Releasable downhole parting and plugging tool, fishing device and method of use

Abstract

The application discloses a downhole detachable internal plugging tool, a fishing device and a use method. In the assembled state, the upper cylinder and the lower cylinder are connected to form a shell, the upper core shaft and the lower core shaft are installed in the shell, the clamping part of the releasing mechanism is limited by the clamping groove under the cooperation of the upper core shaft, after the lower clamping part of the upper core shaft is separated from the clamping groove, the upper cylinder, the upper core shaft and the lower cylinder are separated to realize releasing, the guide cone sliding groove and the guide cone of the sliding guide cone mechanism can be matched with the fisher to realize multiple fishing, the J-shaped key of the J-shaped locking mechanism can lock the positions of the lower core shaft and the lower cylinder after releasing, the ball valve is rotated by 90 degrees in the ball seat through the reversing piece to realize plugging of the through hole of the lower core shaft after the rotary switch mechanism releases, and the anchor tooth structure of the extrusion anchor mechanism can be anchored with the casing. After releasing, internal plugging and anchoring can be realized, pressure relief can be realized in advance during fishing, and repeated disconnection can be realized to realize multiple fishing without the need of tripping the pipe column.

Description

Technical Field

[0001] This invention relates to the field of downhole operations technology for oil and gas wells, and particularly to a repeatedly detachable downhole plugging tool, a retrieval device, and a method of use. Background Technology

[0002] Currently, for multi-layer well testing with two or more layers, apart from large-scale volumetric fracturing and combined well testing, the general approach is to use a layered well testing method. This involves perforating one layer, obtaining ideal formation fluidity through well testing, sealing off that layer, and then proceeding to the next layer for testing. To reduce workload and improve efficiency during well testing, a common method is the perforation-pump-fluid discharge combined testing process. This involves connecting the perforating gun, packer, hydraulic pump, and related tools into a single tubing string, lowering it into the well, and observing for oil and gas indications on the surface after perforation. If the layer lacks self-flowing capability, hydraulic pumping is used to discharge fluid and obtain information on formation fluid production.

[0003] Taking the perforation-pump connection as an example, under normal circumstances, after the hydraulic pumping operation is completed, if it is confirmed that there is no production capacity planned for the layer and the seal is returned to the second layer for oil testing, or if the layer has production capacity but no acidizing, fracturing, or other production-enhancing measures are taken and the layer is temporarily sealed to await subsequent development, then the perforation-pump connection string needs to be removed and the seal string lowered to complete the seal operation. The current operation mainly has the following problems:

[0004] (1) Multiple trips of the working string are required. With current operating technology, it is necessary to first trip the perforation-pump joint working string, and then lower the sealing working string. Whether using tubing or coiled tubing, it is impossible to complete these two construction processes in one trip. The multiple trips of the working string result in high labor intensity and low construction efficiency.

[0005] (2) Well control operations are required. Before moving the tubing string, well control fluid is needed to balance the well pressure and ensure well control safety. This is especially important for formations with production potential. However, using well control fluid increases the cost of the fluid, and the fluid entering the reservoir can contaminate it, affecting oil and gas recovery. Furthermore, the subsequent flushing of the fluid out of the well will cause environmental pollution and increase treatment costs. If a single tubing string can be used for both oil testing and subsequent sealing operations, it will save on construction costs and improve efficiency. Summary of the Invention

[0006] The inventors of this application have discovered that the currently common method involves using a drop tool to discard the tubing connected to the casing. Although the discarded tubing contains a packer to seal the tubing and casing annulus, the tubing connected to the drop tool also has an internal channel, i.e., it communicates with the formation, requiring well control operations. Furthermore, if production is to be resumed, the discarded tubing needs to be retrieved. After a period of sealing, pressure accumulates at the lower end of the tubing, creating high pressure. Abrupt retrieval could cause a sudden pressure release, potentially damaging the tubing or even causing a well control accident. Therefore, the drop tool needs to have internal plugging and pre-depressurization capabilities. For retrieving the discarded tubing and below, the settling of sand, oil, etc., after a period in the well increases the difficulty of retrieval, and success is not guaranteed on the first attempt. Therefore, the drop tool should have the function of repeated disengagement and reconnection to facilitate handling complex well conditions. However, existing drop tools cannot fully meet the requirements for these downhole operations.

[0007] In view of the above problems, the present invention is proposed to provide a repeatedly detachable downhole hand-plugging tool, a retrieval device, and a method of use that overcomes or at least partially solves the above problems.

[0008] This invention provides a repeatedly detachable downhole plugging tool, comprising: an upper cylinder, an upper mandrel, a lower cylinder, and a lower mandrel; in the assembled state, the upper cylinder and the lower cylinder are connected to form a housing, and the upper mandrel and the lower mandrel are installed inside the housing, including the following functional modules:

[0009] The release mechanism includes a locking part on the upper cylinder and a locking groove on the lower cylinder. The locking part is limited by the locking groove under the cooperation of the upper spindle. When the upper spindle is subjected to force and moves downward, the locking part and the locking groove are disengaged, and the upper cylinder and the upper spindle and the lower cylinder are separated to realize the release.

[0010] The sliding guide cone mechanism includes a guide cone sliding groove and a guide cone provided on the lower cylinder, so as to cooperate with the retrieval device to achieve multiple retrievals;

[0011] The J-shaped locking mechanism includes a J-shaped key in a J-shaped keyhole on the lower spindle and a first elastic element. After being released, the lower spindle moves upward, and the straight section of the J-shaped key extends into the locking groove of the lower cylinder under the action of the first elastic element to lock the position of the lower spindle and the lower cylinder.

[0012] The rotary switch mechanism includes a ball valve, a ball seat, and a reversing component, which are disposed in the ball valve hole of the lower spindle. The ball valve is provided with a ball valve through hole. After being released, the lower spindle moves upward. The reversing component drives the ball valve to rotate in the ball seat under the restriction of the reversing component sliding groove on the lower cylinder, so that the ball valve rotates 90 degrees and the ball valve blocks the through hole of the lower spindle.

[0013] The compression anchoring mechanism includes an anchor tooth structure disposed in the anchor tooth window of the lower cylinder. The lower mandrel moves upward and compresses the anchor tooth structure to make the anchor tooth body extend out and anchor with the sleeve.

[0014] In some optional embodiments, the release mechanism includes: an upper cylinder section I, an upper spindle section I, and a lower cylinder section I;

[0015] The upper cylinder section I is provided with a locking part and the lower cylinder section I is provided with a locking groove. The locking part is limited by the locking groove under the cooperation of the upper mandrel. When the upper mandrel section I is subjected to force and moves downward, the locking part and the locking groove disengage, and the upper cylinder separates from the upper mandrel and the lower cylinder to achieve release.

[0016] The upper cylinder section I is provided with a connecting hole for pressure relief, and the upper part of the central through hole of the upper mandrel section I is provided with a flared mouth to accommodate a sealing steel ball.

[0017] In some optional embodiments, the locking part includes a locking ring and a locking head. The locking ring has a segmented structure, with a locking head at the bottom of each segment. The locking head has protruding steps inside and outside. The protruding steps cooperate with the locking shoulder of the upper mandrel and the locking groove of the lower cylinder to connect the upper cylinder and the lower cylinder.

[0018] In some optional embodiments, the upper cylinder section I is provided with a torque transmission protrusion, and the upper spindle section I is provided with a torque transmission groove. The torque transmission protrusion and the torque transmission groove cooperate to achieve torque transmission.

[0019] The upper cylinder section I is provided with a limiting step, and the upper mandrel section I is provided with a positioning step. The limiting step and the positioning step cooperate to limit the downward movement distance of the upper mandrel.

[0020] The lower part of the locking groove is provided with a pin through hole, and the upper mandrel is provided with a pin countersunk hole at the corresponding position. A screw-in pin is provided in the pin through hole and the pin countersunk hole.

[0021] In some alternative embodiments, the sliding guide cone mechanism includes:

[0022] The lower cylinder section II is equipped with a guide cone sliding groove and a guide cone with an inclined surface, so as to cooperate with the retrieval device to achieve multiple retrievals.

[0023] In some alternative embodiments, the J-shaped locking mechanism includes a lower spindle section I, a lower cylinder section III, a J-shaped key, a first elastic element, and a pressure cap;

[0024] The lower mandrel section I has two J-shaped key holes, each J-shaped key hole is provided with a J-shaped key, the J-shaped key includes a hooked part and a straight part, the outer end of the hooked part is provided with a support post to support the first elastic element, the pressure cap is located outside the first elastic element, and cooperates with the hooked part to form an elastic element receiving cavity;

[0025] The lower cylinder section III is provided with a locking groove. After the release, the lower spindle moves upward, and the straight section of the J-shaped key extends out into the locking groove under the action of the first elastic element to lock the position of the lower spindle and the lower cylinder.

[0026] In some optional embodiments, the inner diameter of the hook portion is the same as the diameter of the central through hole of the lower mandrel section I, the end of the straight portion is arc-shaped, and the diameter of the arc is the same as the maximum outer diameter of the lower mandrel section I; the cover is arc-shaped, and the outer diameter of the cover is the same as the maximum outer diameter of the lower mandrel section I.

[0027] The elastic element is a compression spring.

[0028] In some optional embodiments, the rotary switch mechanism includes a lower spindle section I, a lower cylinder section III, a ball valve disposed in a ball valve hole in the lower spindle section I, a ball seat, a reversing component, and a second elastic component;

[0029] The lower mandrel section I is provided with a ball valve hole that communicates with its central through hole to install a ball valve and a ball seat. The ball valve hole is provided with an elastic element groove to install a second elastic element to limit the ball seat. The lower cylinder section III is provided with a reversing element sliding groove.

[0030] The ball seat has a concave spherical surface to accommodate the ball valve, the ball valve is provided with a ball valve through hole, and both the ball seat and the ball valve are provided with a reversing element mounting hole for mounting the reversing element;

[0031] After being released, the lower mandrel section I moves upward, and the reversing component, restricted by the reversing component sliding groove on the lower cylinder section III, drives the ball valve to rotate in the ball seat, causing the ball valve to rotate 90 degrees and block the through hole of the lower mandrel.

[0032] In some optional embodiments, the reversing element includes a Z-shaped reversing key and a circular stabilizing key, which are symmetrically arranged on both sides of the ball valve;

[0033] The reversing component sliding groove includes sliding groove I and sliding groove II. Sliding groove I is a vertical groove, and sliding groove II is divided into three through sections: upper, middle and lower. The lower section is a vertical groove symmetrically arranged with sliding groove I, the upper section is a vertical groove spaced apart from the lower section by a distance, the size of which is set according to the length of the vertical section of the Z-shaped reversing key, and the middle section connects the upper and lower sections.

[0034] Sliding groove I limits the circular stabilizing key, and sliding groove II limits the Z-shaped reversing key.

[0035] In some alternative embodiments, the diameter of the ball valve through hole is the same as the diameter of the central through hole of the lower mandrel section I, and the elastic element is a snap ring.

[0036] In some optional embodiments, the compression anchoring mechanism includes a lower mandrel section II, a lower cylinder section IV, and an anchor tooth structure, wherein the anchor tooth structure includes an anchor tooth body, a limiting block, and a fourth elastic element;

[0037] The lower cylinder section IV is provided with an anchor tooth window for installing the anchor tooth structure. The inner side of the anchor tooth is an upward inclined surface, and the outer side is an arc surface. The outer side has a transverse anchor tooth. The outer side of the anchor tooth body has a groove to accommodate the fourth elastic element. The limiting block is installed on the anchor tooth body and cooperates with the groove of the anchor tooth body to accommodate the fourth elastic element and limit its movement.

[0038] The lower mandrel section II has a downward-sloping inclined surface, which cooperates with the inclined surface of the inner side of the anchor tooth body to compress the anchor tooth body so that it extends out and is anchored to the sleeve.

[0039] In some alternative embodiments, the compression anchoring mechanism further includes a third elastic element located below the lower mandrel section II.

[0040] In some alternative embodiments, the diameter of the outer surface of the anchor tooth is the same as the outer diameter of the lower cylinder section IV;

[0041] Several anchor teeth windows are evenly distributed along the circumference of the lower cylinder section IV, and the anchor teeth windows are stepped holes.

[0042] In some alternative embodiments, the above-described tool further includes: a well pressure sealing mechanism;

[0043] The well pressure sealing mechanism includes a lower mandrel section III and a lower cylinder section V. The lower mandrel section III has an outer conical surface, and the lower cylinder section V has an inner conical surface. The lower mandrel section III moves upward, and under the action of well pressure, the inner and outer conical surfaces are pressed together to achieve a sealing effect.

[0044] In some alternative embodiments, the outer conical surface and the inner conical surface are smooth planes, and the outer conical surface and the inner conical surface have the same inclination angle.

[0045] In some alternative embodiments, the above-described tools further include:

[0046] The upper connector is located at the top of the upper cylinder.

[0047] The lower connector is located at the bottom of the lower cylinder.

[0048] This invention provides a repeatedly detachable downhole plugging tool retrieval device, comprising: an upper connector, a body, and a retrieval mandrel.

[0049] The end of the retrieval mandrel is provided with a guide head, which can extend into the J-shaped locking mechanism of the downhole hand-dropping plugging tool to release the J-shaped locking mechanism from locking the lower mandrel and the lower cylinder.

[0050] The retrieval mandrel has a central through hole and a telescopic block fixing hole. The telescopic block fixing hole is equipped with a telescopic retrieval mechanism, which can extend or retract from the telescopic block fixing hole and cooperate with the sliding guide cone mechanism on the lower cylinder to achieve multiple retrievals.

[0051] In some alternative embodiments, the telescopic retrieval mechanism includes a telescopic block fixing hole, a compression spring III, a telescopic block, and a hollow plug;

[0052] The telescopic block is a stepped cylindrical shape, with a fixed limiting wing in the middle part with the largest diameter, a fifth elastic element fitted at the end with a smaller diameter, and a sloping surface at the other end.

[0053] The salvage mandrel is provided with a telescopic block fixing hole for installing the telescopic block. The telescopic block fixing hole is provided with a limiting groove at the top and bottom for installing and fixing the limiting wing. The outer end of the telescopic block fixing hole is provided with a thread for installing the hollow plug.

[0054] In some alternative embodiments, the above-mentioned retrieval device further includes:

[0055] Several torque-transmitting protrusions are evenly distributed circumferentially on the outer wall of the main body to cooperate with the torque-transmitting grooves on the lower cylinder to realize torque transmission.

[0056] This invention provides a reusable downhole drop-off plugging tool retrieval device, comprising: the aforementioned reusable downhole drop-off plugging tool and the aforementioned retrieval device;

[0057] The telescopic retrieval mechanism of the retrieval device cooperates with the sliding guide cone mechanism of the repeatedly detachable downhole hand-release plugging tool to achieve repeated retrieval and detachment;

[0058] The J-shaped locking mechanism, rotary switch mechanism, compression anchoring mechanism, and well pressure-assisted sealing mechanism in the retrievable downhole plugging tool enable locking, plugging, anchoring, and auxiliary sealing functions when the retrieval tool is detached from the plugging tool.

[0059] This invention provides a method for using a repeatedly detachable downhole plugging tool, comprising:

[0060] Release operation: Insert a steel ball into the flared end of the upper mandrel to block the central through hole, inject high-pressure fluid into the oil pipe, causing the upper mandrel to move downwards. The locking part disengages from the upper mandrel and the upper cylinder and separates from the lower cylinder. After the high-pressure liquid is depressurized through the connecting hole on the upper cylinder, the upper cylinder and the upper mandrel are pulled out from the lower cylinder. The high-pressure liquid enters the central through hole from below the upper mandrel, carrying the steel ball to the ground.

[0061] Anchoring and sealing process: The lower mandrel moves upward to squeeze the anchor tooth body out and bite the inner wall of the casing to achieve anchoring; the reversing component in the rotary switch mechanism slides in the reversing component sliding groove to rotate the ball valve and block the middle through hole of the lower mandrel to achieve sealing; after the J-type locking mechanism moves upward to the locking groove, the straight section of the J-shaped key in the J-type locking mechanism extends and enters the locking groove to lock the lower mandrel in this position; the inner conical surface at the bottom of the lower mandrel and the inner conical surface of the inner wall of the lower cylinder cooperate to achieve sealing under the action of well pressure.

[0062] In some optional embodiments, the upper mandrel moves downward, and the locking part disengages from the limiting position of the upper mandrel and the upper cylinder and separates from the lower cylinder, specifically including:

[0063] The upper mandrel moves downward, shearing off the screw pin. The locking shoulder of the upper mandrel is misaligned with the locking head of the locking part. The locking head pops out from the locking groove of the upper cylinder, separating the upper cylinder from the lower cylinder. The connecting hole on the upper cylinder connects with the central through hole on the steel ball.

[0064] In some optional embodiments, the lower mandrel moves upward to compress the anchor tooth body to extend out of the inner wall of the sleeve to achieve anchoring, including: the lower mandrel moves upward under the rebound force of the compression spring II in a compressed state, causing the cone on the lower mandrel II section to move upward to compress the anchor tooth body, and the anchor tooth body moves outward to compress the return spring, so that the anchor tooth extends out and bites the inner wall of the sleeve to achieve anchoring;

[0065] The method of driving the Z-shaped reversing key in the rotary switch mechanism to slide in the sliding groove to rotate the ball valve and block the middle through hole of the lower spindle, thereby achieving the blockage, includes: the lower spindle moving upward, causing the Z-shaped reversing key of the rotary switch mechanism to move upward in the sliding groove II, passing through the lower, middle and upper sections of the sliding groove II, driving the ball valve to rotate 90° in the ball seat, so that the through hole of the ball valve and the through hole of the lower spindle change from being connected to intersecting, thereby achieving the blockage.

[0066] This invention provides a method for using a repeatedly detachable downhole plugging tool retrieval device, including:

[0067] Salvage Operation: Lower the salvage device. The salvage mandrel of the salvage device enters the lower cylinder. The telescopic block retracts into the salvage mandrel. Continue to lower the salvage device. The bottom guide head of the salvage mandrel is inserted into the inner circle of the J-shaped locking mechanism to open it. The straight section of the J-shaped key retracts to unlock it. The lower mandrel moves down with the salvage device. It pushes the Z-shaped reversing key in the rotary switch mechanism to slide in the sliding groove, causing the ball valve to rotate and release the blockage of the middle through hole of the lower mandrel, so as to release the pressure of the release internal plug tool. When the salvage device moves down and the telescopic block reaches the sliding groove of the guide cone sliding mechanism, the telescopic block extends and enters the sliding groove. Through the cooperation of the telescopic block and the sliding groove, the release internal plug tool is lifted.

[0068] Disengagement operation: Continue to lower the retrieval device so that the telescopic block of the retrieval device slides to the bottom of the guide cone. Lift the retrieval device upward. After the telescopic block drives the guide cone to the top of the sliding groove, the telescopic block retracts under the cooperation of the conical surfaces of the telescopic block and the guide cone. The retrieval device is pulled out from the lower mandrel and disengaged from the release internal plug tool. The lower mandrel performs the anchoring and sealing process.

[0069] Repeatedly perform the retrieval and disengagement operations to repeatedly retrieve and detach the retrieval device and the hand-release internal plug tool until retrieval is successful.

[0070] This invention provides an application of the aforementioned repeatedly detachable downhole plugging tool and the aforementioned repeatedly detachable downhole plugging tool retrieval device in oil and gas well sealing operations.

[0071] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0072] The reusable detachable downhole plugging tool provided in this invention includes an upper cylinder, an upper mandrel, a lower cylinder, and a lower mandrel. In the assembled state, the upper and lower cylinders are connected to form a housing, and the upper and lower mandrels are installed inside the housing. The housing contains multiple functional modules. The locking part of the plugging mechanism is limited by a locking groove in cooperation with the upper mandrel. When the upper mandrel is subjected to downward force, the locking part and locking groove can disengage, separating the upper cylinder from the upper mandrel from the lower cylinder to achieve plugging. The sliding guide cone mechanism's guide cone sliding groove and guide cone can cooperate with a retrieval device. The tool features a J-shaped locking mechanism. After release, when the lower mandrel reaches a certain position, its straight section extends into the locking groove of the lower cylinder, locking the positions of the lower mandrel and lower cylinder. The rotary switch mechanism, after release, when the lower mandrel reaches a certain position, uses its reversing element, restricted by the reversing element sliding groove on the lower cylinder, to rotate the ball valve in the ball seat, causing it to rotate 90 degrees and block the through hole of the lower mandrel. The anchoring mechanism's anchor tooth structure extends and anchors to the casing when the lower mandrel reaches a certain position. Through its various functional modules, this tool achieves functions such as release, locking the positions of the lower cylinder and lower mandrel, anchoring the lower cylinder to the casing, and sealing between the lower cylinder and lower mandrel. It can also be used in conjunction with a retrieval device to achieve repeated retrieval without lowering the tubing string. Its ability to repeatedly disconnect and reconnect facilitates handling complex well conditions and meets the needs of downhole operations.

[0073] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0074] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0075] 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:

[0076] Figure 1 This is a half-sectional view of the downhole unloading plugging tool in an embodiment of the present invention;

[0077] Figure 2 This is a half-sectional view of the release mechanism in an embodiment of the present invention;

[0078] Figure 3 This is a half-sectional view of section I of the upper mandrel in an embodiment of the present invention;

[0079] Figure 4a This is a half-sectional view of the upper cylinder in an embodiment of the present invention;

[0080] Figure 4b This is a bottom view of the upper cylinder in an embodiment of the present invention;

[0081] Figure 5 This is a half-sectional view of the sliding guide cone mechanism in an embodiment of the present invention;

[0082] Figure 6 This is a half-sectional view of the J-shaped locking mechanism and the rotary switch mechanism in an embodiment of the present invention;

[0083] Figure 7 This is a cross-sectional view of the J-shaped locking mechanism in the open state in an embodiment of the present invention;

[0084] Figure 8 This is a cross-sectional view of the locking state of the J-shaped locking mechanism in an embodiment of the present invention;

[0085] Figure 9 This is a perspective view of the J-shaped key in an embodiment of the present invention;

[0086] Figure 10 This is a schematic diagram of the installation of one side of the J-shaped locking mechanism in an embodiment of the present invention;

[0087] Figure 11 This is a schematic diagram of the other side of the J-shaped locking mechanism in an embodiment of the present invention;

[0088] Figure 12 This is a full sectional view of the rotary switch mechanism in an embodiment of the present invention;

[0089] Figure 13 This is a schematic diagram of the installation of the rotary switch mechanism in an embodiment of the present invention;

[0090] Figure 14 This is a schematic diagram of the ball valve in an embodiment of the present invention;

[0091] Figure 15 This is a partial sectional view of the lower cylinder section III in an embodiment of the present invention;

[0092] Figure 16 This is an external view of the lower cylinder section III in an embodiment of the present invention;

[0093] Figure 17a This is a full sectional view of the lower cylinder section III in an embodiment of the present invention;

[0094] Figure 17b This is a top view of the lower cylinder section III in an embodiment of the present invention;

[0095] Figure 18a This is one of the schematic diagrams of the operation of the rotary switch mechanism in an embodiment of the present invention;

[0096] Figure 18b This is a second schematic diagram of the operation of the rotary switch mechanism in an embodiment of the present invention;

[0097] Figure 19 This is a half-sectional view of the compression anchoring mechanism in an embodiment of the present invention;

[0098] Figure 20 This is a schematic diagram of the installation of the compression anchoring mechanism in an embodiment of the present invention;

[0099] Figure 21 This is a full view of the compression anchoring mechanism in an embodiment of the present invention;

[0100] Figure 22 This is an external view of the compression anchoring mechanism in an embodiment of the present invention;

[0101] Figure 23 This is an external view of the anchor tooth body in an embodiment of the present invention;

[0102] Figure 24 This is a half-sectional view of the well pressure sealing mechanism in an embodiment of the present invention;

[0103] Figure 25 This is a half-sectional view of the retrieval device in an embodiment of the present invention;

[0104] Figure 26 As described in the embodiments of the present invention Figure 25 Enlarged view of a section at point D;

[0105] Figure 27 This is an external view of the telescopic block fixing hole in an embodiment of the present invention;

[0106] Figure 28 This is an external view of the telescopic block in an embodiment of the present invention;

[0107] Figure 29a This is one of the schematic diagrams illustrating the process of the retrieval device detaching in an embodiment of the present invention;

[0108] Figure 29b This is a second schematic diagram of the detachment process of the retrieval device in an embodiment of the present invention;

[0109] Figure 29c This is the third schematic diagram of the detachment process of the retrieval device in an embodiment of the present invention;

[0110] Figure 30 This is a schematic diagram of the drop-out tubing in an embodiment of the present invention.

[0111] Explanation of reference numerals in the attached figures:

[0112] 1. Upper cylinder; 1-1. Upper cylinder section I; 2. Upper mandrel; 2-1. Upper mandrel section I;

[0113] 3. Lower cylinder; 3-1. Lower cylinder section I; 3-2. Lower cylinder section II; 3-3. Lower cylinder section III; 3-4. Lower cylinder section IV; 3-5. Lower cylinder section V; 4. Lower mandrel; 4-1. Lower mandrel section I; 4-2. Lower mandrel section II; 4-3. Lower mandrel section III;

[0114] 5. Release mechanism; 5-1. Steel ball; 5-2. Pin; 5-3. Connecting hole; 5-4. Limiting step; 5-5. Torque transmission protrusion; 5-6. Torque transmission groove; 5-7. Locking ring; 5-8. Locking head; 5-9. Locking shoulder; 5-10. Locking groove; 5-11. Positioning step; 5-12. Pin countersunk hole; 6. Sliding guide cone mechanism; 6-1. Guide cone; 6-2. Guide cone sliding groove;

[0115] 7. J-shaped locking and reversing section; 7-1. J-shaped locking mechanism; 7-1-1. J-shaped key; 7-1-1-1. Hooked section; 7-1-1-2. Straight section; 7-1-1-3. Support column; 7-1-2. Compression spring I; 7-1-3. Pressure cap; 7-1-4. Locking groove; 7-1-5. J-shaped keyhole; 7-1-6. Movable window; 7-2. Rotary switch mechanism; 7-2-1. Ball valve; 7-2-1-1. Z-shaped reversing key; 7-2-1-2. Circular stabilizing key; 7-2-2. Ball seat; 7- 2-3. Snap ring; 7-2-4. Reversing component sliding groove; 7-2-4-1. Sliding groove I; 7-2-4-2. Sliding groove II; 7-2-4-2-1. Upper section; 7-2-4-2-2. Middle section; 7-2-4-2-3. Lower section; 7-2-5. Ball valve hole; 7-2-6. Snap ring groove; 8. Compression anchoring mechanism; 8-1. Anchor tooth body; 8-2. Return spring; 8-3. Limiting block; 8-4. Fixing screw; 8-5. Compression spring II; 8-6. Anchor tooth window; 8-7. Cone; 9. Well pressure sealing mechanism;

[0116] 10. Salvage device; 10-1. Salvage mandrel; 10-2. Guide head; 10-2-1. Flushing hole; 10-3. Telescopic salvage mechanism; 10-3-1. Telescopic block fixing hole; 10-3-1-1. Restriction groove; 10-3-2. Compression spring III; 10-3-3. Telescopic block; 10-3-3-1. Restriction wing; 10-3-4. Hollow plug; 11. Hand-release internal plugging tool; 12. Packer; 13. Screen tube; 14. Perforation gun. Detailed Implementation

[0117] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0118] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0119] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0120] To address the shortcomings of existing drop tools, which lack the functions of internal plugging and pre-depressurization after drop, pre-retrieval depressurization, and repeated disconnection, thus hindering the handling of complex well conditions and failing to meet the needs of downhole operations, this invention provides a repeatedly disconnectable downhole drop and internal plugging tool. Suitable for drop and retrieval operations of tubing or coiled tubing, this tool features a drop mechanism to drop the tubing string. A rotary switch mechanism and a well pressure-assisted sealing mechanism achieve internal plugging of the dropped tubing string. The rotary switch mechanism also provides pre-depressurization during retrieval. A J-shaped locking mechanism and a compression anchoring mechanism prevent the dropped tubing string from shifting. A sliding guide cone mechanism enables repeated retrieval and disconnection of the tubing string. Using this tool, drop, internal plugging, and anchoring can be completed in a single tubing run without well pressure. Furthermore, it allows for pre-retrieval depressurization and repeated disconnection during retrieval, reducing construction steps, effectively lowering labor intensity and operational risks, significantly improving construction efficiency, saving production costs, and achieving cost reduction and efficiency improvement.

[0121] The downhole plugging tool that can be repeatedly disconnected and reconnected according to embodiments of the present invention, such as... Figure 1 The half-sectional view of the downhole drop-off plugging tool shown includes: an upper cylinder 1, an upper mandrel 2, a lower cylinder 3, and a lower mandrel 4. In the assembled state, the upper cylinder 1 and lower cylinder 3 are connected to form a housing, and the upper mandrel 2 and lower mandrel 4 are installed inside the housing. From top to bottom, the tool includes the following functional modules:

[0122] The release mechanism 5 includes a locking part disposed on the upper cylinder and a locking groove disposed on the lower cylinder. The locking part is limited by the locking groove under the cooperation of the upper spindle. When the upper spindle is subjected to force and moves downward, the locking part and the locking groove disengage, and the upper cylinder, the upper spindle and the lower cylinder separate to realize the release.

[0123] The sliding guide cone mechanism includes a guide cone sliding groove and a guide cone provided on the lower cylinder, so as to cooperate with the retrieval device to achieve multiple retrievals;

[0124] The J-shaped locking mechanism includes a J-shaped key in a J-shaped keyhole on the lower spindle and a first elastic element. After being released, the lower spindle moves upward, and the straight section of the J-shaped key extends into the locking groove of the lower cylinder under the action of the first elastic element to lock the position of the lower spindle and the lower cylinder.

[0125] The rotary switch mechanism includes a ball valve, a ball seat, and a reversing component, which are disposed in the ball valve hole of the lower spindle. The ball valve is provided with a ball valve through hole. After being released, the lower spindle moves upward. The reversing component drives the ball valve to rotate in the ball seat under the restriction of the reversing component sliding groove on the lower cylinder, so that the ball valve rotates 90 degrees and the ball valve blocks the through hole of the lower spindle.

[0126] The compression anchoring mechanism includes an anchor tooth structure disposed in the anchor tooth window of the lower cylinder. The lower mandrel moves upward and compresses the anchor tooth structure to make the anchor tooth body extend out and anchor with the sleeve.

[0127] In some optional embodiments, the aforementioned internal blocking tool further includes

[0128] The upper connector is located at the top of the upper cylinder. The upper connector is a section at the top of the upper cylinder 1 and can be connected to other tools via threads or other connection methods.

[0129] The lower connector is located at the bottom of the lower cylinder. The lower connector is a section at the lower end of the lower cylinder 3, and can be connected to other tools via threads or other connection methods.

[0130] Preferably, the aforementioned reusable downhole release plugging tool, in terms of its functional mechanisms from top to bottom, comprises an upper connector, a release mechanism 5, a sliding guide cone mechanism 6, a J-shaped locking mechanism 7-1, a rotary switch mechanism 7-2, a compression anchoring mechanism 8, a well pressure assist sealing mechanism 9, and a lower connector, all connected as a single tool unit. The following description uses the release of the packer 12, screen 13, and perforating gun 14 tubing string as an example.

[0131] In some alternative embodiments, the uppermost end of the upper cylinder 1, i.e., the upper connector, may be equipped with a thickened tubing female thread for connecting to the downhole tubing or other tools. If used in a perforation-pump-bundle combined tubing string, the upper end is connected to the pump barrel of the hydraulic pump, and the lower end is connected to the packer 12.

[0132] In some alternative embodiments, the release mechanism 5 includes a portion of an upper cylinder 1, an upper spindle 2, and a lower cylinder 3, such as... Figure 2 , Figure 3 As shown in Figure 4, the release mechanism 5 includes an upper cylindrical section I 1-1, an upper mandrel section I 2-1, and a lower cylindrical section I 3-1. The upper cylindrical section I has a locking part, and the lower cylindrical section I has a locking groove. The locking part is limited by the locking groove in cooperation with the upper mandrel. When the upper mandrel section I is subjected to downward force, the locking part and the locking groove disengage, and the upper cylindrical section, upper mandrel, and lower cylindrical section separate to release the hand. The upper cylindrical section I 1-1 has a connecting hole for pressure relief, and the upper part of the central through hole of the upper mandrel section I 2-1 has a flared opening to accommodate a sealing steel ball. Optionally, the release mechanism 5 also includes a steel ball 5-1 and a pin 5-2.

[0133] Optionally, the upper cylinder section 1-1 is provided with a torque transmission protrusion, and the upper mandrel section 2-1 is provided with a torque transmission groove. The torque transmission protrusion and the torque transmission groove cooperate to achieve torque transmission. The upper cylinder section 1-1 is provided with a limiting step, and the upper mandrel section 2-1 is provided with a positioning step. The limiting step and the positioning step cooperate to limit the downward movement distance of the upper mandrel. The lower part of the locking groove of the upper cylinder section 1-1 is provided with a pin through hole, and the corresponding position of the upper mandrel section 2-1 is provided with a pin countersunk hole. A screwing pin is provided in the pin through hole and the pin countersunk hole.

[0134] The following is combined with Figure 2 , Figure 3 Figure 4 details the specific structure and arrangement of each part of the release mechanism 5. Figure 2 This is a half-sectional view of the release mechanism. Figure 3 This is a half-sectional view of section I of the upper mandrel. Figure 4a This is a half-sectional view of the upper cylinder. Figure 4b This is a bottom view of the upper cylinder.

[0135] The upper cylindrical section 1-1 is cylindrical in shape, with stepped interior and exterior. Four downward-sloping connecting holes 5-3 are evenly distributed circumferentially in the middle. Below the connecting holes 5-3, the interior of the upper cylindrical section 1-1 features a limiting step 5-4. Torque-transmitting protrusions are provided on the upper cylindrical section 1-1, and torque-transmitting grooves are provided on the upper spindle section 1-1. The torque-transmitting protrusions and grooves cooperate to transmit torque. For example, below the limiting step 5-4, on the outer step of the upper cylindrical section 1-1, two square torque-transmitting protrusions 5-5 are evenly distributed circumferentially, which can cooperate with the torque-transmitting grooves 5-6 on the lower cylindrical section 3-1 to achieve torque transmission.

[0136] At the lowest end of the upper cylinder section I 1-1 is the locking part, which includes a locking ring 5-7 and a locking head 5-8. The locking ring 5-7 has a segmented structure and a certain degree of elasticity. The bottom end of each segment is a locking head 5-8 with a longitudinal section that is approximately dew-shaped. When all segments are combined, the bottom end resembles a ring. The locking head 5-8 has protruding steps on both the inside and outside. These protruding steps cooperate with the locking shoulder 5-9 of the upper mandrel section I 2-1 and the locking groove 5-10 on the inner wall of the lower cylinder section I 3-1 to connect and fix the upper and lower cylinders.

[0137] The upper mandrel section 1, 2-1, is a hollow cylinder with a stepped exterior. Its central through-hole is machined axially upwards, and its diameter can be determined based on the diameter of the upper mandrel section 1, 2-1, ensuring smooth passage of the working fluid. At the top of the central through-hole inside the upper mandrel section 1, 2-1, is a flared inner sealing surface that mates with the steel ball 5-1 to seal the central through-hole. The two ends of the outer wall of the upper mandrel section 1, 2-1, and the inner walls of the upper cylinder section 1, 1-1, and the lower cylinder section 1, 3-1, form a piston seal through sealing rings. Near the upper sealing area, the step where the diameter of the upper mandrel section 1, 2-1, decreases is a positioning step 5-11. During downward movement, it can rest on the limiting step 5-4 on the inner wall of the upper cylinder section 1, 1-1, thus limiting the movement distance of the upper mandrel section 1, 2-1. Below the positioning step 5-11 of the upper mandrel section I 2-1 is a locking shoulder 5-9. The outer diameter of the upper mandrel section I 2-1 is increased by a certain dimension to form a beveled shoulder. The end face of the shoulder mates with the locking ring 5-7 on the upper cylinder section I 1-1 to prevent the locking ring 5-7 from retracting. Below the locking shoulder 5-9 is a circular pin countersunk hole 5-12. Its diameter and number can be determined based on the shearing pressure, and its depth must not penetrate the central through hole of the upper mandrel section I 2-1.

[0138] The lower cylindrical section 3-1 is cylindrical in shape, with the same outer diameter as the upper cylindrical section 1-1. At the top of the lower cylindrical section 3-1, two square torque-transmitting grooves 5-6 are evenly distributed circumferentially, their number and size matching those of the torque-transmitting protrusions 5-5. After the inner diameter of the lower cylindrical section 3-1 decreases to form a beveled shoulder, the diameter increases to form a beveled groove, which is the locking groove 5-10. Its size matches that of the locking ring 5-7, used to limit the outward expansion of the locking ring 5-7. The locking groove 5-10 and the locking shoulder 5-9 form a locking space, the size of which can lock the locking head 5-8 of the locking ring 5-7. Below the locking groove 5-10 is a circular pin through-hole with internal threads, used for screwing in the pin 5-2.

[0139] Steel ball 5-1 is a sphere with a diameter slightly larger than the diameter of the central through hole in section I of the upper mandrel 2-1. Pin 5-2 is an integral copper columnar pin, the length and diameter of which can be adjusted according to the outer diameter of the upper and lower cylinders and the shearing pressure.

[0140] When installing the release mechanism 5, first insert the upper cylinder section 1-1 into the lower cylinder section 3-1, aligning the torque transmission protrusion 5-5 with the torque transmission groove 5-6. Then, insert the upper mandrel section 2-1 into the upper cylinder section 1-1. Using the locking shoulder 5-9 of the upper mandrel section 2-1, squeeze the locking head 5-8 of the locking ring 5-7 of the upper cylinder section 1-1 into the locking groove 5-10 on the inner wall of the lower cylinder section 3-1. Finally, adjust the positions of the lower cylinder section 3-1 and the upper mandrel section 2-1 so that the pin countersunk hole and the pin through hole are aligned. Use the threaded pin 5-2 to connect the lower cylinder section 3-1 and the upper mandrel section 2-1.

[0141] In some alternative embodiments, the sliding guide cone mechanism 6 includes a lower cylinder section II 3-2 with a guide cone sliding groove and a guide cone 6-1 with an inclined surface, to cooperate with the retrieval device to achieve multiple retrievals. For example... Figure 5 The half-sectional view of the sliding guide cone mechanism shown depicts a portion of the lower cylinder 3, specifically section II 3-2, which also includes a guide cone 6-1. At the lower end of the pin through-hole, an annular groove of a certain length is machined on the inner wall of section II 3-2, forming the guide cone sliding groove 6-2. Both the upper and lower sides of the guide cone sliding groove 6-2 are right-angled steps. The depth of the groove can be determined based on the outer diameter of section II 3-2 and the dimensions of the guide cone 6-1. The guide cone 6-1 is a ring with a right-angled triangular cross-section. The inner diameter of the ring is slightly larger than the outer diameters of the upper mandrel 2 and lower mandrel 4, while the outer diameter is slightly smaller than the outer diameter of the guide cone sliding groove 6-2. This ensures that the length of the right-angled side of the guide cone 6-1 is slightly less than the depth of the guide cone sliding groove 6-2. Placed within the guide cone sliding groove 6-2, it can slide freely up and down within the groove. When the guide cone 6-1 slides to its uppermost position, one right-angled side of the guide cone 6-1 is in close contact with the upper step surface of the guide cone sliding groove 6-2, and the other right-angled side is in close contact with the side of the groove, making the upper right-angled step of the guide cone sliding groove 6-2 become a sloped step inclined towards the center. Here, "slightly greater than" and "slightly less than" mean that the difference in outer diameter is not greater than a set threshold, which can be set as needed.

[0142] In some alternative embodiments, such as Figure 6-11The J-shaped locking and reversing part 7 shown includes a lower spindle section I 4-1, a lower cylinder section III 3-3, a J-shaped key 7-1-1, a first elastic element, and a pressure cap 7-1-3. Two J-shaped keyholes 7-1-5 are provided on the lower spindle section I 4-1, each J-shaped keyhole 7-1-5 is provided with a J-shaped key 7-1-1, and the J-shaped key 7-1-1 includes a rounded portion 7-1-1-1 and a straight portion 7-1-1-2. -1-1-1 has a support column 7-1-1-3 at the outer end of the outer circle to support the first elastic element. The pressure cap 7-1-3 is located outside the first elastic element and cooperates with the hook-shaped part 7-1-1-1 to form an elastic element receiving cavity. The lower cylinder III section 3-3 is provided with a locking groove 7-1-4. After the release, the lower spindle moves upward and the straight part 7-1-1-2 of the J-shaped key extends out of the locking groove 7-1-4 under the action of the first elastic element to lock the position of the lower spindle 4 and the lower cylinder 3.

[0143] Preferably, the inner diameter of the hooked portion 7-1-1-1 is the same as the diameter of the central through hole of the lower mandrel section I 4-1, the end of the straight portion 7-1-1-2 is arc-shaped, and the diameter of the arc is the same as the maximum outer diameter of the lower mandrel section I 4-1; the pressure cap 7-1-3 is arc-shaped, and the outer diameter of the pressure cap 7-1-3 is the same as the maximum outer diameter of the lower mandrel section I 4-1; the elastic element is a compression spring.

[0144] The following is combined with Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 and Figure 11 The specific structure and configuration of each part of the J-shaped locking mechanism are described in detail. Figure 6 This is a half-sectional view of the J-shaped locking mechanism and the rotary switch mechanism, specifically... Figure 7 BB view in the middle; Figure 7 This is a cross-sectional view of the J-shaped locking mechanism in its open state, specifically... Figure 6 AA view in the middle; Figure 8 A cross-sectional view of the locked state of the J-shaped locking mechanism; Figure 9 A three-dimensional view of a J-shaped key; Figure 10 A schematic diagram showing the installation of one side of the J-shaped locking mechanism; Figure 11 This is a schematic diagram of the other side of the J-shaped locking mechanism.

[0145] The J-shaped locking mechanism 7-1 is taken from a portion of the lower cylinder 3 and the lower mandrel 4, namely, lower mandrel section I 4-1 and lower cylinder section III 3-3. It also includes a J-shaped key 7-1-1, a compression spring I 7-1-2, and a pressure cap 7-1-3. The lower cylinder section III 3-3 is provided with a locking groove 7-1-4. The lower mandrel section I 4-1 is a hollow cylinder with a stepped outer surface. The diameter of the central through hole is the same as the diameter of the central through hole of the upper mandrel section I 2-1, and the maximum outer diameter is the same as the maximum outer diameter of the upper mandrel section I 2-1.

[0146] Near the upper major diameter of section I, 4-1 of the lower mandrel, there are rectangular through holes radially connected to the central through hole, namely J-shaped keyholes 7-1-5, one on each side symmetrically arranged. The height and width of the J-shaped keyholes 7-1-5 are determined according to the thickness of the J-shaped key 7-1-1 and the overall width. The height of the J-shaped keyholes 7-1-5 is consistent with the thickness of the J-shaped key 7-1-1, and the width of the J-shaped keyholes 7-1-5 is consistent with the sum of the outer width of the rounded portion 7-1-1-1 of the J-shaped key 7-1-1 and the width of the straight portion 7-1-1-2 of the J-shaped key 7-1-1.

[0147] The J-shaped key 7-1-1 is J-shaped and can be divided into a hooked section 7-1-1-1 and a straight section 7-1-1-2. The hooked section 7-1-1-1 consists of two non-concentric semicircles, with the inner circle's diameter matching the diameter of the central through hole in the lower mandrel section I 4-1. A cylindrical support post 7-1-1-3 is welded to the outer end of the hooked section 7-1-1-1 to support the compression spring I 7-1-2. The compression spring I 7-1-2 is a compression spring. The straight section 7-1-1-2 intersects with the hooked section 7-1-1-1, and its end is arc-shaped, with the arc's diameter matching the maximum outer diameter of the lower mandrel section I 4-1.

[0148] The pressure cap 7-1-3 is an arc-shaped pressure cap. Its outer diameter is the same as the maximum outer diameter of section 4-1 of the lower mandrel I. Its inner diameter is slightly smaller than its outer diameter, but much larger than the outer diameter of the hook-shaped part 7-1-1-1, providing installation space for the compression spring I 7-1-2, thus providing room for the inward and outward movement of the J-shaped key 7-1-1. The width of the pressure cap 7-1-3 is the same as the outer width of the hook-shaped part of the J-shaped key 7-1-1, and its thickness is the same as the height of the J-shaped key hole 7-1-5.

[0149] During installation, first align the straight section 7-1-1-2 of the J-key 7-1-1 with the J-key hole 7-1-5, with the center of the rounded section 7-1-1-1 facing inwards, and insert it into the J-key hole 7-1-5. Then, mount the compression spring I 7-1-2 onto the support column 7-1-1-3. Finally, near the side where the rounded section 7-1-1-1's arc is located, install the pressure cap 7-1-3, aligning the outer circle of the pressure cap 7-1-3 with the outer circle of the lower mandrel I section 4-1, and then weld it to the lower mandrel I section 4-1 as a single unit. At this point, because the width of the pressure cap 7-1-3 is smaller than the width of the J-key hole 7-1-5, a small window is left, the width of which is the width of the straight section 7-1-1-2 of the J-key 7-1-1, which is the movable window 7-1-6 of the straight section. Using the same method, J-shaped key 7-1-1, compression spring I 7-1-2, and pressure cap 7-1-3 are installed in the J-shaped keyhole 7-1-5 on the symmetrical side, making the installation on both sides centrally symmetrical. Thus, the straight section 7-1-1-2 of J-shaped key 7-1-1 is inserted into the movable window 7-1-6 formed by pressure cap 7-1-3 and J-shaped keyhole 7-1-5. Under the action of compression spring I 7-1-2, J-shaped key 7-1-1 can extend and retract parallel within J-shaped keyhole 7-1-5. When the inner circles of the rounded sections 7-1-1-1 of the two J-shaped keys 7-1-1 are aligned, the diameter of the formed inner circle is equal to the diameter of the central through hole of lower mandrel I section 4-1.

[0150] At the upper end of the lower cylinder section III 3-3, two locking grooves 7-1-4 are cut downwards along the central axis of the cross-section on its inner wall. The width of the locking grooves 7-1-4 is slightly larger than the width of the straight section 7-1-1-2 of the J-shaped key 7-1-1. The two locking grooves 7-1-4 are centrally symmetrical along the central axis. Since the inner diameter of the lower cylinder section III 3-3, which is close to the locking grooves 7-1-4, is the same as the outer diameter of the lower mandrel section I 4-1, when the lower mandrel section I is located below the locking grooves 7-1-4, the J-shaped key 7-1-1 of the J-shaped locking mechanism 7-1 compresses the compression spring I 7-1-2 and retracts into the J-shaped key hole 7-1-5 due to the restriction of the inner wall of the lower cylinder section III 3-3. At this time, the inner circles of the hooked portions 7-1-1-1 of the two J-shaped keys 7-1-1 are aligned to form a complete circle.

[0151] In some alternative embodiments, such as Figure 6 , Figure 12-1As shown in Figure 8, the rotary switch mechanism 7-2 includes a lower spindle section I 4-1, a lower cylinder section III 3-3, a ball valve 7-2-1 disposed in a ball valve hole in the lower spindle section I 4-1, a ball seat 7-2-2, a reversing element, and a second elastic element; the lower spindle section I 4-1 is provided with a ball valve hole 7-2-5 communicating with its central through hole to install the ball valve 7-2-1 and the ball seat 7-2-2, and the ball valve hole 7-2-5 is provided with an elastic element groove to install the second elastic element to limit the ball seat 7-2-2; the lower cylinder section III 3-3 is provided with a reversing element sliding groove. 7-2-4; Ball seat 7-2-2 has a concave spherical surface to accommodate ball valve 7-2-1. Ball valve 7-2-1 is provided with a ball valve through hole. Both ball seat 7-2-2 and ball valve 7-2-1 are provided with reversing component mounting holes for installing reversing components. After being released, the lower spindle section I 4-1 moves upward. Under the restriction of the reversing component sliding groove 7-2-4 on the lower cylinder section III 3-3, the reversing component drives the ball valve 7-2-1 to rotate in the ball seat 7-2-2, causing the ball valve 7-2-1 to rotate 90 degrees. The ball valve 7-2-1 blocks the through hole of the lower spindle section I 4-1.

[0152] Optionally, the reversing component includes a Z-shaped reversing key 7-2-1-1 and a circular stabilizing key 7-2-1-2, which are symmetrically arranged on both sides of the ball valve; the reversing component sliding groove 7-2-4 includes sliding groove I 7-2-4-1 and sliding groove II 7-2-4-2, where sliding groove I 7-2-4-1 is a vertical groove, and sliding groove II 7-2-4-2 is divided into three continuous sections: upper, middle, and lower. The lower section 7-2-4-2-3 is connected to sliding groove I 7-2-4-1. 4-1 Symmetrically arranged vertical slots, the upper section 7-2-4-2-1 is a vertical slot spaced apart from the lower section 7-2-4-2-3 by a distance, the size of which is set according to the length of the vertical segment of the Z-shaped reversing key 7-2-1-1, the middle section 7-2-4-2-2 connects the upper section 7-2-4-2-1 and the lower section 7-2-4-2-3; sliding slot I 7-2-4-1 limits the circular stabilizing key 7-2-1-2, and sliding slot II 7-2-4-2 limits the Z-shaped reversing key 7-2-1-1.

[0153] Preferably, the diameter of the ball valve through hole is the same as the diameter of the central through hole of the lower mandrel section I 4-1, and the elastic element is a snap ring 7-2-3, which is installed in the snap ring groove 7-2-6.

[0154] The following is combined with Figure 6 , Figure 12-1 8. Describe in detail the specific structure and arrangement of each part of the rotary switch mechanism. Among them, Figure 12 This is a full sectional view of the rotary switch mechanism; Figure 13 This is a schematic diagram of the installation of the rotary switch mechanism; Figure 14 This is a schematic diagram of a ball valve;

[0155] Figure 15This is a partial sectional view of section III of the lower cylinder; Figure 16 This is an external view of the lower cylinder section III; Figure 17a This is a full sectional view of section III of the lower cylinder, i.e. Figure 17b CC view, Figure 17b This is a top view of section III of the lower cylinder; Figure 18a and Figure 18b This is a schematic diagram of the rotary switch mechanism.

[0156] The rotary switch mechanism 7-2 is located below the J-shaped locking mechanism 7-1, and is taken from the lower spindle section I 4-1 and the lower cylinder section III 3-3 respectively. It also includes a ball valve 7-2-1, a ball seat 7-2-2, a snap ring 7-2-3 and a reversing component sliding groove 7-2-4.

[0157] At the lower part of the J-shaped locking mechanism 7-1 of the lower mandrel section I 4-1, two circular holes are machined symmetrically on the left and right, which are the ball valve holes 7-2-5. Inside the ball valve hole 7-2-5, near the outer edge of the lower mandrel section I 4-1, a circular retaining ring groove 7-2-6 is machined.

[0158] Ball valve 7-2-1 is a smooth sphere with a central through-hole. The diameter of the through-hole is the same as the diameter of the central through-hole of lower mandrel section I 4-1. Perpendicular to the central through-hole of ball valve 7-2-1, on the side center axis of ball valve 7-2-1, there is a Z-shaped reversing key 7-2-1-1 on one side and a circular stabilizing key 7-2-1-2 on the symmetrical side. Z-shaped reversing key 7-2-1-1 is welded from a cylinder, and circular stabilizing key 7-2-1-2 is a cylinder of the same diameter. The vertical section of Z-shaped reversing key 7-2-1-1 faces downward and is fixed to ball valve 7-2-1 parallel to the perpendicular bisector of ball valve 7-2-1.

[0159] The ball seat 7-2-2 is a cylinder in shape. One side is a concave spherical surface with a diameter equal to that of the ball valve 7-2-1, and the other side is a circular surface with a through hole drilled in the center. The diameter of the through hole is slightly larger than that of the circular stabilizing key 7-2-1-2. The cylinders of the Z-shaped reversing key 7-2-1-1 and the circular stabilizing key 7-2-1-2 can pass through this hole.

[0160] The retaining ring 7-2-3 is installed by fitting it into the retaining ring groove 7-2-6.

[0161] When installing the ball valve 7-2-1 on the lower mandrel section I 4-1, first place the ball valve 7-2-1 into the ball valve hole 7-2-5, aligning the through hole of the ball valve 7-2-1 with the center through hole of the lower mandrel section I 4-1. Then, insert the concave spherical surfaces of the ball seat 7-2-2 into the ball valve hole 7-2-5 on both symmetrical sides. Insert the Z-shaped reversing key 7-2-1-1 and the circular stabilizing key 7-2-1-2 into the side through holes of the ball seat 7-2-2 and fix them to the ball valve 7-2-1. When installing the Z-shaped reversing key 7-2-1-1, ensure that the vertical section of the Z-shaped reversing key 7-2-1-1 faces downwards and is parallel to the vertical line of the ball valve 7-2-1. Finally, insert the retaining rings 7-2-3 into the retaining ring grooves 7-2-6 on both symmetrical sides, thereby confining the ball valve 7-2-1 and the ball seat 7-2-2 within the ball valve hole 7-2-5. They can only rotate around the horizontal central axis, but cannot translate along the horizontal central axis. At this time, the ball valve 7-2-1 is in the open state. When the Z-shaped reversing key 7-2-1-1 is rotated, the ball valve 7-2-1 rotates within the ball seat 7-2-2 around the horizontal central axis, causing its through hole to coincide with or intersect with the central through hole on the lower mandrel section I 4-1. When rotated 90°, the central through hole is fully opened or closed, thereby opening or closing the channel inside the tubing string, which is internal plugging, thus realizing the well opening or closing within the tubing string.

[0162] The reversing component sliding groove 7-2-4 is located on the inner wall of section III 3-3 of the lower cylinder, below the locking groove 7-1-4, and is divided into sliding groove I 7-2-4-1 and sliding groove II 7-2-4-2. Sliding groove I 7-2-4-1 is a vertical square groove, and its width is slightly larger than the cylindrical diameter of the circular stabilizing key 7-2-1-2. Sliding groove II 7-2-4-2 is divided into three sections: upper, middle, and lower, with the same width as sliding groove I 7-2-4-1. Among them, the lower section 7-2-4-2-3 is symmetrically arranged with sliding groove I 7-2-4-1 and is a vertical groove. The upper section 7-2-4-2-1 and the lower section 7-2-4-2-3 are spatially separated by a distance equal to the length of the vertical section of the Z-shaped reversing key 7-2-1-1, and are also vertical grooves. The middle section 7-2-4-2-2 is inclined upwards, smoothly connecting the upper section 7-2-4-2-1 and the lower section 7-2-4-2-3. The three sections are connected together to form the sliding groove II 7-2-4-2. The middle section 7-2-4-2-2 is the projection of the straight line connecting the upper section 7-2-4-2-1 and the lower section 7-2-4-2-3 on the inner wall of the lower cylinder III section 3-3. When the Z-shaped reversing key 7-2-1-1 passes through the middle section 7-2-4-2-2, it can rotate 90°. In the horizontal cross-sectional orientation, the arrangement of the reversing component sliding groove 7-2-4 is offset from the locking groove 7-1-4 by a certain distance in the circumferential direction, so as to ensure that the straight section 7-1-1-2 of the J-shaped key 7-1-1 will not extend into the reversing component sliding groove 7-2-4, but is restricted to the inner wall of the lower cylinder section II 3-2, thereby ensuring the unobstructed flow of the central through hole of the lower mandrel section I 4-1.

[0163] When the lower mandrel section I 4-1, with ball valve 7-2-1 installed, is inserted into the lower cylinder section III 3-3, the Z-shaped reversing key 7-2-1-1 is inserted into the sliding groove II 7-2-4-2, and the circular stabilizing key 7-2-1-2 is inserted into the sliding groove I 7-2-4-1. The function of the sliding groove II 7-2-4-2 is to restrict the sliding of the Z-shaped reversing key 7-2-1-1 and ensure that during its upward sliding from the lower section 7-2-4-2-3 of the sliding groove II 7-2-4-2 through the middle section 7-2-4-2-2 to the upper section 7-2-4-2-1, the Z-shaped reversing key 7-2-1-1 can rotate 90°, thereby driving the internal ball valve 7-2-1 to rotate 90°, realizing the opening and closing of the well within the tubing string.

[0164] In some alternative embodiments, such as Figure 19-23As shown, the compression anchoring mechanism 8 includes a lower mandrel section II 4-2, a lower cylinder section IV 3-4, and an anchor tooth structure. The anchor tooth structure includes an anchor tooth body 8-1, a limiting block 8-3, and a fourth elastic element. The lower cylinder section IV 3-4 is provided with an anchor tooth window 8-6 for installing the anchor tooth structure. The inner surface of the anchor tooth body 8-1 is an upwardly inclined surface, and the outer surface is an arc surface. The outer surface has a transverse anchor tooth. The outer side of the anchor tooth body 8-1 has a groove to accommodate the fourth elastic element. The limiting block is installed on the anchor tooth body 8-1 and cooperates with the groove of the anchor tooth body 8-1 to accommodate the fourth elastic element and limit its movement. The lower mandrel section II 4-2 has a downwardly inclined surface, which cooperates with the inclined surface of the inner surface of the anchor tooth body 8-1 to compress the anchor tooth body 8-1 so that it extends out and anchors with the sleeve.

[0165] Optionally, the compression anchoring mechanism 8 also includes a third elastic element located below the lower mandrel section II, which can provide a restoring elastic force to move the lower mandrel section II upward.

[0166] Preferably, the diameter of the outer surface of the anchor tooth body 8-1 is the same as the outer diameter of the lower cylinder section IV 3-4, and several anchor tooth windows 8-6 are evenly distributed along the circumference of the lower cylinder section IV, and the anchor tooth windows 8-6 are stepped holes.

[0167] The following is combined with Figures 19-23 The specific structure and arrangement of each part of the compression anchoring mechanism 8 are described in detail. Figure 19 A half-sectional view of the compression anchoring mechanism; Figure 20 This is a schematic diagram of the installation of the compression anchoring mechanism; Figure 21 A full view of the compression anchoring mechanism; Figure 22 External view of the compression anchoring mechanism; Figure 23 This is an external view of the anchor tooth body.

[0168] The compression anchoring mechanism 8 is located at the lower part of the rotary switch mechanism 7-2, and is taken from the lower spindle section II 4-2 and the lower cylinder section IV 3-4 respectively. It also includes an anchor tooth body 8-1, a third elastic element, a limiting block 8-3, a fixing screw 8-4, and a fourth elastic element. The third elastic element can be a return spring 8-2, and the fourth elastic element can be a compression spring II 8-5.

[0169] The anchor tooth body 8-1 is block-shaped, with an outer arc surface whose diameter matches the outer diameter of section IV 3-4 of the lower cylinder. The inner surface is an upward-sloping surface, and both ends are support blocks. Anchor teeth are transversely cut into the outer arc surface of the anchor tooth body 8-1, with the tooth openings facing upwards. Grooves are longitudinally cut into the outer arc surface of the anchor tooth body 8-1 to accommodate the return spring 8-2.

[0170] The limiting block 8-3 is a long strip plate with an outer arc surface. The diameter of the arc is the same as the outer diameter of the lower cylinder section IV 3-4. The inner surface is a plane with a width that is the same as the width of the groove on the anchor tooth body 8-1, and a length greater than the total height of the anchor tooth body 8-1. The limiting block 8-3 has through holes drilled at both the top and bottom ends.

[0171] On the outer wall of section IV (3-4) of the lower cylinder, slightly above the middle, there is a rectangular stepped hole, which serves as the anchor tooth window 8-6. The anchor tooth window 8-6 is located below the sliding groove 7-2-4 of the reversing component. Four anchor tooth windows 8-6 are evenly distributed circumferentially. From the outside in, the first stepped hole of the anchor tooth window 8-6 is used to place the limiting block 8-3, and the second stepped hole is used to place the anchor tooth body 8-1. Their dimensions are the same as those of the limiting block 8-3 and the anchor tooth body 8-1, respectively. Threaded holes are drilled at both ends of the first stepped hole. Near the lower end of section IV (3-4) of the lower cylinder, the diameter narrows inward, forming a stepped surface.

[0172] When installing the anchor tooth body 8-1 of the compression anchoring mechanism 8, first place the anchor tooth body 8-1 in the anchor tooth window 8-6, so that the groove on the anchor tooth body 8-1 faces outward. Then, place three return springs 8-2 evenly in the groove longitudinally, and place the limiting block 8-3 so that its plane faces the groove. Finally, tighten the fixing screw 8-4.

[0173] The lower mandrel section II 4-2 extends downwards from the lower mandrel section I 4-1 after its diameter is reduced, and then tilts outwards towards the center to form a cone 8-7, meaning the upper diameter is smaller than the lower diameter. The length and taper of the cone 8-7 can be adjusted according to the taper of the inner surface of the anchor tooth body 8-1 and the diameter of the lower mandrel section II 4-2. When the cone 8-7 moves upwards, the taper applies a radial force to the anchor tooth body 8-1, causing the anchor tooth to extend and bite against the inner wall of the sleeve for anchoring. The lower end of the cone 8-7 of the lower mandrel section II 4-2 has an inwardly tapered diameter, forming a stepped surface.

[0174] A compression spring II 8-5 is placed between the stepped surface of the cone 8-7 and the stepped surface of the lower cylinder IV section 3-4. Because the upper spindle 2 is relatively long, it compresses the lower spindle 4 downwards during installation, thus compressing the compression spring II 8-5. Simultaneously, when the release mechanism 5 performs its release operation, the upper spindle 2 moves downwards, further increasing the compression of the compression spring II 8-5.

[0175] In some alternative embodiments, the aforementioned reusable downhole plugging tool further includes a well pressure sealing mechanism 9, such as... Figure 24 As shown, the well pressure sealing mechanism 9 includes a lower mandrel section III 4-3 and a lower cylinder section V 3-5. The lower mandrel section III 4-3 has an outer conical surface, and the lower cylinder section V 3-5 has an inner conical surface. The lower mandrel section III 4-3 moves upward, and under the action of well pressure, the inner and outer conical surfaces are pressed together to achieve a sealing effect.

[0176] The well pressure sealing mechanism 9 is derived from section III (4-3) of the lower mandrel and section V (3-5) of the lower cylinder. Section III (4-3) of the lower mandrel extends downward after the diameter is reduced from section II (4-2) of the lower mandrel, and then tilts outward towards the center to form an outer conical surface. The inner wall of section V (3-5) of the lower cylinder extends downward after the diameter is reduced from section IV (3-4) of the lower cylinder, and then tilts outward to form an inner conical surface.

[0177] Preferably, both the outer and inner conical surfaces are smooth planes with the same inclination angle and width. When the lower mandrel section III 4-3 moves upward, the outer and inner conical surfaces coincide, and under the pressure inside the well, they achieve a sealing effect.

[0178] In some alternative embodiments, the lower connector is a thickened tubing male thread for connecting to a tool below, such as packer 12.

[0179] The aforementioned reusable downhole plugging tool can be assembled into a single unit by processing the lower mandrel 4 and lower cylinder 3 in sections for ease of installation. The J-shaped locking mechanism 7-1, rotary switch mechanism 7-2, compression anchoring mechanism 8, and well pressure sealing mechanism 9 are connected in series.

[0180] This invention provides a method for using the aforementioned repeatedly detachable downhole plugging tool, including:

[0181] Release operation: Insert a steel ball into the flared end of the upper mandrel to block the central through hole, inject high-pressure fluid into the oil pipe, causing the upper mandrel to move downwards. The locking part disengages from the upper mandrel and the upper cylinder and separates from the lower cylinder. After the high-pressure liquid is depressurized through the connecting hole on the upper cylinder, the upper cylinder and the upper mandrel are pulled out from the lower cylinder. The high-pressure liquid enters the central through hole from below the upper mandrel, carrying the steel ball to the ground.

[0182] Anchoring and sealing process: The lower mandrel moves upward to squeeze the anchor tooth body out and bite the inner wall of the casing to achieve anchoring; the Z-shaped reversing key in the rotary switch mechanism slides in the sliding groove to rotate the ball valve and block the middle through hole of the lower mandrel to achieve sealing; after the J-type locking mechanism moves upward to the locking groove, the straight section of the J-shaped key in the J-type locking mechanism extends and enters the locking groove to lock the lower mandrel in this position; the inner conical surface at the bottom of the lower mandrel and the inner conical surface of the inner wall of the lower cylinder cooperate to achieve sealing under well pressure.

[0183] During the aforementioned release operation, the upper mandrel moves downward, and the locking part disengages from the upper mandrel and the upper cylinder and separates from the lower cylinder. Specifically, the upper mandrel moves downward, shears off the screw pin, the locking shoulder of the upper mandrel is misaligned with the locking head of the locking part, the locking head pops out from the locking groove of the upper cylinder, the upper cylinder separates from the lower cylinder, and the connecting hole on the upper cylinder connects with the central through hole on the steel ball.

[0184] The aforementioned release operation specifically includes: when release is required, a steel ball 5-1 is inserted into the well through the tubing and sits on the funnel-shaped inner sealing surface of the upper mandrel section I 2-1. High-pressure fluid is pumped into the tubing from the surface via a pump truck. Due to the sealing effect of the upper part of the upper mandrel section I 2-1, the high-pressure fluid acts on the steel ball 5-1, generating downward shearing pressure. When the shearing pressure is sufficient to shear the pin 5-2, the pin 5-2 is sheared off, causing the upper mandrel section I 2-1 to slide downwards. This causes the locking shoulder 5-9 on the upper mandrel section I 2-1 to gradually lose its restraining effect on the locking head 5-8. When the upper mandrel section I 2-1 descends to the point where the locking head 5-8 of the locking ring 5-7 enters the space formed by the outer wall of the upper mandrel section I 2-1 and the inner wall of the locking ring 5-7, the locking head 5-8 completely loses its restraint and, under the action of elastic force, pops out of the locking groove 5-10. At this point, the upper mandrel section 1 (2-1) continues to descend. When the positioning step 5-11 descends to the limiting step 5-4 on the inner wall of the upper cylinder section 1 (1-1), the piston sealing structure passes the connecting hole 5-3. After losing its sealing function, the high-pressure fluid is depressurized through the connecting hole 5-3, and the pump truck displays a sudden drop in pump pressure, indicating successful release. Lifting the tubing string will then bring out the upper mandrel 2 and the upper cylinder 1, completing the release operation. Using the ground pump truck, fluid is injected into the annular space between the tubing and the casing, allowing the fluid to enter through the central through-hole of the upper mandrel 2. Under the propulsion of the fluid, the steel ball 5-1 can be carried to the ground, restoring the passage of the central through-hole and providing a flow channel for subsequent operations, including ash injection and sand filling.

[0185] During the above-mentioned anchoring and sealing process, the lower mandrel moves upward to squeeze the anchor tooth body out and bite the inner wall of the sleeve to achieve anchoring. This includes: the lower mandrel moves upward under the rebound force of the compression spring II in a compressed state, causing the cone on the lower mandrel II section to move upward to squeeze the anchor tooth body, and the anchor tooth body moves outward to squeeze the return spring, so that the anchor tooth extends out and bites the inner wall of the sleeve to achieve anchoring.

[0186] During the aforementioned anchoring and sealing process, the Z-shaped reversing key in the rotary switch mechanism slides in the sliding groove, causing the ball valve to rotate and block the middle through hole of the lower mandrel, thus achieving the sealing. This includes: the lower mandrel moving upward, causing the Z-shaped reversing key of the rotary switch mechanism to move upward within the sliding groove II, passing through the lower, middle, and upper sections of the sliding groove II, causing the ball valve to rotate 90° within the ball seat, so that the through hole of the ball valve and the through hole of the lower mandrel change from being connected to intersecting, thereby achieving the sealing.

[0187] In summary, the working principle of the aforementioned reusable downhole release plugging tool is as follows: Before the release mechanism 5 releases, the through hole of the ball valve 7-2-1 is connected to the central through hole of the lower mandrel 4, indicating an open well. When the upper mandrel 2 and upper cylinder 1 are released, the lifting tubing string is pulled out of the lower cylinder 3 together. At this time, the lower mandrel 4 loses the downward constraint of the upper mandrel 2. Under the rebound force of the compression spring II 8-5, which is in a compressed state, the lower mandrel 4 will move upward, causing the cone 8-7 on the lower mandrel II section 4-2 to move upward and squeeze the anchor tooth body 8-1. Under the mutual constraint of the cone surfaces, the anchor tooth body 8-1 moves outward and squeezes the return spring 8-2, gradually causing the anchor tooth to extend and bite onto the inner wall of the casing, thus achieving anchoring. The upward movement of the lower spindle 4 causes the Z-shaped reversing key 7-2-1-1 of the rotary switch mechanism 7-2 to move upward within the sliding groove II 7-2-4-2. The circular stabilizing key 7-2-1-2 ensures the stability of the upward movement within the sliding groove I 7-2-4-1. During the upward movement, the Z-shaped reversing key 7-2-1-1 is constrained by the tracks of the lower, middle, and upper reversing component sliding grooves 7-2-4, achieving a 90° rotation. This causes the fixed ball valve 7-2-1 to rotate 90° within the ball seat 7-2-2, changing the connection between the through hole of the ball valve 7-2-1 and the through hole of the lower spindle 4 from being connected to intersecting, thus achieving well shut-off. Simultaneously, the J-shaped locking mechanism 7-1 moves upward along with the lower spindle 4, causing the J-shaped key 7-1-1 to break free from the constraint of the inner wall of the lower cylinder 3 and enter the locking groove 7-1-4. The straight section 7-1-1-2 of the J-shaped key 7-1-1 extends into the locking groove 7-1-4, locking the entire lower mandrel 4 in this position. This prevents the lower mandrel 4 from shifting downwards again under the pressure of the fluid inside the tubing, thus losing its shut-in and anchoring functions. During the upward movement of the lower mandrel 4, the inner conical surface at the bottom coincides with the outer conical surface on the inner wall of the lower cylinder. Under the pressure inside the well, the inner and outer conical surfaces fit together more tightly. The greater the pressure inside the well, the greater the compressive force acting on the lower end of the inner conical surface, resulting in a tighter fit between the inner and outer conical surfaces, thereby achieving the effect of well pressure-assisted sealing.

[0188] The reusable downhole drop-and-plug tool provided in this invention allows for 100% drop-and-plug operation via ball dropping and surface pressurization, dropping a portion of the tubing string. A rotary switch mechanism and a well pressure-assisted sealing mechanism achieve internal plugging of the dropped tubing string, ensuring well sealing. The rotary switch mechanism automatically depressurizes during retrieval, ensuring operational safety. A J-shaped locking mechanism and a compression anchoring mechanism prevent the dropped tubing string from shifting, ensuring its stability within the wellbore. A sliding guide cone mechanism enables repeated retrieval and disconnection of the tubing string, guaranteeing successful retrieval. This tool allows for drop-and-plugging, internal plugging, and anchoring of the tubing string in a single trip without well pressure. Furthermore, it allows for depressurization before retrieval and repeated disconnection during retrieval, reducing construction steps, effectively lowering labor intensity and operational risks, significantly improving construction efficiency, saving production costs, and ensuring safe, efficient, and economical operations.

[0189] The downhole unloading plugging tool retrieval device 10 provided in this embodiment of the invention, such as... Figures 25-28 As shown, it includes: upper connector, body and salvage mandrel 10-1;

[0190] The end of the retrieval mandrel 10-1 is provided with a guide head 10-2, which can extend into the J-shaped locking mechanism 7-1 of the downhole hand-dropping plugging tool to release the J-shaped locking mechanism 7-1 from locking the lower mandrel 4 and the lower cylinder 3.

[0191] The retrieval mandrel 10-1 has a central through hole and a telescopic block fixing hole. The telescopic retrieval mechanism 10-3 is installed in the telescopic block fixing hole. The telescopic retrieval mechanism 10-3 can extend or retract from the telescopic block fixing hole and cooperate with the sliding guide cone mechanism 6 on the lower cylinder 3 to achieve multiple retrievals.

[0192] The telescopic retrieval mechanism 10-3 includes a telescopic block fixing hole 10-3-1, a compression spring Ⅲ 10-3-2, a telescopic block 10-3-3, and a hollow plug 10-3-4. The telescopic block 10-3-3 is a stepped cylinder with a fixed limiting wing in the middle part with the largest diameter. A fifth elastic element is fitted at the end with the smaller diameter, and the other end has a sloping surface. The retrieval spindle 10-1 has a telescopic block fixing hole for installing the telescopic block 10-3-3. The telescopic block fixing hole has a limiting groove 10-3-1-1 above and below it for installing the fixed limiting wing 10-3-3-1. The outer end of the fixing hole of the telescopic block 10-3-3 has a thread for installing the hollow plug.

[0193] Optionally, the above-mentioned retrieval device also includes several torque transmission protrusions 5-5 evenly distributed circumferentially on the outer wall of the main body, which cooperate with the torque transmission grooves 5-6 on the lower cylinder to realize torque transmission.

[0194] The following is combined with Figures 25-28 Describe in detail the specific structure and setup of the salvage device. Figure 25 This is a half-sectional view of the salvage device; Figure 26 for Figure 25 Enlarged view of a section at point D; Figure 27 External view of the mounting holes for the telescopic block; Figure 28 This is the external view of the expansion block.

[0195] The upper connector of the retrieval device 10 is a thickened tubing female thread, which can be connected to the downhole tubing or other tools. On the outer wall of the retrieval device 10 body, close to the outer step of the upper connector, there are two square torque transmission protrusions 5-5 evenly distributed around the circumference. These can mate with the torque transmission grooves 5-6 on the lower cylinder 3 to achieve torque transmission. At the lower part of the upper connector is the retrieval mandrel 10-1, whose outer diameter is equal to the maximum outer diameter of the lower mandrel 4. It has a central through hole inside to ensure smooth passage of working fluid.

[0196] In the middle part of the retrieval mandrel 10-1 is the telescopic retrieval mechanism 10-3. The telescopic retrieval mechanism 10-3 includes a telescopic block fixing hole 10-3-1, a compression spring Ⅲ 10-3-2, a telescopic block 10-3-3, and a hollow thread plug 10-3-4.

[0197] The telescopic block fixing hole 10-3-1 is a circular blind hole on the salvage mandrel 10-1. A square-section limiting groove 10-3-1-1 is opened on the upper and lower walls of the blind hole, and an internal thread is machined at the entrance of the hole.

[0198] The telescopic block 10-3-3 is a stepped cylinder, with one end being a short cylinder and the other end having a slightly larger diameter. The end is machined into a bevel, and the diameters of both ends are smaller than the diameter of the telescopic block fixing hole 10-3-1. The diameter of the middle part is approximately the same as the diameter of the telescopic block fixing hole 10-3-1. The upper and lower sides are fixed with limiting wings 10-3-3-1. The limiting wings 10-3-3-1 are elongated strips, and their width is slightly smaller than the width of the limiting groove 10-3-1-1.

[0199] The hollow plug 10-3-4 has external threads that mate with the internal threads of the telescopic block fixing hole 10-3-1. It is hollow in the middle and its diameter is slightly larger than the diameter of the beveled part of the telescopic block 10-3-3.

[0200] During installation, first insert the compression spring Ⅲ10-3-2 into the telescopic block fixing hole 10-3-1. Then, align the limiting wing 10-3-3-1 of the telescopic block 10-3-3 with the limiting groove 10-3-1-1, with the inclined portion facing outwards into the telescopic block fixing hole 10-3-1, ensuring the inclined surface of the telescopic block 10-3-3 faces downwards. Finally, install the hollow threaded plug 10-3-4. The limiting groove 10-3-1-1 restricts the limiting wing 10-3-3-1, preventing the telescopic block 10-3-3 from rotating within the telescopic block fixing hole 10-3-1 and thus losing its salvage function.

[0201] The bottom end of the retrieval mandrel 10-1 is the guide head 10-2, with a flushing hole 10-2-1 on the side, which serves as a fluid flow channel during well cleaning. The guide head 10-2 is conical, with an outer diameter matching the diameter of the central through hole of the lower mandrel 4. It can be inserted into the inner circle of the hook portion 7-1-1-1 of the J-shaped key 7-1-1 during retrieval, thus unlocking the J-shaped locking mechanism 7-1.

[0202] This invention provides a reusable downhole drop-off plugging tool retrieval device, comprising the aforementioned reusable downhole drop-off plugging tool and the aforementioned retrieval device;

[0203] The telescopic retrieval mechanism of the retrieval device works in conjunction with the sliding guide cone mechanism of the downhole release plugging tool that can be repeatedly detached, enabling repeated retrieval and detachment;

[0204] The J-shaped locking mechanism, rotary switch mechanism, compression anchoring mechanism, and well pressure-assisted sealing mechanism in the repeatedly detachable downhole plugging tool enable locking, plugging, anchoring, and auxiliary sealing functions when the retrieval tool is detached from the plugging tool.

[0205] This invention provides a method for using the above-mentioned repeatedly detachable downhole hand-operated plugging tool retrieval device, including:

[0206] Salvage Operation: Lower the salvage device. The salvage mandrel of the salvage device enters the lower cylinder. The telescopic block retracts into the salvage mandrel. Continue to lower the salvage device. The bottom guide head of the salvage mandrel is inserted into the inner circle of the J-shaped locking mechanism to open it. The straight section of the J-shaped key retracts to unlock it. The lower mandrel moves down with the salvage device. It pushes the Z-shaped reversing key in the rotary switch mechanism to slide in the sliding groove, causing the ball valve to rotate and release the blockage of the middle through hole of the lower mandrel, so as to release the pressure of the release internal plug tool. When the salvage device moves down and the telescopic block reaches the sliding groove of the guide cone sliding mechanism, the telescopic block extends and enters the sliding groove. Through the cooperation of the telescopic block and the sliding groove, the release internal plug tool is lifted.

[0207] Disengagement operation: Continue to lower the retrieval device so that the telescopic block of the retrieval device slides to the bottom of the guide cone. Lift the retrieval device upward. After the telescopic block drives the guide cone to the top of the sliding groove, the telescopic block retracts under the cooperation of the conical surfaces of the telescopic block and the guide cone. The retrieval device is pulled out from the lower mandrel and disengaged from the release internal plug tool. The lower mandrel performs the anchoring and sealing process.

[0208] Repeatedly perform the retrieval and disengagement operations to repeatedly retrieve and detach the retrieval device and the hand-release internal plug tool until retrieval is successful.

[0209] When it is necessary to retrieve the hand-dropping internal plug tool 11, use the bottom-connected oil pipe retrieval device 10. When it reaches the upper end of the hand-dropping internal plug tool 11, slowly lower it so that the retrieval mandrel 10-1 enters the interior of the lower cylinder 3. Under the restriction of the inner wall of the lower cylinder 3, the telescopic block 10-3-3 of the telescopic retrieval mechanism 10-3 compresses the compression spring Ⅲ 10-3-2 and retracts into the telescopic block fixing hole 10-3-1.

[0210] The retrieval device 10 continues to be lowered, and the guide head 10-2 at the bottom of the retrieval mandrel 10-1 is inserted into the inner circle of the hook portion 7-1-1-1 of the J-shaped key 7-1-1 in the J-shaped locking mechanism 7-1. During locking, the straight section 7-1-1-2 of the J-shaped key 7-1-1 is inserted into the locking groove 7-1-4, causing the inner circles of the hook portions 7-1-1-1 of the two J-shaped keys 7-1-1 to not align but rather contract inwards, forming an irregular shape. When the guide head 10-2 is inserted into this irregular shape, because the outer diameter of the guide head 10-2 is the same as the diameter of the inner circle of the hook portion 7-1-1-1, the hook portion 7-1-1-1 opens outwards, thereby causing the straight section 7-1-1-2 to move inwards, disengaging from the locking groove 7-1-4, until the outer surface of its straight section 7-1-1-2 is flush with the outer surface of the lower mandrel 4, effectively unlocking the J-shaped locking mechanism 7-1. As the retrieval device 10 continues to be lowered, the lower spindle 4 descends as the J-shaped locking mechanism 7-1 is unlocked, thereby pushing the Z-shaped reversing key 7-2-1-1 of the rotary switch mechanism 7-2 downward within the sliding groove II 7-2-4-2. After changing direction in the upper, middle, and lower sections, the Z-shaped reversing key 7-2-1-1 rotates 90°, causing the ball valve 7-2-1, which was originally closed, to open. At this time, the pressure accumulated below the ball valve 7-2-1 will be released into the tubing through the ball valve 7-2-1, thus achieving the function of pressure relief. When the telescopic retrieval mechanism 10-3 is lowered to the upper right-angled step surface of the guide cone sliding groove 6-2 of the sliding guide cone mechanism 6, the telescopic block 10-3-3 is ejected into the space of the guide cone sliding groove 6-2 under the elastic force of the compression spring Ⅲ 10-3-2, thereby restricting the telescopic block 10-3-3 below the right-angled step surface. Lifting the tubing column can retrieve the lower tool string, thus achieving the retrieval function.

[0211] However, because the internal plugging tool 11 and the lower tool string remain in the well for an extended period, sediment and other factors may cause the initial retrieval attempt to fail. In this case, they need to be detached and retrieved again, requiring repeated detachment and reconnection. Figure 29a Figure 29b and Figure 29cAs shown, when the telescopic block 10-3-3 of the telescopic retrieval mechanism 10-3 enters the space of the guide cone sliding groove 6-2, if the lifting of the tubing exceeds the normal lifting load, the release internal plug tool needs to be disengaged. Then, the retrieval device 10 continues to be lowered, causing the telescopic block 10-3-3 to slide downwards in the guide cone sliding groove 6-2. At the guide cone 6-1, the telescopic block 10-3-3 compresses the compression spring Ⅲ 10-3-2 inwards under the restriction of the outer edge of the guide cone 6-1. After passing the guide cone 6-1, it enters the lower inclined surface of the guide cone 6-1 under the rebound of the compression spring Ⅲ 10-3-2. Then, the tubing is lifted, and the telescopic block 10-3-3 drives the guide cone 6-1 to slide upward along the guide cone sliding groove 6-2 until the upper plane of the guide cone 6-1 coincides with the upper right-angled step surface of the guide cone sliding groove 6-2. The upper right-angled step surface of the guide cone sliding groove 6-2, in conjunction with the lower inclined surface of the guide cone 6-1, forms an inclined slope. The tubing is then lifted, and the telescopic block 10-3-3 moves upward along this slope, disengaging from the guide cone sliding groove 6-2. Continuing upward, it completely disengages. The guide cone 6-1 then slides down to the bottom of the guide cone sliding groove 6-2 under gravity, allowing for repeated disengagement and reconnection. When the retrieval mandrel moves upward, similar to the upward movement of the lower mandrel 4 described above, the rotary switch mechanism 7-2 closes under the action of the compression spring II 8-5. During the upward movement of the J-shaped locking mechanism 7-1, the straight section of the J-shaped key 7-1-1 extends into the locking groove 7-1-4, restoring the tool to its locked state, thus completing the disengagement process and exiting the retrieval operation. To continue retrieval, the above process is repeated until the downhole tool is successfully retrieved.

[0212] This invention provides an application of the aforementioned reusable downhole plugging tool and the aforementioned reusable downhole plugging tool retrieval device in oil and gas well sealing operations. For example... Figure 30 The diagram shown is of a drop string. Between the first and second layers, the packer 12, screen 13 and perforating gun 14 can be dropped using the downhole drop plug tool 11. The tool string, including the downhole drop plug tool 11, packer 12, screen 13 and perforating gun 14, can also be repeatedly retrieved.

[0213] The downhole drop-out internal plugging tool provided in this invention, through its designed drop-out mechanism, can drop the tubing string inside the well. By designing a rotary switch mechanism and a well pressure-assisted sealing mechanism, it achieves internal plugging of the dropped tubing string. Simultaneously, the rotary switch mechanism also has the function of depressurizing before retrieval. A J-shaped locking mechanism and a compression anchoring mechanism prevent the dropped tubing string from shifting. A sliding guide cone mechanism enables repeated retrieval and disconnection of the tubing string. Using this tool, the purpose of drop-out, internal plugging, and anchoring can be achieved in a single trip of the tubing string without well pressure. Furthermore, it allows for depressurization before retrieval and repeated disconnection during retrieval, thereby reducing construction steps, effectively reducing labor intensity and operational risks, significantly improving construction efficiency, saving production costs, and ensuring safe, efficient, and economical operations.

[0214] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0215] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.

[0216] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A detachable downhole internal packer tool, characterized in that, include: The tool comprises an upper cylinder, an upper mandrel, a lower cylinder, and a lower mandrel; in its assembled state, the upper cylinder and the lower cylinder are connected to form a housing, and the upper mandrel and the lower mandrel are installed within the housing, including the following functional modules: The release mechanism includes a locking part on the upper cylinder and a locking groove on the lower cylinder. The locking part is limited by the locking groove under the cooperation of the upper spindle. When the upper spindle is subjected to force and moves downward, the locking part and the locking groove are disengaged, and the upper cylinder, the upper spindle and the lower cylinder are separated to release the hand. The sliding guide cone mechanism includes a guide cone sliding groove and a guide cone provided on the lower cylinder, so as to cooperate with the retrieval device to achieve multiple retrievals; The J-shaped locking mechanism includes a J-shaped key in a J-shaped keyhole on the lower spindle and a first elastic element. After being released, the lower spindle moves upward, and the straight section of the J-shaped key extends into the locking groove of the lower cylinder under the action of the first elastic element to lock the position of the lower spindle and the lower cylinder. The rotary switch mechanism includes a ball valve, a ball seat, and a reversing component, which are disposed in the ball valve hole of the lower spindle. The ball valve is provided with a ball valve through hole. After being released, the lower spindle moves upward. The reversing component drives the ball valve to rotate in the ball seat under the restriction of the reversing component sliding groove on the lower cylinder, so that the ball valve rotates 90 degrees and the ball valve blocks the through hole of the lower spindle. The compression anchoring mechanism includes an anchor tooth structure disposed in the anchor tooth window of the lower cylinder. The lower mandrel moves upward and compresses the anchor tooth structure to make the anchor tooth body extend out and anchor with the sleeve.

2. The tool of claim 1, wherein, The release mechanism includes: an upper cylinder section I, an upper spindle section I, and a lower cylinder section I; The upper cylinder section I is provided with a locking part and the lower cylinder section I is provided with a locking groove. The locking part is limited by the locking groove under the cooperation of the upper mandrel. When the upper mandrel section I is subjected to force and moves downward, the locking part and the locking groove disengage, and the upper cylinder separates from the upper mandrel and the lower cylinder to achieve release. The upper cylinder section I is provided with a connecting hole for pressure relief, and the upper part of the central through hole of the upper mandrel section I is provided with a flared mouth to accommodate a sealing steel ball.

3. The tool of claim 2, wherein, The locking part includes a locking ring and a locking head. The locking ring has a split structure, with a locking head at the bottom of each segment. The locking head has protruding steps inside and outside. The protruding steps cooperate with the locking shoulder of the upper mandrel and the locking groove of the lower cylinder to connect the upper cylinder and the lower cylinder.

4. The tool of claim 3, wherein, The upper cylinder section I is provided with a torque transmission protrusion, and the upper spindle section I is provided with a torque transmission groove. The torque transmission protrusion and the torque transmission groove cooperate to achieve torque transmission. The upper cylinder section I is provided with a limiting step, and the upper mandrel section I is provided with a positioning step. The limiting step and the positioning step cooperate to limit the downward movement distance of the upper mandrel. The lower part of the locking groove is provided with a pin through hole, and the upper mandrel is provided with a pin countersunk hole at the corresponding position. A screw-in pin is provided in the pin through hole and the pin countersunk hole.

5. The tool of claim 1, wherein, The sliding guide cone mechanism includes: The lower cylinder section II is equipped with a guide cone sliding groove and a guide cone with an inclined surface, so as to cooperate with the retrieval device to achieve multiple retrievals.

6. The tool of claim 1, wherein, The J-shaped locking mechanism includes a lower spindle section I, a lower cylinder section III, a J-shaped key, a first elastic element, and a pressure cap; The lower mandrel section I has two J-shaped key holes, each J-shaped key hole is provided with a J-shaped key, the J-shaped key includes a hooked part and a straight part, the outer end of the hooked part is provided with a support post to support the first elastic element, the pressure cap is located outside the first elastic element, and cooperates with the hooked part to form an elastic element receiving cavity; The lower cylinder section III is provided with a locking groove. After the release, the lower spindle moves upward, and the straight section of the J-shaped key extends out into the locking groove under the action of the first elastic element to lock the position of the lower spindle and the lower cylinder.

7. The tool of claim 6, wherein, The inner diameter of the hooked section is the same as the diameter of the central through hole of the lower mandrel section I, and the end of the straight section is arc-shaped with the diameter of the arc being the same as the maximum outer diameter of the lower mandrel section I; the cover is arc-shaped with the outer diameter of the cover being the same as the maximum outer diameter of the lower mandrel section I. The elastic element is a compression spring.

8. The tool of claim 1, wherein, The rotary switch mechanism includes a lower spindle section I, a lower cylinder section III, a ball valve disposed in a ball valve hole in the lower spindle section I, a ball seat, a reversing component, and a second elastic component; The lower mandrel section I is provided with a ball valve hole that communicates with its central through hole to install a ball valve and a ball seat. The ball valve hole is provided with an elastic element groove to install a second elastic element to limit the ball seat. The lower cylinder section III is provided with a reversing element sliding groove. The ball seat has a concave spherical surface to accommodate the ball valve, the ball valve is provided with a ball valve through hole, and both the ball seat and the ball valve are provided with a reversing element mounting hole for mounting the reversing element; After being released, the lower mandrel section I moves upward, and the reversing component, restricted by the reversing component sliding groove on the lower cylinder section III, drives the ball valve to rotate in the ball seat, causing the ball valve to rotate 90 degrees and block the through hole of the lower mandrel.

9. The tool as described in claim 8, characterized in that, The reversing component includes a Z-shaped reversing key and a circular stabilizing key, which are symmetrically arranged on both sides of the ball valve. The reversing component sliding groove includes sliding groove I and sliding groove II. Sliding groove I is a vertical groove, and sliding groove II is divided into three through sections: upper, middle and lower. The lower section is a vertical groove symmetrically arranged with sliding groove I, the upper section is a vertical groove spaced apart from the lower section by a distance, the size of which is set according to the length of the vertical section of the Z-shaped reversing key, and the middle section connects the upper and lower sections. Sliding groove I limits the circular stabilizing key, and sliding groove II limits the Z-shaped reversing key.

10. The tool as claimed in claim 8, characterized in that, The diameter of the ball valve through hole is the same as the diameter of the central through hole of the lower mandrel section I, and the elastic element is a snap ring.

11. The tool as claimed in claim 1, characterized in that, The compression anchoring mechanism includes a lower mandrel section II, a lower cylinder section IV, and an anchor tooth structure. The anchor tooth structure includes an anchor tooth body, a limiting block, and a fourth elastic element. The lower cylinder section IV is provided with an anchor tooth window for installing the anchor tooth structure. The inner side of the anchor tooth is an upward inclined surface, and the outer side is an arc surface. The outer side has a transverse anchor tooth. The outer side of the anchor tooth body has a groove to accommodate the fourth elastic element. The limiting block is installed on the anchor tooth body and cooperates with the groove of the anchor tooth body to accommodate the fourth elastic element and limit its movement. The lower mandrel section II has a downward-sloping inclined surface, which cooperates with the inclined surface of the inner side of the anchor tooth body to compress the anchor tooth body so that it extends out and is anchored to the sleeve.

12. The tool as claimed in claim 11, characterized in that, The compression anchoring mechanism further includes a third elastic element located below the lower mandrel section II.

13. The tool as claimed in claim 11, characterized in that, The diameter of the outer surface of the anchor tooth is the same as the outer diameter of the lower cylinder section IV; Several anchor teeth windows are evenly distributed along the circumference of the lower cylinder section IV, and the anchor teeth windows are stepped holes.

14. The tool as claimed in claim 1, characterized in that, Also includes: Well pressure sealing mechanism; The well pressure sealing mechanism includes a lower mandrel section III and a lower cylinder section V. The lower mandrel section III has an outer conical surface, and the lower cylinder section V has an inner conical surface. The lower mandrel section III moves upward, and under the action of well pressure, the inner and outer conical surfaces are pressed together to achieve a sealing effect.

15. The tool as claimed in claim 14, characterized in that, The outer conical surface and the inner conical surface are smooth planes, and the outer conical surface and the inner conical surface have the same inclination angle.

16. The tool as described in any one of claims 1-15, characterized in that, Also includes: The upper connector is located at the top of the upper cylinder. The lower connector is located at the bottom of the lower cylinder.

17. A reusable downhole hand-operated plugging tool retrieval device, characterized in that, include: Upper connector, main body, salvage mandrel, The end of the retrieval mandrel is provided with a guide head, which can extend into the J-shaped locking mechanism of the downhole hand-dropping plugging tool to release the J-shaped locking mechanism from locking the lower mandrel and the lower cylinder. The retrieval mandrel has a central through hole and a telescopic block fixing hole. The telescopic block fixing hole is equipped with a telescopic retrieval mechanism, which can extend or retract from the telescopic block fixing hole and cooperate with the sliding guide cone mechanism on the lower cylinder to achieve multiple retrievals.

18. The retrieval device as described in claim 17, characterized in that, The telescopic retrieval mechanism includes a telescopic block fixing hole, a compression spring III, a telescopic block, and a hollow plug; The telescopic block is a stepped cylindrical shape, with a fixed limiting wing in the middle part with the largest diameter, a fifth elastic element fitted at the end with a smaller diameter, and a sloping surface at the other end. The salvage mandrel is provided with a telescopic block fixing hole for installing the telescopic block. The telescopic block fixing hole is provided with a limiting groove at the top and bottom for installing and fixing the limiting wing. The outer end of the telescopic block fixing hole is provided with a thread for installing the hollow plug.

19. The retrieval device as described in claim 17 or 18, characterized in that, Also includes: Several torque-transmitting protrusions are evenly distributed circumferentially on the outer wall of the main body to cooperate with the torque-transmitting grooves on the lower cylinder to realize torque transmission.

20. A reusable downhole hand-operated plugging tool retrieval device, characterized in that, include: The reusable downhole plugging tool as described in any one of claims 1-16 and the retrieval device as described in any one of claims 17-19; The telescopic retrieval mechanism of the retrieval device cooperates with the sliding guide cone mechanism of the repeatedly detachable downhole hand-release plugging tool to achieve repeated retrieval and detachment; The J-shaped locking mechanism, rotary switch mechanism, compression anchoring mechanism, and well pressure-assisted sealing mechanism in the retrievable downhole plugging tool enable locking, plugging, anchoring, and auxiliary sealing functions when the retrieval tool is detached from the plugging tool.

21. A method for using a reusable downhole hand-operated plugging tool, characterized in that, include: Release operation: Insert a steel ball into the flared end of the upper mandrel to block the central through hole, inject high-pressure fluid into the oil pipe, causing the upper mandrel to move downwards. The locking part disengages from the upper mandrel and the upper cylinder and separates from the lower cylinder. After the high-pressure liquid is depressurized through the connecting hole on the upper cylinder, the upper cylinder and the upper mandrel are pulled out from the lower cylinder. The high-pressure liquid enters the central through hole from below the upper mandrel, carrying the steel ball to the ground. Anchoring and sealing process: The lower mandrel moves upward to squeeze the anchor tooth body out and bite the inner wall of the casing to achieve anchoring; the reversing component in the rotary switch mechanism slides in the reversing component sliding groove to rotate the ball valve and block the middle through hole of the lower mandrel to achieve sealing; after the J-type locking mechanism moves upward to the locking groove, the straight section of the J-shaped key in the J-type locking mechanism extends into the locking groove to lock the lower mandrel in this position; the inner conical surface at the bottom of the lower mandrel and the inner conical surface of the inner wall of the lower cylinder cooperate to achieve sealing under well pressure.

22. The method as described in claim 21, characterized in that, The upper mandrel moves downward, and the locking part disengages from the upper mandrel and the upper cylinder, separating from the lower cylinder. Specifically, this includes: The upper mandrel moves downward, shearing off the screw pin. The locking shoulder of the upper mandrel is misaligned with the locking head of the locking part. The locking head pops out from the locking groove of the upper cylinder, separating the upper cylinder from the lower cylinder. The connecting hole on the upper cylinder connects with the central through hole on the steel ball.

23. The method as described in claim 21 or 22, characterized in that, The anchoring is achieved by the lower mandrel moving upward to compress the anchor tooth body and extend it to bite the inner wall of the sleeve. This includes: the lower mandrel moving upward under the rebound force of the compression spring II in a compressed state, causing the cone on the lower mandrel II section to move upward to compress the anchor tooth body, and the anchor tooth body moving outward to compress the return spring, so that the anchor tooth extends out and bites the inner wall of the sleeve to achieve anchoring. The method of driving the Z-shaped reversing key in the rotary switch mechanism to slide in the sliding groove to rotate the ball valve and block the middle through hole of the lower spindle, thereby achieving the blockage, includes: the lower spindle moving upward, causing the Z-shaped reversing key of the rotary switch mechanism to move upward in the sliding groove II, passing through the lower, middle and upper sections of the sliding groove II, driving the ball valve to rotate 90° in the ball seat, so that the through hole of the ball valve and the through hole of the lower spindle change from being connected to intersecting, thereby achieving the blockage.

24. A method for using a reusable downhole hand-operated plugging tool retrieval device, characterized in that, include: Salvage Operation: Lower the salvage device. The salvage mandrel of the salvage device enters the lower cylinder. The telescopic block retracts into the salvage mandrel. Continue to lower the salvage device. The bottom guide head of the salvage mandrel is inserted into the inner circle of the J-shaped locking mechanism to open it. The straight section of the J-shaped key retracts to unlock it. The lower mandrel moves down with the salvage device. It pushes the Z-shaped reversing key in the rotary switch mechanism to slide in the sliding groove, causing the ball valve to rotate and release the blockage of the middle through hole of the lower mandrel, so as to release the pressure of the release internal plug tool. When the salvage device moves down and the telescopic block reaches the sliding groove of the guide cone sliding mechanism, the telescopic block extends and enters the sliding groove. Through the cooperation of the telescopic block and the sliding groove, the release internal plug tool is lifted. Disengagement operation: Continue to lower the retrieval device so that the telescopic block of the retrieval device slides to the bottom of the guide cone. Lift the retrieval device upward. After the telescopic block drives the guide cone to the top of the sliding groove, the telescopic block retracts under the cooperation of the conical surfaces of the telescopic block and the guide cone. The retrieval device is pulled out from the lower mandrel and disengaged from the release internal plug tool. The lower mandrel performs the anchoring and sealing process. Repeatedly perform the retrieval and disengagement operations to repeatedly retrieve and detach the retrieval device and the hand-release internal plug tool until retrieval is successful.

25. The application of a repeatedly detachable downhole plugging tool as described in any one of claims 1-16 and a repeatedly detachable downhole plugging tool retrieval device as described in any one of claims 17-19 in oil and gas well sealing operations.

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