Elastic pressure expansion oil sleeve plugging device

Abstract

The invention discloses an elastic pressure expansion oil sleeve plugging device, which relates to the technical field of oil well production equipment, and comprises an upper joint, an upper baffle ring, a central pipe, a lower baffle ring, an upper adjusting spring seat, a spring, a lower spring seat, a soluble baffle ring, a companding rubber cylinder upper protective cylinder, a companding rubber cylinder, a companding rubber cylinder lower protective cylinder, a sealing ball and a lower joint, the device is suitable for backflushing oil sleeve annulus blocking during oil well production, and well flushing fluid is prevented from entering a low-pressure oil layer to pollute and block the oil layer; the whole device is easy to machine and assemble, uncertain factors are not prone to occurring, and the use success rate of downhole tools is effectively increased. The diameter of the companding rubber sleeve is small during well descending, so that the companding rubber sleeve cannot be scraped by burrs on the casing wall, and the service time is prolonged. And the well is not easy to block, the service time is longer than that of a leather cup, and the sealing device is more reliable.

Description

Technical Field

[0001] The invention relates to the technical field of oil well production equipment, in particular to a spring-loaded expansion oil casing plugger. Background Art

[0002] Conventional hot washing non-pressure oil layer devices generally have the following shortcomings:

[0003] Leather cup packer + check valve type, the leather cup has a larger diameter than the casing in order to seal the oil casing space. When lowering into the well, it rubs against the casing, which can easily scratch the leather cup rubber tube, resulting in poor sealing, leakage, and easy overturning of the pipe string when lifted, reducing the number of well washing times and poor reliability.

[0004] The construction process of the release joint + packer + support pipe string type is complicated, and the pipe string needs to be lowered twice. The packer needs to be pressurized and sealed by a pressure truck. The support pipe string increases the construction cost, and the operation cycle is long and the operation cost is high. It is also easy to be buried in sand during the secondary operation. Summary of the invention

[0005] The purpose of the present invention is to provide a spring-loaded expansion oil casing plugger to solve the problems existing in the above-mentioned prior art, and the plugger has the advantages of simple structure and long service life.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a spring-expandable oil casing plug, comprising an upper joint, an upper retaining ring, a center tube, a lower retaining ring, an upper adjusting spring seat, a spring, a lower spring seat, a soluble retaining ring, an upper casing of a compression-expanding rubber tube, a compression-expanding rubber tube, a lower casing of a compression-expanding rubber tube, a sealing ball and a lower joint;

[0008] The upper joint is sleeved on the top of the center tube, the top of the upper joint is used to connect the lower oil pipe of the oil pump, the lower retaining ring is arranged at the bottom end of the inner cavity wall of the upper joint, the upper retaining ring is arranged at the top end of the outer wall of the center tube, the outer diameter of the upper retaining ring is smaller than the inner cavity diameter of the upper joint, the inner diameter of the lower retaining ring is larger than the outer diameter of the center tube, and a buffer cavity is formed between the upper retaining ring and the lower retaining ring;

[0009] The central tube is provided with a liquid-passing slot along the axial direction;

[0010] The upper adjustment spring seat is arranged at the bottom of the upper joint and sleeved on the outside of the center tube. The upper adjustment spring seat can adjust its axial position on the center tube. The lower spring seat is arranged below the upper adjustment spring seat and is slidably connected to the center tube. The spring is sleeved on the outside of the center tube and arranged between the upper adjustment spring seat and the lower spring seat.

[0011] The soluble retaining ring is arranged at the bottom of the lower spring seat, the top end of the upper casing of the compression and expansion rubber tube is clamped with the shoulder arranged at the bottom of the lower spring seat, the lower end of the upper casing of the compression and expansion rubber tube is connected to the top of the compression and expansion rubber tube through a thread, the compression and expansion rubber tube is sleeved on the outside of the central tube, the lower casing of the compression and expansion rubber tube is arranged at the bottom of the compression and expansion rubber tube sleeve and is connected through a thread, the lower joint is connected to the bottom of the central tube, the bottom of the lower casing of the compression and expansion rubber tube is sleeved on the lower joint and fixed with shear nails, the sealing ball is arranged in the inner cavity of the lower joint, and can seal the liquid hole of the lower joint.

[0012] Preferably, the upper retaining ring is connected to the central tube via threads and stabilizing pins, and the lower retaining ring is connected to the upper joint via threads and stabilizing pins.

[0013] Preferably, the upper adjusting spring seat is connected to the central tube via a threaded connection.

[0014] Preferably, the material of the soluble retaining ring is soluble metal.

[0015] Preferably, the soluble retaining ring is threadedly connected to the outside of the central tube.

[0016] Preferably, the bottom end of the lower casing of the compression and expansion rubber tube is sleeved on the outside of the top outer wall of the lower joint, and the lower casing of the compression and expansion rubber tube is connected to the lower joint by unsealing shear nails.

[0017] Preferably, a sealing rubber ring is provided at the connection between the lower casing of the compression and expansion rubber cylinder and the lower joint.

[0018] Preferably, a ball baffle is provided between the inner cavity of the lower joint and the tube cavity of the central tube, and a plurality of liquid holes are provided on the ball baffle.

[0019] Preferably, a pressure relief seam is provided on the outer side of the compression and expansion rubber cylinder along the radial direction, and a pressure relief groove is provided on the inner side of the compression and expansion rubber cylinder.

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

[0021] The elastic expansion casing plug in the present invention is suitable for backwashing well casing annulus blocking during oil well production to prevent well washing fluid from entering the low-pressure oil layer and contaminating and blocking the oil layer; the entire device is simple to process and easy to assemble, and is not prone to uncertain factors, effectively improving the success rate of downhole tool use. When going down the well, the diameter of the pressure expansion rubber tube is small and will not be scratched by the burrs on the casing wall, extending the service life. When lifting up, there are two ways to unseal, which is not easy to get stuck in the well, and has a longer service life and is more reliable than the leather cup. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a structural schematic diagram of the elastic expansion sleeve plugging device in the present invention;

[0024] Figure 2 It is a schematic diagram of the working state in the casing of the present invention;

[0025] In the figure: 1. upper joint; 2. upper retaining ring; 3. center tube; 4. lower retaining ring; 5. upper adjusting spring seat; 6. spring; 7. lower spring seat; 8. soluble retaining ring; 9. upper casing of compression expansion rubber cylinder; 10. compression expansion rubber cylinder; 11. lower casing of compression expansion rubber cylinder; 12. unsealing shear pins; 13. ball retaining plate; 14. sealing ball; 15. lower joint; 16. stabilizing pins; 17. liquid gap; 18. rubber ring; 19. casing; 20. oil pipe; 21. buffer chamber; 22. sand control pipe. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The purpose of the present invention is to provide a spring-loaded expansion oil sleeve plugger to solve the problems existing in the prior art.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] The spring-pressed expansion sleeve plug in this embodiment is as follows: Figure 1-Figure 2 As shown, it includes an upper joint 1, an upper retaining ring 2, a center tube 3, a lower retaining ring 4, an upper adjusting spring seat 5, a spring 6, a lower spring seat 7, a soluble retaining ring 8, an upper casing 9 of a compression expansion rubber tube, a compression expansion rubber tube 10, a lower casing 11 of a compression expansion rubber tube, a sealing ball 14 and a lower joint 15;

[0030] The upper joint 1 is sleeved on the top of the center pipe 3. The top of the upper joint 1 is used to connect the lower oil pipe 20 of the oil pump. The bottom end of the inner cavity wall of the upper joint 1 is provided with a lower retaining ring 4. The top end of the outer wall of the center pipe 3 is provided with an upper retaining ring 2. The outer diameter of the upper retaining ring 2 is smaller than the inner cavity diameter of the upper joint 1. The inner diameter of the lower retaining ring 4 is larger than the outer diameter of the center pipe 3. A buffer cavity 21 is formed between the upper retaining ring 2 and the lower retaining ring 4.

[0031] The central tube 3 is provided with a liquid gap 17 along the axial direction;

[0032] The upper adjusting spring seat 5 is arranged at the bottom of the upper joint 1 and sleeved on the outside of the center tube 3. The upper adjusting spring seat 5 can adjust its axial position on the center tube 3. The lower spring seat 7 is arranged below the upper adjusting spring seat 5 and is slidably connected with the center tube 3. The spring 6 is sleeved on the outside of the center tube 3 and arranged between the upper adjusting spring seat 5 and the lower spring seat 7.

[0033] The soluble retaining ring 8 is arranged at the bottom of the lower spring seat 7, the top end of the upper casing 9 of the compression and expansion rubber tube is clamped with the shoulder arranged at the bottom of the lower spring seat 7, the lower end of the upper casing 9 of the compression and expansion rubber tube is connected to the top of the compression and expansion rubber tube 10 through a thread, the compression and expansion rubber tube 10 is sleeved on the outside of the central tube 3, the lower casing 11 of the compression and expansion rubber tube is arranged at the bottom of the compression and expansion rubber tube 10 sleeve and is connected through a thread, the lower joint 15 is connected to the bottom of the central tube 3, the bottom of the lower casing 11 of the compression and expansion rubber tube is sleeved on the lower joint 15 and fixed with shear nails, the sealing ball 14 is arranged in the inner cavity of the lower joint 15, and can seal the liquid hole of the lower joint 15.

[0034] In this specific embodiment, the upper retaining ring 2 is connected to the central tube 3 through threads and stabilizing pins, and the lower retaining ring 4 is connected to the upper joint 1 through threads and stabilizing pins 16 .

[0035] In this specific embodiment, the upper adjusting spring seat 5 and the central tube 3 are connected via threads.

[0036] In this specific embodiment, the material of the soluble retaining ring 8 is soluble metal.

[0037] In this specific embodiment, the soluble retaining ring 8 is threadedly connected to the outside of the central tube 3 .

[0038] In this specific embodiment, the bottom end of the compression and expansion rubber tube lower casing 11 is sleeved on the outside of the top outer wall of the lower joint 15, and the compression and expansion rubber tube lower casing 11 and the lower joint 15 are connected by the unsealing shear nail 12.

[0039] In this specific embodiment, a sealing rubber ring 18 is provided at the connection between the compression and expansion rubber sleeve lower casing 11 and the lower joint 15 .

[0040] In this specific embodiment, a ball baffle plate 13 is disposed between the inner cavity of the lower joint 15 and the tube cavity of the central tube 3 , and a plurality of liquid passing holes are disposed on the ball baffle plate 13 .

[0041] In this specific embodiment, a pressure relief seam is disposed on the outer side of the compression expansion rubber cylinder 10 along the radial direction, and a pressure relief groove is disposed on the inner side of the compression expansion rubber cylinder 10 .

[0042] The working principle of the elastic expansion sleeve plugger in the present invention is as follows:

[0043] The upper joint 1 is threadedly connected to the lower oil pipe 20 of the oil well pump, and the lower joint 15 is connected to the sand control pipe 22;

[0044] The soluble baffle ring 8 presses against the lower spring seat 7 so that the pre-tightened spring 6 cannot go down. The upper spring 6 seat is adjusted according to the compression distance to keep the diameter of the compression expansion rubber tube 10 unchanged. After the device is lowered into the oil well for a period of time, the underground oil and water impact the soluble baffle ring 8 through the liquid gap 17 on the central pipe 3 to dissolve the threads on the soluble baffle ring 8. When the elastic force of the spring 6 is greater than the resistance of the soluble baffle ring 8, the spring 6 pushes the lower spring seat 7, the soluble baffle ring 8 and the upper casing 9 of the compression expansion rubber tube to compress the compression expansion rubber tube 10, so that the compression expansion rubber tube 10 expands and seals to the wall of the casing 19 to seal the oil casing annulus.

[0045] After a period of production, the oil pipe 20 is waxed and the oil output decreases. Backwashing is required at this time. When the well washing fluid passes through the oil casing annulus downward, the compression expansion rubber tube 10 is sealed against the casing wall, and the well washing fluid can only enter from the liquid gap 17 on the central pipe 3. The downward movement is blocked by the sealing ball 14, and the well washing fluid can only go upward through the central pipe 3 and the oil pipe 20 to return to the ground. The well washing fluid cannot enter the formation, protecting the oil layer from being contaminated and blocked by the well washing fluid. When pumping oil, the well washing fluid that has entered the oil layer can be pumped out to achieve the purpose of energy saving.

[0046] When pumping oil, the up and down strokes make the downhole tubing move up and down. The upper retaining ring 2 and the lower retaining ring 4 of the device have a certain space. When the compression expansion rubber tube 10 of the device is attached to the casing wall, only the upper joint 1 moves up and down when pumping oil up and down, and the part below the center pipe 3 does not move, thereby increasing the service life of the compression expansion rubber tube 10.

[0047] When the downhole tubing is lifted up for the next operation, the lower retaining ring 4 on the upper joint 1 moves upward against the upper retaining ring 2 on the center pipe 3 to bring out the compression expansion rubber tube 10 and unseal it. If the compression expansion rubber tube 10 cannot be brought out smoothly, the unsealing shear nails 12 will cut off the lower casing 11 of the compression expansion rubber tube and move downward when a certain load is reached, so that the spring 6 can be straightened, the compression expansion rubber tube 10 can restore its original diameter, and the tubing can be lifted out smoothly.

[0048] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A spring-loaded expansion casing plug, characterized in that: It includes an upper joint, an upper retaining ring, a center tube, a lower retaining ring, an upper adjusting spring seat, a spring, a lower spring seat, a soluble retaining ring, an upper casing of a compression expansion rubber tube, a compression expansion rubber tube, a lower casing of a compression expansion rubber tube, a sealing ball and a lower joint; The upper joint is sleeved on the top of the center tube, the top of the upper joint is used to connect the lower oil pipe of the oil pump, the lower retaining ring is arranged at the bottom end of the inner cavity wall of the upper joint, the upper retaining ring is arranged at the top end of the outer wall of the center tube, the outer diameter of the upper retaining ring is smaller than the inner cavity diameter of the upper joint, the inner diameter of the lower retaining ring is larger than the outer diameter of the center tube, and a buffer cavity is formed between the upper retaining ring and the lower retaining ring; The central tube is provided with a liquid-passing slot along the axial direction; The upper adjustment spring seat is arranged at the bottom of the upper joint and sleeved on the outside of the center tube. The upper adjustment spring seat can adjust its axial position on the center tube. The lower spring seat is arranged below the upper adjustment spring seat and is slidably connected to the center tube. The spring is sleeved on the outside of the center tube and arranged between the upper adjustment spring seat and the lower spring seat. The soluble retaining ring is arranged at the bottom of the lower spring seat, the top end of the upper casing of the compression and expansion rubber tube is clamped with the shoulder arranged at the bottom of the lower spring seat, the lower end of the upper casing of the compression and expansion rubber tube is connected to the top of the compression and expansion rubber tube through a thread, the compression and expansion rubber tube is sleeved on the outside of the central tube, the lower casing of the compression and expansion rubber tube is arranged at the bottom of the compression and expansion rubber tube sleeve and is connected through a thread, the lower joint is connected to the bottom of the central tube, the bottom of the lower casing of the compression and expansion rubber tube is sleeved on the lower joint and fixed with shear nails, the sealing ball is arranged in the inner cavity of the lower joint, and can seal the liquid hole of the lower joint.

2. The elastic expansion sleeve plug according to claim 1 is characterized in that: The upper retaining ring is connected to the central tube via threads and stabilizing pins, and the lower retaining ring is connected to the upper joint via threads and stabilizing pins.

3. The elastic expansion sleeve plug according to claim 1, characterized in that: The upper adjusting spring seat is connected to the central tube via threads.

4. The elastic expansion sleeve plug according to claim 1, characterized in that: The material of the soluble retaining ring is soluble metal.

5. The elastic expansion oil sleeve plug according to claim 1, characterized in that: The soluble retaining ring is threadedly connected to the exterior of the central tube.

6. The elastic expansion sleeve plug according to claim 1, characterized in that: The bottom end of the lower casing of the compression and expansion rubber tube is sleeved on the outside of the top outer wall of the lower joint, and the lower casing of the compression and expansion rubber tube is connected to the lower joint by unsealing shear nails.

7. The elastic expansion oil sleeve plug according to claim 1, characterized in that: A sealing rubber ring is provided at the connection between the lower casing of the compression and expansion rubber cylinder and the lower joint.

8. The elastic expansion oil sleeve plug according to claim 1, characterized in that: A ball baffle is provided between the inner cavity of the lower joint and the tube cavity of the central tube, and a plurality of liquid holes are provided on the ball baffle.

9. The elastic expansion sleeve plug according to claim 1, characterized in that: A decompression seam is arranged radially on the outer side of the compression and expansion rubber cylinder, and a decompression groove is arranged on the inner side of the compression and expansion rubber cylinder.

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