Gas well group circulating gas lift drainage system

Abstract

The utility model relates to the field of gas well group exploitation, in particular to a gas well group circulating gas lift drainage system. According to the gas well group circulation gas lift liquid drainage system, the gas-liquid separation device connected with the gas production port of each gas well in the well group can achieve gas-liquid separation of produced gas, the supercharging device can pressurize gas obtained after gas-liquid separation, meanwhile, the gas outlet of the supercharging device is connected with the oil sleeve annulus of each gas well in the well group, and the gas production port of each gas well in the well group is connected with the oil sleeve annulus of each gas well in the well group. Pressurized gas can be injected into the water-flooded well to achieve gas lift drainage of the water-flooded well. According to the gas well group circulating gas lift liquid drainage system, gas source wells can be continuously and repeatedly selected in real time, gas lift liquid drainage of water flooding wells or liquid accumulation wells occurring at different production times in the well group is achieved, long-term stable production of the well group is further achieved, and the gas production rate of the well group is improved.

Description

Technical Field

[0001] The utility model relates to the field of gas well group mining, in particular to a gas well group circulating gas lift drainage system. Background Art

[0002] Tight low-permeability sandstone gas reservoirs have the characteristics of low porosity and low permeability, strong heterogeneity, and high water saturation, and the single well production is generally low. In order to save the initial investment cost, well group development has become the mainstream development mode of tight low-permeability sandstone gas reservoirs in China. However, with the continuous deepening of gas field development, the pressure and production of wells in the well group gradually decrease, causing fluid accumulation in the wellbore, and even water flooding and well closure in severe cases. In order to ensure stable production and increase production of gas wells, it is usually necessary to inject foaming agents into the wellbore or use large-scale equipment such as gas lift and pumping to assist in gas well drainage.

[0003] In order to solve the problem of gas well flooding, gas lift methods such as high-pressure gas lift in adjacent wells, liquid nitrogen gas lift, nitrogen gas lift, and compressed natural gas gas lift are widely used. However, they all have disadvantages such as no stable gas source, high cost of multiple construction, and inability to perform continuous gas lift in real time, resulting in the inability to discharge the liquid in time, affecting the production of the gas well. For example, the Chinese utility model patent with the authorization announcement number CN207750066U discloses a fully enclosed mixed transmission and depressurization circulation gas lift system. The circulation gas lift system disclosed in the patent document adds a gas lift mechanism on the basis of the existing gas production tree. The liquid separated by the gas lift mechanism is pressurized by the mixed transmission pump and then sent to the external transmission pipeline to realize closed transportation without external discharge, realizing the integrated fusion and alternating application of the circulation gas lift process and the mixed transmission and depressurization process, so that the natural gas well forms a virtuous cycle and realizes the stable and high production of the natural gas well under the self-flowing state. A Chinese utility model patent with authorization announcement number CN203394452U discloses a continuous assisted gas lift drainage and gas production compression device. The device disclosed in the patent document is connected to the wellhead external transmission pipeline, and uses the natural gas in the well or pipeline as the engine power to drive the gas compressor to inject natural gas into the annulus of the gas well casing. During the gas injection process, it can provide or increase the liquid carrying capacity, and the excess gas will not enter the formation, which is conducive to the gradual discharge of the accumulated liquid in the wellbore and near-well area, and will not form liquid accumulation again.

[0004] However, the gas lift drainage system disclosed in the above patent document only realizes the circulating gas lift of the same gas well, and has high requirements on the air intake pressure of the gas lift mechanism. When the above system is used for circulating gas lift of gas wells in a well group, multiple systems need to be operated simultaneously, which increases the operating cost and cannot achieve long-term stable production of the entire well group. Utility Model Content

[0005] The utility model aims to provide a gas well group circulating gas lift drainage system, which can solve the problem that the existing circulating gas lift system cannot achieve long-term stable production of the gas well group when used in the gas well group.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the gas well group circulating gas lift drainage system of the utility model is:

[0007] A circulating gas lift drainage system for a gas well group includes a gas-liquid separation device and a pressurizing device. The gas-liquid separation device includes a feed port and a gas outlet, and the pressurizing device includes a gas inlet and a gas outlet. The gas outlet of the gas-liquid separation device is connected to the gas inlet of the pressurizing device, the feed port of the gas-liquid separation device is connected to the gas production port of each gas well in the well group, and the gas outlet of the pressurizing device is connected to the oil casing annulus of each gas well in the well group.

[0008] In the gas well group circulating gas lift drainage system of the utility model, the gas-liquid separation device connected to the gas production port of each gas well in the well group can realize gas-liquid separation of the produced gas, and the booster device can pressurize the gas after gas-liquid separation. At the same time, the gas outlet of the booster device is connected to the oil casing annulus of each gas well in the well group, so that the pressurized gas can be injected into the flooded well to realize gas lift drainage of the flooded well. When the gas well group circulating gas lift drainage system of the utility model is in use, when a flooded well appears in the well group, first select a gas well with stable production (continuous production and gas production ≥5000m 3 / d gas well) is used as a gas source well, and then part of the produced gas from the gas source well is passed into a gas-liquid separation device for gas-liquid separation, and a pressurizing device is used to pressurize the gas after gas-liquid separation, and the pressurized gas enters the oil casing annulus of the water-flooded well, and the accumulated liquid in the water-flooded well is discharged from the oil pipe, thereby realizing gas lift and drainage of the water-flooded well. Since the gas production port of each gas well is connected to the gas-liquid separation device, and the oil casing annulus of each gas well is connected to the pressurizing device, the gas well group circulating gas lift and drainage system of the utility model can realize gas lift and drainage of water-flooded wells or liquid-accumulated wells that appear at different production times in the well group by repeatedly selecting gas source wells in real time, thereby realizing long-term stable production of the well group and increasing the gas production of the well group. Compared with the prior art, the gas well group circulating gas lift and drainage system of the utility model can not only reduce construction costs and save construction time, but also realize self-sufficient resumption of production of water-flooded wells in the well group, thereby improving the success rate of resumption of production and the stable production time rate.

[0009] Preferably, the gas well group circulating gas lift drainage system further comprises a foaming agent injection system, and the foaming agent injection system is used to inject foaming agent into the oil casing annulus of each gas well.

[0010] The beneficial effect of the above technical solution is: by setting up a foaming agent filling system, foaming agent can be added to the flooded wells as needed, thereby improving the liquid carrying capacity of the flooded wells, accelerating the resumption of production of the flooded wells, and improving the stable production capacity of the well group.

[0011] Preferably, the foaming agent filling system includes a foaming agent storage device and a foaming agent delivery pipeline, one end of the foaming agent delivery pipeline is connected to the foaming agent storage device, and the other end of the foaming agent delivery pipeline is connected to the oil casing annulus of each gas well in the well group.

[0012] The beneficial effects of the above technical solution are: improving the convenience of operation and the stability of filling the foaming agent.

[0013] Preferably, a one-way valve is provided on the foaming agent delivery pipeline.

[0014] The beneficial effect of the above technical solution is: to avoid the failure of the foaming agent filling due to the excessively high pressure in the oil casing annulus of the gas well causing the foaming agent to flow back when the foaming agent is added to the gas well.

[0015] Preferably, the foaming agent filling system further comprises a conveying power device, and the conveying power device is arranged on the foaming agent conveying pipeline.

[0016] The beneficial effect of the above technical solution is that by providing a conveying power device, the requirements for the setting of the foaming agent storage device can be reduced, thereby improving the convenience of operation.

[0017] Preferably, the power source of the transport power device is the produced gas from the gas wells in the well group.

[0018] The beneficial effect of the above technical solution is that the output gas of the gas wells in the well group is used as the power source of the transmission power device, which not only saves energy but also improves the compactness and operation stability of the device.

[0019] Preferably, the transport power device comprises an air inlet, and the air inlet of the transport power device is connected to the gas production port of the gas well in the well group through an air supply pipeline, and a filtering device is arranged on the air supply pipeline.

[0020] The beneficial effects of the above technical solution are: directly using the produced gas from the well group as the energy source of the transportation power device to improve the self-sufficiency of the device, and the filtering device can filter and remove solid impurities in the produced gas to improve the gas supply quality.

[0021] Preferably, the gas-liquid separation device also includes a pressure detection device and a pressure relief device.

[0022] The beneficial effect of the above technical solution is that by providing a pressure detection device and a pressure relief device, the gas pressure in the separation system can be detected and controlled to avoid danger caused by excessive pressure in the system.

[0023] Preferably, the gas-liquid separation device further comprises a liquid outlet, and the liquid outlet of the gas-liquid separation device is connected to a gas transmission pipeline of the well group produced gas.

[0024] The beneficial effects of the above technical solution are: achieving the treatment of the output fluid and reducing the transportation cost of the output fluid.

[0025] Preferably, the boosting device includes a compressor, and the boosting device also includes a liquid outlet, and the liquid outlet of the boosting device is connected to the gas transmission pipeline of the well group production gas.

[0026] The beneficial effects of the above technical solution are: achieving the treatment of the output fluid and reducing the transportation cost of the output fluid.

[0027] Preferably, the circulating gas lift drainage system of the gas well group also includes a venting and liquid separation device and a venting flare, the venting and liquid separation device includes a feed port, a gas outlet and a liquid outlet, the boosting device also includes a gas-liquid mixture outlet, the gas-liquid mixture outlet is connected to the feed port of the venting and liquid separation device, the gas outlet of the venting and liquid separation device is connected to the venting flare, and the liquid outlet of the venting and liquid separation device is connected to the gas transmission pipeline of the well group produced gas.

[0028] The beneficial effects of the above technical scheme are: a gas-liquid mixture outlet is set on the boosting device, which can increase the gas content of the high-pressure gas at the gas outlet of the boosting device and avoid bringing in liquid; the venting and liquid separation device can further separate the gas-liquid mixture output from the gas-liquid mixture outlet, and the venting torch can burn the separated gas to achieve waste gas treatment; the liquid outlet of the venting and liquid separation device is connected to the gas transmission pipeline of the well group production gas, which can realize the treatment of the produced liquid and reduce the transportation cost of the produced liquid.

[0029] Preferably, the circulating gas lift drainage system of the gas well group also includes a water storage device, which includes a liquid inlet, an air inlet and a liquid outlet. The liquid inlet of the water storage device is connected to the liquid outlet of the gas-liquid separation device, the liquid outlet of the boosting device, and the liquid outlet of the venting and liquid separation device. The air inlet of the water storage device is connected to the air outlet of the boosting device, and the liquid outlet of the water storage device is connected to the gas transmission pipeline of the well group.

[0030] The beneficial effect of the above technical solution is that by setting up a water storage device, the output liquid separated by the gas-liquid separation device, the boosting device and the venting and liquid separation device can be stored, and at the same time, the high-pressure gas obtained by the boosting device can be used to realize the pressure replenishment and transportation of the discharged liquid from the flooded gas well, thereby saving the transportation cost of the gas lift output liquid.

[0031] Preferably, a one-way valve is provided on the pipeline connecting the liquid outlet of the water storage device and the gas transmission pipeline of the well group production gas.

[0032] The beneficial effect of the above technical solution is that a one-way valve is arranged on the pipeline connecting the liquid outlet of the water storage device and the gas transmission pipeline of the well group production gas, which can avoid the backflow of the produced liquid due to excessive pressure in the gas transmission pipeline of the well group production gas, resulting in drainage failure.

[0033] Preferably, the gas well group circulating gas lift drainage system further comprises a gas-fired power generation device, the gas-fired power generation device comprises an air inlet, and the air inlet of the gas-fired power generation device is connected to the air outlet of the gas-liquid separation device.

[0034] The beneficial effect of the above technical solution is that by setting up a gas-fired power generation device, the produced gas of the well group can be fully utilized, converted into electrical energy, and provided with power for various electrical devices in the circulating gas lift drainage system of the gas well group. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is an exploded schematic diagram of the cementing head stop pin device of Example 1 of the utility model;

[0036] The accompanying drawings are marked as follows: 1-gas tree; 2-gas-liquid separator; 101-first gate valve; 102-second gate valve; 103-third gate valve; 104-fourth gate valve; 105-fifth gate valve; 106-sixth gate valve; 107-seventh gate valve; 108-oil pipe gas production line; 109-casing gas production line; 110-gas production merging line; 111-needle valve; 112-second flat gate valve; 113-first pressure regulating valve; 114-emergency shut-off valve; 115-flow meter ; 116-first flat gate valve; 117-first non-return valve; 118-output gas transmission main pipeline; 119-produced gas transmission pipeline; 21-gas-liquid separator body; 22-safety valve; 23-pressure gauge; 24-first gas phase transmission pipeline; 25-first liquid phase outlet pipeline; 26-first drain valve; 301-compressor; 302-gas generator; 303-third pressure regulating valve; 304-third flat gate valve; 305-fourth flat gate valve; 306-fourth pressure regulating valve; 307-first Second liquid phase outlet pipeline; 308-second liquid discharge valve; 309-fourth gas phase delivery pipeline; 310-sixth flat gate valve; 311-gas injection main pipeline; 312-gas injection branch pipeline; 313-gas injection flat gate valve; 314-gas-liquid mixture delivery pipeline; 315-fifth flat gate valve; 401-third check valve; 402-venting liquid separation tank; 403-venting pipeline; 404-flame arrester; 405-venting torch; 406-fourth liquid discharge valve; 407-third liquid phase outlet pipeline; 408 - the third liquid discharge valve; 409- throttling stop valve; 410- pressure replenishing pipeline; 411- the seventh flat gate valve; 412- water storage tank; 413- the fourth liquid phase outlet pipeline; 501- air supply pipeline; 502- filter; 503- the second pressure regulating valve; 504- air inlet of pneumatic pump; 505- reagent storage tank; 506- dosing port; 507- reagent delivery pipeline; 508- pneumatic pump; 509- the second one-way valve; 510- drug injection main pipeline; 511- drug injection branch pipeline; 512- drug injection ball valve. DETAILED DESCRIPTION

[0037] The technical solution of the utility model is further described below in conjunction with specific embodiments.

[0038] The utility model aims to provide a circulating gas lift and drainage system for a gas well group, by sequentially connecting a gas-liquid separation device and a pressure boosting device to the gas production port of each gas well in the gas well group, and the gas outlet of the pressure boosting device is connected to the oil casing annulus of each gas well. When a water-flooded well appears in the well group, a gas well with stable production and high pressure is used as a gas source well, and a gas-liquid separation device connected to the gas production port of the gas source well is used to separate the gas and liquid of the produced gas, and then the pressure boosting device is used to pressurize the gas after the gas-liquid separation, and the pressurized gas enters the oil casing annulus of the water-flooded well, thereby realizing gas lift and drainage of the water-flooded well. By adopting the circulating gas lift and drainage system for a gas well group, long-term stable production of the gas well group can be achieved.

[0039] The present invention is further described in detail below in conjunction with the embodiments.

[0040] Embodiment 1 of the gas well group circulating gas lift drainage system provided by the utility model:

[0041] The gas well group circulating gas lift drainage system of this embodiment is as follows: Figure 1 As shown, it includes three wellhead gas production trees 1, a gas-liquid separator 2, a compressor 301, a gas generator 302, a venting and liquid separation system and a foaming agent filling system.

[0042] Each wellhead gas production tree 1 includes a tubing spool and a casing spool. The upper port, left port and right port of the casing spool are respectively provided with a first gate valve 101, a second gate valve 102 and a third gate valve 103. The upper port, left port, lower port and right port of the tubing spool are respectively provided with a fourth gate valve 104, a fifth gate valve 105, a sixth gate valve 106 and a seventh gate valve 107. The lower port of the tubing spool and the upper port of the casing spool are connected by a transition pipeline. The number of gas production trees 1 in this embodiment is 3.

[0043] The circulating gas lift drainage system of the gas well group of the present embodiment also includes a gas production pipeline and a gas injection branch pipeline. The gas production pipeline includes an oil pipe gas production pipeline 108, a casing gas production pipeline 109 and a gas production merging pipeline 110; one end of the oil pipe gas production pipeline 108 is connected to the fifth gate valve 105 of the gas production tree, and the other end of the oil pipe gas production pipeline 108 is connected to the inlet of the gas production merging pipeline; one end of the casing gas production pipeline 109 is connected to the second gate valve 102 of the gas production tree, and the other end of the casing gas production pipeline 109 is connected to the inlet of the gas production merging pipeline; the gas production merging pipeline 110 is sequentially provided with a needle valve 111, an emergency shut-off valve 114, a flow meter 115, a first flat gate valve 116, and a first check valve 117 in the direction away from its inlet; the outlets of each gas production merging pipeline 110 are connected to the produced gas transmission pipeline 119.

[0044] The circulating gas lift drainage system of the gas well group of the present embodiment also includes three produced gas transmission branch pipelines, the outlets of the three produced gas transmission branch pipelines are connected to the produced gas transmission main pipeline 118, and the inlets of the three produced gas transmission branch pipelines are respectively connected to the three gas production merging pipelines 110, and the connection position between each produced gas transmission branch pipeline and the corresponding gas production merging pipeline 110 is located on the pipe section between the needle valve 111 and the emergency shut-off valve 114 on the gas production merging pipeline 110; each produced gas transmission branch pipeline is sequentially provided with a second flat gate valve 112 and a first pressure regulating valve 113 in the direction close to its outlet.

[0045] The outlet of the gas injection branch pipeline 312 is connected to the third gate valve 103 of the gas tree. A gas injection flat gate valve 313 is provided on the gas injection branch pipeline 312. The three gas injection branch pipelines 312 are connected to the outlet of the gas injection main line 311 after merging.

[0046] The foaming agent filling system includes a medicine storage tank 505, a pneumatic pump 508, a medicine injection main line 510, and a medicine injection branch line 511. The medicine storage tank 505 is used to store the foaming agent. The medicine storage tank 505 has a medicine adding port 506. The outlet of the medicine storage tank 505 and the liquid inlet of the pneumatic pump 508 are connected through a medicine delivery pipeline 507. The liquid outlet of the pneumatic pump 508 is connected to the inlet of the medicine injection main line 510. A second one-way valve 509 is provided on the pipe section of the medicine injection main line 510 close to the pneumatic pump 508. There are three injection branch lines 511, each of which is provided with an injection ball valve 512. The inlets of the three injection branch lines 511 are connected to the injection main line 510, and the outlets of the three injection branch lines 511 are respectively connected to the three gas injection branch lines 312. The connection position of each injection branch line 511 and the corresponding gas injection branch line 312 is located on the pipe section between the gas injection flat gate valve 313 on the gas injection branch line 312 and the outlet of the gas injection branch line 312. The drug delivery pipeline 507 and the injection main line 510 constitute the foaming agent delivery pipeline.

[0047] The air inlet 504 of the pneumatic pump is connected to the air supply pipeline 501, the air inlet of the air supply pipeline 501 is connected to the casing gas production pipeline 109, and the air supply pipeline 501 is sequentially provided with a filter 502 and a second pressure regulating valve 503 in the direction away from its air inlet. Such a setting is conducive to converting the gas produced by the gas wells of the well group into the power for the operation of the pneumatic pump, making full use of the energy of the gas wells themselves, without the need for other power sources, and has the advantages of simple equipment flow and low energy consumption.

[0048] The gas-liquid separator 2 includes a gas-liquid separator body 21, on which a feed inlet, a gas outlet, a liquid outlet, a pressure gauge 23 and a safety valve 22 are provided (the safety valve 22 contributes to the safe operation of the entire system); the feed inlet of the gas-liquid separator 2 is connected to the outlet of the output gas delivery main pipeline 118, the gas outlet is connected to the first gas phase delivery pipeline 24, the liquid outlet is connected to the first liquid phase outlet pipeline 25, and the first liquid phase outlet pipeline 25 is provided with a first drain valve 26; the gas-liquid separator 2 in this embodiment is a gravity horizontal separator with a volume of 25m 3 The design pressure is 6.3MPa and the material is 20# steel.

[0049] The outlet of the first gas phase transport pipeline 24 is split to form a second gas phase transport pipeline and a third gas phase transport pipeline. The outlet of the second gas phase transport pipeline is connected to the feed port of the gas generator 302, and the outlet of the third gas phase transport pipeline is connected to the air inlet of the compressor 301; the second gas phase transport pipeline is sequentially provided with a third pressure regulating valve 303 and a third flat gate valve 304 in the direction away from its outlet, and the third gas phase transport pipeline is sequentially provided with a fourth pressure regulating valve 306 and a fourth flat gate valve 305 in the direction away from its outlet.

[0050] The gas generator 302 includes a generator body and a control cabinet. The generator body has a feed port. The feed port of the gas generator 302 is connected to the outlet of the second gas phase transmission pipeline. The gas generator 302 is used to power various electrical devices (such as the compressor 301) in the circulating gas lift and drainage system of the gas well group in this embodiment.

[0051] The compressor 301 has an air inlet, an air outlet, a liquid outlet and a gas-liquid mixture outlet. The air inlet of the compressor 301 is connected to the outlet of the third gas phase delivery pipeline, the air outlet of the compressor 301 is connected to the fourth gas phase delivery pipeline 309, the liquid outlet is connected to the second liquid phase outlet pipeline 307, the gas-liquid mixture outlet is connected to the gas-liquid mixture delivery pipeline 314, and the second liquid phase outlet pipeline 307 is provided with a second drain valve 308. Generally, the air inlet pressure of the compressor 301 is 0.3-12MPa, the maximum exhaust pressure is 35MPa, and the output gas delivery main pipeline 118 and the first gas phase delivery pipeline 24 are steel pipelines with a pressure of 6.3MPa.

[0052] A fifth flat gate valve 315 is provided on the gas-liquid mixture delivery pipeline 314 , and the outlet of the gas-liquid mixture delivery pipeline 314 is connected to the feed port of the venting separator tank 402 .

[0053] The fourth gas phase transmission pipeline 309 is provided with a sixth flat gate valve 310, and the outlet of the fourth gas phase transmission pipeline 309 is split to form a gas injection main pipeline 311 and a pressure boosting pipeline 410. The outlet of the pressure boosting pipeline 410 is connected to the air inlet of the water storage tank 412, and the pressure boosting pipeline 410 is sequentially provided with a throttling stop valve 409 and a seventh flat gate valve 411 in the direction close to the outlet thereof. The outlet of the pressure boosting pipeline 410 is connected to the air inlet of the water storage tank 412, which can provide pressure for the water storage tank 412, so that the liquid inside can better enter the produced gas transmission pipeline 119, thereby realizing the clean treatment of the produced water, which is both environmentally friendly and can save the cost of transporting produced water.

[0054] The first liquid phase outlet pipeline 25 and the second liquid phase outlet pipeline 307 merge to form a liquid phase merge pipeline, and the outlet of the liquid phase merge pipeline is connected to the main liquid inlet of the water storage tank 412.

[0055] The venting and liquid separation system includes a venting and liquid separation tank 402, a venting flare 405 and a water storage tank 412. The venting and liquid separation tank 402 has a feed port, a gas outlet and a liquid outlet. The gas outlet of the venting and liquid separation tank 402 is connected to a venting pipeline 403, a flame arrester 404 is provided on the venting pipeline 403, and the outlet of the venting pipeline 403 is connected to the venting flare 405 to achieve clean treatment of vented natural gas; the liquid outlet of the venting and liquid separation tank 402 is connected to a third liquid phase outlet pipeline 407, a third liquid discharge valve 408 is provided on the third liquid phase outlet pipeline 407, and the outlet of the third liquid phase outlet pipeline 407 is connected to the auxiliary liquid inlet of the water storage tank 412. The water storage tank 412 has a main liquid inlet, an air inlet, an auxiliary liquid inlet and a liquid outlet. The liquid outlet of the water storage tank 412 is connected to a fourth liquid phase outlet pipeline 413. The outlet of the fourth liquid phase outlet pipeline 413 is connected to the produced gas transmission pipeline 119. The fourth liquid phase outlet pipeline 413 is sequentially provided with a fourth drain valve 406 and a third one-way valve 401 in the direction close to its outlet.

[0056] The circulating gas lift and drainage system for the gas well group of the present embodiment connects the various devices in sequence along the direction of the pressurized airflow in the gas well casing to eventually form a circulation system. The oil pipeline output gas of the gas source well in the well group can be compressed and pressurized to carry out self-sufficient gas lift resumption of production and timely injection of foam drainage agents for the flooded wells in the well group in the same well field, thereby ensuring the economical and efficient resumption of production of the flooded gas wells in the well group and the long-term stable production of the well group, while reducing the construction and operation costs and environmental risks.

[0057] The method of using the circulating gas lift drainage system of the gas well group of the present embodiment is as follows: the flooding situation of each gas well in the well group is detected and analyzed. When a flooded well appears in the well group, a gas well with stable production and high pressure is selected as the gas source well, and then the fifth gate valve 105 and the sixth gate valve 106 of the gas source well production tree and the second flat gate valve 112 and the first pressure regulating valve 113 on the output gas transmission branch line connected to the gas source well are opened, so that the output gas of the gas source well enters the gas-liquid separator 2 for gas-liquid separation, part of the gas flowing out of the gas-liquid separator 2 enters the gas generator 302 for combustion and power generation, and part enters the compressor 301 for compression and pressurization to form pressurized gas and pressurized liquid, part of the pressurized gas enters the water storage tank 412 for pressure replenishment, and part enters the gas injection branch line 312 connected to the flooded well after passing through the gas injection main line 311, and then enters the oil casing annulus of the flooded well, and the accumulated liquid in the wellbore of the flooded well is discharged from the oil pipe under the action of the pressurized gas. According to actual needs, the foaming agent filling system can be turned on. After the compressor 301 is started, the second pressure regulating valve 503 is opened to allow part of the output gas from the gas source well to drive the pneumatic pump 508 to work. At the same time, the injection ball valve 512 on the injection branch pipeline 511 connected to the flooded well is opened, and the liquid foaming agent located in the agent storage tank 505 is injected into the gas injection branch pipeline 312 connected to the flooded well through the pneumatic pump 508. Under the action of pressurized gas, the liquid foaming agent enters the oil casing annulus of the flooded well together with the pressurized gas, and the accumulated liquid in the wellbore of the flooded well is discharged from the oil pipe under the action of the pressurized gas and the foaming agent.

[0058] In addition, the first drain valve 26, the second drain valve 308 and the third drain valve 408 can be opened to allow the liquid in the gas-liquid separator 2, the compressor 301 and the venting separator tank 402 to pass into the water storage tank 412, so as to realize the draining operation of the gas-liquid separator 2, the compressor 301 and the venting separator tank 402, and at the same time, the throttling stop valve 409, the seventh flat gate valve 411 and the fourth drain valve 414 can be opened to realize the pressure replenishment and transportation of the discharged liquid of the flooded gas well, thus saving the transportation cost of the gas lift output liquid. Therefore, the gas well group circulating gas lift drainage system of this embodiment can not only realize the self-sufficient circulating gas lift resumption of production of the flooded gas wells in the well group and the long-term stable production of the well group, but also save the transportation cost of the output liquid and reduce the safety risk.

[0059] Embodiment 2 of the gas well group circulating gas lift drainage system provided by the utility model:

[0060] The foaming and filling system is omitted in the circulating gas lift drainage system of the gas well group of this embodiment. In specific implementation, foaming agent is not added to the flooded well, but the accumulated liquid in the flooded well is only discharged by gas lift.

[0061] Embodiment 3 of the gas well group circulating gas lift drainage system provided by the utility model:

[0062] In the circulating gas lift drainage system of the gas well group of this embodiment, the reagent storage tank 505 is set at a high position, and gravity is used as the power source for adding the foam drainage agent. At the same time, the pneumatic pump 508, the air supply pipeline 501, the filter 502 and the second pressure regulating valve 503 are omitted.

[0063] Embodiment 4 of the gas well group circulating gas lift drainage system provided by the utility model:

[0064] In the circulating gas lift drainage system of the gas well group of this embodiment, the water storage tank 412, the venting liquid separation tank 402, the venting pipeline 403, the flame arrester 404 and the venting flare 405 are omitted. During the specific implementation, the produced liquid flowing out of the liquid outlet of the gas-liquid separator 2 and the compressor 301 is collected and then processed subsequently.

[0065] Embodiment 5 of the gas well group circulating gas lift drainage system provided by the utility model:

[0066] In the circulating gas lift drainage system of the gas well group of this embodiment, the second one-way valve 509 in the foaming agent filling system is omitted. During implementation, the agent storage tank 505 is set at a high position or the outlet pressure of the pneumatic pump 508 is increased to avoid backflow of the foaming agent in the injection main line 510.

[0067] Embodiment 6 of the gas well group circulating gas lift drainage system provided by the utility model:

[0068] The third one-way valve 401 is omitted in the circulating gas lift drainage system of the gas well group in this embodiment. During implementation, the internal pressure of the water storage tank 412 is increased by increasing the amount of high-pressure gas entering the water storage tank 412 to avoid backflow of the produced liquid in the fourth liquid phase outlet pipeline 413.

[0069] The actual application effects of the circulating gas lift and drainage system for gas well groups of the utility model are as follows: taking the A1, A2, and A3 gas well groups as an example, after adopting the circulating gas lift and drainage system for gas well groups of the utility model, continuous and stable production of the A1, A2, and A3 gas well groups is achieved, the production time rate is increased by 65.9%, the daily output is increased by 7,800 cubic meters / day, the cumulative output is increased by 1,692,600 cubic meters, and the cumulative benefits are 1.894 million yuan, achieving good stable production and increased production effects and economic benefits.

Claims

1. A circulating gas lift drainage system for a gas well group, characterized in that: It includes a gas-liquid separation device and a boosting device. The gas-liquid separation device includes a feed port and a gas outlet. The boosting device includes a gas inlet and a gas outlet. The gas outlet of the gas-liquid separation device is connected to the gas inlet of the boosting device. The feed port of the gas-liquid separation device is connected to the gas production port of each gas well in the well group. The gas outlet of the boosting device is connected to the oil casing annulus of each gas well in the well group.

2. The circulating gas lift drainage system for a gas well group according to claim 1, characterized in that: The gas well group circulating gas lift drainage system also includes a foaming agent injection system, and the foaming agent injection system is used to inject foaming agent into the oil casing annulus of each gas well.

3. The circulating gas lift drainage system for a gas well group as claimed in claim 2, characterized in that: The foaming agent filling system comprises a foaming agent storage device and a foaming agent delivery pipeline, one end of the foaming agent delivery pipeline is connected to the foaming agent storage device, and the other end of the foaming agent delivery pipeline is connected to the oil casing annulus of each gas well in the well group.

4. The circulating gas lift drainage system for a gas well group as claimed in claim 3, characterized in that: A one-way valve is arranged on the foaming agent delivery pipeline.

5. The circulating gas lift drainage system for a gas well group according to any one of claims 2 to 4, characterized in that: The foaming agent filling system also includes a conveying power device.

6. The circulating gas lift drainage system for a gas well group according to claim 5, characterized in that: The power source of the transport power device is the produced gas of the gas wells in the well group.

7. The circulating gas lift drainage system for a gas well group according to claim 6, characterized in that: The transport power device comprises an air inlet, which is connected to the gas production port of the gas well in the well group through an air supply pipeline, and a filter device is arranged on the air supply pipeline.

8. The circulating gas lift drainage system for a gas well group according to any one of claims 1 to 4, characterized in that: The gas-liquid separation device also includes a liquid outlet, which is connected to the gas pipeline of the well group produced gas; the boosting device also includes a liquid outlet, which is connected to the gas pipeline of the well group produced gas; the gas well group circulating gas lift drainage system also includes a venting liquid separation device and a venting flare, the venting liquid separation device includes a feed port, a gas outlet and a liquid outlet, the boosting device also includes a gas-liquid mixture outlet, the gas-liquid mixture outlet is connected to the feed port of the venting liquid separation device, the gas outlet of the venting liquid separation device is connected to the venting flare, and the liquid outlet of the venting liquid separation device is connected to the well group produced gas pipeline.

9. The circulating gas lift drainage system for a gas well group according to claim 8, characterized in that: The circulating gas lift drainage system of the gas well group also includes a water storage device, which includes a liquid inlet, an air inlet and a liquid outlet. The liquid inlet of the water storage device is connected to the liquid outlet of the gas-liquid separation device, the liquid outlet of the boosting device, and the liquid outlet of the venting and liquid separation device. The air inlet of the water storage device is connected to the air outlet of the boosting device, and the liquid outlet of the water storage device is connected to the gas transmission pipeline of the well group.

10. The circulating gas lift drainage system for a gas well group according to claim 9, characterized in that: A one-way valve is arranged on the pipeline connecting the liquid outlet of the water storage device and the gas transmission pipeline of the well group.

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