all pipelines except the water storage tank and the oil-gas-water three-phase separator in step S2. 11 Except for the oil storage tank and the oil-gas-water three-phase separator, the volume V of oil in all other pipelines is... o1 The fourth calculation formula is: In 11 =h1S2-h7S2-v l1 ; In o1 =h2S3-h8S3-v o1 ; Wherein, S2 is the cross-sectional area of ​​the water tank, S3 is the cross-sectional area of ​​the oil tank, h1 is the initial height of the water in the water tank, h8 is the height of the oil in the oil tank in step S2, h7 is the water level in the water tank in step S2, and h2 is the initial height of the oil in the oil tank.

13. The method for detecting the cross-sectional content of an oil-gas-water three-phase flow pipeline according to claim 12, characterized in that, The fifth calculation formula is used to obtain the three-phase content of oil, gas, and water in the cross-section of the test section. The fifth calculation formula is: Among them, V 12 V is the volume of water in the pipe segment between the test section and the straight pipe section under S2 conditions. o2 S represents the volume of oil in the pipe segment between the test section and the straight pipe section under condition S2. 31 L3 is the cross-sectional area of ​​the pipe in the test section, L3 is the difference in length between the test section and the straight pipe section, and F is the cross-sectional area of ​​the pipe in the test section. l F represents the cross-sectional water content of the test section. o F represents the cross-sectional oil content of the test section. g The cross-sectional gas holdup of the test section.

14. The method for detecting the cross-sectional content of an oil-gas-water three-phase flow pipeline according to claim 10, characterized in that, A sixth calculation formula is set to obtain the volume of water and the volume of oil in the oil-gas-water three-phase separator at state S3. The sixth calculation formula is: v l2 =(m3-m0-ρ2h 11 S1) / (ρ1-ρ2); v o2 =(m3-m0-ρ1h 11 S1) / (ρ2-ρ1); Among them, v l2 v represents the volume of water in the three-phase oil-gas-water separator during step S2. o2 Let m be the volume of oil in the three-phase oil-gas-water separator at state S2, m3 be the mass of the three-phase oil-gas-water separator at state S2, ρ1 be the density of water, ρ2 be the density of oil, and h be the density of water. 11 The height of the water-oil mixture in the three-phase separator during step S2.

15. The method for detecting the cross-sectional content of an oil-gas-water three-phase flow pipeline according to claim 14, characterized in that, The seventh calculation formula is used to obtain the volume of water reduced in the water storage tank and the oil-gas-water three-phase separator after directly running from step S1 to step S3, which is V. l3 The volume of oil reduced in the oil storage tank and the oil-gas-water three-phase separator is V. o3 The seventh calculation formula is: In l3 =(h4S2+v l )-(h 12 S2+v l2 ); V o3 =(h5S3+v o )-(h 13 S3+v o2 ); Where S2 is the cross-sectional area of ​​the water storage tank, S3 is the cross-sectional area of ​​the oil storage tank, and v l v represents the volume of water in the three-phase oil-gas-water separator at state S1. o h1 is the volume of oil in the three-phase oil-gas-water separator in state S1, h4 is the water level in the water tank after dynamic equilibrium in state S1, h5 is the oil level in the oil tank after dynamic equilibrium in state S1, and v is the volume of oil in the oil tank. l2 v represents the volume of water in the oil-gas-water three-phase separator at state S3. o2 Let h be the volume of oil in the oil-gas-water three-phase separator at state S3. 12 h represents the liquid level in the storage tank during step S3. 13 The oil level in the storage tank during step S3.

16. The method for detecting the cross-sectional content of an oil-gas-water three-phase flow pipeline according to claim 15, characterized in that, The eighth calculation formula is set to obtain the three-phase content of oil, gas and water in the cross section of the test section. The eighth calculation formula is as follows: Among them, F l F represents the cross-sectional water content of the test section. o F represents the cross-sectional oil content of the test section. g S represents the cross-sectional gas holdup of the test section. 31 L1 is the cross-sectional area of ​​the pipe in the test section, L2 is the length of the test section, and V is the cross-sectional area of ​​the pipe in the test section. l3 V represents the sum of the volumes of water reduced in the water storage tank and the oil-gas-water three-phase separator during step S3. o3 The sum of the reduced oil volume in the oil storage tank and the oil-gas-water three-phase separator during step S3.

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