A water blocking bridge plug

Abstract

The invention discloses a water plugging bridge plug, which relates to the technical field of oil production tools, and comprises an upper joint, an upper outer sleeve, a fixed piston, a balancing piston, an upper core tube, a sealing sleeve, a disjointed sleeve, an upper sealing piston, a locking ball seat, an upper piston, an upper outer core tube, a lower sealing piston, a lower outer core tube, an upper pressure ring, a sealing piston, a locking sleeve, a retaining spring, a spacer ring, a center tube, a lower pressure ring, a threaded plug, a lower spare cap, an unsealing pin, a first liquid inlet hole, a second liquid inlet hole, an upper steel ball, a lower steel ball, a third liquid inlet hole, a fourth liquid inlet hole, a fifth liquid inlet hole, a sixth liquid inlet hole, and a rubber cylinder. The water plugging bridge plug described in the invention not only has the friction force of conventional bridge plug slip anchoring, but also has the advantage of not damaging the casing, thereby solving the problems of conventional bridge plug slip anchoring damaging the casing and slips rusting and not being recovered causing well jamming and forced pulling.

Description

Technical Field

[0001] The invention relates to the field of oil production tools, in particular to a water blocking bridge plug. Background Art

[0002] Oilfield development has entered the late stage of high water content. Due to channeling and sudden injection of water, some oil wells are flooded prematurely. In order to eliminate or reduce the harm caused by flooding, a series of downhole process measures to block the water-producing layer are collectively referred to as oil well water plugging. The purpose of oil well water plugging is to control the flow of water in the water-producing layer and change the flow direction of water in water-driven oil, improve the efficiency of water-driven oil, and make the water production of the oil field decrease or stabilize within a certain period of time to maintain the increase or stable production of the oil field. Its ultimate goal is to improve the recovery rate of the oil field. Water plugging, as a major technical measure for oil field stabilization and water control, occupies an important position in oil field development. The water plugging process includes mechanical water plugging, which uses a bridge plug to be stuck above and below the water plugging target layer to isolate the annular space of the oil casing. Only the oil pipe passes through the plugging layer, so that the liquid flow of the water plugging target layer is separated from the upper and lower layers, and at the same time cannot enter the oil pipe, so as to achieve the purpose of plugging the target layer and increase the oil. The conventional water-blocking bridge plug structure is a slip structure. Due to water quality issues in the well for a long time, the slips will rust or scale. When the bridge plug is unsealed, the load will increase. The slip teeth will damage the inner wall of the casing under the pull of high load, causing irreversible damage to the casing. Failure to recover the slips will increase the load, and the use of a forced puller will not only increase the operating cost but also increase the operating risk. Summary of the invention

[0003] The main purpose of the present invention is to provide a water blocking bridge plug, which can effectively solve the problems in the background technology.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] A water blocking bridge plug comprises an upper joint, an upper outer sleeve, a fixed piston, a balancing piston, an upper core tube, a sealing sleeve, a disjointed sleeve, an upper sealing piston, a locking ball seat, an upper piston, an upper outer core tube, a lower sealing piston, a lower outer core tube, an upper pressure ring, a sealing piston, a locking sleeve, a retaining spring, a spacer ring, a center tube, a lower pressure ring, a threaded plug, a lower spare cap, an unsealing pin, a first liquid inlet hole, a second liquid inlet hole, an upper steel ball, a lower steel ball, a third liquid inlet hole, a fourth liquid inlet hole, a fifth liquid inlet hole, a sixth liquid inlet hole, and a rubber cylinder.

[0006] The upper joint is connected to the fixed piston and fixed by an unsealing pin. The fixed piston is connected to the upper core tube by threads. The balancing piston is connected to the upper core tube. The upper outer sleeve is connected to the upper joint, the fixed piston, the balancing piston and the upper core tube. The upper joint, the upper core tube and the upper outer sleeve are sealed by a sealing ring. The fixed piston, the upper core tube and the upper outer sleeve are sealed by a sealing ring. The balancing piston, the upper core tube and the upper outer sleeve are sealed by a sealing ring. The upper core tube and the upper outer sleeve are sealed by a sealing ring.

[0007] The upper core tube is connected to the center tube by threads, the upper core tube is connected to the locking ball seat, the upper core tube is connected to the upper outer sleeve, the upper outer sleeve is connected to the disjointed sleeve, the upper piston is connected to the locking ball seat, the sealing sleeve is connected to the upper outer sleeve, the disjointed sleeve and the upper piston, the upper core tube and the locking ball seat are fixed by the lower steel ball, the upper core tube and the upper outer sleeve are fixed by the upper steel ball, the upper core tube and the center tube are sealed by a sealing ring, the center tube and the locking ball seat are sealed by a sealing ring, the locking ball seat and the upper piston are sealed by a sealing ring, and the sealing sleeve, the upper outer sleeve and the upper piston are sealed by a sealing ring.

[0008] The sealing sleeve is connected to the upper seating piston, the upper seating piston is connected to the upper outer core tube, the upper outer core tube is connected to the lower outer core tube by threads, the lower seating piston is connected to the upper seating piston by threads, the lower seating piston is connected to the upper outer core tube and the lower outer core tube, the lower seating piston is connected to the upper pressure ring by threads, the sealing piston is connected to the lower outer core tube by threads, the upper pressure ring is connected to the lower outer core tube and the sealing piston, the upper seating piston, the sealing sleeve and the upper outer core tube are sealed by sealing rings, the lower seating piston, the upper outer core tube and the lower outer core tube are sealed by sealing rings, the sealing piston and the lower outer core tube are sealed by sealing rings, the upper pressure ring, the sealing piston and the lower outer core tube are sealed by sealing rings.

[0009] The upper pressure ring and the locking sleeve are connected by threads, the locking sleeve is connected to the spacer ring, the rubber cylinder, the lower pressure ring and the lower outer core tube, the lower pressure ring and the lower spare cap are connected by threads, the lower outer core tube and the wire plug are connected by threads, the wire plug is connected to the lower spare cap, the lower outer core tube is connected to the retaining spring, the lower outer core tube is connected to the center tube, the upper pressure ring, the locking sleeve and the lower outer core tube are sealed by a sealing ring, the lower outer core tube and the center tube are sealed by a sealing ring, the center tube and the wire plug are sealed by a sealing ring, the locking sleeve and the lower pressure ring are sealed by a sealing ring, the lower pressure ring and the lower spare cap are sealed by a sealing ring, and the wire plug and the lower spare cap are sealed by a sealing ring.

[0010] The upper core tube is provided with a first liquid inlet hole, the upper outer tube is provided with a second liquid inlet hole, the central tube is provided with a third liquid inlet hole, the upper outer core tube is provided with a fourth liquid inlet hole, and the lower outer core tube is provided with a fifth liquid inlet hole and a sixth liquid inlet hole.

[0011] The retaining spring is provided with external teeth, and the lock sleeve is provided with internal teeth. The external teeth match the internal teeth, and the external teeth and the internal teeth can be clamped and locked.

[0012] Three rubber cylinders are provided, and two spacer rings are provided between the rubber cylinders.

[0013] After the slit on the upper end of the wire plug is divided into 20 parts, it has elasticity and can be compressed inward. The lower outer core tube and the wire plug are connected by threads, and the center tube and the wire plug are connected to support the upper end thread of the wire plug so that it does not disengage. When unsealed, after the center tube goes up to the end face of the lower outer core tube, the wire plug loses the support of the center tube, and the upper end thread of the wire plug disengages from the lower outer core tube under the action of elastic force.

[0014] Working principle of the present invention:

[0015] First, the water plugging bridge provided by the present invention is connected to the oil pipe string and lowered into the oil well. The operation process is as follows:

[0016] Sealing process:

[0017] The present invention is connected to the oil pipe column and lowered to a predetermined position. The upper part of the bridge plug is connected to a conventional packer. There is no water-producing layer at the lower part of the bridge plug, and there is a water-producing layer between the bridge plug and the packer. A ground pump truck pressurizes the oil pipe, and water enters the first liquid inlet hole, the third liquid inlet hole, the fourth liquid inlet hole, the fifth liquid inlet hole, and the sixth liquid inlet hole of the bridge plug through the oil pipe. The water pushes the upper piston through the fourth liquid inlet hole, and the upper piston pushes the disjointed sleeve. The upper outer sleeve and the upper steel ball fixed to the locking ball seat lose the support of the disjointed sleeve and are in a free state. At the same time, the water passes through the fourth liquid inlet hole and the fifth liquid inlet hole. , the sixth liquid inlet hole pushes the upper sealing piston, the lower sealing piston and the upper pressure ring downward, and the upper pressure ring pushes the locking sleeve downward, the outer teeth of the retaining spring engage with the inner teeth of the locking sleeve, and the rubber cylinder is compressed and sealed. When the pump truck is pressurized to the rated pressure and the pressure is stopped, the outer teeth of the retaining spring and the inner teeth of the locking sleeve are locked and will not return, and the rubber cylinder is sealed on the inner wall of the casing. Since there is no water outlet layer at the bottom of the bridge plug, the water at the bottom is in a closed state after the rubber cylinder is sealed. Since water is incompressible, the water at the bottom of the bridge plug is in a vacuum state, which ensures the stable performance of the rubber cylinder sealing. At this time, the bridge plug sealing process is completed.

[0018] Unblocking process:

[0019] The upper sleeve is lifted up, the upper joint moves upward, the unsealing pin is cut off, and the upper outer sleeve is driven upward. Since the upper outer sleeve and the upper core tube lose the support of the disjoint sleeve, the upper steel ball is disengaged, and the upper outer sleeve moves upward to the end face of the balancing piston, driving the balancing piston and the fixed piston upward. The fixed piston drives the upper core tube upward, and the upper core tube and the locking ball seat lose the support of the upper sleeve and are in a free state. The upper core tube drives the center tube upward, and the center tube moves upward to the end face of the lower outer core tube. The lower outer core tube and the threaded plug lose the support of the center tube and disengage at the threaded connection. The threaded plug drives the lower spare cap and the lower pressure ring downward, and the rebound force of the rubber cylinder is fully released downward and returns to its original position after losing the support of the lower pressure ring. The unsealing release mechanism composed of the center tube, the lower outer core tube, the threaded plug, the lower spare cap and the lower pressure ring is in a closed cavity. The rubber cylinder is easily released and recovered, and the bridge plug is lifted to the ground with the pipe column, and the unsealing is completed.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] A water-blocking bridge plug is a tool that uses a rubber tube to complete the sealing and anchoring effect. It utilizes the closed state of the wellbore without opening layers. There is no water-producing layer at the bottom of the bridge plug. The water at the bottom is in a closed state after the rubber tube is expanded and sealed. Since water is incompressible, a vacuum state is formed, and reverse suction is used to anchor the rubber tube to the casing wall. It not only has the friction of conventional bridge plug slip anchoring, but also has the advantage of not damaging the casing. The unsealing and releasing mechanism is in a closed cavity. When working underground for a long time, it will not be unable to be recovered due to scaling or rust, causing the well to be stuck. The load for lifting and unsealing is reduced, and the operation can be completed using a conventional work vehicle, which greatly reduces the safety risk. It has the characteristics of simple operation, novel structure, safety and environmental protection.

[0022] The pressure balancing mechanism composed of the balancing piston, the upper outer sleeve, the fixed piston and the upper core tube can well ensure the working pressure of the bridge plug in the well. When the rubber cylinder is sealed, the upper packer is also sealed. The water-producing layer is between the packer and the bridge plug. Water enters the cavity of the balancing piston, the upper core tube and the upper outer sleeve through the second liquid inlet hole. Because the piston area is the same, the pressure above and below is the same, achieving the function of balancing the upper outer sleeve, ensuring that the bridge plug will not be unsealed prematurely, and improving the stability of the bridge plug expansion and sealing anchoring.

[0023] The sealing mechanism composed of the upper sealing piston, the lower sealing piston, the upper pressure ring, the upper outer core tube, the lower outer core tube, the locking sleeve and the retaining spring effectively ensures the sealing force of the rubber cylinder. The upper sealing piston, the lower sealing piston and the upper pressure ring have a three-stage piston function, and the piston thrust is greatly increased, which can ensure the sealing reliability of the rubber cylinder.

[0024] The unsealing and releasing mechanism composed of the center tube, lower outer core tube, thread plug, lower backup cap and lower pressure ring is in a closed cavity. When lifted up to unseal, after the center tube moves up to the end face of the lower outer core tube, the threaded connection between the thread plug and the lower outer core tube loses the support of the center tube and will be detached under the rebound force of the rubber tube. The lower pressure ring will move downward with the thread plug and the lower backup cap. The released space will restore the rubber tube to its original position, ensuring that the rubber tube will not get stuck in the well. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic structural diagram of a water blocking bridge plug of the present invention;

[0026] Figure 2 It is a schematic diagram of a wire plugging structure of a water blocking bridge plug of the present invention;

[0027] In the figure: 1, upper joint, 2, upper outer sleeve, 3, fixed piston, 4, balancing piston, 5, upper core tube, 6, sealing sleeve, 7, disjointed sleeve, 8, upper sealing piston, 9, locking ball seat, 10, upper piston, 11, upper outer core tube, 12, lower sealing piston, 13, lower outer core tube, 14, upper pressure ring, 15, sealing piston, 16, locking sleeve, 17, retaining ring, 18, spacer ring, 19, center tube, 20, lower pressure ring, 21, thread plug, 22, lower spare cap, 23, unsealing pin, 24, first liquid inlet hole, 25, second liquid inlet hole, 26, upper steel ball, 27, lower steel ball, 28, third liquid inlet hole, 29, fourth liquid inlet hole, 30, fifth liquid inlet hole, 31, sixth liquid inlet hole, 32, rubber cylinder. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0029] like Figure 1 As shown, a water blocking bridge plug includes an upper joint 1, an upper outer sleeve 2, a fixed piston 3, a balancing piston 4, an upper core tube 5, a sealing sleeve 6, a disengaging sleeve 7, an upper sealing piston 8, a locking ball seat 9, an upper piston 10, an upper outer core tube 11, a lower sealing piston 12, a lower outer core tube 13, an upper pressure ring 14, a sealing piston 15, a locking sleeve 16, a retaining ring 17, a spacer ring 18, a center tube 19, a lower pressure ring 20, a threaded plug 21, a lower spare cap 22, an unsealing pin 23, a first liquid inlet hole 24, a second liquid inlet hole 25, an upper steel ball 26, a lower steel ball 27, a third liquid inlet hole 28, a fourth liquid inlet hole 29, a fifth liquid inlet hole 30, a sixth liquid inlet hole 31, and a rubber cylinder 32.

[0030] The upper joint 1 is connected to the fixed piston 3 and fixed by the unsealing pin 23. The fixed piston 3 and the upper core tube 5 are connected by threads. The balancing piston 4 is connected to the upper core tube 5. The upper outer sleeve 2 is connected to the upper joint 1, the fixed piston 3, the balancing piston 4 and the upper core tube 5. The upper joint 1, the upper core tube 5 and the upper outer sleeve 2 are sealed by a sealing ring. The fixed piston 3, the upper core tube 5 and the upper outer sleeve 2 are sealed by a sealing ring. The balancing piston 4, the upper core tube 5 and the upper outer sleeve 2 are sealed by a sealing ring. The upper core tube 5 and the upper outer sleeve 2 are sealed by a sealing ring.

[0031] The upper core tube 5 is connected to the center tube 19 by threads, the upper core tube 5 is connected to the lock ball seat 9, the upper core tube 5 is connected to the upper outer sleeve 2, the upper outer sleeve 2 is connected to the disjoint sleeve 7, the upper piston 10 is connected to the lock ball seat 9, the sealing sleeve 6 is connected to the upper outer sleeve 2, the disjoint sleeve 7, and the upper piston 10, the upper core tube 5 and the lock ball seat 9 are fixed by the lower steel ball 27, the upper core tube 5 and the upper outer sleeve 2 are fixed by the upper steel ball 26, the upper core tube 5 and the center tube 19 are sealed by a sealing ring, the center tube 19 and the lock ball seat 9 are sealed by a sealing ring, the lock ball seat 9 and the upper piston 10 are sealed by a sealing ring, and the sealing sleeve 6, the upper outer sleeve 2, and the upper piston 10 are sealed by a sealing ring.

[0032] The sealing sleeve 6 is connected to the upper sealing piston 8, the upper sealing piston 8 is connected to the upper outer core tube 11, the upper outer core tube 11 is threadedly connected to the lower outer core tube 13, the lower sealing piston 12 is threadedly connected to the upper sealing piston 8, the lower sealing piston 12 is connected to the upper outer core tube 11 and the lower outer core tube 13, the lower sealing piston 12 is threadedly connected to the upper pressure ring 14, the sealing piston 15 is threadedly connected to the lower outer core tube 13, the upper pressure ring 14 is connected to the lower outer core tube 13 and the sealing piston 15, the upper sealing piston 8 is sealed with the sealing sleeve 6 and the upper outer core tube 11 by a sealing ring, the lower sealing piston 12 is sealed with the upper outer core tube 11 and the lower outer core tube 13 by a sealing ring, the sealing piston 15 is sealed with the lower outer core tube 13 by a sealing ring, and the upper pressure ring 14 is sealed with the sealing piston 15 and the lower outer core tube 13 by a sealing ring.

[0033] The upper pressure ring 14 is connected to the locking sleeve 16 by threads, the locking sleeve 16 is connected to the spacer ring 18, the rubber cylinder 32, the lower pressure ring 20, and the lower outer core tube 13, the lower pressure ring 20 is connected to the lower spare cap 22 by threads, the lower outer core tube 13 is connected to the wire plug 21 by threads, the wire plug 21 is connected to the lower spare cap 22, the lower outer core tube 13 is connected to the retaining ring 17, the lower outer core tube 13 is connected to the center tube 19, the upper pressure ring 14, the locking sleeve 16, and the lower outer core tube 13 are sealed by a sealing ring, the lower outer core tube 13 and the center tube 19 are sealed by a sealing ring, the center tube 19 and the wire plug 21 are sealed by a sealing ring, the locking sleeve 16 and the lower pressure ring 20 are sealed by a sealing ring, the lower pressure ring 20 and the lower spare cap 22 are sealed by a sealing ring, and the wire plug 21 and the lower spare cap 22 are sealed by a sealing ring.

[0034] When setting the seal, the present invention is connected to the oil pipe column and lowered to a predetermined position. The upper part of the bridge plug is connected to a conventional packer. There is no water-producing layer at the lower part of the bridge plug, and there is a water-producing layer between the bridge plug and the packer. The ground pump truck pressurizes the oil pipe, and water enters the first liquid inlet hole 24, the third liquid inlet hole 28, the fourth liquid inlet hole 29, the fifth liquid inlet hole 30, and the sixth liquid inlet hole 31 of the bridge plug through the oil pipe. The water pushes the upper piston 10 through the fourth liquid inlet hole 29, and the upper piston 10 pushes the disjoint sleeve 7. The upper steel ball 26 fixed by the upper outer sleeve 2 and the locking ball seat 9 loses the support of the disjoint sleeve 7 and is in a free state. At the same time, the water passes through the fourth liquid inlet hole 29, the fifth liquid inlet hole 29, and the fifth liquid inlet hole 31. The hole 30 and the sixth liquid inlet hole 31 push the upper sealing piston 8, the lower sealing piston 12 and the upper pressure ring 14 downward, and the upper pressure ring 14 pushes the locking sleeve 16 downward, and the outer teeth of the retaining spring 17 engage with the inner teeth of the locking sleeve 16, and the rubber cylinder 32 is compressed and sealed. When the pump truck is pressurized to the rated pressure and the pressure is stopped, the outer teeth of the retaining spring 17 and the inner teeth of the locking sleeve 16 are locked and will not return. The rubber cylinder 32 is sealed on the inner wall of the casing. Since there is no water outlet layer at the bottom of the bridge plug, the water at the bottom is in a closed state after the rubber cylinder 32 is sealed. Since water is incompressible, the water at the bottom of the bridge plug is in a vacuum state, which ensures the stable performance of the rubber cylinder sealing. At this time, the bridge plug sealing process is completed.

[0035] When unsealing, the pipe column is lifted, the upper joint 1 moves upward, the unsealing pin 23 is cut off, and the upper outer sleeve 2 moves upward. Since the upper outer sleeve 2 and the upper core tube 5 lose the support of the disjoint sleeve 7, the upper steel ball 26 is disengaged, and the upper outer sleeve 2 moves upward to the end face of the balance piston 4, driving the balance piston 4 and the fixed piston 3 upward. The fixed piston 3 drives the upper core tube 5 upward. The upper core tube 5 and the locking ball seat 9 lose the support of the upper outer sleeve 2 and are in a free state. The upper core tube 5 drives the central tube 19 upward, and the central tube 19 moves upward to the lower outer core tube 13 At the end face, the lower outer core tube 13 and the threaded plug 21 are disengaged at the threaded connection after losing the support of the center tube 19, and the threaded plug 21 drives the lower spare cap 22 and the lower pressure ring 20 downward, and the rebound force of the rubber tube 32 is fully released downward and returns to its original position after losing the support of the lower pressure ring 20. The unsealing and releasing mechanism composed of the center tube 19, the lower outer core tube 13, the threaded plug 21, the lower spare cap 22 and the lower pressure ring 20 is in a closed cavity, and the rubber tube 32 is easily released and recovered, and the bridge plug is lifted to the ground along with the pipe column, and the unsealing is completed.

[0036] The upper core tube 5 is provided with a first liquid inlet hole 24, the upper outer sleeve 2 is provided with a second liquid inlet hole 25, the central tube 19 is provided with a third liquid inlet hole 28, the upper outer core tube 11 is provided with a fourth liquid inlet hole 29, and the lower outer core tube 13 is provided with a fifth liquid inlet hole 30 and a sixth liquid inlet hole 31.

[0037] The retaining spring 17 is provided with external teeth, and the lock sleeve 16 is provided with internal teeth. The external teeth match the internal teeth, and the external teeth and the internal teeth can be clamped and locked.

[0038] There are three rubber cylinders 32 , and two spacer rings 18 are arranged between the rubber cylinders 32 .

[0039] After the upper end of the wire plug 21 is cut into 20 parts, it has elasticity and can be compressed inward. The lower outer core tube 13 is connected to the wire plug 21 by threads, and the center tube 19 is connected to the wire plug 21 to support the upper end thread of the wire plug 21 so that it does not disengage. When unsealed, after the center tube 19 goes up to the end face of the lower outer core tube 13, the wire plug 21 loses the support of the center tube 19, and the upper end thread of the wire plug 21 is disengaged from the lower outer core tube 13 under the action of elastic force.

Claims

1. A water blocking bridge plug, characterized in that: The invention comprises an upper joint (1), an upper outer sleeve (2), a fixed piston (3), a balancing piston (4), an upper core tube (5), a sealing sleeve (6), a disengaging sleeve (7), an upper sealing piston (8), a locking ball seat (9), an upper piston (10), an upper outer core tube (11), a lower sealing piston (12), a lower outer core tube (13), an upper pressure ring (14), a sealing piston (15), a locking sleeve (16), a retaining ring (17), a spacer ring (18), a center tube (19), a lower pressure ring (20), a screw plug (21), a lower spare cap (22), an unsealing pin (23), a first liquid inlet hole (24), a second liquid inlet hole (25), an upper steel ball (26), a lower steel ball (27), a third liquid inlet hole (28), a fourth liquid inlet hole (29), The fifth liquid inlet hole (30), the sixth liquid inlet hole (31) and the rubber cylinder (32), the upper joint (1) is connected to the fixed piston (3) and fixed by the unsealing pin (23), the fixed piston (3) is connected to the upper core tube (5) by threads, the balancing piston (4) is connected to the upper core tube (5), the upper outer sleeve (2) is connected to the upper joint (1), the fixed piston (3), the balancing piston (4) and the upper core tube (5), the upper core tube (5) is connected to the central tube (19) by threads, the upper core tube (5) is connected to the ball lock seat (9), the upper core tube (5) is connected to the upper outer sleeve (2), the upper outer sleeve (2) is connected to the disjoint sleeve (7), the upper piston (10) is connected to the ball lock seat (9), the sealing sleeve (6) is connected to the upper outer sleeve (2), the disjoint sleeve (7), The upper piston (10) is connected, the upper core tube (5) and the lock ball seat (9) are fixed by the lower steel ball (27), the upper core tube (5) and the upper outer sleeve (2) are fixed by the upper steel ball (26), the sealing sleeve (6) is connected to the upper sealing piston (8), the upper sealing piston (8) is connected to the upper outer core tube (11), the upper outer core tube (11) and the lower outer core tube (13) are connected by threads, the lower sealing piston (12) and the upper sealing piston (8) are connected by threads, the lower sealing piston (12) and the upper outer core tube (11) and the lower outer core tube (13) are connected, the lower sealing piston (12) and the upper pressure ring (14) are connected by threads, the sealing piston (15) and the lower outer core tube (13) are connected by threads, the upper pressure ring (14) and the lock sleeve (16) are connected by threads, and the lock The sleeve (16) is connected to the spacer ring (18), the rubber sleeve (32), the lower pressure ring (20), and the lower outer core tube (13); the lower pressure ring (20) is connected to the lower reserve cap (22) by threads; the lower outer core tube (13) is connected to the thread plug (21) by threads; the thread plug (21) is connected to the lower reserve cap (22); the lower outer core tube (13) is connected to the retaining ring (17); the lower outer core tube (13) is connected to the center tube (19); the upper core tube (5) is provided with a first liquid inlet hole (24); the upper outer sleeve (2) is provided with a second liquid inlet hole (25); the center tube (19) is provided with a third liquid inlet hole (28); the upper outer core tube (11) is provided with a fourth liquid inlet hole (29); and the lower outer core tube (13) is provided with a fifth liquid inlet hole (30) and a sixth liquid inlet hole (31).

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