A reversible force increasing device for downhole workover of oil and gas wells

Abstract

The application discloses a reversible force increasing device for downhole workover operation of oil and gas water well, which comprises an upper pulling liquid cylinder and a lower pressing liquid cylinder, and the outer surface of a central control pipe is connected with more than one upper pulling liquid cylinder and is provided with a balanced liquid inlet one-way valve at the lower end of the central control pipe; the upper pulling liquid cylinder outside the central control pipe is hung above the hanging step of the outer wall of the central control pipe through a central pipe connector pressure cap and a central pipe connector; more than one lower pressing liquid cylinder is connected below the central control pipe through a conversion joint and is provided with a balanced liquid inlet one-way valve below the lowermost lower pressing liquid cylinder; a workover tool joint is connected below the lowermost lower pressing liquid cylinder; and the lowermost upper pulling liquid cylinder outside the central control pipe is connected with the conversion joint. The application solves the problem that the existing hydraulic force increasing device cannot perform reversing work, provides a reversible force increasing tool which can increase force upward and downward, and provides safety guarantee for the whole workover operation pipe column.

Description

Technical Field

[0001] This invention relates to a booster device for downhole workover tools in the petroleum industry, and more particularly to a reversible booster device for downhole workover operations in oil, gas and water wells. Background Technology

[0002] As major oilfields both domestically and internationally enter the later stages of exploitation, the service life of casings is nearing its end, and various downhole problems are becoming increasingly apparent. More and more downhole casing damage issues are emerging, such as casing breakage, casing diameter reduction, and casing bending, among which casing bending is the most difficult to manage. This is because bending inevitably involves diameter reduction, and the metal casings used in oil, gas, and water wells have a certain range of elastic deformation. Therefore, when managing wells with bent casings, not only are there no specialized tools for repairing casing bends, but using other large-diameter downhole tools designed to address casing diameter reduction is also very likely to result in the casing springback causing them to become stuck.

[0003] Existing hydraulic booster devices, such as the "A Downhole Unblocking Hydraulic Booster" disclosed in CN204060596U, can only perform unidirectional retrieval boosting. The direction of the shaping boosting, which is opposite to the boosting direction, is fixed to the downward shaping direction. They can only play a unidirectional role during well workover and cannot simultaneously have the function of bidirectional boosting. Therefore, they cannot play the role of boosting force to unblock when the shaping tool in a curved well encounters obstruction.

[0004] Therefore, to effectively address the problem of casing bending in oil, gas, and water wells, it is necessary to overcome the limitation that existing downhole hydraulic booster devices can only work in one direction. Summary of the Invention

[0005] To address the limitation of existing hydraulic booster devices for well workover that cannot simultaneously provide bidirectional boosting, this invention provides a reversible booster device for downhole workover operations in oil, gas, and water wells. This device offers a tool for bidirectional boosting operations in oil, gas, and water wells with bent casing, meeting the needs of well workover processes and solving the current challenges in repairing bent casing wells. It also reduces production costs, minimizes economic losses caused by bent casing wells to oilfields, and improves the economic efficiency of oilfields.

[0006] The technical solution of the present invention is as follows: A reversible booster device for downhole workover operations in oil, gas and water wells includes an upward-pulling hydraulic cylinder and a downward-pressing hydraulic cylinder, wherein: one or more upward-pulling hydraulic cylinders are connected to the outside of the central control pipe and a balanced inlet flow valve is installed at the lower end of the central control pipe; the upward-pulling hydraulic cylinders outside the central control pipe are suspended on the suspension step on the outer wall of the central control pipe through the pressure cap of the central pipe connector and the central pipe connector; one or more downward-pressing hydraulic cylinders are connected to the lower part of the central control pipe by a conversion joint and a balanced inlet flow valve is installed below the lowermost downward-pressing hydraulic cylinder; the workover tool connector is connected below the lowermost downward-pressing hydraulic cylinder; the downward-pulling hydraulic cylinder connected to the lowermost part of the central control pipe is connected to the conversion joint.

[0007] Preferably, the number of upward-pulling cylinders and downward-pressing cylinders connected in the reversible power booster device can be equal or unequal, and the number of upward-pulling cylinders and downward-pressing cylinders connected in series in the reversible power booster device can be increased or decreased according to the repair needs of the downhole casing.

[0008] Preferably, the outside of the central control tube is connected to three upward-pulling cylinders via a central tube connector and an upper protective cylinder. These three upward-pulling cylinders are a primary upward-pulling cylinder, a secondary upward-pulling cylinder, and a tertiary upward-pulling cylinder. The primary upward-pulling cylinder mainly consists of an outer cylinder connector for the first upward-pulling cylinder, an upward-pulling central tube, a connector for the first upward-pulling central tube, and an outer cylinder for the first upward-pulling cylinder. The secondary upward-pulling cylinder mainly consists of an outer cylinder connector for the second upward-pulling cylinder, an upward-pulling central tube, a connector for the second upward-pulling central tube, and an outer cylinder for the second upward-pulling cylinder. The tertiary upward-pulling cylinder mainly consists of an outer cylinder connector for the third upward-pulling cylinder, an upward-pulling central tube, an outer cylinder for the third upward-pulling cylinder, and a connector for the third upward-pulling central tube. Pressure relief holes are provided in the cylinders near the lower threaded connection section of the upper protective cylinder, the outer cylinder of the first upper pull liquid cylinder, the outer cylinder of the second upper pull liquid cylinder, and the outer cylinder of the third upper pull liquid cylinder. The three upper pull liquid cylinders are sequentially threaded to the lower part of the upper protective cylinder from top to bottom through the joint of the first upper pull liquid cylinder, the outer cylinder of the first upper pull liquid cylinder, the joint of the second upper pull liquid cylinder, the outer cylinder of the second upper pull liquid cylinder, the joint of the third upper pull liquid cylinder, and the outer cylinder of the third upper pull liquid cylinder. The three upper pull liquid cylinders are sequentially threaded to the lower part of the center tube connector from top to bottom through the first upper pull center tube, the joint of the first upper pull center tube, the second upper pull center tube, the joint of the second upper pull center tube, the third upper pull center tube, and the joint of the third upper pull center tube.

[0009] Preferably, the central control tube, the first connector of the upward-pulling central tube, the second connector of the upward-pulling central tube, and the third connector of the upward-pulling central tube are all provided with pressure transmission holes, and the upper inner circle and the lower inner circle of the third connector of the upward-pulling central tube are provided with pressure transmission grooves that do not penetrate the cylinder of the third connector of the upward-pulling central tube; a liquid flow annular gap is provided between the second and third connectors of the upward-pulling central tube and the central control tube; the central control tube, the first connector of the upward-pulling central tube, the second connector of the upward-pulling central tube, the pressure transmission holes and pressure transmission grooves provided in the third connector of the upward-pulling central tube, and the liquid flow annular gap between the second and third connectors of the upward-pulling central tube and the central control tube constitute the liquid inlet channel between the central control tube and each upward-pulling liquid cylinder.

[0010] Preferably, when the central control tube is at the bottom dead center of the reversing stroke of the externally connected upward hydraulic cylinder, the pressure transmission hole located at the lower part of the central control tube corresponds to the pressure transmission groove on the lower inner circle of the three-joint of the upward central tube, and sealing rings are installed above and below the pressure transmission hole at the lower part of the central control tube.

[0011] Preferably, pressure relief holes are provided above the lower threaded sections of the upper protective cylinder, the first outer cylinder of the upper pull liquid cylinder, the second outer cylinder of the upper pull liquid cylinder, and the third outer cylinder of the upper pull liquid cylinder. The pressure relief holes in the upper protective cylinder, the first outer cylinder of the upper pull liquid cylinder, the second outer cylinder of the upper pull liquid cylinder, and the third outer cylinder of the upper pull liquid cylinder constitute the pressure relief channel of the upper pull liquid cylinder connected to the outside of the central control pipe.

[0012] Preferably, the balanced inlet flow valve mainly consists of a balanced inlet flow valve retaining ring, a balanced inlet flow valve outer cylinder, a balanced inlet flow valve spring, and a sealing ball. The balanced inlet flow valve retaining ring, the balanced inlet flow valve spring, and the sealing ball are installed sequentially from top to bottom inside the balanced inlet flow valve outer cylinder 4. The upper end of the balanced inlet flow valve outer cylinder is threaded to connect with the lower thread of the central control pipe. The lower inner cavity of the balanced inlet flow valve outer cylinder is a ball seat with a larger upper inner diameter and a smaller lower inner diameter. The lower body of the balanced inlet flow valve retaining ring is a spring mounting cavity, and the upper body is provided with a liquid flow hole. The balanced inlet flow valve spring is installed inside the balanced inlet flow valve outer cylinder 4 and is located between the balanced inlet flow valve retaining ring and the sealing ball.

[0013] Preferably, the distance between the pressure transmission grooves in the upper and lower inner circles of the three-way connector of the pull-up center tube matches the height of the upper inner cavity of the center tube connector.

[0014] Preferably, three hydraulic cylinders are connected below the central control pipe by the conversion joint. These three hydraulic cylinders are a primary hydraulic cylinder, a secondary hydraulic cylinder, and a tertiary hydraulic cylinder. The primary hydraulic cylinder mainly consists of a conversion joint, a first-stage hydraulic cylinder, a first-stage hydraulic cylinder outer cylinder, and a connector for the first-stage hydraulic cylinder outer cylinder. The secondary hydraulic cylinder mainly consists of a first-stage hydraulic cylinder connector, a second-stage hydraulic cylinder, a second-stage hydraulic cylinder outer cylinder, and a connector for the second-stage hydraulic cylinder outer cylinder. The tertiary hydraulic cylinder mainly consists of a second-stage hydraulic cylinder connector, a third-stage hydraulic cylinder, a third-stage hydraulic cylinder outer cylinder, and a connector for the third-stage hydraulic cylinder outer cylinder. The external components of the three hydraulic cylinders, from top to bottom, are sequentially connected to the first-stage hydraulic cylinder outer cylinder, the first-stage hydraulic cylinder outer cylinder connector, the second-stage hydraulic cylinder outer cylinder, the second-stage hydraulic cylinder outer cylinder connector, and the third-stage hydraulic cylinder outer cylinder. The outer cylinder connector of the three lower hydraulic cylinders is threaded and connected to the lower protective cylinder via the outer cylinder connector of the three lower hydraulic cylinders. The interiors of the three lower hydraulic cylinders, from top to bottom, are sequentially connected via a conversion joint, lower central tube one, lower central tube one connector, lower central tube two, and lower central tube two connector. The lower central tube two connector is sequentially connected to lower central tube three and the balance inlet check valve two via threads. The upper outer circle of the conversion joint is threaded to the outer cylinder of the upper hydraulic cylinder three, and the lower inner circle is threaded to the lower central tube one. The lower part of the outer cylinder of lower hydraulic cylinder one is threaded to the upper part of the outer cylinder connector of lower hydraulic cylinder one. Pressure transmission holes are provided in the conversion joint, lower central tube one connector, and lower central tube two connector. Pressure relief holes are provided below the upper threaded sections of the outer cylinders of lower hydraulic cylinder two, lower hydraulic cylinder three, and lower protective cylinder.

[0015] Preferably, the pressure transmission holes in the adapter, the first connector of the lower pressure center tube, and the second connector of the lower pressure center tube, the center holes in the first, second, and third lower pressure center tubes, and the pressure transmission gaps left when the first, second, and third lower pressure center tubes are threadedly connected to the first and second connectors of the lower pressure center tube constitute the inlet channels of each lower pressure cylinder connected by the adapter.

[0016] Preferably, the pressure relief holes in the second outer cylinder of the lower pressure cylinder, the third outer cylinder of the lower pressure cylinder, and the lower protective cylinder constitute the pressure relief channels for each lower pressure cylinder connected by the conversion joint.

[0017] Preferably, the second balanced flow valve includes an outer cylinder, a ball seat baffle, a spring, and a sealing ball. The ball seat baffle, spring, and sealing ball are installed from top to bottom inside the outer cylinder. The upper end of the outer cylinder is threaded and can be connected to the lower thread of the third pressure tube via a ball seat connector. The lower inner cavity of the outer cylinder is a ball seat with a larger upper inner diameter and a smaller lower inner diameter. The lower body of the ball seat baffle is a spring mounting cavity, and the upper body has a flow hole. The spring is installed inside the outer cylinder and located between the ball seat baffle and the sealing ball.

[0018] Preferably, the upper part of the upper protective cylinder is also provided with a shearing nail hole, which can be used to insert a connecting shearing nail and connect it to the central tube connector.

[0019] Compared to existing technologies, this invention has the following significant advantages: The working principle of this invention is as follows: When the entire device is in a downward pressure state, the central control tube is at the bottom dead center of the downward pressure reversing stroke. The inlet channel of the central control tube is connected to the inlet channels of each downward pressure cylinder in the lower part of the device, while the inlet channel of the upward pull cylinder in the upper part of the device is closed. At this time, when pressure is applied from the oil pipe, the entire device is in a downward force-increasing working state. If the tubing string is lifted, the entire tubing string is in a stretched state, and the entire device is in an upward pull state. At this time, the central control tube is at the top dead center of the reversing stroke. The pressure transmission hole at the bottom of the central control tube is connected to the inlet channels of each upward pull cylinder in the upper part of the device, while being closed to the pressure relief channels of each downward pressure cylinder in the lower part of the device. At this time, when pressure is applied to the device from the oil pipe, each upward pull cylinder in the device is in an upward force-increasing working state. During the downward pressure process of the central control pipe, the lower pressure cylinders also move upward to restore the stroke required for pressure boosting. At this time, the liquid in the pressure cylinders below the central control pipe enters the tubing connected to the upper tubing string through the balance inlet check valve at the end of the central control pipe, preventing the formation of dead space within the device. Meanwhile, the lower balance inlet check valve replenishes liquid from the wellbore when the central control pipe is raised, preventing a vacuum from forming inside the device.

[0020] The working principle of this device is reliable, the structure is simple, the operation is convenient, the economy is practical, the safety factor is high, and the specific effects are also reflected in: (1) This invention solves the problem that existing hydraulic power amplification devices cannot perform reversing work, and provides a reversible power amplification tool that can amplify power upwards or downwards.

[0021] (2) In the process of hydraulic reversing control of this device, by utilizing the different positions of the central control tube, liquid can be supplied to one or more multi-stage upward hydraulic cylinders and multi-stage downward hydraulic cylinders, which simplifies the tool structure and working principle and improves the reliability of tool use.

[0022] (3) The two sets of multi-stage upward hydraulic cylinders and downward hydraulic cylinders set in this invention have simple basic unit structures for each hydraulic cylinder. The number of upward hydraulic cylinders and downward hydraulic cylinders connected in this device can be equal or unequal, and the number of upward hydraulic cylinders and downward hydraulic cylinders connected in series in the reversible force-enhancing device can be increased or decreased according to the repair needs of the downhole casing, which greatly improves the applicability of this invention.

[0023] This invention can be connected in series in the casing straightening and workover string to provide hydraulic boost for workover operations in oil, gas and water wells with bent casing. At the same time, during the lifting and lowering of the workover string, the direction of hydraulic boost can be changed by changing the upward and downward states of the tool, thus providing a safety guarantee for the entire workover string.

[0024] This invention effectively solves the problem of casing wall rebound after casing reshaping and repair in oil, gas and water wells, which can cause the workover string to get stuck. With the corresponding casing reshaping and repair tools, it can effectively avoid downhole accidents caused by the workover string getting stuck in wells with curved casing and being unable to be pulled out. It can also save huge costs in subsequent accident handling and effectively reduce the cost of workover operations.

[0025] Compared to the existing well workover tubing, which has the problem of hydraulic boosting not being able to be reversed, this invention has made substantial improvements in the working principle of the tool, effectively filling the technological gap of this type of tool at home and abroad, greatly improving the safety of well workover tubing. Using this invention in well workover tubing can bring significant economic and social benefits and has great potential for promotion. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0027] Figure 1 This is a schematic diagram of the structure of the present invention.

[0028] Figure 2 for Figure 1 A schematic diagram of the central control tube in the diagram.

[0029] Figure 3 for Figure 1 A schematic diagram of the structure of the balanced inlet flow valve with a retaining ring.

[0030] In the diagram: 1. Control pipe connector; 2. Central control pipe; 3. Balanced inlet flow valve retaining ring; 4. Balanced inlet flow valve outer cylinder; 5. Balanced inlet flow valve spring; 6. Central pipe connector cap; 7. Central pipe connector; 8. Central pipe connector 1; 9. Central pipe connector 1; 10. Central pipe connector 2; 11. Central pipe connector 3; 12. Central pipe connector 3; 13. Upper protective cylinder; 14. Central cylinder connector 1; 15. Central cylinder connector 1; 16. Central cylinder connector 2; 17. Central cylinder connector 2; 18. Central cylinder connector 3; 19. Central cylinder connector 3. 20. Outer cylinder; 21. Converter joint; 22. Downward pressure center pipe one; 23. Downward pressure center pipe one connector; 24. Downward pressure center pipe two; 25. Downward pressure center pipe two connector; 26. Downward pressure center pipe three; 27. Downward pressure center pipe ball seat connector; 28. Balanced fluid inlet check valve two outer cylinder; 29. ​​Balanced fluid inlet check valve two ball seat baffle; 30. Balanced fluid inlet check valve two spring; 31. Downward pressure cylinder one outer cylinder; 32. Downward pressure cylinder one outer cylinder connector; 33. Downward pressure cylinder two outer cylinder connector; 34. Downward pressure cylinder three outer cylinder; 35. Downward pressure cylinder three outer cylinder connector; 36. Lower protective cylinder; 37. Well workover tool connector; 38. Detailed Implementation

[0031] The accompanying drawings are for reference and illustration only and are not intended to limit the scope of protection of this invention. The technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the 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 the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] See Figure 1 - Figure 3 A reversible booster device for downhole workover operations in oil, gas, and water wells includes an upward-pulling hydraulic cylinder and a downward-pressing hydraulic cylinder. One or more upward-pulling hydraulic cylinders are connected to the outside of a central control pipe 2, and a balanced inlet check valve is installed at the lower end of the central control pipe 2. The upward-pulling hydraulic cylinders outside the central control pipe 2 are suspended on a suspension step on the outer wall of the central control pipe 2 via a central pipe connector cap 6 and a central pipe connector 7. One or more downward-pressing hydraulic cylinders are connected to the lower part of the central control pipe 2 via a conversion joint 21, and a balanced inlet check valve is installed below the lowest downward-pressing hydraulic cylinder. A workover tool connector 38 is connected below the lowest downward-pressing hydraulic cylinder. The lowest upward-pulling hydraulic cylinder connected to the outside of the central control pipe 2 is connected to the conversion joint 21.

[0035] When the workover tool connected to the reversible booster device encounters obstruction downhole, the central control pipe 2 of the reversible booster device and the outer cylinder of the externally connected pull-up cylinder can be positioned in different hydraulic boosting directions under the control of mechanical force. For example, when both ends of the reversible booster device are in a stretched state, the central control pipe 2 is located at the top dead center of the reversing stroke, the downward pressure cylinder connected by the conversion joint 21 is at the bottom dead center of the downward pressure cylinder stroke, and the pull-up cylinder is at the bottom dead center of the pull-up cylinder stroke. Conversely, when both ends of the reversible booster device are in a compressed state, the central control pipe 2 is located at the bottom dead center of the reversing stroke, the downward pressure cylinder connected by the conversion joint 21 is at the top dead center of the downward pressure cylinder stroke, and the pull-up cylinder is at the top dead center of the pull-up cylinder stroke.

[0036] The upper end of the central control pipe 2 of this invention can be connected to the hydraulic anchor in the workover string via tubing through the control pipe connector 1; the outer cylinder of the lower pressure cylinder connected to the lowest end is connected to the workover tool connector 38 and can be connected to the workover tool in the workover string via the workover tool connector 38; when both ends of the reversible booster device are in a compressed state, pressure is applied from the tubing to the central control pipe 2, and when the central control pipe 2 is at the bottom dead center of the reversing stroke of the externally connected upper pressure cylinder, the inlet channel of the central control pipe 2 is connected to the pressure transmission channel of each lower pressure cylinder connected below, and the reversible booster... When the force-boosting device is in a downward force-boosting state, causing the workover tools connected below to move downwards; after depressurization, when the reversible force-boosting device is lifted through the tubing of the workover string, both ends of the reversible force-boosting device are in a stretched state. When the central control pipe 2 is at the top dead center of the reversing stroke of the externally connected upward hydraulic cylinder, the inlet channel of the central control pipe 2 is connected to the inlet channels of each externally connected upward hydraulic cylinder, and the pressure transmission channels of each downward hydraulic cylinder located below the central control pipe 2 are closed. The reversible force-boosting device is in an upward force-boosting state, causing the workover tools connected below to move upwards.

[0037] This invention combines the advantages of existing downhole booster devices while overcoming their shortcomings. It provides both upward and downward boosting capabilities, allowing the workover tool connected to the lower end of the workover string to move downwards and upwards within the casing with boosted force. This effectively prevents the workover string and tool from getting stuck or jammed in the casing. This invention is particularly suitable for workover operations in wells with casing bends or reduced diameters. When used with the appropriate workover tool, it can repair bends or reduced diameters in the target well.

[0038] The number of pull-up hydraulic cylinders and pressure-down hydraulic cylinders connected in the reversible power booster device can be equal or unequal, and the number of pull-up hydraulic cylinders and pressure-down hydraulic cylinders connected in series in the reversible power booster device can be increased or decreased according to the repair needs of the downhole casing.

[0039] Based on the above embodiment one, the present invention also has the following embodiments: The connection structure of the upward liquid cylinder and the downward liquid cylinder in this device is described below, taking the three upward liquid cylinders and three downward liquid cylinders connected to the outside of the central control pipe 2 and the bottom of the central control pipe 2 respectively as an example.

[0040] The central control tube 2 is connected to three upward-pulling cylinders via a central tube connector 7 and an upper protective cylinder 14. These three upward-pulling cylinders are a primary upward-pulling cylinder, a secondary upward-pulling cylinder, and a tertiary upward-pulling cylinder. The primary upward-pulling cylinder mainly consists of an outer cylinder connector 15, an upward-pulling central tube 8, an upper central tube connector 9, and an outer cylinder 16. The secondary upward-pulling cylinder mainly consists of an outer cylinder connector 17, an upper central tube 10, an upper central tube connector 11, and an outer cylinder 18. The tertiary upward-pulling cylinder mainly consists of an outer cylinder connector 19, an upper central tube 12, an upper cylinder 20, and an upper central tube connector 13. The upper protective cylinder 14... Pressure relief holes are provided in the cylinders near the lower threaded connection section of the outer cylinders of the first, second, and third pull-up cylinders. The three outer cylinders are connected to the lower part of the upper protective cylinder 14 by the outer cylinder connector 15, the outer cylinder connector 16, the outer cylinder connector 17, the outer cylinder connector 18, the outer cylinder connector 19, and the outer cylinder connector 20 in sequence from top to bottom. The three outer cylinders are connected to the lower part of the central tube connector 7 by the central tube connector 13 in sequence from top to bottom by the central tube connector 8, the central tube connector 9, the central tube connector 10, the central tube connector 11, the central tube connector 12, and the central tube connector 13.

[0041] The central control tube 2, the first connector 9 of the upward pull central tube, the second connector 11 of the upward pull central tube, and the third connector 13 of the upward pull central tube are all provided with pressure transmission holes, and the upper inner circle and the lower inner circle of the third connector 13 of the upward pull central tube are provided with pressure transmission grooves that do not penetrate the cylinder of the third connector 13 of the upward pull central tube; the second connector 10 and the third connector 12 of the upward pull central tube are provided with a liquid flow annular gap between the central control tube 2 and the central control tube 2; the central control tube 2, the first connector 9 of the upward pull central tube, the second connector 11 of the upward pull central tube, the pressure transmission holes and pressure transmission grooves provided in the third connector 13 of the upward pull central tube, and the liquid flow annular gap between the second connector 10 and the third connector 12 of the upward pull central tube and the central control tube 2 constitute the liquid inlet channel between the central control tube 2 and each upward pull liquid cylinder.

[0042] When the central control tube 2 is at the bottom dead center of the reversing stroke of the externally connected upward hydraulic cylinder, the pressure transmission hole located at the lower part of the central control tube 2 corresponds to the pressure transmission groove on the lower inner circle of the three-way connector 13 of the upward central tube. Sealing rings are installed above and below the pressure transmission hole at the lower part of the central control tube 2.

[0043] Pressure relief holes are provided above the lower threaded sections of the upper protective cylinder 14, the first outer cylinder 16 of the upper pull liquid cylinder, the second outer cylinder 18 of the upper pull liquid cylinder, and the third outer cylinder 20 of the upper pull liquid cylinder. The pressure relief holes in the upper protective cylinder 14, the first outer cylinder 16 of the upper pull liquid cylinder, the second outer cylinder 18 of the upper pull liquid cylinder, and the third outer cylinder 20 of the upper pull liquid cylinder constitute the pressure relief channel of the upper pull liquid cylinder connected to the outside of the central control pipe 2.

[0044] The balanced flow valve mainly consists of a balanced flow valve retaining ring 3, a balanced flow valve outer cylinder 4, a balanced flow valve spring 5, and a sealing ball. The balanced flow valve retaining ring 3, the balanced flow valve spring 5, and the sealing ball are installed sequentially from top to bottom inside the balanced flow valve outer cylinder 4. The upper end of the balanced flow valve outer cylinder 4 is threaded to connect with the lower thread of the central control pipe 2. The lower inner cavity of the balanced flow valve outer cylinder 4 is a ball seat with a larger upper inner diameter and a smaller lower inner diameter. The lower body of the balanced flow valve retaining ring 3 is a spring mounting cavity, and the upper body is provided with a liquid flow hole. The balanced flow valve spring 5 is installed inside the balanced flow valve outer cylinder 4 and is located between the balanced flow valve retaining ring 3 and the sealing ball. The function of the balance inlet single-flow valve is to ensure that when the central control pipe 2 is reversed downwards, the fluid in the pressure cylinder of this device can be released through the balance inlet single-flow valve, without creating a dead space and hindering the downward reversal stroke of the central control pipe 2.

[0045] The distance between the pressure transmission grooves in the upper and lower inner circles of the pull-up center tube three-way connector 13 matches the height of the upper inner cavity of the center tube connector 7. When the resistance at the point where the upper workover string and workover tool encounter an obstacle causes the reversible booster device to be in a compressed state, the suspension step outside the center control tube 2 descends to the step in the upper inner cavity of the center tube connector 7, and the pressure transmission hole at the lower part of the center control tube 2 connects precisely with the pressure transmission groove in the lower inner circle of the pull-up center tube three-way connector 13. The fluid inlet channel in the pull-up hydraulic cylinder connected to the outside of the center control tube 2 is closed, and the pressure transmission channels of each downward hydraulic cylinder located below the center control tube 2 are opened. The reversible booster device is in a downward boosting state, causing the workover tool connected below to be in a downward working state. Conversely, when the resistance at the point where the upper workover string and workover tool encounter an obstacle causes the reversible booster device to be in a stretched state, and the suspension step outside the central control pipe 2 rises to the pressure cap 6 of the central pipe connector, the pressure transmission hole at the lower part of the central control pipe 2 connects precisely with the pressure transmission groove in the upper inner circle of the pull-up central pipe three-way connector 13. The fluid inlet channel in the pull-up hydraulic cylinder connected to the outside of the central control pipe 2 opens, and the pressure transmission channels of each lower hydraulic cylinder located below the central control pipe 2 close. The reversible booster device is in an upward boosting state, causing the workover tool connected below to rise.

[0046] Three pressure cylinders are connected to the central control pipe 2 via the conversion connector 21. These three pressure cylinders are a primary pressure cylinder, a secondary pressure cylinder, and a tertiary pressure cylinder. The primary pressure cylinder mainly consists of the conversion connector 21, a first-stage pressure central pipe 22, a first-stage pressure cylinder outer cylinder 31, and a first-stage pressure cylinder outer cylinder connector 32. The secondary pressure cylinder mainly consists of a first-stage pressure central pipe connector 23, a second-stage pressure central pipe 24, and a second-stage pressure cylinder outer cylinder. The three-stage lowering hydraulic cylinder is composed of a lowering center tube connector 25, a lowering center tube 26, a lowering hydraulic cylinder outer cylinder 35, and a lowering hydraulic cylinder outer cylinder connector 36. The three lowering hydraulic cylinders are connected from top to bottom sequentially by a lowering hydraulic cylinder outer cylinder 31, a lowering hydraulic cylinder outer cylinder connector 32, a lowering hydraulic cylinder outer cylinder 33, a lowering hydraulic cylinder outer cylinder connector 34, a lowering hydraulic cylinder outer cylinder 35, and a lowering hydraulic cylinder. The three outer cylinder connectors 36 are threaded together and connected to the lower protective cylinder 37 via the three outer cylinder connectors 36 of the lower pressure cylinder; the interiors of the three lower pressure cylinders, from top to bottom, are threaded together via conversion connector 21, lower pressure center tube one 22, lower pressure center tube one connector 23, lower pressure center tube two 24, and lower pressure center tube two connector 25, and are then threaded together via lower pressure center tube two connector 25 to lower pressure center tube three 26 and the balanced inlet check valve two; the conversion connector 21... The upper outer circle of 1 is threadedly connected to the upper pull cylinder three outer cylinder 20 and the lower inner circle is threadedly connected to the lower pressure center tube 22. The lower part of the lower pressure cylinder one outer cylinder 31 is threadedly connected to the upper part of the lower pressure cylinder one outer cylinder connector 32. Pressure transmission holes are provided in the conversion connector 21, the lower pressure center tube one connector 23 and the lower pressure center tube two connector 25. Pressure relief holes are provided below the upper threaded section of the lower pressure cylinder two outer cylinder 33, the lower pressure cylinder three outer cylinder 35 and the lower protective cylinder 37.

[0047] The conversion joint 21 here connects to the outer cylinder 20 of the upper pull-up hydraulic cylinder and the lower pressure center tube 22. The upper and lower parts of the lower pressure hydraulic cylinder outer cylinder connector 32 are threaded to the outer cylinder 31 of the lower pressure hydraulic cylinder and the outer cylinder 33 of the lower pressure hydraulic cylinder, respectively. The series connection from the outer cylinder of the upper pull-up hydraulic cylinder to the center tube of the lower pressure hydraulic cylinder is completed at the conversion joint 21. Under the action of tension and pressure, the upper pull-up hydraulic cylinders and the lower pressure hydraulic cylinders in the reversible force boosting device are reset and, under the action of tension and pressure, the upper pull-up hydraulic cylinders and the lower pressure hydraulic cylinders are repeatedly switched in the force boosting direction, realizing the upward force boosting and downward force boosting of the workover tool connected below the workover string.

[0048] The pressure transmission holes in the conversion joint 21, the first connector 23 of the lower pressure center tube, and the second connector 25 of the lower pressure center tube, the center holes in the first lower pressure center tube 22, the second lower pressure center tube 24, and the third lower pressure center tube 26, and the pressure transmission gaps left when the first lower pressure center tube 22, the second lower pressure center tube 24, and the third lower pressure center tube 26 are threadedly connected to the first lower pressure center tube 23 and the second lower pressure center tube 25, corresponding to the pressure transmission holes in the first lower pressure center tube 23 and the second lower pressure center tube 25, constitute the liquid inlet channels of each lower pressure cylinder connected by the conversion joint 21.

[0049] The pressure relief holes in the outer cylinder 33 of the second pressure cylinder, the outer cylinder 35 of the third pressure cylinder, and the lower protective cylinder 37 constitute the pressure relief channels for each pressure cylinder connected by the conversion joint 21.

[0050] The second balanced flow valve is provided with an outer cylinder 28, a ball seat baffle 29, a spring 30, and a sealing ball. The ball seat baffle 29, spring 30, and sealing ball are installed from top to bottom inside the outer cylinder 28. The upper end of the outer cylinder 28 is threaded and can be connected to the lower thread of the third pressure tube 26 through the ball seat joint 27. The lower inner cavity of the outer cylinder 28 is a ball seat with a larger upper inner diameter and a smaller lower inner diameter. The lower body of the ball seat baffle 29 is a spring mounting cavity and the upper body is provided with a liquid flow hole. The spring 30 is installed inside the outer cylinder 28 and is located between the ball seat baffle 29 and the sealing ball. The function of the balanced inlet flow valve 2 is to ensure that when the central control pipe 2 is raised, the liquid in the downhole working string can enter the device through the balanced inlet flow valve 2, and prevent the central control pipe 2 from forming a vacuum state.

[0051] The upper part of the upper protective cylinder 14 is also provided with a shearing nail hole, into which a connecting shearing nail can be inserted to connect with the central tube connector 7. This prevents the upper protective cylinder 14 from becoming loose when lowered into the well, and under normal circumstances, shearing nails are not required. In this invention, all connections requiring sealing are equipped with sealing rings.

[0052] When the reversible booster is in the compression state, the central control tube 2 is at the bottom dead center. The hydraulic pressure passes through the pressure transmission holes of the upper connector 1 and the central control tube 2, and enters the central holes of the conversion connector 21, the first downward pressure central tube 22, the second downward pressure central tube 24, and the third downward pressure central tube 26 through the pressure transmission groove at the bottom of the upper pull-up central tube three connector 13. It also enters each downward pressure booster cylinder through the pressure transmission holes on the conversion connector 21, the first downward pressure central tube connector 23, and the second downward pressure central tube connector 25.

[0053] When the reversible force-increasing device is in the tension state, the central control tube 2 is at the top dead center. Hydraulic fluid enters the gap between the upper central control tube 2 and the upper central control tube 3 joint 13 through the pressure transmission holes in the upper joint 1, the pressure transmission groove in the upper part of the upper central control tube 3 joint 13, and the upper central control tube 2. It also enters each upper hydraulic cylinder through the pressure transmission holes in the upper central control tube 1 joint 9, the upper central control tube 2 joint 11, and the upper central control tube 3 joint 13.

[0054] The embodiments described above are merely typical examples, but the present invention is not limited to these embodiments. Those skilled in the art can make modifications without departing from the spirit and teachings of 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 described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the inventive spirit and concept of the present invention should be included within the protection scope of the present invention. Therefore, the protection scope is not limited to the above description.

Claims

1. A reversible booster device for downhole workover operations in oil, gas and water wells, comprising an upward-pulling hydraulic cylinder and a downward-pressing hydraulic cylinder, characterized in that: One or more pull-up cylinders are connected to the outside of the central control pipe (2), and a balanced inlet flow valve is installed at the lower end of the central control pipe (2); the pull-up cylinders outside the central control pipe (2) are suspended on the suspension steps on the outer wall of the central control pipe (2) through the central pipe connector cap (6) and the central pipe connector (7); one or more pressure cylinders are connected to the lower part of the central control pipe (2) by the conversion connector (21), and a balanced inlet flow valve is installed below the pressure cylinder at the lowest end; the workover tool connector (38) is connected below the pressure cylinder at the lowest end; the pull-up cylinder at the lowest end of the central control pipe (2) is connected to the conversion connector (21). 1) Connection; The outside of the central control tube (2) is connected to three upward liquid cylinders through the central tube connector (7) and the upper protective cylinder (14). The three upward liquid cylinders are a first-stage upward liquid cylinder, a second-stage upward liquid cylinder and a third-stage upward liquid cylinder. The first-stage upward liquid cylinder is mainly composed of an outer cylinder connector (15) of the first upward liquid cylinder, an upward central tube (8), an upper central tube connector (9) and an outer cylinder (16) of the first upward liquid cylinder. The second-stage upward liquid cylinder is mainly composed of an outer cylinder connector (17) of the second upward liquid cylinder, an upper central tube (10), an upper central tube connector (11) and an outer cylinder (18) of the second upward liquid cylinder. The third-stage upward liquid cylinder is... It mainly consists of an upper-pull hydraulic cylinder outer cylinder connector (19), an upper-pull central tube three (12), an upper-pull hydraulic cylinder outer cylinder (20), and an upper-pull central tube three connector (13); the three upper-pull hydraulic cylinders are connected from top to bottom to the lower part of the central tube connector (7) via upper-pull central tube one (8), upper-pull central tube one connector (9), upper-pull central tube two (10), upper-pull central tube two connector (11), upper-pull central tube three (12), and upper-pull central tube three connector (13); the central control tube (2), upper-pull central tube one connector (9), upper-pull central tube two connector (11), and upper-pull central tube three connector (13) are all provided with pressure transmission holes and Furthermore, pressure transmission grooves that do not communicate with the cylinder of the three-joint joint (13) of the pull-up center tube are provided on the upper inner circle and the lower inner circle of the three-joint joint (13); a liquid flow annular gap is provided between the two-joint joint (10) and the three-joint joint (12) of the pull-up center tube and the central control tube (2); the central control tube (2), the one-joint joint (9) of the pull-up center tube, the two-joint joint (11) of the pull-up center tube, the pressure transmission holes and pressure transmission grooves provided in the three-joint joint (13) of the pull-up center tube, and the liquid flow annular gap between the two-joint joint (10) and the three-joint joint (12) of the pull-up center tube and the central control tube (2) constitute the liquid inlet channel between the central control tube (2) and each pull-up liquid cylinder.

2. The reversible booster device for downhole workover operations in oil, gas and water wells as described in claim 1, characterized in that, The number of pull-up cylinders and pressure cylinders connected in the reversible booster device can be equal or unequal, and the number of pull-up cylinders and pressure cylinders connected in series in the reversible booster device can be increased or decreased according to the repair needs of the downhole casing.

3. The reversible booster device for downhole workover operations in oil, gas, and water wells as described in claim 2, characterized in that, Pressure relief holes are provided in the cylinders near the lower threaded connection section of the upper protective cylinder (14), the first outer cylinder of the upper pull liquid cylinder (16), the second outer cylinder of the upper pull liquid cylinder (18), and the third outer cylinder of the upper pull liquid cylinder (20); the three upper pull liquid cylinders are sequentially threaded to the lower part of the upper protective cylinder (14) through the first outer cylinder connector (15), the first outer cylinder of the upper pull liquid cylinder (16), the second outer cylinder connector (17), the second outer cylinder of the upper pull liquid cylinder (18), the third outer cylinder connector (19), and the third outer cylinder of the upper pull liquid cylinder (20) from top to bottom.

4. The reversible booster device for downhole workover operations in oil, gas and water wells as described in claim 3, characterized in that, When the central control tube (2) is at the bottom dead center of the reversing stroke of the externally connected upward hydraulic cylinder, the pressure transmission hole located at the lower part of the central control tube (2) corresponds to the pressure transmission groove of the lower inner circle of the three-way connector (13) of the upward central tube. Sealing rings are installed above and below the pressure transmission hole at the lower part of the central control tube (2).

5. The reversible booster device for downhole workover operations in oil, gas, and water wells as described in claim 3, characterized in that, Pressure relief holes are provided above the lower threaded sections of the upper protective cylinder (14), the first outer cylinder (16) of the upper pull liquid cylinder, the second outer cylinder (18) of the upper pull liquid cylinder, and the third outer cylinder (20) of the upper pull liquid cylinder. The pressure relief holes in the upper protective cylinder (14), the first outer cylinder (16) of the upper pull liquid cylinder, the second outer cylinder (18) of the upper pull liquid cylinder, and the third outer cylinder (20) of the upper pull liquid cylinder constitute the pressure relief channel of the upper pull liquid cylinder connected to the outside of the central control pipe (2).

6. The reversible booster device for downhole workover operations in oil, gas, and water wells as described in claim 2, characterized in that, The balanced flow valve is mainly composed of a balanced flow valve retaining ring (3), a balanced flow valve outer cylinder (4), a balanced flow valve spring (5), and a sealing ball. The balanced flow valve retaining ring (3), the balanced flow valve spring (5), and the sealing ball are installed in the balanced flow valve outer cylinder (4) from top to bottom. The upper end of the balanced flow valve outer cylinder (4) is threaded and can be connected to the lower thread of the central control pipe (2). The lower inner cavity of the balanced flow valve outer cylinder (4) is a ball seat with a large upper inner diameter and a small lower inner diameter. The lower body of the balanced flow valve retaining ring (3) is a spring mounting cavity and the upper body is provided with a liquid flow hole. The balanced flow valve spring (5) is installed in the balanced flow valve outer cylinder (4) and is located between the balanced flow valve retaining ring (3) and the sealing ball.

7. The reversible booster device for downhole workover operations in oil, gas and water wells as described in claim 3, characterized in that, The distance between the pressure transmission grooves in the upper and lower inner circles of the three-way connector (13) of the upper pull-up center tube matches the height of the upper inner cavity of the center tube connector (7).

8. The reversible booster device for downhole workover operations in oil, gas and water wells as described in claim 2, characterized in that, There are three pressure cylinders connected to the central control pipe (2) by the conversion connector (21). The three pressure cylinders are a first-stage pressure cylinder, a second-stage pressure cylinder, and a third-stage pressure cylinder. The first-stage pressure cylinder is mainly composed of the conversion connector (21), a first-stage pressure central pipe (22), an outer cylinder (31) of the first-stage pressure cylinder, and a connector (32) for the outer cylinder of the first-stage pressure cylinder. The second-stage pressure cylinder is mainly composed of a connector (23) of the first-stage pressure central pipe, a second-stage pressure central pipe (24), and an outer cylinder (33) of the second-stage pressure cylinder. The three-stage lowering hydraulic cylinder is composed of a lowering center tube connector (25), a lowering center tube (36), a lowering hydraulic cylinder outer cylinder (35), and a lowering hydraulic cylinder outer cylinder connector (36). The three lowering hydraulic cylinders are connected from top to bottom to the lowering hydraulic cylinder outer cylinder (31), the lowering hydraulic cylinder outer cylinder connector (32), the lowering hydraulic cylinder outer cylinder (33), the lowering hydraulic cylinder outer cylinder connector (34), the lowering hydraulic cylinder outer cylinder (35), and the lowering hydraulic cylinder outer cylinder connector (36). The cylinder connector (36) is threaded and connected to the lower protective cylinder (37) via the lower cylinder outer cylinder connector (36); the interiors of the three lower cylinders are connected sequentially from top to bottom via the conversion connector (21), lower central tube one (22), lower central tube one connector (23), lower central tube two (24), and lower central tube two connector (25), and are connected sequentially via the lower central tube two connector (25) to the lower central tube three (26) and the balanced inlet flow valve two; the conversion connector (21) The upper outer circle of the cylinder is threadedly connected to the upper outer cylinder (20) of the upper hydraulic cylinder and the lower inner circle is threadedly connected to the lower pressure center tube (22). The lower part of the lower pressure cylinder outer cylinder (31) is threadedly connected to the upper part of the lower pressure cylinder outer cylinder connector (32). Pressure transmission holes are provided in the conversion connector (21), the lower pressure center tube connector (23) and the lower pressure center tube connector (25). Pressure relief holes are provided below the upper threaded section of the lower pressure cylinder outer cylinder (33), the lower pressure cylinder outer cylinder (35) and the lower protective cylinder (37).

9. A reversible booster device for downhole workover operations in oil, gas, and water wells as described in claim 8, characterized in that, The pressure transmission holes provided in the conversion joint (21), the first connector of the lower pressure center tube (23), and the second connector of the lower pressure center tube (25), the center holes in the first lower pressure center tube (22), the second lower pressure center tube (24), and the third lower pressure center tube (26), and the pressure transmission gaps left when the first lower pressure center tube (22), the second lower pressure center tube (24), and the third lower pressure center tube (26) are threadedly connected to the first lower pressure center tube (23) and the second lower pressure center tube (25), corresponding to the pressure transmission holes in the first lower pressure center tube (23) and the second lower pressure center tube (25), constitute the liquid inlet channels of each lower pressure cylinder connected by the conversion joint (21).

10. A reversible booster device for downhole workover operations in oil, gas, and water wells as described in claim 8, characterized in that, The pressure relief holes in the outer cylinder of the second pressure cylinder (33), the outer cylinder of the third pressure cylinder (35), and the lower protective cylinder (37) constitute the pressure relief channels of each pressure cylinder connected by the conversion joint (21).

11. The reversible booster device for downhole workover operations in oil, gas and water wells as described in claim 8, characterized in that, The second balanced flow valve is provided with an outer cylinder (28), a ball seat baffle (29), a spring (30), and a sealing ball. The ball seat baffle (29), spring (30), and sealing ball are installed from top to bottom inside the outer cylinder (28). The upper end of the outer cylinder (28) is threaded to allow the lower pressure center tube ball seat connector to pass through. 27) is threaded to the lower part of the pressure center tube three (26); the lower inner cavity of the outer cylinder (28) of the balanced liquid inlet flow valve is a ball seat with a large upper inner diameter and a small lower inner diameter; the lower body of the ball seat baffle (29) of the balanced liquid inlet flow valve is a spring mounting cavity and the upper body is provided with a liquid flow hole; the spring (30) of the balanced liquid inlet flow valve is installed in the outer cylinder (28) of the balanced liquid inlet flow valve and is located between the ball seat baffle (29) of the balanced liquid inlet flow valve and the sealing ball.

12. The reversible booster device for downhole workover operations in oil, gas and water wells as described in claim 3, characterized in that, The upper part of the upper protective cylinder (14) is also provided with a shearing nail hole, which can be used to insert a connecting shearing nail and connect it to the central tube connector (7).

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