Hydraulic drive underground motor pump assembly for drainage and gas recovery of horizontal well

Abstract

The invention provides a hydraulic drive underground motor pump assembly for drainage and gas recovery of a horizontal well, which comprises a first liquid flow channel between an outer sleeve and an inner sleeve, and a pump cylinder is provided with a second liquid flow channel; a flow guide hole is formed in the end, close to the pump cylinder, of the inner sleeve and communicates with the first liquid flow channel. A plunger cavity is formed in the plunger assembly, one part of the plunger assembly is located in the inner sleeve and slidably connected with the inner sleeve, the other part of the plunger assembly is located in the pump cylinder and slidably connected with the pump cylinder, a compression cavity is formed between the side, close to the pump cylinder, of the part, located in the inner sleeve, of the plunger assembly and the inner sleeve, the flow guide hole communicates with the compression cavity, and the plunger cavity communicates with the inner sleeve. A drainage hole is formed in the side, away from the inner sleeve, of the part, located in the pump cylinder, of the plunger assembly and communicates with the plunger cavity. One end of the second liquid flow channel is communicated with the drainage hole; the guide rod type swash plate valve assembly is connected with the plunger assembly, located in the pump cylinder and used for cutting off or conducting the second liquid flow channel. The hydraulic channel can be effectively opened and closed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of horizontal well exploitation pump in natural gas and coal bed methane drainage gas recovery, and particularly relates to a hydraulic drive downhole motor pump assembly for horizontal well drainage gas recovery. BACKGROUND

[0002] At present, vertical wells are used as a traditional exploitation method in the field of natural gas and coal bed methane resource exploitation and have been applied to oil and gas reservoir development for a long time. The wellhead is perpendicular to the ground or the inclined angle of the inclined well is not greater than 70 degrees, and the well bottom liquid accumulation is naturally gathered to the bottom under the action of gravity, and the natural gas and coal bed methane spontaneously flows upward and is finally discharged from the wellbore. The related drainage gas recovery equipment can be stably deployed along the vertical wellbore and the inclined well, and the gravity is used to assist in realizing efficient discharge of the liquid accumulation, and the overall operation environment is relatively stable. However, compared with the horizontal well, the pressure difference between the two ends of the device is small in the process of drainage gas recovery, and a large amount of gas may exist in the wellbore, and the originally used ball type fixed valve and traveling valve cannot realize normal opening and closing of the hydraulic passage in the process of operation.

[0003] Therefore, there is an urgent need for a hydraulic drive downhole motor pump for horizontal well drainage gas recovery to effectively open and close the hydraulic passage. SUMMARY

[0004] The present application aims to provide a hydraulic drive downhole motor pump assembly for horizontal well drainage gas recovery to solve the problem that the hydraulic passage cannot be normally and effectively opened and closed when the existing hydraulic drive downhole motor pump is used for horizontal well drainage gas recovery.

[0005] To solve the above technical problems, the present application provides a hydraulic drive downhole motor pump assembly for horizontal well drainage gas recovery, which comprises an outer sleeve, an inner sleeve, a plunger assembly, a pump barrel and a guide rod type swash plate valve assembly. The inner sleeve is arranged in the lumen of the outer sleeve, the inner sleeve is connected with the pump barrel, the outer sleeve and the inner sleeve have a first liquid flow passage therebetween, and the pump barrel has a second liquid flow passage. A flow guide hole is formed in the end of the inner sleeve close to the pump barrel, and the flow guide hole is in communication with the first liquid flow passage. The plunger assembly has a plunger cavity inside, a part of the plunger assembly is in sliding connection with the inner sleeve and located in the inner sleeve, and another part of the plunger assembly is in sliding connection with the pump barrel and located in the pump barrel. A compression cavity is formed between the part of the plunger assembly located in the inner sleeve and the inner sleeve close to the side of the pump barrel, the flow guide hole is in communication with the compression cavity, the plunger cavity is in communication with the inner sleeve, and a drainage hole is formed in the side of the part of the plunger assembly located in the pump barrel away from the inner sleeve, and the drainage hole is in communication with the plunger cavity. One end of the second liquid flow passage is in communication with the drainage hole. The guide rod type swash plate valve assembly is connected with the plunger assembly and located in the pump barrel, and is used for cutting off or conducting the second liquid flow passage.

[0006] Optionally, the guide rod type swashplate valve assembly includes a valve core, a fixed valve disc, a fixed valve seat, a floating slide, and a limiting disc; the valve core is disposed inside the pump barrel and connected to the end of the plunger assembly away from the inner sleeve; the valve core has a first boss and a second boss spaced apart along the axial direction of the pump barrel, and the second boss is disposed further away from the inner sleeve than the first boss; the floating slide is disposed inside the pump barrel, slidably connected to the inner wall of the pump barrel, and sleeved on the valve core, located between the first boss and the second boss, forming an annular valve cavity between the floating slide and the valve core; the fixed valve seat is fixedly disposed inside the pump barrel and located on the side of the second boss away from the inner sleeve; the fixed valve disc is slidably sleeved on the valve core and located between the second boss and the fixed valve seat, with the end of the fixed valve disc away from the inner sleeve. The limiting disc is fixedly disposed on the valve core and located between the second protrusion and the fixed valve seat, in conjunction with the fixed valve seat, to limit the movement of the fixed valve disc toward the inner sleeve. When the first protrusion can contact the end face of the floating slide near the inner sleeve, there is a first predetermined distance between the second protrusion and the floating slide. A fluid flow hole is formed between the first protrusion and the end face of the floating slide near the inner sleeve. One end of the annular valve cavity is connected to the second fluid flow channel through the fluid flow hole, and the other end is connected through the gap between the second protrusion and the floating slide. When the second protrusion can contact the end face of the floating slide away from the inner sleeve, there is a second predetermined distance between the first protrusion and the floating slide. The second protrusion and the floating slide cooperate to cut off the second fluid flow channel.

[0007] Optionally, the valve core includes a first valve core and a second valve core arranged along the axial direction of the pump barrel, and the second valve core is disposed at one end further away from the inner sleeve than the first valve core; the second valve core is fixedly connected to the first valve core, the first valve core has a first boss, and the second valve core has a second boss.

[0008] Optionally, the mating surface between the first boss and the floating slide is an inclined surface.

[0009] Optionally, the mating surface between the second boss and the floating slide is an inclined surface.

[0010] Optionally, it also includes a gas-liquid separator, which is connected to the pump cylinder and communicates with the second liquid flow channel, for providing a third liquid flow channel for the accumulated liquid to enter the second liquid flow channel from the gas-liquid separator.

[0011] Optionally, the gas-liquid separator includes an outer separator tube, an inner separator tube, a counterweight rod, and a plug. The outer separator tube has a liquid inlet. The inner separator tube is located inside the outer separator tube and is rotatably connected to the outer separator tube. The inner separator tube communicates with the second liquid flow channel. The inner separator tube includes a first arc plate and a second arc plate, which are connected to form a circular tube. The first arc plate has a liquid inlet. The counterweight rod is connected to the first arc plate and the second arc plate. When the downhole motor pump is located in a horizontal well, the counterweight rod is used to position the first arc plate below the second arc plate. The plug is used to seal the outer separator tube. The liquid inlet, the liquid inlet, and the cavity of the inner separator tube are located on the third liquid flow channel.

[0012] Optionally, the surface area of ​​the first arc plate is smaller than the surface area of ​​the second arc plate.

[0013] Optionally, the liquid inlet of the separator's outer tube is a slotted groove.

[0014] Optionally, the gas-liquid separator is threadedly connected to the pump barrel.

[0015] The present invention provides a hydraulically driven downhole motor pump for horizontal well drainage and gas production, which has the following beneficial effects: First, in order to adapt to the drainage needs of horizontal wells, the ball-type fixed valve and the traveling valve of the traditional oil pump are replaced with a guide rod type swashplate valve assembly, which adopts a forced opening and closing structure to facilitate the normal opening and closing of the pump valve under horizontal conditions.

[0016] Secondly, a dedicated gas-liquid separator for horizontal wells is installed to prevent a large amount of gas from entering the pump. The liquid inlet of the separator's inner tube is kept at the bottom by the weight of the counterweight rod to prevent gas from entering the pump.

[0017] Furthermore, the liquid inlet on the circumference of the separator's outer tube is slitted to increase the suction inlet area and reduce suction resistance.

[0018] Then, to facilitate transportation (avoiding the trouble of transporting over long distances), the pump assembly was designed as two sections, which were manufactured separately for easy transport and assembled into one unit during on-site installation in the well.

[0019] Secondly, the size and stroke of the first and second plungers can be selected according to needs. Different sizes of the first and second plungers can be used for different well types. Larger displacements use larger first and second plungers and larger strokes, while smaller displacements use smaller first and second plungers and smaller strokes. Currently available models are 63 / 32, 70 / 38, 70 / 44, and 83 / 51, with the strokes of the first and second plungers ranging from 2.5 to 4.2 meters.

[0020] Finally, an upper hydraulic buffer chamber and a lower hydraulic buffer chamber are set on the plunger assembly to reduce the impact and vibration when the plunger reaches the upper and lower dead points, and to significantly reduce the anti-surge distance of the pump plunger, ensuring the operating stroke of the plunger and extending the service life of the motor. Attached Figure Description

[0021] Figure 1 This is a structural cross-sectional view of the pump body device of the hydraulically driven downhole motor pump assembly used for horizontal well drainage and gas production in an embodiment of the present invention. Figure 2 This is a structural cross-sectional view of the gas-liquid separator of the hydraulically driven downhole motor pump assembly used for horizontal well drainage and gas production in an embodiment of the present invention. Figure 3 This is a schematic diagram of the liquid flow direction during the upstroke of the guide rod type swashplate valve assembly of the hydraulically driven downhole motor pump assembly used for horizontal well drainage and gas production in an embodiment of the present invention. Figure 4 This is a schematic diagram of the liquid flow direction during the downstroke of the guide rod type swashplate valve assembly of the hydraulically driven downhole motor pump assembly used for horizontal well drainage and gas production in an embodiment of the present invention.

[0022] Explanation of reference numerals in the attached figures: 100 - Outer sleeve; 200 - Inner sleeve; 210 - Flow guide hole; 310 - Upper buffer section; 311 - First buffer orifice; 320 - Lower buffer section; 321 - Second buffer orifice; 330 - First plunger; 340 - Second plunger; 350 - Plunger cavity; 360 - Drainage hole; 370 - Compression chamber; 410 - First pump barrel; 420 - Second pump barrel; 430 - Upper connector; 510-Valve core; 511-First boss; 512-Second boss; 513-First valve core; 514-Second valve core; 520-Fixed valve disc; 530-Fixed valve seat; 540-Floating slide; 541-Slide end plate; 542-Flow hole; 543-Annular valve cavity; 550-Limiting disc; 610 - First fluid flow channel; 620 - Second fluid flow channel; 710 - Double-ended connector; 711 - Upper hydraulic buffer chamber; 720 - Center tube; 730 - Connecting outer tube; 740 - Setting seal connector; 750 - Intermediate joint; 751 - Lower hydraulic buffer chamber; 810 - Separator outer tube; 811 - Liquid inlet; 820 - Separator inner tube; 821 - Liquid inlet; 830 - Counterweight rod; 840 - Plug; 850 - Support ring; 860 - Support joint. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0027] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0028] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] refer to Figure 1 , Figure 2 ,Figure 3 and Figure 4 , Figure 1 This is a structural cross-sectional view of the pump body of the hydraulically driven downhole motor pump assembly used for horizontal well drainage and gas production in an embodiment of the present invention. Figure 2 This is a structural cross-sectional view of the gas-liquid separator in the hydraulically driven downhole motor pump assembly used for horizontal well drainage and gas production in an embodiment of the present invention. Figure 3 This is a schematic diagram of the liquid flow direction during the upstroke of the guide rod type swashplate valve assembly of the hydraulically driven downhole motor pump assembly used for horizontal well drainage and gas production in an embodiment of the present invention. Figure 4 This is a schematic diagram of the liquid flow direction during the downstroke of the guide rod type swashplate valve assembly of a hydraulically driven downhole motor pump assembly for horizontal well drainage and gas production in an embodiment of the present invention. This embodiment provides a hydraulically driven downhole motor pump assembly for horizontal well drainage and gas production, including an outer sleeve 100, an inner sleeve 200, a plunger assembly, a pump barrel, and a guide rod type swashplate valve assembly. The inner sleeve 200 is disposed within the cavity of the outer sleeve 100 and is connected to the pump barrel. A first liquid flow channel 610 is provided between the outer sleeve 100 and the inner sleeve 200, and the pump barrel has a second liquid flow channel 620. A guide hole 210 is provided at the end of the inner sleeve 200 near the pump barrel, and the guide hole 210 communicates with the first liquid flow channel 610. The plunger assembly has a plunger cavity 350 inside. A portion of the plunger assembly is located inside and slidably connected to the inner sleeve 200, and a portion is located inside and slidably connected to the pump barrel. A compression chamber 370 is formed between the plunger assembly located inside the inner sleeve 200 and the inner sleeve 200 on the side near the pump barrel. The guide hole 210 communicates with the compression chamber 370. The plunger cavity 350 communicates with the inner sleeve 200. A drainage hole 360 ​​is provided on the side of the plunger assembly located inside the pump barrel away from the inner sleeve 200, and the drainage hole 360 ​​communicates with the plunger cavity 350. One end of the second liquid flow channel 620 communicates with the drainage hole 360. The guide rod type swashplate valve assembly is connected to the plunger assembly and located inside the pump barrel, used to cut off or open the second liquid flow channel 620.

[0030] By introducing high-pressure fluid into the first fluid flow channel 610, the high-pressure fluid enters the compression chamber 370 through the guide hole 210. This high-pressure fluid drives the plunger assembly within the compression chamber 370 to move away from the pump barrel, i.e., upwards. This creates a negative pressure within the plunger assembly. Under this negative pressure, the guide rod type swashplate valve assembly opens the second fluid flow channel 620. The accumulated fluid then flows through the second fluid flow channel 620, through the guide hole 360, into the plunger chamber 350, and then into the inner cavity of the inner sleeve 200, finally being discharged upwards. By introducing high-pressure fluid into the cavity of the inner sleeve 200, the plunger... The cavity 350 is filled with high-pressure fluid, which allows the guide rod type swashplate valve assembly to cut off the second fluid flow channel 620 under pressure. The high-pressure fluid causes the plunger assembly to move towards the pump barrel, i.e., downward. As the guide rod type swashplate valve assembly drives the plunger assembly to move up or down, it forces the guide rod type swashplate valve assembly to open or close the second fluid flow channel 620, and allows the downhole motor pump to work normally under hydraulic drive. Therefore, the hydraulic channel can be effectively opened and closed when the hydraulically driven downhole motor pump is used for horizontal well drainage and gas production.

[0031] The hydraulically driven downhole motor pump for horizontal well drainage and gas production further includes a double-connector 710, a central pipe 720, and a connecting outer pipe 730. The central pipe 720 is disposed within the cavity of the connecting outer pipe 730, forming an annular cavity between them. One end of the double-connector 710 connects the central pipe 720 and the connecting outer pipe 730, and the other end connects the outer sleeve 100 and the inner sleeve 200, allowing the inner cavity of the central pipe 720 to communicate with the first fluid flow channel 610, and the annular cavity to communicate with the inner cavity of the inner sleeve 200. This avoids deformation of the inner sleeve 200 under the action of high-pressure fluid when the plunger assembly moves upward when high-pressure fluid is directly introduced into the first fluid flow channel 610, thus improving the service life of the hydraulically driven downhole motor pump.

[0032] Preferably, the hydraulically driven downhole motor pump for horizontal well drainage and gas production further includes a setting joint 740, and the central pipe 720 is sealed to the double-through joint 710 through the setting joint 740.

[0033] The central tube 720 is connected to the upper inner oil pipe, and the connecting outer tube 730 is connected to the upper outer oil pipe.

[0034] The dual-connector 710 is provided with an upper hydraulic buffer chamber 711 that cooperates with the plunger assembly.

[0035] Specifically, the upper hydraulic buffer chamber 711 is an annular cavity, and the plunger assembly has an upper buffer portion 310 that can extend into and exit the upper hydraulic buffer chamber 711.

[0036] Furthermore, the upper buffer part 310 is provided with a first buffer hole 311. By setting the first buffer hole 311, high-pressure liquid can enter the upper hydraulic buffer chamber 711 through the first buffer hole 311 during the upward and downward movement of the plunger assembly, thereby increasing the contact area of ​​the high-pressure liquid and reducing the working hydraulic pressure.

[0037] Preferably, the hydraulically driven downhole motor pump for horizontal well drainage and gas production further includes an intermediate connector 750, one end of which is connected to the outer casing 100 and the inner casing 200, and the other end is connected to the pump barrel.

[0038] Preferably, the intermediate joint 750 is provided with a lower hydraulic buffer chamber 751 that cooperates with the plunger assembly.

[0039] Specifically, the lower hydraulic buffer chamber 751 is an annular cavity, and the plunger assembly has a lower buffer portion 320 that can extend into and exit the lower hydraulic buffer chamber.

[0040] Furthermore, a second buffer hole 321 is provided on the lower buffer part 320. By providing the second buffer hole 321, high-pressure liquid can enter the upper hydraulic buffer chamber 711 through the second buffer hole 321 during the upward and downward movement of the plunger assembly, thereby increasing the contact area of ​​the high-pressure liquid and reducing the working hydraulic pressure.

[0041] The plunger assembly includes a first plunger 330 and a second plunger 340. The first plunger 330 is disposed inside the inner sleeve 200 and slidably connected to the inner sleeve 200. One end of the first plunger 330 near the pump barrel forms the compression chamber 370 with the inner sleeve 200. The second plunger 340 is partially located inside the inner sleeve 200 and connected to the first plunger 330. The second plunger 340 is partially located inside the pump barrel. The guide rod type swashplate valve assembly is connected to the second plunger 340.

[0042] The size and stroke of the plunger assembly can be selected according to the needs. Different plunger sizes are suitable for different well types. Larger displacement pumps use larger plungers and longer strokes, while smaller displacement pumps use smaller plungers and shorter strokes. Currently available models are 63 / 32, 70 / 38, 70 / 44, and 83 / 51, with plunger strokes ranging from 2.5 to 4.2 meters.

[0043] The pump barrel includes a first pump barrel 410 and a second pump barrel 420. The first pump barrel 410 is connected to the intermediate joint 750 and is slidably connected to the second plunger 340. The second pump barrel 420 is connected to the first pump barrel 410. The second plunger 340 is partially located inside the second pump barrel 420. The second pump barrel 420 has a second fluid flow channel 620. The guide rod type swashplate valve assembly is located inside the second pump barrel 420.

[0044] The pump barrel also includes an upper connector 430, one end of which is connected to the second pump barrel 420.

[0045] The guide rod type swashplate valve assembly includes a valve core 510, a fixed valve disc 520, a fixed valve seat 530, a floating slide 540, and a limiting disc 550. The valve core 510 is disposed within the pump barrel and connected to the end of the plunger assembly away from the inner sleeve 200. The valve core has a first boss 511 and a second boss 512 spaced apart along the axial direction of the pump barrel, with the second boss 512 positioned further away from the inner sleeve 200 than the first boss 511. The floating slide 540 is disposed within the pump barrel (second pump barrel 420) and connected to the pump barrel's... The inner wall is slidably connected and sleeved on the valve core 510, located between the first boss 511 and the second boss 512. An annular valve cavity 543 is formed between the floating slide cylinder 540 and the valve core 510. The fixed valve seat 530 is fixedly disposed inside the pump cylinder (second pump cylinder 420) and located on the side of the second boss 512 away from the inner sleeve 200. The fixed valve disc 520 is slidably sleeved on the valve core 510 and located between the second boss 512 and the fixed valve seat 530. The fixed valve disc 520 is away from the inner sleeve. One end of the tube 200 mates with the fixed valve seat 530; the limiting disc 550 is fixedly disposed on the valve core 510 and located between the second boss 512 and the fixed valve seat 530, used to limit the position of the fixed valve disc 520 moving closer to the inner sleeve 200; when the first boss 511 can contact the end face of the floating slide cylinder 540 near the inner sleeve 200, there is a first predetermined distance between the second boss 512 and the floating slide cylinder 540, and the first boss 511 can contact the end face of the floating slide cylinder 540 near the inner sleeve 200. A fluid flow hole 542 is formed between the end faces of the inner sleeve 200, and one end of the annular valve cavity 543 is connected to the second fluid flow channel 620 through the fluid flow hole 542, and the other end is connected to the floating slide cylinder 540 through the gap between the second boss 512 and the floating slide cylinder 540. When the second boss 512 can contact the end face of the floating slide cylinder 540 away from the inner sleeve 200, the first boss 511 and the floating slide cylinder 540 have a second predetermined distance, and the second boss 512 and the floating slide cylinder 540 cooperate to cut off the second fluid flow channel 620.

[0046] When the plunger assembly moves the valve core 510 away from the inner sleeve 200, the valve core 510 moves the first boss 511 away from the inner sleeve 200. After moving a certain distance, the first boss 511 contacts the end face of the floating slide 540 near the inner sleeve 200. One end of the annular valve cavity 543 is connected to the second liquid flow channel 620 through the liquid flow hole 542, and the other end is connected to the floating slide 540 through the gap between the second boss 512 and the floating slide 540. As the valve core 510 continues to move away from the inner sleeve 200, it pushes the floating slide 540 to move away from the inner sleeve 200. At this time, the liquid at the end of the fixed valve disc 520 near the inner sleeve 200 is compressed by the valve core and the floating slide 540. The liquid pressure at the end of the fixed valve disc 520 near the inner sleeve 200 is greater than the liquid pressure at the end away from the inner sleeve 200. This forces the fixed valve disc 520 to move closer to the fixed valve seat 530, thereby cutting off the second liquid flow channel 620 by engaging the fixed valve seat 530 at the end of the fixed valve disc 520 away from the inner sleeve 200. This prevents liquid from flowing out of the pump barrel away from the inner sleeve 200. At the same time, the liquid at the end of the pump barrel near the inner sleeve 200 of the fixed valve disc 520 flows upward into the plunger cavity 350 under the compression of the plunger assembly and valve core 510. The liquid in the compression cavity 370 and the first liquid flow channel 610 is discharged away from the pump barrel from the inner sleeve 200 under the action of the plunger assembly.

[0047] When the plunger assembly moves the valve core 510 closer to the inner sleeve 200, the valve core 510 moves the second protrusion 512 closer to the inner sleeve 200. After moving a certain distance, the second protrusion 512 contacts the end face of the floating slide 540 away from the inner sleeve 200. The second protrusion 512 and the floating slide 540 cooperate to cut off the second liquid flow channel 620. As the plunger assembly continues to move the valve core 510 closer to the inner sleeve 200, the volume of the second liquid flow channel 620 at the end of the floating slide 540 away from the inner sleeve 200 increases, creating a negative pressure. This causes the liquid pressure at the end of the fixed valve disc 520 closer to the inner sleeve 200 to be less than that at the end further away from the inner sleeve 200. The liquid pressure at one end of the inner sleeve 200 forces the fixed valve disc 520 to move away from the fixed valve seat 530 until it contacts the limiting disc 550. This causes the fixed valve disc 520 to move away from the inner sleeve 200 and the fixed valve seat 530, increasing the volume of the second liquid flow channel 620 at the end of the floating slide 540 away from the inner sleeve 200. This creates a negative pressure that draws liquid from the end of the pump cylinder away from the inner sleeve 200 into the second liquid flow channel 620. Liquid in the annular valve chamber 543 and the plunger chamber 350 enters the inner sleeve upwards from the pump cylinder towards the inner sleeve 200 and flows out from the end of the inner sleeve away from the pump cylinder.

[0048] Preferably, the valve core includes a first valve core 513 and a second valve core 514 arranged along the axial direction of the pump barrel, and the second valve core 514 is disposed at one end further away from the inner sleeve 200 than the first valve core 513; the second valve core 514 is fixedly connected to the first valve core 513, the first valve core 513 has a first boss 511, and the second valve core 514 has a second boss 512.

[0049] The mating surface between the first boss and the floating slide 540 is an inclined surface.

[0050] The mating surface between the second boss and the floating slide 540 is an inclined surface.

[0051] Preferably, the floating slide 540 has a slide end plate 541 on its end face near the first boss, and the liquid flow hole 542 is located on the slide end plate 541.

[0052] The hydraulically driven downhole motor pump assembly for horizontal well drainage and gas production also includes a gas-liquid separator. The gas-liquid separator is connected to the pump barrel (upper connector 430) and communicates with the second liquid flow channel 620, providing a third liquid flow channel for the accumulated liquid to enter the second liquid flow channel 620 from the gas-liquid separator.

[0053] Specifically, the gas-liquid separator includes an outer separator tube 810, an inner separator tube 820, a counterweight rod 830, and a plug 840. The outer separator tube 810 has a liquid inlet 811. The inner separator tube 820 is located inside the outer separator tube 810 and is rotatably connected to it. The inner separator tube 820 communicates with the second liquid flow channel 620. The inner separator tube 820 includes a first arcuate plate and a second arcuate plate. The first arcuate plate and the second arcuate plate... Two arc-shaped plates are connected to form a circular tube. The first arc-shaped plate has a liquid inlet 821. A counterweight rod 830 is connected to both the first and second arc-shaped plates. When the downhole pump is located in a horizontal well, the counterweight rod 830 positions the first arc-shaped plate below the second arc-shaped plate. A plug 840 seals the outer tube 810 of the separator. The inlet 811, the liquid inlet 821, and the cavity of the inner tube 820 of the separator are located on the third liquid flow channel. This allows the accumulated liquid in the horizontal well to enter the second liquid flow channel 620 through the third liquid flow channel. Specifically, the accumulated liquid in the horizontal well enters the inner tube 820 of the separator through the inlet 811 and then through the liquid inlet 821, and then enters the second liquid flow channel 620, preventing a large amount of gas from entering the pump and affecting its normal operation and efficiency.

[0054] Preferably, the surface area of ​​the first arc plate is smaller than the surface area of ​​the second arc plate.

[0055] Preferably, the liquid inlet 811 of the separator outer tube 810 is slitted to increase the suction inlet area and reduce suction resistance. The slits of the liquid inlet 811 are distributed at 30-45° along the bottom surface of the outer tube.

[0056] The liquid inlet 821 is arranged with small holes, with 3-5 holes per row and the holes in each row are spaced 5-20° apart in the circumferential direction.

[0057] Preferably, the gas-liquid separator further includes a support ring 850 and a support joint 860. The support ring 850 and the support joint 860 are both located inside the outer tube 810 of the separator. The support ring 850 is connected to the support joint 860, the support joint 860 is threadedly connected to the inner tube 820 of the separator, and the support ring 850 is rotatably connected to the outer tube 810 of the separator.

[0058] Preferably, the counterweight rod 830 includes a round rod, one end of which is fixedly connected to the first arc plate and the second arc plate, and the other end is rotatably connected to the plug 840, and the round rod is provided with a through groove.

[0059] Preferably, the bottom of the through groove is flush with the center surface of the round rod.

[0060] Preferably, the gas-liquid separator is threadedly connected to the pump barrel, which facilitates the separation of the gas-liquid separator from the downhole motor pump for transportation and installation, and also increases the stroke of the motor pump.

[0061] refer to Figure 3 and Figure 4 The working process of the hydraulically driven downhole motor pump used for horizontal well drainage and gas production is as follows: Top Stroke: The power fluid (high-pressure fluid) is pressurized into high-pressure power fluid by the ground power unit and injected from the central pipe 720 into the first fluid flow channel 610 between the outer sleeve 100 and the inner sleeve 200 through the double-connector 710. Finally, it enters the compression chamber 370 through the guide hole 210, pushing the first plunger 330 upward (from the pump barrel towards the inner sleeve 200). The first plunger 330 drives the second plunger 340 upward. When the second plunger 340 drives the valve core 510 upward, the valve core 510 drives the second plunger 340 upward. The second protrusion 512 moves towards the inner sleeve 200. After moving a certain distance, the second protrusion 512 contacts the end face of the floating slide 540 away from the inner sleeve 200. The second protrusion 512 and the floating slide 540 cooperate to cut off the second fluid flow channel 620. When the plunger assembly drives the valve core 510 to continue moving towards the inner sleeve 200, the pump cylinder is located at the end of the floating slide 540 away from the inner sleeve 200 in the second fluid flow channel 620. The increased volume creates a negative pressure, causing the liquid pressure at the end of the fixed valve disc 520 near the inner sleeve 200 to be less than the liquid pressure at the end away from the inner sleeve 200. This forces the fixed valve disc 520 to move away from the fixed valve seat 530 until it contacts the limiting disc 550. As a result, the end of the fixed valve disc 520 away from the inner sleeve 200 moves away from the fixed valve seat 530, and the pump cylinder is located on the side of the floating slide 540 away from the inner sleeve 200. The volume of the second liquid flow channel 620 at the end increases, forming a negative pressure. The produced liquid enters the second liquid flow channel 620 through the third liquid flow channel (inlet 811, outlet 821 and separator inner tube 820). The liquid in the pump barrel located in the annular valve chamber 543 and the plunger chamber 350 enters the inner cavity of the inner sleeve 200 from the pump barrel towards the direction close to the inner sleeve 200, and finally enters the annular cavity between the central tube 720 and the connecting outer tube 730 through the double-connector 710 and is discharged to the ground. The ground production phenomenon is liquid discharge state.

[0062] Downstroke: The power fluid is pressurized into high-pressure power fluid by the ground power unit and injected into the annular cavity between the central tube 720 and the connecting outer tube 730. It then enters the inner sleeve 200 through the double-connector 710, pushing the first plunger 330 downwards (from the inner sleeve 200 towards the pump barrel). The first plunger 330 drives the second plunger 340 downwards. When the second plunger 340 drives the valve core 510 downwards, the valve core 510 drives the first boss 511 to move away from the inner sleeve 200. After moving a certain distance, the first boss 511 contacts the end face of the floating slide cylinder 540 near the inner sleeve 200. One end of the annular valve cavity 543 is connected to the second liquid flow channel 620 through the liquid flow hole 542, and the other end is connected to the floating slide cylinder 540 through the gap between the second boss 512 and the floating slide cylinder 540. As the valve core 510 continues to move away from the inner sleeve 200, it pushes the floating slide cylinder 540 to move away from the inner sleeve 200. At this time, the fixed valve disc... The liquid near the inner sleeve 200 is compressed by the valve core and the floating slide 540, causing the liquid pressure at the end of the fixed valve disc 520 near the inner sleeve 200 to be greater than the liquid pressure at the end away from the inner sleeve 200. This forces the fixed valve disc 520 to move towards the fixed valve seat 530, thereby allowing the end of the fixed valve disc 520 away from the inner sleeve 200 to engage with the fixed valve seat 530 to cut off the second liquid flow channel 620, avoiding... Liquid flows away from the pump barrel and away from the inner sleeve 200. At the same time, the liquid at the end of the fixed valve disc 520 near the inner sleeve 200 is squeezed upward by the plunger assembly and valve core 510 and flows into the plunger chamber 350. That is, the produced liquid sucked into the guide rod swashplate valve during the upstroke is mixed with the power fluid through the second plunger 340 and the first plunger 330, and the liquid in the compression chamber 370 and the first liquid flow channel 610 is discharged away from the pump barrel and away from the inner sleeve 200 by the action of the plunger assembly.

[0063] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A hydraulically driven downhole motor pump assembly for use in water drainage gas recovery in horizontal wells, characterized by, The pump comprises an outer sleeve, an inner sleeve, a plunger assembly, a pump cylinder and a guide rod type swash plate valve assembly. The inner sleeve is arranged in the lumen of the outer sleeve and is connected with the pump cylinder, and a first liquid flow channel is formed between the outer sleeve and the inner sleeve. The inner sleeve is provided with a flow guide hole near the end of the pump cylinder. The plunger assembly is internally provided with a plunger cavity, and a part of the plunger assembly is arranged in the inner sleeve and is in sliding connection with the inner sleeve, and another part of the plunger assembly is arranged in the pump cylinder and is in sliding connection with the pump cylinder. The second liquid flow channel is in communication with the drainage hole. The guide rod type swash plate valve assembly is connected with the plunger assembly and is arranged in the pump cylinder, and is used for cutting off or conducting the second liquid flow channel.

2. The hydraulically powered downhole motor pump assembly for water drainage gas production from horizontal wells of claim 1, wherein, The guide rod type swash plate valve assembly comprises a valve core, a fixed valve disc, a fixed valve seat, a floating sliding cylinder and a limiting disc. The valve core is arranged in the pump cylinder and is connected with the end of the plunger assembly away from the inner sleeve, and the valve core is provided with a first boss and a second boss which are arranged in the axial direction of the pump cylinder and are spaced apart from each other, and the second boss is arranged farther away from the inner sleeve than the first boss. The floating sliding cylinder is arranged in the pump cylinder, is in sliding connection with the inner wall of the pump cylinder, is sleeved on the valve core and is located between the first boss and the second boss, and an annular valve cavity is formed between the floating sliding cylinder and the valve core. The fixed valve seat is fixedly arranged in the pump cylinder and is located on the side of the second boss away from the inner sleeve. The fixed valve disc is sleeved on the valve core and is located between the second boss and the fixed valve seat, and the end of the fixed valve disc away from the inner sleeve is matched with the fixed valve seat. The limiting disc is fixedly arranged on the valve core and is located between the second boss and the fixed valve seat, and is used for limiting the position of the fixed valve disc moving towards the inner sleeve. When the first boss can be in contact with the end surface of the floating sliding cylinder close to the inner sleeve, the second boss has a first predetermined distance from the floating sliding cylinder, a liquid flow hole is formed between the first boss and the end surface of the floating sliding cylinder close to the inner sleeve, one end of the annular valve cavity is in communication with the second liquid flow channel through the liquid flow hole, and the other end of the annular valve cavity is in communication with the floating sliding cylinder through the gap between the second boss and the floating sliding cylinder; when the second boss can be in contact with the end surface of the floating sliding cylinder away from the inner sleeve, the first boss has a second predetermined distance from the floating sliding cylinder, and the second boss and the floating sliding cylinder cooperate to cut off the second liquid flow channel.

3. The hydraulically powered downhole motor pump assembly for water drainage gas production from horizontal wells of claim 2, wherein, The valve core comprises a first valve core and a second valve core arranged axially along the pump barrel, and the second valve core is arranged farther away from the end of the inner sleeve than the first valve core; the second valve core is fixedly connected with the first valve core, the first valve core has a first boss, and the second valve core has a second boss.

4. The hydraulically powered downhole motor pump assembly for water drainage gas production in horizontal wells of claim 2, wherein, The matching surface of the first boss with the floating sliding cylinder is a slope.

5. The hydraulically powered downhole motor pump assembly for water drainage gas production from horizontal wells of claim 2, wherein, The matching surface of the second boss with the floating sliding cylinder is a slope.

6. The hydraulically powered downhole motor pump assembly for water alternating gas recovery from horizontal wells of claim 1, wherein, Further comprising a gas-liquid separator, which is connected with the pump barrel and communicates with the second liquid flow channel, for providing a third liquid flow channel for the accumulated liquid to enter the second liquid flow channel from the gas-liquid separator.

7. The hydraulically driven downhole motor pump assembly for water drainage gas production in horizontal wells of claim 6, wherein, The gas-liquid separator comprises an outer separator pipe, an inner separator pipe, a counterweight rod and a plug, the outer separator pipe is provided with a liquid inlet, the inner separator pipe is located in the outer separator pipe and rotationally connected with the outer separator pipe, the inner separator pipe communicates with the second liquid flow channel, the inner separator pipe comprises a first circular arc piece and a second circular arc piece, the first circular arc piece and the second circular arc piece are connected in a circular tube shape, the first circular arc piece is provided with a liquid inlet, the counterweight rod is connected with the first circular arc piece and the second circular arc piece, when the downhole motor pump is located in the horizontal well, the counterweight rod is used to make the first circular arc piece located below the second circular arc piece, the plug is used to block the outer separator pipe, the liquid inlet, the liquid inlet and the lumen of the inner separator pipe are located on the third liquid flow channel.

8. The hydraulically powered downhole motor pump assembly for water drainage gas production from horizontal wells of claim 7, wherein, The surface area of the first circular arc piece is smaller than that of the second circular arc piece.

9. The hydraulically powered downhole motor pump assembly for water alternating gas recovery from horizontal wells of claim 7, wherein, The liquid inlet of the outer separator pipe adopts a slotted groove.

10. The hydraulically powered downhole motor pump assembly for water alternating gas recovery from a horizontal well of claim 6, wherein, The gas-liquid separator is threadedly connected with the pump barrel.

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