Oil well wellhead gas-liquid sampling device

Abstract

The invention relates to the technical field of oil well fluid sampling, in particular to an oil well wellhead gas-liquid sampling device which comprises a liquid inlet pipe and a hollow separation tank. The device is reasonable and compact in structure, convenient to use and easy to operate, during sampling, a gas-liquid mixture is subjected to depressurization separation through the separation tank, a separated water-vapor mixed gas sample is conveyed to the gas sample filtering assembly through the gas sample collecting pipe, and after moisture in the water-vapor mixed gas sample is filtered out, a dry and high-accuracy gas sample can be collected through the U-shaped gas outlet pipe; after the separated oil-liquid mixture cleanly washes the liquid sample collecting pipe, a clean and high-accuracy liquid sample can be collected; when sampling is not carried out, a gas-liquid mixture flows out of the separation tank and then flows back to the main pipeline through the liquid outlet pipe, so that dead oil generated in the sampling device is greatly reduced; and the collected dead oil can be poured back into the separation tank through the dead oil treatment assembly when sampling is not carried out, and flows back to the main pipeline along with the gas-liquid mixture entering the separation tank, so that waste of petroleum resources and environmental pollution can be effectively avoided.

Description

Technical Field

[0001] The invention relates to the technical field of oil well fluid sampling, in particular to a gas-liquid sampling device at an oil well head. Background Art

[0002] At present, during the oil production process, oil wells need to be sampled regularly. The following problems exist in the oil well sampling process: before sampling, the dead oil in the nozzle casing must be drained before sampling can be performed. The crude oil in the oil barrel is not easy to handle, and the oil barrel also causes environmental pollution in an open air environment; each time a sample is taken, at least three liters of crude oil are released from a well, and at least fifteen liters of crude oil are released every month. A large amount of crude oil is released nationwide within a year. According to specific environmental protection requirements, the crude oil released during sampling cannot be handled or buried at will, nor can it be recovered, resulting in a huge waste of resources; during the oil well sampling process, oil samples often splash, which increases the workload of on-site operators, increases safety risks, and toxic gases endanger the health of operators, while also causing ground pollution.

[0003] In addition, with the advancement of carbon capture, utilization and storage technology (CCUS), new requirements have been put forward for oil wellhead sampling operations. In addition to the conventional method of taking liquid samples at the wellhead to test indicators such as water content, it is also necessary to collect gas samples at the wellhead to test the carbon dioxide content.

[0004] The existing wellhead sampling device has the following shortcomings in actual use: when sampling gas, there is no dedicated sampling port, oil stains are easy to splash, and sampling is difficult; the sampling port is relatively far from the position of the flowing oil well output liquid, and there is a large amount of dead oil, which makes the sampling accuracy low; during the liquid sampling process, the dead oil released will cause a waste of resources, and if not handled in time, it will easily pollute the environment. Summary of the invention

[0005] The present invention provides an oil wellhead gas-liquid sampling device, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problems of sampling difficulty and low accuracy of the existing wellhead sampling device and easy splashing of oil samples during the sampling process.

[0006] The technical solution of the present invention is achieved through the following measures: a gas-liquid sampling device at the wellhead of an oil well, comprising a liquid inlet pipe and a hollow separation tank, a liquid inlet is provided at the left side of the upper part of the separation tank, a liquid inlet pipe is fixedly installed in the liquid inlet, a gas outlet is provided on the right side of the separation tank corresponding to the position above the liquid inlet pipe, a gas sample collection tube is fixedly installed in the gas outlet, and a gas sampling control valve is provided on the gas sample collection tube; a liquid outlet is provided at the middle part of the lower end of the separation tank, a three-way joint is fixedly installed in the liquid outlet, a liquid sample collection tube is fixedly installed on the lower joint of the three-way joint, a liquid sample collection tube is fixedly installed on the liquid sample collection tube, a liquid sample collection control valve is provided on the liquid sample collection tube, and a liquid outlet pipe is fixedly installed on the left joint of the three-way joint.

[0007] The following are further optimizations and / or improvements to the above technical solutions: The upper end of the above-mentioned separation tank may be provided with a dead oil treatment component that connects the inside and outside of the separation tank. The dead oil treatment component may include a central guide pipe, an oil inlet funnel and a dead oil treatment control valve. The upper end of the separation tank is provided with an oil inlet, and a central guide pipe connected to the liquid inlet pipe on the lower left side is fixedly installed in the oil inlet. An oil inlet funnel is provided at the upper end of the central guide pipe, and a dead oil treatment control valve is provided on the central guide pipe corresponding to the position between the oil inlet funnel and the separation tank.

[0008] The above-mentioned dead oil treatment component may also include a bell mouth, a filter and an oil baffle. A bell mouth which is small at the top and large at the bottom is fixedly installed at the lower end of the central guide pipe, a filter is fixedly installed on the inner side of the lower part of the bell mouth, and an oil baffle is fixedly installed on the outer side of the central guide pipe corresponding to the position between the liquid inlet and the air outlet.

[0009] An air sample filter assembly may be installed at the other end of the above-mentioned air sample collection tube, and the air sample filter assembly may include a filter element, a bent pipe, a U-shaped air outlet pipe, a drain pipe, a drain valve, a sealing cover and a filter tank with an opening upward. A sealing cover is detachably installed on the outer side of the upper end of the filter tank, and a filter element capable of removing moisture from the gas sample is provided on the inner side of the middle part of the filter tank. The filter element is provided with a first through hole, a second through hole and a third through hole which are connected up and down from left to right in sequence. An air inlet which is connected inside and outside is provided at the upper left part of the filter tank, and a bent pipe which is located in the first through hole at the lower right part is fixedly installed in the air inlet. The left end of the bent pipe is fixedly installed together with the other end of the air sample collection tube, and a fourth through hole which is connected up and down is provided on the sealing cover corresponding to the position of the third through hole, and a U-shaped air outlet pipe which is located in the second through hole and the third through hole at the lower part is provided in the fourth through hole. A drain port which is connected inside and outside is provided in the middle part of the lower end of the filter tank, a drain pipe is fixedly installed in the drain port, and a drain valve is provided on the drain pipe.

[0010] The above may also include a liquid inlet control valve and a liquid outlet control valve. The liquid inlet pipe is provided with a liquid inlet control valve, and the liquid outlet pipe is provided with a liquid outlet control valve.

[0011] The above may also include a thread plug, a T-shaped tee and an inlet guide tube. A thread plug with an axial channel is threadedly connected to the right joint of the T-shaped tee. The inlet guide tube with the left end located in the left joint of the T-shaped tee is sealed and installed inside the thread plug. The right end of the inlet guide tube and the left end of the liquid inlet pipe are detachably installed together. A wrench groove is provided on the outside of the right end of the thread plug. The lower joint of the T-shaped tee is fixedly installed together with one end of the liquid outlet pipe.

[0012] The present invention has a reasonable and compact structure, is easy to use, and is simple and easy to operate. When sampling, the gas-liquid mixture is separated by reducing the pressure through the separation tank, and the separated water vapor mixed gas sample is transported to the gas sample filtering component through the gas sample collection tube. After filtering out the moisture in the water vapor mixed gas sample, a dry and highly accurate gas sample can be collected through the U-shaped gas outlet pipe; after the separated oil-liquid mixture flushes the liquid sample collection tube clean, a clean and highly accurate liquid sample can be collected; when not sampling, the gas-liquid mixture can flow back to the main pipeline through the liquid outlet pipe after flowing out of the separation tank, which greatly reduces the generation of dead oil in the sampling device; the collected dead oil can also be poured back into the separation tank through the dead oil processing component when not sampling, and flow back to the main pipeline together with the gas-liquid mixture entering the separation tank, which can effectively avoid the waste of petroleum resources and environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Attached Figure 1 It is a schematic diagram of the main view and partial cross-section structure of embodiments 1-6 of the present invention.

[0014] The codes in the accompanying drawings are: 1 is a liquid inlet pipe, 2 is a separation tank, 3 is a gas sample collection tube, 4 is a gas sampling control valve, 5 is a three-way connector, 6 is a liquid sample collection tube, 7 is a liquid sample collection control valve, 8 is a liquid outlet pipe, 9 is a central guide pipe, 10 is an oil inlet funnel, 11 is a dead oil treatment control valve, 12 is a bell mouth, 13 is a filter screen, 14 is an oil baffle, 15 is a filter element, 16 is a bend pipe, 17 is a U-shaped air outlet pipe, 18 is a drain pipe, 19 is a drain valve, 20 is a sealing cover, 21 is a filter tank, 22 is a liquid inlet control valve, 23 is a liquid outlet control valve, 24 is a thread plug, 25 is a T-type three-way, 26 is an inlet guide pipe, and 27 is an oil wellhead nozzle sleeve. DETAILED DESCRIPTION

[0015] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0016] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached Figure 1 The positional relationships such as front, back, top, bottom, left, and right are described according to the layout directions of the drawings in the specification.

[0017] The present invention will be further described below in conjunction with embodiments and drawings: Embodiment 1: As attached Figure 1 As shown, the oil well wellhead gas-liquid sampling device includes a liquid inlet pipe 1 and a hollow separation tank 2, a liquid inlet is provided on the left upper part of the separation tank 2, the liquid inlet pipe 1 is fixedly installed in the liquid inlet, a gas outlet is provided on the right side of the separation tank 2 corresponding to the position above the liquid inlet pipe 1, a gas sample collection tube 3 is fixedly installed in the gas outlet, and a gas sampling control valve 4 is provided on the gas sample collection tube 3; a liquid outlet is provided in the middle part of the lower end of the separation tank 2, a three-way joint 5 is fixedly installed in the liquid outlet, a liquid sample collection tube 6 is fixedly installed on the lower joint of the three-way joint 5, a liquid sample collection tube 6 is provided on the liquid sample collection control valve 7, and a liquid outlet pipe 8 is fixedly installed on the left joint of the three-way joint 5.

[0018] During use, the gas-liquid mixture to be sampled is depressurized and separated from the gas and liquid in the separation tank 2. When sampling is required, the gas-liquid mixture sample enters the separation tank 2 through the liquid inlet pipe 1, depressurizes the separation tank 2, and separates the oil and gas; the separated oil-liquid mixture will flow back to the main pipeline through the liquid outlet pipe 8. At this time, if the liquid sample collection container is connected to the liquid sample collection tube 6, the liquid sample collection control valve 7 is opened, and the liquid sample can flow into the liquid sample collection container through the liquid sample collection tube 6. After reaching the sampling volume, the liquid sample collection control valve 7 is closed; the separated gas is lighter and floats to the top of the separation tank 2. After the gas sample collection container is connected to the gas sample collection tube 3, the gas sampling control valve 4 is opened, and the gas sample can flow into the gas sample collection container through the gas sample collection tube 3. After reaching the sampling volume, the gas sampling control valve 4 is closed. The above sampling process is simple and easy to operate, and the gas and liquid are sampled separately, and the sample accuracy is high; in addition, the gas separated from the separation tank 2 is more completely separated and the pressure is relatively small, which can effectively avoid the oil splashing phenomenon when collecting gas samples.

[0019] According to the needs, the liquid sample collection control valve 7 and the gas sampling control valve 4 can be realized by gate valves, ball valves or butterfly valves in the existing known technology; the liquid inlet pipe 1 can be directly connected to the main pipeline, or it can be connected to the oil well nozzle sleeve and the main oil pipeline through a three-way pipe fitting. In this way, when no sampling is taken, the separation tank 2, the liquid inlet pipe 1 and the liquid outlet pipe 8 can be flushed by the gas-liquid mixture, so that the liquid in the device is always in a flowing state, thereby effectively avoiding the dead oil in the separation tank 2 and the pipeline affecting the quality of liquid sample sampling; in addition, in order to avoid a small amount of dead oil remaining in the liquid sample collection tube 6, before collecting the liquid sample, the liquid sample collection control valve 7 can be opened first, and the dead oil remaining in the liquid sample collection tube 6 can be flushed away by the oil-liquid mixture, and then the liquid sample can be taken to improve the oil sampling quality.

[0020] The above-mentioned oil wellhead gas-liquid sampling device can be further optimized and / or improved according to actual needs: Embodiment 2: As attached Figure 1As shown, a dead oil treatment component connecting the inside and outside of the separation tank 2 is provided at the upper end of the separation tank 2, and the dead oil treatment component includes a central guide pipe 9, an oil inlet funnel 10 and a dead oil treatment control valve 11. An oil inlet is provided at the upper end of the separation tank 2, and a central guide pipe 9 connected to the liquid inlet pipe 1 on the lower left side is fixedly installed in the oil inlet. An oil inlet funnel 10 is provided at the upper end of the central guide pipe 9, and a dead oil treatment control valve 11 is provided on the central guide pipe 9 corresponding to the position between the oil inlet funnel 10 and the separation tank 2.

[0021] During use, the dead oil mixture used to flush the dead oil accumulated in the liquid sample collection tube 6 can be opened when no sampling is performed. The dead oil treatment control valve 11 can also be poured back into the separation tank 2 through the oil inlet funnel 10 and the central flow guide tube 9, and flow back to the main line together with the mixed liquid in the separation tank 2, thereby effectively avoiding the waste of oil resources and environmental pollution. According to the needs, the oil inlet funnel 10 and the central flow guide tube 9 can be connected together by a detachable installation method such as screw connection, clamping connection or set screws, or by a fixed installation method such as welding or riveting; in order to reduce the dead oil generated in the wall of the separation tank 2, the lower end of the central flow guide tube 9 is located at the lower part of the separation tank 2.

[0022] Embodiment 3: As attached Figure 1 As shown, the dead oil treatment component also includes a bell mouth 12, a filter 13 and an oil baffle 14. A bell mouth 12 with a small upper part and a large lower part is fixedly installed at the lower end of the central guide pipe 9. A filter 13 is fixedly installed on the inner side of the lower part of the bell mouth 12, and an oil baffle 14 is fixedly installed on the outer side of the central guide pipe 9 corresponding to the position between the liquid inlet and the air outlet.

[0023] During use, the central guide tube 9 and the bell mouth 12 can not only effectively prevent the gas-liquid mixture from spraying and diffusing toward the right inner wall of the separation tank 2, but also facilitate the gas-liquid mixture to directly hit the bottom of the separation tank 2, thereby accelerating the gas-liquid separation; the filter screen 13 can filter out the granular impurities in the dead oil, thereby preventing the impurities from entering the separation tank 2; when the separated gas contacts the oil baffle plate 14 during the floating process, the gas flow direction will be changed, so that the gas will flow along the lower side of the oil baffle plate 14 to the gap between the oil baffle plate 14 and the separation tank 2, and the oil baffle plate 14 will gradually absorb the tiny droplets and impurities in the gas, and make them gather together to form droplets, which then fall back into the oil-liquid mixture at the bottom of the separate tube and flow out of the separation tank 2, thereby improving the accuracy and purity of the gas sample.

[0024] Embodiment 4: As attached Figure 1As shown, a gas sample filter assembly is installed at the other end of the gas sample collection tube 3, and the gas sample filter assembly includes a filter element 15, a bent pipe 16, a U-shaped air outlet pipe 17, a drain pipe 18, a drain valve 19, a sealing cover 20 and a filter tank 21 with an opening upward. The sealing cover 20 is detachably installed on the outer side of the upper end of the filter tank 21, and a filter element 15 capable of removing moisture from the gas sample is provided on the inner side of the middle part of the filter tank 21. The filter element 15 is provided with a first through hole, a second through hole and a third through hole which are connected from left to right in sequence, and the filter tank 21 is provided with a An air inlet is connected inside and outside, and a curved pipe 16 is fixedly installed in the air inlet, and the lower right part is located in the first through hole. The left end of the curved pipe 16 is fixedly installed together with the other end of the gas sample collection tube 3. A fourth through hole that is connected from top to bottom is provided on the sealing cover 20 corresponding to the position of the third through hole. The fourth through hole is provided with a U-shaped air outlet pipe 17 whose lower part is respectively located in the second through hole and the third through hole. A drain port is provided in the middle part of the lower end of the filter tank 21, and a drain pipe 18 is fixedly installed in the drain port, and a drain valve 19 is provided on the drain pipe 18.

[0025] During use, the separated gas sample flows to the bottom of the filter tank 21 through the bend 16 and then gradually rises. When the rising gas sample passes through the filter element 15, water can be filtered out to obtain a relatively dry gas sample. The dried gas sample can flow into the gas sample collection container from the U-shaped outlet pipe 17; the water accumulated in the filter tank 21 can be discharged from the filter tank 21 through the drain pipe 18 by opening the drain valve 19 regularly. According to the needs, the gas sample filter assembly can effectively improve the dryness and accuracy of the gas sample and obtain a higher quality gas sample, wherein the bend 16 can be realized by a semicircular bend or a right-angle bend in the prior art, or by a straight pipe with an elbow; for easy replacement, the filter element 15 and the filter tank 21 can be connected by plugging, snapping or interference connection in the prior art, and the filter element 15 can be realized by a highly polar water-absorbing material in the prior art that does not react chemically with the gas sample, or by a semi-permeable membrane in the prior art that only allows gas to pass and does not allow water vapor to pass.

[0026] Embodiment 5: As attached Figure 1 As shown, it also includes a liquid inlet control valve 22 and a liquid outlet control valve 23. The liquid inlet pipe 1 is provided with a liquid inlet control valve 22, and the liquid outlet pipe 8 is provided with a liquid outlet control valve 23.

[0027] Through such an arrangement, the liquid inlet control valve 22 can control the inlet flow rate of the gas-liquid mixture, and adjusting the liquid outlet control valve 23 is more convenient for adjusting the sampling flow rate in the liquid sample collection tube 6; in addition, after the two are closed, it is easier to clean the impurities and inner wall attachments in the separation tank 2 without affecting the main pipeline, so as to improve the accuracy of sampling.

[0028] Embodiment 6: As attached Figure 1As shown, it also includes a screw plug 24, a T-shaped tee 25 and an inlet guide tube 26. The right joint of the T-shaped tee 25 is threaded with a screw plug 24 having an axial channel. The inner side of the screw plug 24 is sealed with an inlet guide tube 26 with the left end located in the left joint of the T-shaped tee 25. The right end of the inlet guide tube 26 is detachably installed with the left end of the liquid inlet pipe 1. A wrench groove is provided on the outer side of the right end of the screw plug 24. The lower joint of the T-shaped tee 25 is fixedly installed with one end of the liquid outlet pipe 8.

[0029] During use, the left joint of the T-type tee 25 is first connected to the wellhead nozzle sleeve 27 of the oil well, and then the lower joint of the T-type tee 25 is connected to the main pipeline, so that the inlet guide tube 26 can be suspended in the middle of the wellhead liquid flow to avoid impurities such as wax on the inner wall of the pipeline affecting the sampling results; according to requirements, the shape of the wrench groove is adapted to the opening shape of the fixed wrench or the movable wrench.

[0030] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A gas-liquid sampling device at the wellhead of an oil well, characterized in that It includes a liquid inlet pipe and a hollow separation tank. A liquid inlet is provided on the left side of the upper part of the separation tank, and the liquid inlet pipe is fixedly installed in the liquid inlet. A gas outlet is provided on the right side of the separation tank corresponding to the position above the liquid inlet pipe, and a gas sample collection tube is fixedly installed in the gas outlet, and a gas sampling control valve is provided on the gas sample collection tube; a liquid outlet is provided in the middle part of the lower end of the separation tank, and a three-way joint is fixedly installed in the liquid outlet, a liquid sample collection tube is fixedly installed on the lower joint of the three-way joint, a liquid sample collection tube is fixedly installed on the liquid sample collection tube, and a liquid sample collection control valve is provided on the liquid sample collection tube, and a liquid outlet pipe is fixedly installed on the left joint of the three-way joint.

2. The oil wellhead gas-liquid sampling device according to claim 1, characterized in that A dead oil treatment component connecting the inside and outside of the separation tank is provided at the upper end of the separation tank. The dead oil treatment component includes a central guide pipe, an oil inlet funnel and a dead oil treatment control valve. An oil inlet is provided at the upper end of the separation tank. A central guide pipe connected to the liquid inlet pipe on the lower left side is fixedly installed in the oil inlet. An oil inlet funnel is provided at the upper end of the central guide pipe. A dead oil treatment control valve is provided on the central guide pipe corresponding to the position between the oil inlet funnel and the separation tank.

3. The oil wellhead gas-liquid sampling device according to claim 2, characterized in that The dead oil treatment component also includes a bell mouth, a filter and an oil baffle. A bell mouth which is small at the top and large at the bottom is fixedly installed at the lower end of the central guide pipe. A filter is fixedly installed on the inner side of the lower part of the bell mouth, and an oil baffle is fixedly installed on the outer side of the central guide pipe corresponding to the position between the liquid inlet and the air outlet.

4. The oil wellhead gas-liquid sampling device according to claim 1, 2 or 3, characterized in that An air sample filter assembly is installed at the other end of the air sample collection tube, and the air sample filter assembly includes a filter element, a bent pipe, a U-shaped air outlet pipe, a drain pipe, a drain valve, a sealing cover and a filter tank with an opening upward. A sealing cover is detachably installed on the outer side of the upper end of the filter tank, and a filter element capable of removing moisture from the gas sample is provided on the inner side of the middle part of the filter tank. The filter element is provided with a first through hole, a second through hole and a third through hole which are connected up and down from left to right in sequence. An air inlet which is connected inside and outside is provided at the upper left part of the filter tank, and a bent pipe which is located in the first through hole at the lower right part is fixedly installed in the air inlet. The left end of the bent pipe is fixedly installed together with the other end of the air sample collection tube, and a fourth through hole which is connected up and down is provided on the sealing cover corresponding to the position of the third through hole, and a U-shaped air outlet pipe which is located in the second through hole and the third through hole at the lower part is provided in the fourth through hole. A drain port which is connected inside and outside is provided in the middle part of the lower end of the filter tank, a drain pipe is fixedly installed in the drain port, and a drain valve is provided on the drain pipe.

5. The oil wellhead gas-liquid sampling device according to claim 1, 2 or 3, characterized in that It also includes a liquid inlet control valve and a liquid outlet control valve. The liquid inlet pipe is provided with the liquid inlet control valve, and the liquid outlet pipe is provided with the liquid outlet control valve.

6. The oil wellhead gas-liquid sampling device according to claim 4, characterized in that It also includes a liquid inlet control valve and a liquid outlet control valve. The liquid inlet pipe is provided with the liquid inlet control valve, and the liquid outlet pipe is provided with the liquid outlet control valve.

7. The oil wellhead gas-liquid sampling device according to claim 1, 2, 3 or 6, characterized in that It also includes a thread plug, a T-shaped tee and an inlet guide tube. A thread plug with an axial channel is threaded inside the right joint of the T-shaped tee. The inlet guide tube with the left end located in the left joint of the T-shaped tee is sealed and installed inside the thread plug. The right end of the inlet guide tube and the left end of the liquid inlet pipe are detachably installed together. A wrench groove is provided on the outside of the right end of the thread plug. The lower joint of the T-shaped tee is fixedly installed together with one end of the liquid outlet pipe.

8. The oil wellhead gas-liquid sampling device according to claim 4, characterized in that It also includes a thread plug, a T-shaped tee and an inlet guide tube. A thread plug with an axial channel is threaded inside the right joint of the T-shaped tee. The inlet guide tube with the left end located in the left joint of the T-shaped tee is sealed and installed inside the thread plug. The right end of the inlet guide tube and the left end of the liquid inlet pipe are detachably installed together. A wrench groove is provided on the outside of the right end of the thread plug. The lower joint of the T-shaped tee is fixedly installed together with one end of the liquid outlet pipe.

9. The oil wellhead gas-liquid sampling device according to claim 5, characterized in that It also includes a thread plug, a T-shaped tee and an inlet guide tube. A thread plug with an axial channel is threaded inside the right joint of the T-shaped tee. The inlet guide tube with the left end located in the left joint of the T-shaped tee is sealed and installed inside the thread plug. The right end of the inlet guide tube and the left end of the liquid inlet pipe are detachably installed together. A wrench groove is provided on the outside of the right end of the thread plug. The lower joint of the T-shaped tee is fixedly installed together with one end of the liquid outlet pipe.

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