Gas well underground jet flow enhanced multi-stage gas-liquid efficient separation device

Abstract

The invention relates to a gas well downhole jet enhanced multistage gas-liquid efficient separation device, which comprises a gas-liquid separation structure and a gas-liquid diversion structure, the gas-liquid separation structure comprises a lower outer pipe and an inner pipe, the lower outer pipe and the inner pipe are coaxially arranged, the upper end of the lower outer pipe and the lower end of the inner pipe are both provided with a liquid inlet, and the lower end of the inner pipe is provided with a liquid outlet. A first-stage spiral flow channel, a drainage inverted cone, a second-stage spiral flow channel and a drainage taper pipe are arranged in the inner pipe; the gas-liquid flow dividing structure comprises an upper outer pipe, a pump outer pipe, a fixing ring, a bypass flow channel and a bridge type channel, the upper outer pipe and the pump outer pipe are coaxially arranged, the upper end of the bridge type channel is connected with the upper outer pipe, the bypass flow channel is arranged below the bridge type channel and extends into an inner sleeve of the fixing ring, and an annular space between the bypass flow channel and the inner sleeve of the fixing ring is a flow guide cavity and is gradually shrunk. And the flow guide cavity is an annular gap between the bypass flow channel and the upper port of the fixed ring inner sleeve. Separated gas and liquid are separately discharged, a gas phase is ejected and discharged under the action of underground pressure, a liquid phase is pumped out, and the gas phase is not in contact with a pump body.

Description

Technical Field

[0001] The present invention relates to a separation device used in the field of high-pressure underground gas-liquid separation, and specifically to a device capable of realizing efficient separation of oil and gas two-phase media in a narrow underground space, and a jet-enhanced multi-stage gas-liquid efficient separation device for gas wells. Background Art

[0002] With the continuous development of gas well mining technology in my country, underground gas-liquid separation is a key link in mining and processing. However, the increase in water content increases the difficulty of gas well drainage and gas production. It is necessary to strengthen the drainage efforts to achieve production goals and increase production. This requires more technology and equipment investment, which increases production costs.

[0003] In order to solve the problem of low gas-liquid separation efficiency in gas wells and difficulty in sufficient separation underground, technicians have proposed some solutions. As shown in Patent Document 1, CN201510683020.8, it uses blades on the spiral rod to separate gas and liquid, so that the gas-liquid mixture flows to the separation joint through the spiral rod inside the cylinder, thereby realizing gas-liquid separation. However, under this solution, a small amount of liquid droplets are still carried in the separated gas phase, and gas-liquid separation can only be performed once, and gas-liquid separation cannot be performed again on the separated gas phase. Therefore, the gas-liquid separation efficiency is not high.

[0004] As shown in Patent Document 2, CN201621062438.3, the gas separated from the gas-liquid separation no longer contacts the produced mixed liquid, but a small amount of gas still enters the oil pump, which will affect the working efficiency of the oil pump and cause damage to the oil pump over a long period of time. Summary of the invention

[0005] The purpose of the present invention is to provide a downhole jet-enhanced multi-stage gas-liquid high-efficiency separation device for a gas well. This downhole jet-enhanced multi-stage gas-liquid high-efficiency separation device for a gas well is used to solve the problem of low separation efficiency of gas-liquid separation devices in the prior art, or the problem that a small amount of gas still enters the oil pump after gas-liquid separation, affecting the working efficiency of the oil pump.

[0006] The technical solution adopted by the present invention to solve its technical problems is: this downhole jet-enhanced multi-stage gas-liquid high-efficiency separation device for gas wells includes a gas-liquid separation structure and a gas-liquid diversion structure. The gas-liquid separation structure is arranged below the gas-liquid diversion structure. The gas-liquid separation structure includes a lower outer tube and an inner tube. The lower outer tube and the inner tube are coaxially arranged. The upper end of the lower outer tube and the lower end of the inner tube are both provided with liquid inlets. A primary spiral flow channel and a secondary spiral flow channel are arranged in the inner tube. The upper end of the primary spiral flow channel is connected to a drainage inverted cone, and the upper end of the secondary spiral flow channel is connected to a drainage cone tube; the gas-liquid diversion structure includes an upper outer tube, a pump outer tube, a fixed ring, a bypass flow channel, and a bridge channel. The upper outer tube and the pump outer tube are coaxially arranged. The fixed ring is threadedly connected to the upper end of the lower outer tube. The middle part of the fixed ring is provided with an annular groove to form an inner and outer two-layer cylinder, the inner layer is an inner sleeve, the upper part of the fixed ring is a single-layer cylinder with only an outer wall, the upper end of the outer wall of the fixed ring is connected to the bridge channel, the upper end of the bridge channel is connected to the upper outer tube, a screw pump is arranged in the outer tube of the pump, the bypass flow channel is a tapered tube, a plurality of bypass flow channel openings are arranged at the lower part of the tapered tube, the bypass flow channel is arranged under the bridge channel and extends into the inner sleeve of the fixed ring, the annular space between the bypass flow channel and the inner sleeve of the fixed ring is a guide cavity, the guide cavity is gradually contracted, and the guide cavity is on the upper side of the bypass flow channel and the inner sleeve of the fixed ring. There is an annular gap between the ports; the mixed liquid containing gas and liquid phases first enters the gas-liquid separation structure for secondary gas-liquid separation, and the separated gas phase runs upward in the bypass flow channel, enters the annular gas channel between the upper outer tube and the pump outer tube through the bridge channel and flows out, and the liquid phase mixed with a small amount of gas phase runs upward along the guide cavity under the action of the pressure difference provided by the screw pump, and the gas phase mixed in the liquid phase gathers into the bypass flow channel from the opening below the bypass flow channel, and the liquid phase separated again is ejected from the annular gap and flows out of the pump outer tube through the bridge channel under the suction of the screw pump.

[0007] In the above scheme, the bridge channel is a cylinder with a partition inside, and the partition divides the cylinder into an air chamber and an oil chamber. The air chamber is connected to the bypass flow channel through a channel connection, and the air chamber is connected to the upper annular opening of the bridge channel arranged in the oil chamber wall through the openings on both sides of the center of the bridge channel, and the upper annular opening of the bridge channel is connected to the annular air channel; the air chamber wall is provided with a lower annular opening of the bridge channel, and the lower annular opening of the bridge channel is connected to the oil chamber, and the top of the oil chamber is provided with a central opening at the upper end of the bridge channel, and the oil chamber is connected to the lead-out pipe through the central opening at the upper end of the bridge channel, and the oil chamber is threadedly connected to the tube pump connection through the central opening at the upper end of the bridge channel, and the tube pump connection is threadedly connected to the screw pump; the outer wall diameter of the middle part of the bridge channel is equal to the diameter of the outer wall of the fixed ring, the outer wall of the top of the oil chamber of the bridge channel has an external thread, and the air chamber wall of the bridge channel is provided with an external thread.

[0008] In the above scheme, the lower end of the inner tube and the lower end of the lower outer tube are respectively threadedly connected to the inner and outer tube connection, and the lower ends of the inner and outer tube connection are threadedly connected to the oil pipe coupling; the lower end of the first-level spiral flow channel is threadedly connected to the upper end opening of the inner and outer tube connection, and the upper end of the first-level spiral flow channel is threadedly connected to the lower end of the drainage inverted cone.

[0009] In the above scheme, the upper end of the inner tube is threadedly connected to the spiral link, the upper end of the spiral link is threadedly connected to the secondary spiral flow channel, and the upper end of the secondary spiral flow channel is threadedly connected to the drainage cone tube.

[0010] In the above scheme, the inner wall diameter of the lower end of the fixing ring is equal to the inner wall diameter of the inner tube, the lower end of the fixing ring has an external thread, the upper end of the lower outer tube has an internal thread, the fixing ring and the outer tube are connected by threads, and the lower port of the fixing ring closes the annular space between the lower outer tube and the inner tube.

[0011] In the above scheme, the bypass channel openings at the lower part of the bypass channel are evenly distributed in a ring shape and are divided into 5 layers from top to bottom; the upper end of the bypass channel is connected to the lower end of the channel connection through a thread; the upper end of the channel connection is connected to the lower end of the bridge channel through a thread.

[0012] In the above scheme, the lower end of the upper outer tube is connected to the bridge channel through a thread, and the lower end of the pump outer tube is connected to the inner wall of the bridge channel outlet tube wall through a thread.

[0013] The present invention has the following beneficial effects: 1. After the gas-containing mixed liquid is subjected to primary cyclone separation, the gas phase containing a small amount of liquid enters the secondary separation through the drainage inverted cone, thereby realizing secondary gas filtration treatment. The secondary gas-liquid separation and the cyclone separation do not interfere with each other. It has the characteristics of high separation efficiency and rapid separation, and can adapt to the fast flow rate inside the cyclone.

[0014] 2. The present invention innovatively proposes a screw pump gas well exploitation process technology, which realizes efficient separation of gas-liquid two-phase media by adding a high-precision gas-liquid cyclone separator to a conventional screw pump, greatly reduces the occurrence of water-flooded well problems, enhances the adaptability of screw pump equipment in gas wells, and realizes the combined use of separation, diversion and pump body.

[0015] 3. The diversion structure proposed in the present invention utilizes its special structure to discharge the separated gas and liquid separately, so that the gas phase is ejected and discharged under the action of downhole pressure, and the liquid phase is pumped out under the action of the pressure difference provided by the screw pump. While ensuring the gas-liquid separation efficiency, the gas phase does not contact the pump body, which can also increase the service life of the pump and enhance the overall compatibility of the device.

[0016] 4. The separation structure proposed in the present invention can be connected to the narrow space of the wellbore, realizing efficient separation and achieving the purpose of collecting the liquid phase and discharging the gas phase. The two-stage cyclone device involved is arranged inside a very small space, which not only improves the gas-liquid separation efficiency, but also enhances the practicability of the equipment. It is an integrated downhole two-phase efficient separation device that combines aggregation and cyclone technology, which can realize efficient separation of gas-liquid two-phase media in a limited space and improve the economy of gas well exploitation.

[0017] 5. The internal structure of the bridge channel of the present invention separates the gas-liquid two-phase flow, so that the gas phase does not contact the pump body, and the gas-liquid two-phase is pumped out by the pressure difference.

[0018] 6. The present invention utilizes the spiral flow channel structure in the separation chamber to separate gas and liquid. At the same time, the arrangement of the two-stage spiral flow channel can realize gas-liquid re-separation and achieve secondary separation. In addition, a small aperture opening is provided at the top of the drainage cone tube at the upper end of the perforated spiral flow channel, and the gas phase flow diameter becomes smaller. While the flow rate increases, a small part of the gas phase outside the drainage cone tube can be further gathered to achieve jet discharge of the gas phase, thereby improving the separation efficiency. At the same time, the gas phase extracted by the pressure difference of the screw pump does not contact the pump body, which can extend the service life of the pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 (a) is an 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 diagram of the gas-liquid separation structure; Figure 2 (b) is a cross-sectional view of the gas-liquid separation structure.

[0021] Figure 3 This is an exploded diagram of the gas-liquid separation structure.

[0022] Figure 4 (a) is the appearance diagram of the gas-liquid diversion structure; Figure 4 (b) is a cross-sectional view of the gas-liquid diversion structure.

[0023] Figure 5 This is an exploded diagram of the gas-liquid diversion structure.

[0024] Figure 6 (a) is the appearance of the bridge channel; Figure 6 (b) is a top view of the bridge channel; Figure 6 (c) is a front cross-sectional view of the bridge channel; Figure 6 (d) is the right side cross-sectional view of the bridge channel.

[0025] In the figure: 101-oil pipe coupling, 102-lower outer pipe, 1021-outer pipe liquid inlet, 103-inner and outer pipe connection, 104-inner pipe, 1041-inner pipe liquid inlet, 105-first-stage spiral flow channel, 1051-first-stage spiral flow channel separation chamber, 106-drainage inverted cone, 107-spiral link, 108-secondary spiral flow channel, 1081-secondary spiral flow channel separation chamber, 109-drainage cone pipe, 1091-drainage cone pipe Opening, 201-fixing ring, 202-bridge channel, 2021-annular opening at the bottom of the bridge channel, 2022-openings on both sides of the center of the bridge channel, 2023-annular opening at the upper end of the bridge channel, 2024-center opening at the upper end of the bridge channel, 203-bypass flow channel, 2031-bypass flow channel opening, 204-channel connection, 205-upper outer tube, 206-tube pump connection, 207-screw pump, 208-pump outer tube. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings: This downhole jet-enhanced multi-stage gas-liquid high-efficiency separation device for a gas well includes a gas-liquid separation structure with an oil pipe coupling 101 and a gas-liquid diversion structure with a screw pump 207, so that the gas-containing mixed liquid can achieve gas-liquid two-phase medium separation 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, indirectly improves the gas well recovery rate, and reduces the energy consumption of the subsequent separation system.

[0027] The gas-liquid separation structure includes an inner and outer tube connection 103, a lower outer tube 102, an inner tube 104, a primary spiral flow channel 105, a primary spiral flow channel separation chamber 1051, a drainage inverted cone 106, a spiral link 107, a secondary spiral flow channel 108, a drainage cone tube 109, a drainage cone tube opening 1091 and a secondary spiral flow channel separation chamber 1081; the spiral flow channel and the drainage cone tube 109 are both hollow structures; liquid inlets are provided on the inner tube 104 and the lower outer tube 102. The outer tube liquid inlet 1021 is provided at the upper end of the lower outer tube 102 to enable the liquid phase to fully gather from top to bottom in the inner and outer tube cavities, thereby facilitating the next step of separation. The upper end of the tubing coupling 101 is connected to the lower end of the inner-outer tube connection 103 by means of threads; the inner tube 104 and the lower outer tube 102 are connected to the upper end of the inner-outer tube connection 103 by means of a threaded structure; the lower end of the hollow primary spiral flow channel 105 is connected to the upper opening of the inner-outer tube connection 103 by means of threads; the upper end of the hollow primary spiral flow channel 105 is connected to the lower end of the drainage inverted cone 106 by means of threads; the lower end of the spiral link 107 is connected to the upper end of the inner tube 104 by means of a threaded structure; the upper end of the spiral link 107 is provided with a threaded structure and connected to the secondary spiral flow channel 108; the upper end of the secondary spiral flow channel 108 is connected to the lower end of the drainage cone tube 109 by means of threads.

[0028] During operation, a mixture containing gas and liquid phases enters the inner and outer tube cavities from the outer tube liquid inlet 1021 around the upper end of the lower outer tube 102, and then the gas-liquid mixture enters the gas-liquid separation part through the inner tube liquid inlet 1041 around the lower end of the inner tube 104. After the mixture is centrifugally accelerated by the hollow primary spiral flow channel 105, the gas phase is distributed on the outer wall of the drainage inverted cone 106, and the liquid phase carries part of the unseparated gas phase in the outer layer close to the inner wall of the primary spiral flow channel separation cavity 1051. Then, the liquid phase further gathers along the inner wall of the spiral link 107 and flows to the secondary spiral flow channel 108. The gas phase flows along the central opening of the spiral link 107 to the secondary spiral flow channel 108, and continues to flow from the The center of the secondary spiral flow channel 108 flows toward the drainage cone opening 1091, which reduces the gas flow diameter. The flow rate increases and a small amount of gas on the periphery of the drainage cone can be further gathered to realize the jet discharge of the gas to the next stage. The gas-liquid two phases separated by the spiral link 107 are further accelerated and separated by the secondary spiral flow channel 108, so that the gas phase is located inside the secondary spiral flow channel separation chamber 1081, and further flows to the outer wall of the drainage cone 109, and further converges with the gas phase discharged from the drainage cone opening 1091, while the liquid phase flows to the next stage along the inner wall of the secondary spiral flow channel separation chamber 1081 on the outside of the secondary spiral flow channel 108, further completing the gas-liquid separation. More specifically, the gas-liquid separation 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 inner and outer tube connection 103, a lower outer tube 102, an inner tube 104, a first-level spiral flow channel separation chamber 1051, a first-level spiral flow channel 105, and a drainage inverted cone 106; wherein the first-level spiral flow channel 105 adopts a hollow structure, and liquid inlets 1021 are distributed around the upper end of the lower outer tube 102, and liquid inlets 1041 are distributed around the lower end of the inner tube 104 to achieve staggered distribution. The threaded structure at the upper end of the inner and outer tube connection 103 is connected to the lower outer tube 102 and the inner tube 104. A threaded hole is opened in the center of the upper end of the inner and outer tube connection 103 and is threadedly connected to the lower end of the primary spiral flow channel 105. The threaded structure at the lower end of the drainage inverted cone 106 is connected to the threaded hole at the upper end of the primary spiral flow channel 105. The mixed liquid entering from the outer tube liquid inlet 1021 flows into the cyclone primary spiral flow channel separation cavity 1051 from the inner and outer tube cavities and the inner tube liquid inlet 1041. After the mixed liquid is accelerated and separated through the primary spiral flow channel 105, the centrifugal force exerted on the gas phase is less than that on the liquid phase. The gas phase carries a small amount of liquid phase and resides in the drainage inverted cone 106 to flow to the next level. Most of the liquid phase gathers on the inner wall of the inner tube 104 and flows to the next level, completing the primary separation.

[0029] The secondary gas-liquid separation module includes a spiral link 107, a secondary spiral flow channel 108, a drainage cone tube 109, a drainage cone tube opening 1091, and a secondary spiral flow channel separation chamber 1081. The lower end of the spiral link 107 is connected to the upper end of the inner tube 104 by threads, and a threaded hole is opened in the center of the upper end of the spiral link 107 and is connected to the lower end of the secondary spiral flow channel 108 by threads; the wall thickness of the spiral link 107 is the same as that of the inner tube 104; the center of the upper end of the secondary spiral flow channel 108 is connected to the lower end of the drainage cone tube 109 by threads, and the drainage cone tube 109 is a hollow structure; the liquid phase further gathers along the inner wall of the spiral link 107 and flows to the secondary spiral flow channel 108, and the gas phase flows along the central opening of the spiral link 107 to the secondary spiral flow channel 108, and continues to flow from the center of the secondary spiral flow channel 108 to the drainage cone tube opening 1091, and the drainage cone tube 109 is a hollow structure. The opening 1091 of the flow cone tube has a small diameter, which makes the gas flow diameter smaller. While the flow rate increases, a small part of the gas phase outside the drainage cone tube can be further gathered to realize the jet discharge of the gas phase to the next stage. The gas-liquid two phases separated by the spiral link 107 are further accelerated by the secondary spiral flow channel 108 to separate the gas phase inside the secondary spiral flow channel separation chamber 1081, and further flow to the outer wall of the drainage cone tube 109, and further converge with the gas phase discharged from the opening 1091 of the drainage cone tube, while the liquid phase flows to the next stage along the inner wall of the secondary spiral flow channel separation chamber 1081 outside the secondary spiral flow channel 108, and further completes the gas-liquid separation. The gas-liquid flow splitting module of the present invention comprises a fixed ring 201, a bypass flow channel 203, a bridge channel 202, a channel connection 204, a deep well screw pump 207, an upper outer tube 205, a pump outer tube 208, and a tube pump connection 206; the inner wall of the fixed ring 201 is consistent with the inner wall thickness of the inner tube 104, and the outer wall thereof is consistent with the outer wall thickness of the outer tube 102; the upper end of the fixed ring 201 is provided with an outlet pipe of a certain thickness; the bypass flow channel 203 is a conical tube wall, and there are evenly distributed openings in the annular position below it; the middle part of the bridge channel 202 is connected to the fixed ring 20 1 The thickness of the outer wall is consistent; the upper and lower ends of the bridge channel 202 are threaded, and there is a lead-out pipe at its upper end; the lower end of the fixing ring 201 is connected to the inner side of the upper end of the outer tube 102 by thread; the upper end of the bypass flow channel 203 is connected to the lower end of the channel connection 204 by thread; the lower end of the channel connection 204 is connected to the central opening of the bridge channel 202 by thread; the lower end of the upper outer tube 205 is connected to the upper end of the bridge channel 202 by thread; the lower end of the tube pump connection 206 is connected to the upper opening of the bridge channel 202 by thread, and the upper end of the tube pump connection 206 is connected to the upper opening of the bridge channel 202 by thread. It is connected to the lower end of the screw pump 207 by a thread; the lower end of the pump outer tube 208 is connected to the inner side of the outlet wall of the upper end of the bridge channel 202 by a thread; when working, the gas phase separated once and twice flows along the center of the drainage cone 109 to the central opening of the bypass channel 203, and the liquid phase mixed with a small amount of gas phase separated in the previous stage flows to the next stage along the outer annular cavity of the bypass channel 203 under the action of the pressure difference provided by the screw pump, and the opening 2031 below the bypass channel further gathers the gas phase mixed in the liquid phase and the gas phase flowing down from the central opening of the drainage cone, and then Then they enter together from the lower entrance of the bridge channel 202, which is conducive to gas-liquid separation; the gas phase then flows in from the center of the lower end of the bridge channel 202, flows to the two side channels of the lower end of the bridge channel 202 through the openings on both sides of the center, and the liquid phase flows into the inner center through the annular opening at the lower end of the bridge channel 202 and flows out; the screw pump 207 provides power for the entire device, and draws the liquid phase flowing out from the center of the bridge channel 202 to the pump outer tube 208 and transports it to the surface. The separated gas phase flows out to the next structure through the gap cavity between the upper outer tube 205 and the pump outer tube 208.

[0030] like Figure 1As shown, the present invention is placed vertically in the downhole pipeline to ensure that the oil pipe coupling 101 is located at the bottom, and the various parts are connected upward in sequence according to the corresponding connection methods. During operation, the gas-containing liquid phase enters the inner and outer tube cavities from the outer tube liquid inlet 1021, and the mixed liquid flows from top to bottom in the inner and outer tube cavities, and enters the primary spiral flow channel separation chamber 1051 from the inner tube liquid inlet 1041. After that, it is centrifugally accelerated by the hollow primary spiral flow channel 105, and the drainage inverted cone 106 drains the liquid phase to distribute it on the inner wall of the primary spiral flow channel separation chamber 1051. The gas phase carries a small amount of liquid phase and flows upward at the center of the drainage inverted cone 106. Then, the liquid phase further gathers along the inner wall of the spiral link 107 and flows to the secondary spiral flow channel 108. The gas phase flows along the central opening of the spiral link 107 to the secondary The spiral flow channel 108 continues to flow from the center of the secondary spiral flow channel 108 to the drainage cone opening 1091. The opening 1091 of the drainage cone has a small diameter, which makes the gas flow diameter smaller. While the flow rate is increased, a small part of the gas phase outside the drainage cone can be further gathered to achieve the jet discharge of the gas phase to the next level. The gas-liquid two phases separated by the spiral link 107 are further accelerated by the secondary spiral flow channel 108 to separate the gas phase inside the separation cavity 1081 of the secondary spiral flow channel, and further flow to the outer wall of the drainage cone 109, and further converge with the gas phase discharged from the drainage cone opening 1091, while the liquid phase is discharged from the secondary spiral flow channel 108. The outer side of the primary spiral flow channel 108 flows along the inner wall of the secondary spiral flow channel separation chamber 1081 to the next stage, further completing gas-liquid separation; the gas phase separated once and twice flows along the center of the drainage cone 109 to the central opening of the bypass flow channel 203, and the liquid phase separated in the previous stage and mixed with a small amount of gas phase flows to the next stage along the outer annular cavity of the bypass flow channel 203 under the action of the pressure difference provided by the screw pump, while the opening 2031 below the bypass flow channel further aggregates the gas phase mixed in the liquid phase and the gas phase flowing down from the central opening of the drainage cone, and then enters together from the lower end entrance of the bridge channel 202, which is conducive to gas-liquid separation; Then the gas phase flows in from the center of the bridge channel 202, flows to the openings 2023 on both sides of the center wall of the bridge channel 202 to be discharged, and the liquid phase flows into the lower annular opening 2021 of the bridge channel through the outer ring of the bypass channel 203, converges to the center and is discharged from the upper opening 2024; the screw pump 207 pumps the liquid phase converged in the bridge channel 202 into the cavity of the pump outer tube 208 by the pressure difference, and the gas phase flows into the upper outer tube 205 and the cavity of the pump outer tube 208, and finally the gas and liquid phases are respectively connected to the next part of the device; the appearance and cross-sectional view of the gas-liquid separation structure are shown in Figure 2As shown, during operation, a mixed liquid containing gas and liquid phases enters the inner and outer tube cavities from the outer tube liquid inlet 1021 around the upper end of the lower outer tube 102, and then the gas-liquid mixed liquid enters the gas-liquid separation part from top to bottom through the liquid inlet 1041 around the lower end of the inner tube 104. After the mixed liquid is centrifugally accelerated by the hollow primary spiral flow channel 105, the gas phase is distributed on the outer layer of the drainage inverted cone 106, and the liquid phase carries a small amount of gas phase on the inner wall of the primary spiral flow channel separation cavity 1051. Then, the liquid phase further gathers along the inner wall of the spiral link 107 and flows to the secondary spiral flow channel 108. The gas phase flows along the central opening of the spiral link 107 to the secondary spiral flow channel 108, and continues to flow from the center of the secondary spiral flow channel 108 to the drainage The cone tube opening 1091 and the drainage cone tube opening 1091 have a smaller diameter, which makes the gas flow diameter smaller. While the flow rate increases, a small amount of gas phase can be further gathered on the periphery of the drainage cone tube, so that the gas phase can be discharged to the next stage by jet. The gas-liquid two phases separated by the spiral link 107 are further accelerated and separated by the secondary spiral flow channel 108, so that the gas phase is located on the inner side of the secondary spiral flow channel separation cavity 1081, and further flows to the outer wall of the drainage cone tube 109, and further converges with the gas phase discharged from the drainage cone tube opening 1091, while the liquid phase flows to the next stage along the inner wall of the secondary spiral flow channel separation cavity 1081 on the outside of the secondary spiral flow channel 108, so as to further complete the gas-liquid separation. The gas-liquid separation structure explosion diagram is shown in Figure 3 The appearance and cross-sectional view of the gas-liquid diversion structure are shown in Figure 4 As shown in (a) and (b), the gas phase after the primary and secondary separation flows along the center of the drainage cone 109 to flow into the central opening of the bypass channel 203. The liquid phase mixed with a small amount of gas phase separated in the previous stage flows along the outer annular cavity of the bypass channel 203 to the next stage under the action of the pressure difference provided by the screw pump, and the opening 2031 below the bypass channel makes the gas phase mixed in the liquid phase and the gas phase flowing down from the central opening of the drainage cone further gather, and then enter together from the lower end entrance of the bridge channel 202, which is beneficial to gas-liquid separation; then the gas phase flows from the center of the bridge channel 202 The liquid flows into the bridge channel 202 through the openings 2022 on both sides of the center of the bridge channel and flows to the annular openings 2023 on both sides of the upper end of the bridge channel. The liquid phase flows into the annular opening 2021 at the lower part of the bridge channel through the outer ring of the bypass channel 203, and converges to the center position and is discharged from the central opening 2024 at the upper end of the bridge channel. The screw pump 207 pumps the liquid phase converged in the bridge channel 202 into the cavity of the pump outer tube 208 by the pressure difference, and the gas phase flows into the upper outer tube 205 and the cavity of the pump outer tube 208. Finally, the gas and liquid phases are connected to the next part of the device respectively. The exploded diagram of the gas-liquid diversion structure is shown in Figure 5 The appearance, top view and cross-sectional view of the bridge channel are shown in Figure 6As shown in (a), (b), (c), and (d), the gas phase flows in from the center of the bridge channel 202, flows to the openings 2022 on both sides of the center of the bridge channel, and is discharged from the annular opening 2023 at the upper end of the bridge channel. The liquid phase flows through the outer ring of the bypass channel 203 and flows into the annular opening 2021 at the lower end of the bridge channel 202, converges to the center, and is discharged from the center opening 2024 at the upper end of the bridge channel.

[0031] The overall structure of the present invention is simple, and it can realize efficient separation of gas-liquid two-phase media in a small space underground, and has a wide range of applications. The device utilizes a combination of cyclone technology and coalescence technology to realize efficient separation of two-phase media, and rationally handles the two separated media through innovative structural layout. It has extremely high applicability, greatly improves the recovery rate of gas wells, enhances the economy of the production system, and reduces the operating pressure of subsequent separation equipment.

Claims

1. A downhole jet enhanced multi-stage gas-liquid high-efficiency separation device for a gas well, characterized in that The invention comprises the following steps: the downhole jet-enhanced multi-stage gas-liquid high-efficiency separation device of the gas well comprises a gas-liquid separation structure and a gas-liquid diversion structure, the gas-liquid separation structure is arranged under the gas-liquid diversion structure, the gas-liquid separation structure comprises a lower outer tube and an inner tube, the lower outer tube and the inner tube are coaxially arranged, the upper end of the lower outer tube and the lower end of the inner tube are both provided with liquid inlets, a primary spiral flow channel and a secondary spiral flow channel are arranged in the inner tube, the upper end of the primary spiral flow channel is connected to a drainage inverted cone, and the upper end of the secondary spiral flow channel is connected to a drainage cone tube; the gas-liquid diversion structure comprises an upper outer tube, a pump outer tube, a fixing ring, a bypass flow channel, and a bridge channel, the upper outer tube and the pump outer tube are coaxially arranged, the fixing ring is threadedly connected to the upper end of the lower outer tube, The middle part of the fixed ring is provided with an annular groove to form an inner and outer two-layer cylinder, the inner layer is an inner sleeve, the upper part of the fixed ring is a single-layer cylinder with only an outer wall, the upper end of the outer wall of the fixed ring is connected to the bridge channel, the upper end of the bridge channel is connected to the upper outer tube, a screw pump is arranged in the outer tube of the pump, the bypass flow channel is a tapered tube, a plurality of bypass flow channel openings are arranged at the lower part of the tapered tube, the bypass flow channel is arranged under the bridge channel and extends into the inner sleeve of the fixed ring, the annular space between the bypass flow channel and the inner sleeve of the fixed ring is a guide cavity, the guide cavity is gradually contracted, and the guide cavity is on the upper side of the bypass flow channel and the inner sleeve of the fixed ring. There is an annular gap between the ports; the mixed liquid containing gas and liquid phases first enters the gas-liquid separation structure for secondary gas-liquid separation, and the separated gas phase runs upward in the bypass flow channel, enters the annular gas channel between the upper outer tube and the pump outer tube through the bridge channel and flows out, and the liquid phase mixed with a small amount of gas phase runs upward along the guide cavity under the action of the pressure difference provided by the screw pump, and the gas phase mixed in the liquid phase gathers into the bypass flow channel from the opening below the bypass flow channel, and the liquid phase separated again is ejected from the annular gap and flows out of the pump outer tube through the bridge channel under the suction of the screw pump.

2. The downhole jet-enhanced multi-stage gas-liquid efficient separation device for a gas well according to claim 1 is characterized in that: The bridge channel is a cylinder with a partition inside, and the partition divides the cylinder into an air chamber and an oil chamber. The air chamber is connected to the bypass flow channel through a channel connection, and the air chamber is connected to the upper annular opening of the bridge channel arranged in the oil chamber wall through openings on both sides of the center of the bridge channel, and the upper annular opening of the bridge channel is connected to the annular air channel; the air chamber wall is provided with a lower annular opening of the bridge channel, and the lower annular opening of the bridge channel is connected to the oil chamber, and the top of the oil chamber is provided with a central opening of the bridge channel, and the oil chamber is connected to the lead-out pipe through the central opening of the bridge channel, and the oil chamber is threadedly connected to the tube pump connection through the central opening of the bridge channel, and the tube pump connection is threadedly connected to the screw pump; the outer wall diameter of the middle part of the bridge channel is equal to the diameter of the outer wall of the fixed ring, the outer wall of the top of the oil chamber of the bridge channel has an external thread, and the air chamber wall of the bridge channel is provided with an external thread.

3. The downhole jet-enhanced multi-stage gas-liquid efficient separation device for a gas well according to claim 2 is characterized by: The lower end of the inner tube and the lower end of the lower outer tube are respectively threadedly connected to the inner and outer tube connection lower ends, and the inner and outer tube connection lower ends are threadedly connected to the oil pipe coupling; the lower end of the first-stage spiral flow channel is threadedly connected to the upper end opening of the inner and outer tube connection, and the upper end of the first-stage spiral flow channel is threadedly connected to the lower end of the drainage inverted cone.

4. The downhole jet-enhanced multi-stage gas-liquid efficient separation device for a gas well according to claim 2 is characterized by: The upper end of the inner tube is threadedly connected to the spiral link, the upper end of the spiral link is threadedly connected to the secondary spiral flow channel, and the upper end of the secondary spiral flow channel is threadedly connected to the drainage cone tube.

5. The downhole jet-enhanced multi-stage gas-liquid efficient separation device for a gas well according to claim 4 is characterized in that: The inner wall diameter of the lower end of the fixing ring is equal to the inner wall diameter of the inner tube. The lower end of the fixing ring has an external thread, and the upper end of the lower outer tube has an internal thread. The fixing ring and the outer tube are connected by threads, and the lower port of the fixing ring closes the annular space between the lower outer tube and the inner tube.

6. The downhole jet-enhanced multi-stage gas-liquid efficient separation device for a gas well according to claim 5 is characterized by: The bypass channel openings at the lower part of the bypass channel are evenly distributed in a ring shape and are divided into five layers from top to bottom; the upper end of the bypass channel is connected to the lower end of the channel connection through a thread; the upper end of the channel connection is connected to the lower end of the bridge channel through a thread.

7. The downhole jet-enhanced multi-stage gas-liquid efficient separation device for a gas well according to claim 6, characterized in that: The lower end of the upper outer tube is connected to the bridge channel through threads, and the lower end of the pump outer tube is connected to the inner wall of the pipe wall leading out of the bridge channel through threads.

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