Underground multi-stage gas flow self-adaptive cyclone separation device for gas recovery well

Abstract

The invention relates to a gas recovery well downhole multistage gas flow self-adaption cyclone separation device which comprises a degassing structure and a deposition reinjection structure, the degassing structure comprises a first-stage gas-liquid separation module, and the first-stage gas-liquid separation module comprises a gas-liquid inlet outer pipe, an upper gas pipe, a gas return spiral flow channel, a vent pipe, an upper liquid gathering conical pipe and a gas return liquid conveying conical pipe; an upper air guide pipe is arranged on the upper portion of the air return spiral flow channel, an air return conical cavity is formed in the air return spiral flow channel, the upper air guide pipe is communicated with the air return conical cavity, a lower port of the air return conical cavity is in butt joint with an air return infusion conical pipe, and the upper air pipe penetrates out of the upper air guide pipe. An annular space between the vent pipe and the upper air pipe and an annular space between the upper air guide pipe and the upper air pipe form an upper air channel; the upper liquid gathering conical pipe surrounds the outside of the air returning and liquid conveying conical pipe; the deposition reinjection structure comprises a lower spiral flow channel, a lower liquid gathering conical pipe, an inverted cone and a centrifugal pump. The coalescence reinjection technology and the rotational flow technology are combined, the efficiency is high, and the service life is long.

Description

Technical Field

[0001] The present invention relates to a device used in the field of underground oil-water separation and capable of realizing efficient separation of gas-liquid two-phase media in a narrow underground space, and specifically relates to an underground multi-stage gas volume adaptive cyclone separation device for a gas production well. Background Art

[0002] As oil and gas exploration and development deepen, the production of gas wells continues to increase, but it also brings about the problem of gas-liquid mixing. Formation water often flows into the bottom of the gas well. When the gas well production is high, the gas-liquid velocity at the bottom of the well is large, and the amount of fluid in the well is relatively small, the water will be carried to the surface by the airflow. However, the presence of accumulated liquid will increase the back pressure on the gas layer, limit its production capacity, and sometimes even completely crush the gas layer and cause the well to be shut down.

[0003] In order to solve the problem of excessive gas content in gas wells, technicians have proposed some solutions. Patent document 1, CN201811502377.1, uses a submersible electric pump and a gas-liquid separator to separate the water and gas in the well fluid. The separated gas continues to ascend along the casing and is discharged from the wellhead through the oil pipe or casing. The separated water is pressurized by a centrifugal pump and injected into the injection layer. However, under this solution, the gas in the gas phase after separation still carries a small amount of liquid, and only one gas-liquid separation can be performed. The gas-liquid phase mixture after separation cannot be subjected to gas-liquid separation again. Therefore, the gas-liquid separation efficiency is not high. Patent document 2, CN202110068457.6, has three-stage spiral blades, two-stage throttling devices, two-stage conical tubes, two-stage wire meshes and tail pipes at the top of the pipeline to separate gas and liquid. Under the centrifugal action, it moves around and is captured by the wall, separating most of the droplets, and a small part is separated by the wire mesh. However, under this scheme, under the condition of fast flow rate of each phase medium, a small amount of gas will be mixed into the liquid, which is difficult to achieve efficient separation. In addition, the device described in patent document CN202210691687.2 uses cyclone separation to completely separate the gas phase and liquid phase, but the device occupies a large space, and the various parts are complex, which is not convenient for disassembly and maintenance, and is not suitable for gas wells with narrow space. Summary of the invention

[0004] The purpose of the present invention is to provide a multi-stage gas volume adaptive cyclone separation device for a gas well. The multi-stage gas volume adaptive cyclone separation device for a gas well is used to solve the problems that the gas-liquid separation device in the prior art is complicated, not suitable for gas wells with narrow space, and has low gas-liquid separation efficiency.

[0005] The technical solution adopted by the present invention to solve its technical problems is: this underground multi-stage gas volume adaptive cyclone separation device for gas production wells includes a degassing structure and a sedimentation reinjection structure, the degassing structure includes a primary gas-liquid separation module, the primary gas-liquid separation module includes a gas-liquid inlet outer tube, an upper gas pipe, a return gas spiral flow channel, a vent pipe, an upper liquid collecting conical tube, and a return gas infusion conical tube; the return gas spiral flow channel is arranged in the gas-liquid inlet outer tube, the upper part of the return gas spiral flow channel is the upper gas guide tube, a return gas conical cavity is arranged inside the return gas spiral flow channel, the upper gas guide tube is communicated with the return gas conical cavity, the lower port of the return gas conical cavity is connected to the return gas infusion conical tube, the upper gas pipe passes through the return gas infusion conical tube and passes out from the upper gas guide tube The air permeable pipe is sleeved outside the upper air pipe, and the annulus between the air permeable pipe and the upper air pipe and the annulus between the upper air guide pipe and the upper air pipe constitute the upper air channel. The air permeable pipe is provided with multiple air inlets at the position of the return air conical cavity; the upper liquid collecting conical pipe is arranged at the lower end of the return air spiral flow channel and surrounds the return air infusion conical pipe, and multiple return air infusion ports are arranged at the upper cone part of the return air infusion conical pipe; the sedimentation reinjection structure includes a lower spiral flow channel, a lower liquid collecting conical pipe, an inverted cone, and a centrifugal pump. The lower spiral flow channel is connected to the upper air pipe through its return air channel, the upper port of the lower liquid collecting conical pipe is connected to the bottom of the lower spiral flow channel, the lower port of the lower liquid collecting conical pipe is connected to the inverted cone, the inverted cone is connected to the centrifugal pump, and the centrifugal pump is connected to the lower oil pipe coupling.

[0006] The degassing structure in the above scheme also includes a secondary gas-liquid separation module, which is arranged between the primary gas-liquid separation module and the deposition reinjection structure. The secondary gas-liquid separation module includes an intermediate connecting outer tube, a secondary spiral flow channel, an internal gas-liquid separation porous tube, and multiple liquid-permeable conical tubes. The lower port of the secondary spiral flow channel is threadedly connected to the internal gas-liquid separation porous tube, and the upper gas pipe passes through the secondary spiral flow channel and the internal gas-liquid separation porous tube to form an upper gas channel with the annulus between the two. Multiple liquid-permeable conical tubes are installed in series outside the internal gas-liquid separation porous tube, and the internal gas-liquid separation porous tube is provided with multiple return gas ports, each return gas port corresponds to a liquid-permeable conical tube, and each liquid-permeable conical tube is provided with multiple liquid ports, and the flow ports are communicated with the inner cavity of the intermediate connecting outer tube.

[0007] In the above scheme, the gas-liquid inlet outer tube is a cylinder with a top, a center hole is arranged on the top of the cylinder, a first liquid inlet is also arranged on the upper part of the gas-liquid inlet outer tube, the upper end of the gas-liquid inlet outer tube is threadedly connected to the oil pipe coupling, the lower end of the gas-liquid inlet outer tube is threadedly connected to the connecting tube arranged outside the upper port of the upper liquid collecting conical tube, the lower end of the connecting tube is threadedly connected to the upper connecting outer tube, and the lower end of the upper connecting outer tube is threadedly connected to the upper connecting device; the upper end of the upper air pipe is located in the center hole of the gas-liquid inlet outer tube, the lower end of the center hole of the gas-liquid inlet outer tube is threadedly connected to the upper air guide pipe of the return air spiral flow channel, the upper end of the return air conical cavity of the return air spiral flow channel is threadedly connected to the upper end of the air permeable tube, and the lower end of the return air conical cavity is threadedly connected to the upper port of the return air infusion conical tube.

[0008] In the above scheme, the upper end of the middle connecting outer tube is threadedly connected to the upper connecting device, the lower end of the air permeable tube is threadedly connected to the upper end of the return air channel of the secondary spiral flow channel, the lower end of the return air channel of the secondary spiral flow channel is threadedly connected to the upper end of the inner gas-liquid separation porous tube, and the five identical liquid-permeable conical tubes are all threadedly connected to the inner gas-liquid separation porous tube; the upper connecting device is provided with a second liquid inlet, and the upper liquid collecting conical tube is communicated with the middle connecting outer tube through the second liquid inlet.

[0009] In the above scheme, the lower spiral flow channel is arranged in the lower connecting outer tube, the upper end of the lower connecting outer tube is threadedly connected to the lower connecting device, the upper end of the lower connecting device is threadedly connected to the middle connecting outer tube, the lower connecting device is provided with a central threaded hole and a fan-shaped opening, and the lower connecting device is respectively connected to the upper air pipe and the return air channel of the lower spiral flow channel through the central threaded hole; a connecting tube is arranged outside the upper port of the lower collecting conical tube, and threaded structures are arranged at both ends of the connecting tube, the upper end of the connecting tube is threadedly connected to the lower connecting outer tube, and the lower end of the connecting tube is threadedly connected to the pump connecting pipe; the lower end of the pump connecting pipe is connected to The pump pipe connecting device is connected by threads; the lower end of the pump pipe connecting device is threadedly connected to the centrifugal pump; the upper end of the inverted cone is threadedly connected to the lower port of the lower liquid collecting cone pipe, the lower end of the inverted cone is threadedly connected to the upper end of the centrifugal pump, and the inverted cone is used to lift and reinject liquid phase; the lower end of the centrifugal pump is threadedly connected to the upper end of the oil pipe coupling connecting device; the lower end of the oil pipe coupling connecting device is threadedly connected to the upper end of the lower oil pipe coupling; the third-level gas-liquid mixture is separated by the sedimentation reinjection structure, and the separated liquid phase is discharged into the lower oil pipe coupling through the centrifugal pump to complete the three-level gas-liquid separation.

[0010] In the above scheme, the lower part of the lower liquid collecting conical tube is a circular tube section, which passes through the pipe opening of the pump pipe connecting device and is connected to the inverted cone. This structure plays a role in liquid collection and deposition, and better discharges the gas back to the return air channel of the spiral flow channel and flows back to the ground.

[0011] In the above scheme, the lower liquid gathering conical tube and the inverted cone constitute a liquid gathering deposition structure, and the final liquid phase deposition and reinjection are carried out in the liquid gathering deposition structure. After three-level gas-liquid separation, when a large amount of liquid phase passes through the lower liquid gathering conical tube, the small liquid phase droplets are gathered into large droplets again, and then the liquid phase is gathered into the lower circular tube section of the lower liquid gathering conical tube by changing the diameter. The effect of liquid gathering and deposition is achieved by extending and lengthening the lower circular tube section of the lower liquid gathering conical tube. The liquid phase flows to the inverted cone to realize the overall reinjection process and flows into the centrifugal pump. Beneficial Effects

[0012] 1. The present invention proposes a multi-stage gas volume adaptive cyclone separation device for a gas well, which includes a three-stage gas-liquid phase separation structure connected in series. The gas and liquid are changed by factors such as centrifugal acceleration of the spiral flow channel, pressure difference in the tube, and gas-liquid density difference, so that the gas is distributed in the middle and the liquid is distributed on both sides. Through enhanced separation at each level, the gas-liquid phase separation efficiency is greatly improved.

[0013] 2. After the first-level degassing and separation mechanism (i.e., the first-level gas-liquid separation module) of the present invention performs cyclone separation on the gas-liquid mixture, the gas phase in part of the liquid droplets is transported into the upper oil pipe coupling through the return gas and liquid infusion tapered pipe with a gradually decreasing aperture through the return gas spiral flow channel cavity, and the liquid is discharged to the next level through the lower end pipeline, thereby realizing the first-level gas-liquid separation treatment, and the second and third level gas-liquid separations and cyclone separations are separated in different chambers without interfering with each other, and have the characteristics of high separation efficiency and rapid separation, which can adapt to the fast flow rate inside the cyclone.

[0014] 3. The second-stage degassing and separation structure (i.e., the secondary gas-liquid separation module) of the present invention is provided with 5 layers of liquid-permeable conical tubes and an inner gas-liquid separation porous tube. The 5 layers of liquid-permeable conical tubes are provided to better improve the efficiency of gas-liquid separation. The upper end diameter of the liquid-permeable conical tube is set according to the actual liquid flow rate, and a certain fluid channel is maintained between the liquid-permeable conical tube and the middle connecting outer tube to ensure that the liquid can flow into the next stage. The conical surface of the liquid-permeable conical tube is partially opened to pass part of the liquid, and the gas is blocked and flows into the upper oil pipe coupling through the opening on the surface of the inner gas-liquid separation porous tube, thereby completing the secondary gas-liquid separation after the primary gas-liquid separation is completed by centrifugal acceleration, thereby further improving the gas-liquid separation efficiency of the device.

[0015] 4. The deposition and reinjection separation structure of the present invention adds an inverted cone structure at the lower end of the liquid gathering conical tube to completely separate the liquid deposition from the gas. Due to the influence of the internal pressure difference, the gas separated from the three-stage gas-liquid phase flows into the upper oil pipe coupling along the middle pipeline through the lower end pipeline of the spiral flow channel, and the liquid phase is gathered in the lower end pipeline of the liquid gathering conical tube by changing the diameter. The effect of liquid deposition and reinjection is achieved by extending and lengthening the lower end pipeline.

[0016] 5. The present invention can be connected to a small space in the wellbore, achieving multi-level passages without interference with each other, and achieving the purpose of collecting the liquid phase and discharging the gas phase. The three-stage cyclone device involved is arranged internally in a very small space, and only the position occupied by one cyclone is used to achieve efficient arrangement of the series device, which not only improves the gas-liquid separation efficiency, but also enhances the practicability of the equipment. It is an integrated downhole gas-liquid efficient separation device that combines agglomeration reinjection and cyclone technology, which can achieve efficient separation of gas-liquid two-phase media in a limited space and improve the economy of oil field exploitation.

[0017] 6. The present invention enables gas-liquid separation of gas-containing mixed media while occupying a small space. After separation, the gas phase is discharged to the external space of the equipment, thereby increasing the service life of other operating equipment. At the same time, it completes the pre-separation of the produced liquid and reduces the energy consumption of the subsequent separation system.

[0018] 7. The present invention is provided with three-stage gas-liquid separation. After multiple gas-liquid separations, the gas phase and the liquid phase are separated. The gas phase is completely separated, and the degassed liquid phase is pumped back to the underground by a centrifugal pump based on the principle of backflow of the liquid through the liquid collecting conical pipe. The gas phase flows back to the ground through the upper oil pipe coupling, and the separation of the gas and liquid phases can be completed while occupying a small space. At the same time, the spiral flow channel of the present invention avoids the phenomenon of series flow and leakage, and the upper air pipe can discharge the gas phase better. The present invention also reduces the connection between pipelines and avoids unnecessary disassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 (a) is the overall appearance diagram of the present invention; Figure 1 (b) is a cross-sectional view of the present invention.

[0020] Figure 2 (a) is the appearance of the degassing structure; Figure 2 (b) is a cross-sectional view of the degassing structure.

[0021] Figure 3 This is an exploded diagram of the degassing structure.

[0022] Figure 4 (a) is a front view of the secondary gas-liquid separation module; Figure 4 (b) is a side view of the secondary gas-liquid separation module.

[0023] Figure 5 It is a cross-sectional view of the return air spiral flow channel.

[0024] Figure 6 (a) is the appearance of the sedimentary reinjection structure; Figure 6 (b) is a cross-sectional view of the sedimentation reinjection structure.

[0025] Figure 7 Exploded view of the sedimentary reinjection structure.

[0026] Figure 8 This is the appearance diagram of the poly-liquid deposition structure.

[0027] Fig. 9 This is the first-stage gas-liquid phase separation structural module diagram.

[0028] Fig.10 This is a block diagram of the second-stage gas-liquid phase separation structure.

[0029] Fig.11 This is a cross-sectional view of the third-stage gas-liquid phase separation reinjection module.

[0030] In the figure, 1-upper oil pipe coupling, 2-gas-liquid inlet outer pipe, 201-first liquid inlet, 3-upper air pipe, 4-return air spiral flow channel, 401-return air conical cavity, 5-air permeable pipe, 501-air inlet, 6-upper liquid collecting conical pipe, 7-return air infusion conical pipe, 701-return air infusion port, 8-upper connecting outer pipe, 9-upper connecting device, 901-second liquid inlet, 10-middle connecting outer pipe, 11-secondary spiral flow channel, 12-inner gas-liquid separation porous pipe, 1201-return air port, 13-first liquid permeable conical pipe, 14-second liquid permeable conical pipe, 15-third liquid permeable conical pipe, 16-first Four liquid-permeable conical tubes, 17-the fifth liquid-permeable conical tube, 1301-the first liquid port, 1401-the second liquid port, 15301-the third liquid port, 1601-the fourth liquid port, 1701-the fifth liquid port, 18-the lower connecting device, 1801-the fan-shaped port, 19-the lower connecting outer tube, 20-the lower spiral channel, 2001-the return air channel, 21-the lower liquid-collecting conical tube, 2101-the lower end pipeline, 22-the pump inter-connecting pipe, 23-the pump-pipe connecting device, 2301-the pipe port, 24-the centrifugal pump, 25-the inverted cone, 26-the oil pipe coupling connecting device, 27-the lower oil pipe coupling. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings: Combination Figure 1-Figure 11 This underground multi-stage gas volume adaptive cyclone separation device for a gas production well includes a degassing structure with an upper oil pipe coupling 101, and the degassing structure includes a gas-liquid inlet outer pipe 2, an upper gas pipe 3, a return gas spiral flow channel 4, a vent pipe 5, an upper liquid collecting conical pipe 6, a return gas infusion conical pipe 7, an upper connecting outer pipe 8 and an upper connecting device 9; the return gas spiral flow channel and the liquid collecting conical pipe both adopt a hollow structure; a first liquid inlet 201 is provided on the gas-liquid inlet outer pipe 2, a return gas conical cavity 401 is provided on the return gas spiral flow channel 4, and a return gas infusion conical pipe 7 is provided with a return gas infusion port 701.

[0032] The lower end of the upper oil pipe coupling 1 is connected to the upper end of the gas-liquid inlet outer pipe 2 by a thread; the threaded structure at the lower end of the gas-liquid inlet outer pipe 2 is connected to the upper end of the cylinder of the upper liquid collecting tapered pipe 6, and the lower end of the cylinder of the upper liquid collecting tapered pipe 6 is threaded and connected to the upper end of the upper connecting outer pipe 8, and the lower end of the upper connecting outer pipe 8 is threadedly connected to the upper end of the upper connecting device 9; the upper end opening of the gas-liquid inlet outer pipe 2 passes through the upper air pipe 3, and the lower end of the hole is threadedly connected to the upper end tube of the return air spiral flow channel 4, the interior of the return air spiral flow channel 4 is a return air conical cavity 401 channel, the upper end opening is connected to the upper end of the air permeable pipe 5 by a thread, and the upper section of the air permeable pipe has a plurality of openings 501, and the lower end of the return air spiral flow channel 4 is threadedly connected to the upper end tapered pipe of the return air infusion tapered pipe 7.

[0033] After connection, when working, the gas-liquid mixture flows into the device from the first liquid inlet 201, flows through the return gas cyclone flow channel 4, and after the mixed liquid is centrifugally accelerated, due to the density difference between the gas and the liquid and the pressure difference in the cyclone cavity, the liquid is distributed on both sides and the gas is distributed in the middle. The liquid gradually changes from small droplets to large droplets through the upper liquid collecting conical tube 6 and flows into the next level with part of the gas. Part of the gas phase located in the center flows into the return gas conical cavity 401 through the return gas infusion port 701, and is discharged into the upper oil pipe coupling 1 through the gas inlet 501. The liquid in the center will also converge with the remaining unseparated gas-liquid mixture through the return gas infusion port 701 and flow into the second liquid inlet 901, completing the first-stage gas-liquid separation; the liquid entering from the second liquid inlet 901 carries a small amount of gas phase and flows downward along the internal structure to perform the second-stage gas-liquid separation.

[0034] The degassing structure also includes an intermediate connecting device 10, a secondary spiral flow channel 11, an internal gas-liquid separation porous tube 12, and 5 identical liquid-permeable conical tubes (a first liquid-permeable conical tube 13, a second liquid-permeable conical tube 14, a third liquid-permeable conical tube 15, a fourth liquid-permeable conical tube 16, and a fifth liquid-permeable conical tube 17); the internal gas-liquid separation porous tube 12 is provided with a gas return port 1201, and the 5 identical liquid-permeable conical tubes are all provided with the same ports (a first liquid-passing port 1301, a second liquid-passing port 1401, a third liquid-passing port 1501, a fourth liquid-passing port 1601, and a fifth liquid-passing port 1701); the lower end of the upper connecting device 9 is connected to the upper end of the intermediate connecting outer tube 10 by threading, the lower end of the gas-permeable tube 5 is connected to the upper end of the secondary spiral flow channel 11 by threading, the lower end of the secondary spiral flow channel 11 is connected to the upper end of the internal gas-liquid separation porous tube 12 by threading, and the 5 identical liquid-permeable conical tubes are connected to the internal gas-liquid separation porous tube 12 by threading. The upper end diameters of the liquid-permeable conical tubes (the first liquid-permeable conical tube 13, the second liquid-permeable conical tube 14, the third liquid-permeable conical tube 15, the fourth liquid-permeable conical tube 16, and the fifth liquid-permeable conical tube 17) are set according to the actual liquid flow rate, and a certain fluid channel is maintained between the middle connecting outer tube 10 to ensure that the liquid can flow into the next stage.

[0035] After the connection, the gas-liquid mixture flows through the secondary spiral flow channel 11 and is centrifugally accelerated by the spiral flow channel. Due to the density difference between the gas and the liquid and the pressure difference in the cyclone chamber, the liquid is divided on both sides of the outer tube wall and the gas gathers in the middle. Most of the liquid flows through the middle channel connecting the outer tube 10 and the liquid-permeable conical tube, and part of the liquid flows from the openings on the liquid-permeable conical tube (the first liquid-passing opening 1301, the second liquid-passing opening 1401, the third liquid-passing opening 15301, the fourth liquid-passing opening 1601, and the fifth liquid-passing opening 1701) to the lower level, and part of the gas flows into the return gas opening 1201, and flows into the upper oil pipe coupling 1 along the middle pipeline.

[0036] The sedimentation reinjection structure includes a lower connecting device 18, a lower connecting outer tube 19, a lower spiral flow channel 20, a lower liquid collecting conical tube 21, a pump inter-connecting tube 22, a pump-pipe connecting device 23, a centrifugal pump 24, an inverted cone 25 and a lower oil pipe coupling 27 connecting device; the lower connecting device 18 is provided with a fan-shaped opening 1801; a return air channel 2001 is provided at the lower end of the lower spiral flow channel 20, which is used to recover the residual gas in the final liquid; the lower connecting device 18 is provided with threads at both ends, which are respectively used to connect the lower end of the middle connecting outer tube 10 and the upper end of the lower connecting outer tube 19, and the upper and lower ends of the middle opening are also provided with threads, which are respectively connected to the lower end of the upper air pipe 3 and the upper end of the lower spiral flow channel 20; threaded structures are provided at both ends of the cylinder of the lower liquid collecting conical tube 21, which are respectively used to connect The lower end of the lower connecting outer tube 19 and the upper end of the pump-to-pump connecting tube 22 are connected by threads; the lower end of the pump-to-pump connecting tube 22 is connected to the pump-tube connecting device 23 by threads; the lower end of the pump-tube connecting device 23 is connected to the centrifugal pump 24 by threads; the upper end of the inverted cone 25 is connected to the cylindrical lower end of the lower liquid-collecting conical tube 21 by threads, and the lower end of the inverted cone 25 is connected to the inside of the centrifugal pump 24 by threads, and the inverted cone is used to lift and reinject the liquid phase; the lower end of the centrifugal pump 24 is connected to the upper end of the oil pipe coupling connecting device 26 by threads; the lower end of the oil pipe coupling connecting device 26 is connected to the upper end of the lower oil pipe coupling 27 by threads; the oil pipe coupling connecting device is mainly firmly connected to the oil pipe coupling at the lower end; the liquid phase after the third-stage gas-liquid mixture is separated is discharged into the lower oil pipe coupling 27 through the centrifugal pump 24 to complete the three-stage gas-liquid separation.

[0037] After connection, the gas-liquid mixed phase after the secondary gas-liquid separation enters the lower connecting outer pipe 19 from the fan-shaped port 1801 for the third-level gas-liquid separation, and can obtain the speed and centrifugal force to complete the cyclone separation after flowing out from the lower spiral flow channel 20; the gas phase is located in the center close to the return port 2001, flows in through the return port 2001 of the lower spiral flow channel 20, and flows into the upper oil pipe coupling 1 along the middle pipeline together with the gas phases of the secondary and primary gas-liquid separations; the liquid phase flows along the lower liquid gathering conical pipe 21, and as the pipe diameter continues to decrease, all the liquid phase is deposited in this pipe through the extended length of the lower end pipe 2101 (the lower end pipe is the circular pipe section), achieving the effect of liquid gathering deposition; the deposited liquid passes through the inverted cone 25 to complete the third-level gas-liquid separation, and finally the liquid is pumped back by the centrifugal pump 24 and discharged into the lower oil pipe coupling 27.

[0038] The present invention is described in more detail as follows: The underground multi-stage gas volume adaptive cyclone separation device of a gas production well comprises a degassing structure and a deposition reinjection structure.

[0039] The degassing structure is divided into a primary gas-liquid separation module and a secondary gas-liquid separation module according to its function. The specific components involved in the function of each gas-liquid separation module and the connection relationship between the components are as follows: The primary gas-liquid separation module includes an upper oil pipe coupling 1, a gas-liquid inlet outer pipe 2, an upper gas pipe 3, a return gas spiral flow channel 4, a vent pipe 5, an upper liquid collecting conical pipe 6, a return gas infusion conical pipe 7, an upper connecting outer pipe 8, and an upper connecting device 9; wherein the return gas spiral flow channel and the liquid collecting conical pipe both adopt a hollow structure, a first liquid inlet 201 is arranged on the gas-liquid inlet outer pipe 2, a return gas conical cavity 401 is arranged at the lower part of the return gas spiral flow channel 4, a return gas infusion conical pipe 7 is arranged with a return gas infusion port 701, and a second liquid inlet 901 is arranged on the upper connecting device 9. The threaded structures at the upper and lower ends of the gas-liquid inlet outer tube 2 are respectively connected to the lower end of the upper oil pipe coupling 1 and the upper end of the upper liquid collecting conical tube 6. The upper end tube of the return air spiral flow channel 4 is connected to the center hole of the upper end of the gas-liquid inlet outer tube 2 through a thread. The center of the lower end of the return air spiral flow channel 4 is threaded and connected to the upper end of the return air infusion conical tube 7. The upper end of the air permeable tube 5 is connected to the upper middle end of the return air spiral flow channel 4 through a thread. The gas-containing liquid flows from the first liquid inlet 201 through the return air cyclonic flow channel 4. The gas-liquid phase mixture is centrifugally accelerated by the spiral flow channel. Most of the gas phase is Due to the density difference between gas and liquid and the pressure difference in the cyclone cavity, the liquid is distributed on both sides and the gas is distributed in the middle. The liquid gradually changes from small droplets to large droplets through the upper liquid collecting conical tube 6 and flows into the next stage along with part of the gas. Part of the gas phase and a small amount of liquid are located in the return gas conical cavity 401 through the return gas infusion port 701. The gas flows into the upper oil pipe coupling 1 through the middle pipeline through the port 501. The liquid converges with the unseparated gas-liquid mixture through the lower end pipeline of the return gas infusion conical tube 7 and flows into the second liquid inlet 901, completing the first-stage gas-liquid separation. The secondary gas-liquid separation module includes an intermediate connecting outer tube 10, a secondary spiral flow channel 11, an inner gas-liquid separation porous tube 12, and five identical liquid-permeable conical tubes. The upper end of the intermediate connecting outer tube 10 is connected to the lower end of the upper connecting device 9 by a threaded structure, the lower end of the upper air-permeable tube 5 is connected to the upper end of the secondary spiral flow channel 11 by a threaded structure, the inner gas-liquid separation porous tube 12 is provided with a gas return port 1201, and the five identical liquid-permeable conical tubes are all provided with the same liquid-through port. The lower end of the secondary spiral flow channel 11 is connected to the upper end of the inner gas-liquid separation porous tube 12 by a threaded structure, and the five identical liquid-permeable conical tubes are connected to the inner gas-liquid separation porous tube 12 by a threaded structure. The gas-liquid phase mixture flows through the secondary spiral flow channel 11 and is centrifuged through the spiral flow channel. Acceleration, due to the density difference between gas and liquid and the pressure difference in the cyclone chamber, the liquid phase is distributed on both sides and the gas phase is distributed in the middle. Most of the liquid flows through the channel between the middle connecting outer tube 10 and each liquid-permeable conical tube, part of the liquid flows into the fan-shaped port 1801 from the liquid-passing port on the liquid-permeable conical tube, and part of the gas is discharged into the upper oil pipe coupling 1 along the middle pipeline through the return port 1201. The upper end diameter of the liquid-permeable conical tube is set according to the actual liquid flow rate, and a certain fluid channel is maintained between the middle connecting outer tube 10 to ensure that the liquid can flow into the next level.

[0040] The sedimentation reinjection structure is a three-stage gas-liquid separation and reinjection module according to its function. The three-stage gas-liquid reinjection and separation module includes a lower connecting device 18, a lower connecting outer tube 19, a lower spiral flow channel 20, a lower liquid collecting conical tube 21, a pump inter-connecting tube 22, a pump-pipe connecting device 23, a centrifugal pump 24, an inverted cone 25, and an oil pipe coupling connecting device 27; wherein the lower connecting device 18, the lower liquid collecting conical tube 21, and the lower oil pipe coupling 27 are all hollow structures; the lower connecting device 18 is provided with a fan-shaped opening 1801, and the degassed gas-liquid mixture enters the lower connecting outer tube 19 from the fan-shaped opening 1801 for the third-stage gas-liquid separation, and enters the lower spiral flow channel 2 0 can obtain the speed and centrifugal force to complete the cyclone separation after flowing out, the lower end of the lower spiral flow channel 20 is provided with a return air channel 2001, the middle of the pump pipe connecting device 23 is provided with a pipe opening 2301, the upper and lower ends of the lower connecting device 18 are provided with threads, which are respectively used to connect the lower end of the middle connecting outer tube 10 and the upper end of the lower connecting outer tube 19, and the upper and lower ends of the middle opening are also provided with threads, which are respectively connected to the lower end of the upper air pipe 3 and the upper end of the lower spiral flow channel 20. Based on different centrifugal forces, the gas phase is located in the center close to the return air opening 2001, and passes through the lower spiral flow channel 20 The liquid phase flows along the lower conical tube 21 and flows into the upper oil pipe coupling 1 together with the gas phase separated from the secondary and primary stages. Threaded structures are arranged at both ends of the cylinder of the lower liquid collecting conical tube 21, which are respectively used to connect the lower end of the lower connecting outer tube 19 and the upper end of the pump inter-connecting tube 22. The liquid phase flows along the lower liquid collecting conical tube 21, and flows into the lower end pipe 2101 as the pipe diameter is continuously reduced. The entire liquid phase is deposited in this pipe through the through-port 2301 through the extended length of the lower end pipe 2101, achieving the effect of liquid collecting deposition. The lower end of the pump inter-connecting tube 22 is connected to the pump pipe. The connecting device 23 is connected by threads; the lower end of the pump pipe connecting device 23 is threadedly connected to the centrifugal pump 24, the upper end of the inverted cone 25 is threadedly connected to the cylindrical lower end of the lower liquid collecting conical tube 21, the lower end of the inverted cone 25 is threadedly connected to the inner part of the upper end of the centrifugal pump 24, the deposited liquid passes through the inverted cone 25 to complete the three-stage gas-liquid separation and reinjection, the liquid is pumped back by the centrifugal pump 24 and flows into the lower oil pipe coupling 27, the lower end of the centrifugal pump 24 is threadedly connected to the upper end of the oil pipe coupling connecting device 26, and the lower end of the oil pipe coupling connecting device 26 is threadedly connected to the lower oil pipe coupling 27.

[0041] The appearance and cross-sectional view of the multi-stage gas volume adaptive cyclone separation device in the gas well are as follows: Figure 1As shown, the device is placed vertically in the downhole pipeline. When working, the gas-containing liquid flows from the first liquid inlet 201 through the return gas cyclone flow channel 4, and the mixed liquid is centrifugally accelerated through the spiral flow channel. Due to the density difference between gas and liquid and the pressure difference in the cyclone cavity, most of the gas phase is distributed in the middle, and the liquid is distributed on both sides. The liquid gradually changes from small droplets through the upper liquid gathering cone tube 6 to large droplets accompanied by part of the gas flowing into the second liquid inlet 901, and part of the gas phase and a small amount of liquid are located in the return gas conical cavity 401 through the return gas infusion port 701. The gas flows into the upper oil pipe coupling 1 through the port 501 along the middle pipeline, and the liquid converges with the unseparated gas-liquid mixture through the lower end pipeline of the return gas infusion cone tube 7 and flows into the second liquid inlet 901, completing the first stage of gas-liquid separation. The liquid entering from the second liquid inlet 901 carries a small amount of gas phase and flows downward along the internal structure to perform the second stage of gas-liquid separation. The gas-liquid mixture flows through the secondary spiral flow channel 11. After being centrifugally accelerated through the spiral flow channel, the liquid The phases are distributed on both sides, and the gas is distributed in the middle. Most of the liquid flows through the channel between the middle connecting outer tube 10 and each liquid-permeable conical tube. Part of the liquid flows to the lower level from the liquid-passing port on the liquid-permeable conical tube, and part of the gas flows into the upper oil pipe coupling 1 through the return port 1201 along the middle pipeline. The degassed gas-liquid mixture enters the lower connecting outer tube 19 from the fan-shaped port 1801 for the third-level gas-liquid separation. After flowing out from the lower spiral flow channel 20, it can obtain the speed and centrifugal force to complete the cyclone separation. Based on different centrifugal forces, the gas phase is located in the center close to the return port 2001, and flows into the upper oil pipe coupling 1 together with the secondary and primary gas phases along the upper gas pipe 3 through the lower spiral flow channel 20. The liquid phase is distributed on both sides and flows along the lower liquid-collecting conical tube 21. As the pipe diameter continues to decrease, it flows into the lower end pipeline 2101 to achieve the effect of liquid-collecting deposition. The deposited liquid passes through the inverted cone 25 to complete the third-level gas-liquid separation. Finally, the liquid is pumped back to the lower oil pipe coupling 27 by the centrifugal pump 24 and discharged into the underground. The appearance and cross-sectional view of the degassing separation structure are as follows: Figure 2As shown, the gas-containing liquid flows from the first liquid inlet 201 through the return gas cyclone flow channel 4, and the mixed liquid is centrifugally accelerated by the spiral flow channel. Due to the density difference between gas and liquid and the pressure difference in the cyclone cavity, most of the gas phase is distributed on both sides, and the gas is distributed in the middle. The liquid gradually changes from small droplets through the upper liquid collecting conical tube 6 to large droplets accompanied by part of the gas flowing into the next stage. Part of the gas phase and a small amount of liquid are located in the return gas conical cavity 401 through the return gas infusion port 701. The gas flows into the upper oil pipe coupling 1 along the middle pipeline through the port 501, and the liquid converges with the unseparated gas-liquid mixture through the lower end pipeline of the return gas infusion conical tube 7 and flows into the second liquid inlet Port 901, the gas-liquid mixture flows through the secondary spiral flow channel 11. After centrifugal acceleration through the spiral flow channel, due to the density difference between gas and liquid and the pressure difference in the cyclone chamber, the liquid phase is distributed on both sides and the gas phase is distributed in the middle. Most of the liquid flows to the fan-shaped port 1801 through the channel between the middle connecting outer tube 10 and each permeable conical tube. Part of the liquid flows from the liquid-through port on the permeable conical tube to the lower level, and part of the gas flows into the upper oil pipe coupling 1 along the middle pipeline through the return port 1201. The upper end diameter of the permeable conical tube is set according to the actual liquid flow rate, and a certain channel is maintained between the middle connecting outer tube 10 to ensure that the liquid can flow into the next level. The degassing structure explosion diagram is shown in Figure 3 The front and side views of the secondary gas-liquid separation module are shown in Figure 4 As shown in (a) and (b), the liquid-permeable conical tube is connected to the inner gas-liquid separation porous tube 12 through a threaded structure. Five layers of liquid-permeable conical tubes are set to better block the gas phase. Part of the liquid phase can smoothly flow into the 1801 fan-shaped port through the liquid port to enter the next stage. The overall device performs secondary separation of the gas phase and the liquid phase. The cross-sectional view of the return gas spiral flow channel is shown in FIG. Figure 5 The gas-liquid mixture is centrifugally accelerated through the return gas spiral flow channel 4. Due to the density difference between gas and liquid and the pressure difference in the cyclone cavity, the liquid gathers on both sides and the gas is distributed in the middle. Part of the gas will flow into the return gas conical cavity 401 through the return gas infusion port 701 set in the return gas infusion conical tube 7, and then flow into the upper oil pipe coupling 1 along the middle pipeline. The appearance and cross-sectional view of the sedimentation reinjection structure are shown in FIG. Figure 6As shown, the gas-liquid mixture after secondary degassing enters the lower connecting outer tube 19 from the fan-shaped port 1801 for the third-stage gas-liquid separation. After flowing out from the lower spiral flow channel 20, it can obtain the speed and centrifugal force to complete the cyclone separation. Based on different centrifugal forces, the gas phase is located in the center close to the return port 2001, and flows into the oil pipe coupling 1 along the upper air pipe 3 through the lower spiral flow channel 20 together with the gases separated from the second and first stages, completing the third-stage gas-liquid separation. Then, all the liquid phases flow along the lower liquid-collecting conical tube 21. As the pipe diameter continues to decrease, all the liquid phases are deposited in this pipe through the extension and elongation of the lower end pipe 2101, achieving the effect of liquid collection and deposition. A section of pipe is set at the lower end of the cylinder of the lower liquid-collecting conical tube 21, which passes through the pipe port 2301 and is connected to the inverted cone 25, so as to better inject the liquid back into the pump. The deposited liquid passes through the inverted cone 25 and is completely pumped back by the centrifugal pump 24 into the lower oil pipe coupling 27. The exploded diagram of the deposition reinjection structure is shown in FIG. Figure 7 shown. Figure 8 This is an appearance diagram of the liquid gathering deposition structure. The device composed of the lower liquid gathering conical tube 21 and the inverted cone 25 performs the final liquid phase reinjection. After three levels of gas-liquid separation, a large amount of liquid phase passes through the lower liquid gathering conical tube 21 and gathers the liquid phase from small droplets into large droplets again by changing the diameter. The liquid phase is extended and stretched through the lower end pipe 2101 to deposit a large amount of liquid phase to achieve the effect of liquid gathering deposition. The liquid phase flows to the inverted cone 25 through the pipeline. As the diameter of the inverted cone 25 gradually increases, the liquid phase flows into the centrifugal pump 24, thereby realizing the overall liquid phase deposition and reinjection process. Fig. 9 This is a cross-sectional view of the first-stage gas-liquid separation module. Fig.10 This is a cross-sectional view of the second-stage gas-liquid separation module. Fig.11 This is a cross-sectional view of the third-stage gas-liquid phase separation reinjection module.

[0042] This device has a simple overall structure and can achieve efficient separation of gas-liquid two-phase media in a small space underground. It has a wide range of applications. This device utilizes a combination of cyclone technology and liquid sedimentation and reinjection to achieve efficient separation of gas-liquid media. It rationally handles the separated media through innovative structural layout and has extremely high applicability. It greatly improves the recovery rate of the oil field, enhances the economy of the production system, and reduces the operating pressure of subsequent separation equipment.

Claims

1. A multi-stage gas volume adaptive cyclone separation device for a gas well, characterized in that: The multi-stage gas volume adaptive cyclone separation device for a gas production well comprises a degassing structure and a sedimentation reinjection structure. The degassing structure comprises a primary gas-liquid separation module. The primary gas-liquid separation module comprises a gas-liquid inlet outer tube, an upper gas pipe, a return gas spiral flow channel, a vent pipe, an upper liquid collecting conical tube, and a return gas infusion conical tube. The return gas spiral flow channel is arranged inside the gas-liquid inlet outer tube. The upper part of the return gas spiral flow channel is an upper gas guide tube. A return gas conical cavity is arranged inside the return gas spiral flow channel. The upper gas guide tube is communicated with the return gas conical cavity. The lower end of the return gas conical cavity is connected to the return gas infusion conical tube. The upper gas pipe passes through the return gas infusion conical tube and passes out from the upper gas guide tube. The vent pipe is sleeved on the upper gas pipe. In addition, the annulus between the air permeable pipe and the upper air pipe and the annulus between the upper air guide pipe and the upper air pipe constitute an upper air channel, and the air permeable pipe is provided with multiple air inlets at the position of the return air conical cavity; the upper liquid collecting conical pipe is arranged at the lower end of the return air spiral flow channel and surrounds the return air infusion conical pipe, and multiple return air infusion ports are arranged at the upper cone position of the return air infusion conical pipe; the sedimentation reinjection structure includes a lower spiral flow channel, a lower liquid collecting conical pipe, an inverted cone, and a centrifugal pump. The lower spiral flow channel is connected to the upper air pipe through its return air channel, the upper port of the lower liquid collecting conical pipe is connected to the bottom of the lower spiral flow channel, the lower port of the lower liquid collecting conical pipe is connected to the inverted cone, the inverted cone is connected to the centrifugal pump, and the centrifugal pump is connected to the lower oil pipe coupling.

2. The multi-stage gas volume adaptive cyclone separation device for underground gas production wells according to claim 1, characterized in that: The degassing structure also includes a secondary gas-liquid separation module, which is arranged between the primary gas-liquid separation module and the deposition reinjection structure. The secondary gas-liquid separation module includes an intermediate connecting outer tube, a secondary spiral flow channel, an inner gas-liquid separation porous tube, and a plurality of liquid-permeable conical tubes. The lower port of the secondary spiral flow channel is threadedly connected to the inner gas-liquid separation porous tube, and the upper gas pipe passes through the secondary spiral flow channel and the inner gas-liquid separation porous tube to form an upper gas channel with the annulus therebetween. A plurality of liquid-permeable conical tubes are installed in series outside the inner gas-liquid separation porous tube, and a plurality of return gas ports are arranged on the inner gas-liquid separation porous tube, each return gas port corresponds to a liquid-permeable conical tube, and each liquid-permeable conical tube is arranged with a plurality of liquid through ports, and the through ports are communicated with the inner cavity of the intermediate connecting outer tube.

3. The multi-stage gas volume adaptive cyclone separation device for gas production wells according to claim 2, characterized in that: The gas-liquid inlet outer tube is a cylinder with a top, a center hole is provided on the top of the cylinder, a first liquid inlet is also provided on the upper part of the gas-liquid inlet outer tube, the upper end of the gas-liquid inlet outer tube is threadedly connected to the oil pipe coupling, the lower end of the gas-liquid inlet outer tube is threadedly connected to the connecting tube provided outside the upper port of the upper liquid collecting tapered tube, the lower end of the connecting tube is threadedly connected to the upper connecting outer tube, and the lower end of the upper connecting outer tube is threadedly connected to the upper connecting device; the upper end of the upper air pipe is located in the center hole of the gas-liquid inlet outer tube, the lower end of the center hole of the gas-liquid inlet outer tube is threadedly connected to the upper air guide pipe of the return air spiral flow channel, the upper end of the return air conical cavity of the return air spiral flow channel is threadedly connected to the upper end of the air permeable tube, and the lower end of the return air conical cavity is threadedly connected to the upper port of the return air infusion tapered tube.

4. The multi-stage gas volume adaptive cyclone separation device for underground gas production wells according to claim 3, characterized in that: The upper end of the middle connecting outer tube is threadedly connected to the upper connecting device, the lower end of the air permeable tube is threadedly connected to the upper end of the return air channel of the secondary spiral flow channel, the lower end of the return air channel of the secondary spiral flow channel is threadedly connected to the upper end of the inner gas-liquid separation porous tube, and 5 identical liquid-permeable conical tubes are all threadedly connected to the inner gas-liquid separation porous tube; the upper connecting device is provided with a second liquid inlet, and the upper liquid collecting conical tube is communicated with the middle connecting outer tube through the second liquid inlet.

5. The multi-stage gas volume adaptive cyclone separation device for underground gas production wells according to claim 4, characterized in that: The lower spiral flow channel is arranged in the lower connecting outer tube, the upper end of the lower connecting outer tube is threadedly connected to the lower connecting device, the upper end of the lower connecting device is threadedly connected to the middle connecting outer tube, the lower connecting device is provided with a central threaded hole and a fan-shaped opening, and the lower connecting device is respectively connected to the upper air pipe and the return air channel of the lower spiral flow channel through the central threaded hole; a connecting tube is arranged outside the upper port of the lower collecting conical tube, and threaded structures are arranged at both ends of the connecting tube, the upper end of the connecting tube is threadedly connected to the lower connecting outer tube, and the lower end of the connecting tube is threadedly connected to the pump connecting tube; the lower end of the pump connecting tube is connected to the pump The pipe connecting device is connected by threads; the lower end of the pump-pipe connecting device is threadedly connected to the centrifugal pump; the upper end of the inverted cone is threadedly connected to the lower port of the lower liquid-collecting cone pipe, the lower end of the inverted cone is threadedly connected to the upper end of the centrifugal pump, and the inverted cone is used to lift and reinject liquid phase; the lower end of the centrifugal pump is threadedly connected to the upper end of the oil pipe coupling connecting device; the lower end of the oil pipe coupling connecting device is threadedly connected to the upper end of the lower oil pipe coupling; the third-stage gas-liquid mixture is separated by the sedimentation reinjection structure, and the separated liquid phase is discharged into the lower oil pipe coupling through the centrifugal pump to complete the three-stage gas-liquid separation.

6. The multi-stage gas volume adaptive cyclone separation device for underground gas production wells according to claim 5, characterized in that: The lower part of the lower liquid collecting conical pipe is a circular pipe section, which passes through the pipe opening of the pump pipe connecting device and is connected to the inverted cone. This structure plays a role in liquid collection and deposition, and better discharges the gas back to the return air channel of the spiral flow channel and flows back to the ground.

7. The multi-stage gas volume adaptive cyclone separation device for underground gas production wells according to claim 6, characterized in that: The lower liquid gathering conical tube and the inverted cone constitute a liquid gathering deposition structure, and the final liquid phase deposition and reinjection are carried out in the liquid gathering deposition structure. After three-level gas-liquid separation, when a large amount of liquid phase passes through the lower liquid gathering conical tube, the small liquid phase droplets are gathered into large droplets again, and then the liquid phase is gathered into the lower circular tube section of the lower liquid gathering conical tube by changing the diameter. The effect of liquid gathering and deposition is achieved by extending and lengthening the lower circular tube section of the lower liquid gathering conical tube. The liquid phase flows to the inverted cone to realize the overall reinjection process and flows into the centrifugal pump.

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