Sand blasting packer structure with high safety performance for gas well overhaul

Abstract

The invention relates to the technical field of oil field gas well overhaul equipment, in particular to a high-safety-performance sand blasting packer structure for gas well overhaul, which comprises a main body and a sliding sleeve, the sliding sleeve is sleeved in the main body, a rubber sleeve is connected with the main body through an upper rubber sleeve seat and a lower rubber sleeve seat outside the main body, and the upper end of the main body is provided with a throttling hole and a setting opening. The setting opening corresponds to the rubber sleeve in position; a through hole and a working hole which are respectively opposite to the throttling hole and the setting opening are formed in the sliding sleeve; a lower joint is arranged below the main body; a pressure relief opening is formed in the lower joint; the bottom end of the sliding sleeve blocks the pressure relief opening and can move downwards through ball throwing. According to the high-safety-performance sand blasting packer structure for gas well overhaul, the pressure relief opening is formed in the lower connector, the pressure relief opening is blocked through the sliding sleeve, when the rubber barrel cannot be recycled, the sliding sleeve descends to unblock the pressure relief opening to connect the interior and the exterior of the main body, at the moment, the device can conduct forward and reverse or squeezing injection well killing, subsequent procedures continue to be conducted, and the safety performance of the device is improved. And normal operation of work is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of overhaul equipment for oilfield gas wells, and particularly to a sandblasting packer structure with high safety performance for overhaul of gas wells. Background Art

[0002] During the overhaul of oilfield gas wells, equipment needs to be assembled into a tool string in a certain order and then lowered into the well to conduct operations such as channel checking of the casing in the perforated section of the well, testing the injection volume, or conducting step-by-step pressure testing and leakage detection on the casing above the perforated section. In the prior art, after the packer is pressured and released in the well, since the rubber cylinder is soaked in the kill fluid for a long time and is severely corroded and eroded by the downhole environment and the kill fluid, the phenomenon that the rubber cylinder of the packer cannot be recovered after working often occurs. At this time, the entire pipe string cannot be lifted or lowered, and the subsequent processes cannot proceed normally. At the same time, the kill fluid passage is blocked. If directly lifted forcefully, a blowout accident will occur, posing a great safety hazard. Therefore, in view of the above deficiencies, a sandblasting packer structure with high safety performance for overhaul of gas wells is proposed. Summary of the Invention

[0003] (I) Technical Problems to be Solved In view of the deficiencies of the prior art, the present invention provides a sandblasting packer structure with high safety performance for overhaul of gas wells, which solves the problems that the packer cannot contract after being eroded underground, resulting in the inability to lift or lower the pipe string, the subsequent processes cannot continue, and directly lifting forcefully will cause a blowout accident with potential safety hazards.

[0004] (II) Technical Solutions To solve the above problems, the present invention provides a sandblasting packer structure with high safety performance for overhaul of gas wells, including: A main body and a sliding sleeve. A rubber cylinder is provided outside the main body. A radial throttle hole is provided on the side wall of the main body, and the throttle hole is located above the rubber cylinder. A setting port is provided on the side wall of the main body, and the setting port corresponds to the position of the rubber cylinder. The pressure inside the main body pushes the rubber cylinder to expand and set through the setting port. Upper and lower rubber cylinder seats are respectively provided at the upper and lower ends of the rubber cylinder, and the upper and lower rubber cylinder seats are respectively connected to the main body and fix the two ends of the rubber cylinder. A lower joint is provided at the bottom end of the main body, and a pressure relief hole is provided on the side wall of the lower joint. The sliding sleeve is sleeved inside the main body. A through hole corresponding to the throttle hole is provided on the sliding sleeve. The pressure inside the main body is discharged outward through the throttle hole. A working hole corresponding to the position of the setting port is provided on the outer wall of the sliding sleeve, and the bottom of the sliding sleeve seals the inner wall of the pressure relief hole. The inner wall edge at the top end of the sliding sleeve is a tapered surface that contracts downward, and the sliding sleeve can be pushed to move downward by dropping a steel ball.

[0005] Preferably, an upper joint is provided at the top end of the main body, and it is connected to other devices above through the upper joint.

[0006] Preferably, the main body and the upper joint are connected by anti-rotation pins, and several first sealing rings are arranged between the upper joint and the main body.

[0007] Preferably, between the sliding sleeve and the main body, several second sealing rings are respectively arranged at the upper and lower ends of the through hole and the pressure relief port.

[0008] Preferably, the diameter of the throttle hole is in the range of 15 - 20 mm.

[0009] Preferably, the upper rubber cylinder seat, the rubber cylinder and the lower rubber cylinder seat are made of steel wire.

[0010] Preferably, the sliding sleeve and the main body are connected by shear pins. When the pressure on the sliding sleeve is greater than the stress limit of the shear pins, the shear pins are cut off and the sliding sleeve moves downward.

[0011] Preferably, the diameter of the through hole on the sliding sleeve is larger than the diameter of the throttle hole.

[0012] (III) Beneficial Effects The high-safety sandblasting packer structure for major overhaul of gas wells provided by the present invention has a pressure relief port provided on the lower joint, and the pressure relief port is blocked by a sliding sleeve. When the rubber cylinder cannot be recovered, the pressure relief port is unsealed by moving the sliding sleeve downward to connect the inside and outside of the main body. At this time, the device can carry out forward and reverse or squeeze injection well killing to continue the subsequent processes and ensure the normal progress of the work. Description of the Drawings

[0013] Figure 1 It is a schematic structural diagram of the high-safety sandblasting packer structure for major overhaul of gas wells of the present invention.

[0014] Among them, 1. Upper joint; 2. Anti-rotation pin; 3. First sealing ring; 4. Main body; 5. Second sealing ring; 6. Sliding sleeve; 7. Shear pin; 8. Upper rubber cylinder seat; 9. Rubber cylinder; 10. Lower rubber cylinder seat; 11. Lower joint. Embodiment

[0015] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0016] In the description of the present invention, it is necessary to understand that the orientation or positional relationship indicated by "upper", "lower", "inner", "outer", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings. The purpose is only to facilitate the description of the present invention and simplify the description, rather than indicating or implying that the component to be referred must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0017] As Figure 1 shown, the present invention provides a sandblasting packer structure with high safety performance for major repairs of gas wells, specifically including: a main body 4 and a sliding sleeve 6, and the sliding sleeve 6 is sleeved inside the main body 4. The top of the main body 4 is provided with an upper joint 1, and is connected to other devices through the upper joint 1 to form a tool string. The top of the main body 4 is connected to the upper joint 1 by threads. During the working process, pressure is applied to other components of the device through the main body 4.

[0018] Among them, an anti-rotation pin 2 is provided between the main body 4 and the upper joint 1. The anti-rotation pin 2 fixes the positions of the main body 4 and the upper joint 1 to prevent the main body 4 and the upper joint 1 from rotating during downhole operation, resulting in the disassembly of the device.

[0019] It should be noted that several first sealing rings 2 are provided between the main body 4 and the upper joint 1. The first sealing rings 2 seal the space between the main body 4 and the upper joint 1 to prevent the pressure liquid from escaping from the connection between the upper joint 1 and the main body 4 during the working process, improving the sealing performance of the device.

[0020] In the present invention, a rubber cylinder 9 is provided outside the main body 4. Upper rubber cylinder seats 8 and lower rubber cylinder seats 10 are respectively provided at the upper and lower ends of the rubber cylinder 9. The upper rubber cylinder seats 8 and the lower rubber cylinder seats 10 are respectively connected to the main body 4 and fix the upper and lower ends of the rubber cylinder 9. During the working process, the initial state of the rubber cylinder 9 is a contracted state. When the pressure inside the main body 4 increases, the liquid squeezes the rubber cylinder 9 to make the rubber cylinder 9 expand outward and set, thereby fixing the tool string in the well. The upper rubber cylinder seats 8 and the lower rubber cylinder seats 10 fix the two ends of the rubber cylinder 9 to prevent the rubber cylinder 9 from detaching from the main body 4 after expansion during the working process, resulting in the disassembly of the device and blocking the gas well.

[0021] Among them, the rubber cylinder 9, the upper rubber cylinder seats 8 and the lower rubber cylinder seats 10 are all made of wire braiding, enhancing the structural strength of the rubber cylinder 9, enabling it to better adapt to the downhole environment, reducing the erosion affected by the downhole environment, and improving the recovery effect of the device.

[0022] As Figure 1As shown, radial throttle holes are provided on the side wall of the main body 4, and through holes corresponding to the positions of the throttle holes are provided on the sleeve 6. The positions of the throttle holes are above the rubber cylinder 9. During the working process, the throttle holes can connect the internal and external environments of the main body 4, and conduct the pressure inside the main body 4 to the outside of the main body 4 through the throttle holes and the through holes at the beginning of the work, preventing the rubber cylinder 9 from being seated prematurely before reaching the working position during the lowering process of the tool string and affecting the normal progress of the work.

[0023] Among them, a setting hole is provided on the side wall of the main body 4, and the position of the setting hole corresponds to the position of the rubber cylinder 9. A working hole corresponding to the position of the setting hole is provided on the side wall of the sleeve 6. When the device is lowered to the working position, the liquid pressure inside the main body 4 increases, and the pressurized liquid enters the rubber cylinder 9 through the working hole and the setting hole, causing the rubber cylinder 9 to expand outwards and be seated to fix the position of the tool string. A plurality of second sealing rings 5 are respectively provided on the upper and lower sides of the through hole between the sliding sleeve 6 and the main body 4 to prevent liquid from flowing between the sliding sleeve 6 and the main body 4 during the working process and improve the sealing performance of the device.

[0024] It should be noted that the diameter of the throttle hole is generally between 15 - 20 mm, which can not only discharge the pressure inside the main body 4 to prevent the rubber cylinder 9 from being seated prematurely at the initial stage of downhole work, but also cause the internal pressure to build up when the liquid pressure inside the main body 4 increases, enabling the rubber cylinder 9 to be seated normally.

[0025] In the present invention, a lower sub 11 is provided below the main body 4, and is connected to other devices through the lower sub 11 to form a tool string. A through relief port is provided on the lower sub 11. When the rubber cylinder 9 cannot contract normally, the internal and external spaces of the main body 4 are connected through the relief port. At this time, the device can perform forward and reverse or squeeze and inject kill well operations to continue the subsequent processes and ensure the normal progress of the work.

[0026] Among them, the bottom end of the sliding sleeve 6 seals the inside of the relief port, enabling the device to control the connection state between the inside and outside of the main body 4 by controlling the downward movement of the sliding sleeve 6 during the working process, making the working state of the device controllable. The top end of the sliding sleeve 6 is a downwardly tapered surface. During the working process, a steel ball matching the size of the top end of the sliding sleeve 6 is dropped downwards to seal the top end of the sliding sleeve 6, causing the inside of the device to be pressurized. When the downward pressure on the sliding sleeve 6 is greater than the stress limit of the shear pin 7, the shear pin 7 breaks. At this time, the sliding sleeve 6 moves downward to open the relief port, and the inside and outside of the main body 4 are connected to form a stable channel. Through the channel, forward and reverse or squeeze and inject kill well operations can be carried out at any time to continue the subsequent processes and ensure the normal progress of the work.

[0027] It should be noted that the inner diameter of the through hole on the sliding sleeve 6 is larger than that of the throttle hole to ensure the fluidity of the throttle hole. When the steel ball just contacts the conical surface at the top of the sliding sleeve 6, the excess liquid in the sliding sleeve 6 is squeezed out of the main body 4 through the through hole and the throttle hole, reducing the internal pressure and improving the safety of the device. Between the sliding sleeve 6 and the lower joint 11, second sealing rings 5 are respectively provided on the upper and lower sides of the pressure relief port to prevent the liquid from escaping from the pressure relief port when the sliding sleeve 6 does not move downward during the working process, resulting in poor setting effect of the rubber cylinder 9 and waste of the pressure liquid, improving the sealing performance and economy of the device, and reducing the waste of the working medium.

[0028] In the actual application process, in addition to the pressure test process, the present invention can also be applied to the injection test process. At this time, the throttle hole functions as a sandblasting port. By providing a throttle hole capable of achieving a sandblasting effect while providing a rubber cylinder 9 outside the main body 4, the packer and the sandblaster are combined. The structure of the upper pipe string no longer affects the pressure stabilization effect. At the same time, due to the size limitation of the throttle hole, the fluid velocity ejected during the sandblasting process is significantly reduced, effectively solving the problem of casing damage during construction and extending the service life of the oil and gas well.

[0029] The high-safety sandblasting packer structure for major repairs of gas wells provided by the present invention can form a stable channel by connecting the inside and outside of the main body through the downward movement of the sliding sleeve to release the pressure relief port when the rubber cylinder cannot be recovered. At this time, the device can perform forward and reverse or squeeze injection well killing, and continue with the subsequent processes to ensure the normal progress of the work. The specific working process of the device is as follows: First, assemble the device on the tool string according to the working requirements and lower it into the well casing with the tool string. During this process, the pressure inside the main body is low, and the excess pressure flows from the throttle hole to the outside of the main body to maintain the internal pressure and prevent the rubber cylinder from being pressured and set during the downhole process.

[0030] Then, after the device is sent to the working position, increase the liquid pressure inside the main body. At this time, the liquid flows into the rubber cylinder, and the pressure after relieving pressure through the throttle hole is still sufficient to push the rubber cylinder to expand and set, fixing the position of the tool string.

[0031] Finally, after other processes are completed, the liquid inside the main body is depressurized. When the rubber cylinder cannot shrink, a steel ball is dropped to form a squeeze injection channel. After the ball is dropped, the steel ball cooperates with the top of the sliding sleeve to squeeze the sliding sleeve downward and cut off the shear pin. At this time, the sliding sleeve moves downward to open the pressure relief port to connect the inside and outside of the main body to form a channel. At this time, forward and reverse or squeeze injection well killing can be performed through the channel, and the subsequent processes can be continued.

[0032] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A sandblasting packer structure with high safety performance for major repairs of gas wells, characterized in that, Comprising: A body (4) and a sliding sleeve (6), an outer rubber cylinder (9) is provided on the body (4), radial throttle holes are provided on the side wall of the body (4), and the throttle holes are located above the rubber cylinder (9); a setting and sealing port is provided on the side wall of the body (4), the setting and sealing port corresponds to the position of the rubber cylinder (9), and the pressure inside the body (4) pushes the rubber cylinder (9) to expand and set the seal through the setting and sealing port; upper and lower rubber cylinder seats (8) and (10) are respectively provided at the upper and lower ends of the rubber cylinder (9), the upper and lower rubber cylinder seats (8) and (10) are respectively connected to the body (4) and fix the two ends of the rubber cylinder (9); a lower sub (11) is provided at the bottom end of the body (4), and a pressure relief hole is provided on the side wall of the lower sub (11); the sliding sleeve (6) is sleeved inside the body (4), a through hole corresponding to the throttle hole is provided on the sliding sleeve (6), the pressure inside the body (4) is discharged outwards through the throttle hole, a working hole corresponding to the position of the setting and sealing port is provided on the outer wall of the sliding sleeve (6), and the bottom of the sliding sleeve (6) seals the inner wall of the pressure relief hole; the inner wall edge at the top end of the sliding sleeve (6) is a tapered surface that contracts downwards, and the sliding sleeve (6) can be pushed to move downwards by dropping a steel ball downwards.

2. The sandblasting packer structure with high safety performance for major repairs of gas wells according to claim 1, characterized in that, An upper sub (1) is provided at the top end of the body (4), and is connected to other devices above through the upper sub (1).

3. The structure of the sandblasting packer with high safety performance for major repairs of gas wells according to claim 2, characterized in that, The body (4) and the upper sub (1) are connected through anti-rotation pin studs (2), and several first sealing rings (3) are provided between the upper sub (1) and the body (4).

4. The sandblasting packer structure with high safety performance for major overhaul of gas wells according to claim 1, characterized in that, Between the sliding sleeve (6) and the body (4), several second sealing rings (5) are respectively provided at the upper and lower ends of the through hole and the pressure relief port.

5. The structure of the sandblasting packer with high safety performance for major repair of gas wells according to claim 1, characterized in that, The diameter of the throttle hole is in the range of 15 - 20 mm.

6. The sandblasting packer structure with high safety performance for major overhaul of gas wells according to claim 1, characterized in that, The upper rubber cylinder seat (8), the rubber cylinder (9) and the lower rubber cylinder seat (10) are made of steel wire.

7. The sandblasting packer structure with high safety performance for major overhaul of gas wells according to claim 1, characterized in that, The sliding sleeve (6) and the body (4) are connected through a shear pin (7), and when the pressure on the sliding sleeve (6) is greater than the stress limit of the shear pin (7), the shear pin (7) is cut off and the sliding sleeve (6) moves downwards.

8. The structure of the sandblasting packer with high safety performance for major repairs of gas wells according to claim 7, characterized in that, The diameter of the through hole on the sliding sleeve (6) is larger than the diameter of the throttle hole.

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