Downward connection drill column type double-unplugging leakage-blocking packing tool and method

Abstract

The invention belongs to the technical field of underground operation equipment, and particularly relates to a drill string downward connection type double-unplugging leakage-blocking packing tool and method. The device comprises a central shaft, a lifting unsealing device, a rubber sleeve mechanism, a sliding sleeve, an outer cylinder body, a static sleeve, a ball seat, a ball seat cavity, a lower joint, a shear pin and a locking rotary unsealing mechanism, the central shaft is connected to the lower end of the lifting unsealing device; the outer side wall of the central shaft is sequentially connected with a rubber sleeve mechanism, a sliding sleeve, an outer cylinder body and a locking rotary unsealing mechanism from top to bottom; a static sleeve is connected between the outer cylinder and the central shaft; a bypass hole is formed in the upper part of the connecting position of the central shaft and the static sleeve; the lower joint is connected to the lower end of the central shaft through the ball seat cavity; the ball seat is connected to the upper portion in the ball seat cavity through a shear pin. The problems that a traditional unblocking mode is single, the sealing and pressure-bearing effects of a rubber sleeve are poor, and the size of a locking and locking mechanism is large are solved, the two unblocking modes of rotating and lifting are achieved at the same time, and the locking mechanism is small, exquisite, wide in application range and suitable for a small-size well hole.

Description

Technical Field

[0001] The invention belongs to the technical field of downhole operation equipment, and in particular relates to a double-release plugging and isolation tool and method connected to a drill column. Background Art

[0002] During the drilling construction, well leakage occurs frequently. When plugging, due to the large change in the pressure gradient of the open hole formation and the active formation water, the conventional squeeze plugging back pressure is at the wellhead, so that most of the plugging materials or cement slurry cannot effectively enter the leaking layer, which not only increases the labor intensity of the workers, but also increases the drilling time and drilling cost. The invention is called a double-ball plugging packer, and the patent number is 201720005664.6, which is a utility model patent. It includes an upper joint, a locking claw, a locking sleeve, a rubber tube center rod, an unsealing ring, an upper outer sleeve, a rubber tube center tube, an upper pressure ring, a sealing shear pin, a rubber tube, a lower pressure ring, a connector, a lower center tube, an upper piston sleeve, a piston, a lower pressure body, a lower piston sleeve, an adjustment ring, a sliding sleeve shell and a two-stage sliding sleeve. By throwing a ball on the ground to start the pump, the plugging slurry enters between the lower center tube and the piston sleeve, pushing the piston to move upward along the axial direction. The piston drives the piston sleeve, so that the lower pressure ring moves upward under the action of pressure, and then pushes the center tube of the rubber tube. The center tube of the rubber tube drives the locking sleeve to move forward and engage with the locking claw, and the locking device is locked. Since the upper pressure ring does not move, the lower pressure ring pushes the rubber tube to expand and fit with the well wall to achieve a seat seal, isolating the upper and lower well walls of the leaking layer. When the pressure continues to increase to a certain value, the sliding sleeve is knocked off to form a liquid flow channel, and the plugging slurry enters the leaking layer. After the plugging is completed, the drill tool is lifted with a certain amount of suspended weight, driving the upper joint and the upper center tube to move upward, and the upper center tube drives the unsealing ring to move upward. The unsealing ring forces the locking claw and the locking sleeve to disengage from each other, and the rubber tube rebounds and resets to complete the unsealing. Although this patent has improved the plugging efficiency to a certain extent, reduced the labor intensity of workers, and saved drilling time and costs, the tool is prone to "welding iron tree", sticking and sand jamming when it returns to the position of the isolation tool for solidifying and gelling plugging working fluids during plugging; the rubber cartridge has poor pressure-bearing effect and the isolation with the well wall is unreliable; its only way to unseal is a single lifting and unsealing method. Once this unsealing method fails, it can only be achieved by forced means, that is, lifting and tearing the rubber cartridge with a large tonnage to achieve the purpose of drilling. This requires replacing the rubber cartridge before using the tool again, which is cumbersome and inefficient. In addition, the space required for the locking and unlocking mechanism during operation is large, so it is not suitable for small-sized plugging isolation devices. Summary of the invention

[0003] The present invention provides a double-release plugging and isolation tool and method connected to a drill column. One purpose is to provide a plugging and isolation tool and method that can overcome the problems of the prior art such as a single unsealing method, poor pressure-bearing effect of the rubber cylinder seal, and large size of the locking and locking mechanism; the second purpose is to provide a plugging and isolation tool and method that has a lightweight locking mechanism, saves space, has a wide range of applications, and is suitable for small-sized wellbores.

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

[0005] A double-release plugging and isolation tool connected to a drill column, comprising a central shaft, an upward lifting and unsealing device, a rubber cylinder mechanism, a sliding sleeve, an outer cylinder body, a static sleeve, a ball seat, a ball seat cavity, a lower joint, a shear pin and a locking and rotating unsealing mechanism; the central shaft is connected to the lower end of the upward lifting and unsealing device; the outer side wall of the central shaft is connected with the rubber cylinder mechanism, the sliding sleeve, the outer cylinder body and the locking and rotating unsealing mechanism in sequence from top to bottom; a static sleeve is connected between the outer cylinder body and the central shaft, and a bypass hole is provided at the upper part of the connection position between the central shaft and the static sleeve; the lower joint is connected to the lower end of the central shaft through the ball seat cavity; the ball seat is connected to the upper part of the ball seat cavity through the shear pin.

[0006] The lifting and unsealing device includes an unlocking ring, an upper joint, a rotating pin, a rotating pin pressure cover and a torsion spring; the rotating pin pressure cover is fixed to the lower end of the upper joint; the unlocking ring is connected to the bottom of the upper joint through a rotating pin and is placed in the rotating pin pressure cover; the torsion spring is placed between the rotating pin and the rotating pin pressure cover; an annular groove is opened on the end surface of the unlocking ring facing the rubber cylinder mechanism.

[0007] The upper joint is a cone-shaped column with large diameters at both ends and a small diameter in the middle.

[0008] The rubber cylinder mechanism comprises two upper and lower rubber cylinders, an adjustment ring, an axial tension ring and a connecting ring; a connecting ring is connected between the upper rubber cylinder and the lifting and unsealing device; the axial tension ring is connected to the end face of the upper rubber cylinder and is placed inside the connecting ring and contacts the connecting ring; an adjustment ring is connected to the lower end of the lower rubber cylinder, and the adjustment ring contacts the upper end face of the sliding sleeve; a double rubber cylinder connecting ring is connected between the upper rubber cylinder and the lower rubber cylinder.

[0009] A limit ring is connected between the adjustment ring and the sliding sleeve; the double rubber cylinder connecting ring is a circular ring structure with a plurality of rectangular slots on its side wall; through holes for connecting with the upper rubber cylinder and the lower rubber cylinder are provided along the axial direction on the end faces at both ends of the double rubber cylinder connecting ring; the two rubber cylinders are both short cylindrical structures that are symmetrical on the left and right, with small apertures at the two ends of the inner side of the rubber cylinder and a large aperture in the middle part; grooves are provided on the inner walls at both ends of the rubber cylinder, and copper sulfide rings are embedded in the grooves.

[0010] An annular groove is formed on the opposite surface of the axial tension ring and the lifting and unsealing device, and an axial friction ring made of polytetrafluoroethylene is connected in the annular groove; there is a gap between the opposite surfaces of the axial tension ring and the lifting and unsealing device.

[0011] The locking and rotating unsealing mechanism includes a fixed tooth mechanism, a sliding tooth, a tooth sleeve, a spring and a nylon pin; the tooth sleeve is fixed on the inner wall of the outer cylinder; the sliding tooth is connected to the tooth sleeve; the fixed tooth mechanism is fixedly connected to the tooth sleeve through a nylon pin and meshed with the sliding tooth; the spring is placed between the sliding tooth and the outer cylinder to ensure full meshing of the fixed tooth mechanism and the sliding tooth.

[0012] The fixed tooth mechanism is a circular ring structure, and three groups of fixed teeth are evenly arranged on its outer wall along the axial direction; each group of fixed teeth corresponds to a group of sliding teeth to form a group of locking devices; the sliding teeth and fixed teeth are both meshing one-way teeth.

[0013] The ball seat is a hollow cylinder, one end of which is a six-claw structure, and the side wall of the other end is provided with a through hole penetrating the side wall and used for connecting the shear pin perpendicular to the axis.

[0014] A plugging method for a double-release plugging and isolation tool connected to a drill column, comprising the following steps:

[0015] Step 1: lower the double-release plugging and isolation tool connected to the drill string to the regular wellbore section above the leaking layer;

[0016] Step 2: Pressurize the pump by throwing a ball on the ground, and the plugging slurry enters between the central shaft and the static sleeve and the sliding sleeve from the bypass hole of the central shaft, pushing the sliding sleeve to move upward along the axial direction of the central shaft, squeezing the rubber cylinder in the rubber cylinder mechanism, so that the rubber cylinder expands and fits the well wall;

[0017] Step 3: The sliding sleeve drives the outer cylinder to activate the locking and rotating unlocking mechanism, locking and sealing the well, and the rubber cylinder mechanism maintains the sealing state to seal the upper and lower well walls;

[0018] Step 4: When the pressure is continuously increased to the set value, the shear pin connecting the ball seat and the ball seat cavity is cut off, the ball seat moves downward to the upper end of the lower joint, a liquid flow channel is formed between the ball seat and the lower joint, and the plugging slurry enters the leaking layer to plug the leak;

[0019] Step 5: After plugging, the drill bit is lifted, the unsealing device and the central axis are lifted and moved upward, the upper rubber cylinder and the axial tension ring in the rubber cylinder mechanism do not produce relative movement under the action of the static friction force of the well wall, and the connecting ring and the unlocking ring are displaced in the axial direction;

[0020] Step six, the lifting and unsealing device is activated, and the unlocking ring moves upward under the action of the rebound force of the two rubber cylinders in the rubber cylinder mechanism, and the two rubber cylinders are reset to achieve unsealing; or the drill bit is rotated, and the upper joint drives the central axis to rotate, and the two rubber cylinders, the adjusting ring, the sliding sleeve, and the outer cylinder body are kept still by the static friction between the rubber cylinders and the well wall; the locking and rotating unsealing mechanism is activated to release the locking state, and the two rubber cylinders are reset to achieve unsealing.

[0021] Beneficial effects:

[0022] (1) The present invention is composed of a central shaft, a lifting unsealing device, a rubber cylinder mechanism, a sliding sleeve, an outer cylinder, a static sleeve, a ball seat, a ball seat cavity, a lower joint, a shear pin and a locking rotation unsealing mechanism. The present invention has both rotation and lifting unsealing methods, which overcomes the problem of a single unsealing method in the prior art and greatly increases the success rate of unsealing.

[0023] (2) The rubber cylinder mechanism of the present invention is composed of two rubber cylinders, an adjustment ring, an axial tension ring and a connecting ring. The rubber cylinder is a short cylindrical structure with left-right symmetry. The apertures at both ends of the inner side of the rubber cylinder are small, and the aperture in the middle part is large. When the rubber cylinder is deformed under pressure, only one bulge is generated from the thinnest part of the rubber cylinder wall, so that it fits better with the well wall and has a better sealing and pressure-bearing effect. Grooves are set on the inner walls at both ends of the rubber cylinder, and copper sulfide rings are embedded in the grooves to reduce the friction when the rubber cylinder is squeezed and slides on the center rod.

[0024] (3) The locking and rotating unsealing mechanism of the present invention is organically composed of a fixed tooth mechanism, a sliding tooth, a tooth sleeve, a spring and a nylon pin. The mechanism is compact and space-saving, which expands its application range and is more suitable for small-sized wellbores.

[0025] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is an assembly schematic diagram of the present invention.

[0028] Figure 2 It is a schematic diagram of the lifting and unsealing mechanism in the present invention.

[0029] Figure 3 It is a schematic diagram of the rotary pin cover in the present invention.

[0030] Figure 4 It is a schematic diagram of the structure of the rotating pin in the present invention.

[0031] Figure 5 It is the action principle diagram of the lifting and unsealing mechanism in the present invention.

[0032] Figure 6 It is a schematic diagram of the locking and rotation unlocking mechanism in the present invention.

[0033] Figure 7 It is a schematic diagram of the double rubber cylinder connecting ring in the present invention.

[0034] Figure 8 It is a schematic diagram of the ball seat in the present invention.

[0035] Fig. 9 It is a schematic diagram of the use state of the axial friction ring in the present invention.

[0036] Fig.10 It is a schematic diagram of the structure of the rubber cylinder in the present invention.

[0037] In the figure: 1. center axis; 2. sliding sleeve; 3. rubber cylinder; 4. static sleeve; 5. unlocking ring; 6. upper joint; 7. outer cylinder; 8. fixed tooth; 9. sliding tooth; 10. gear sleeve; 11. spring; 12. ball seat; 13. ball seat cavity; 14. lower joint; 15. shear pin; 16. rotating pin; 17. rotating pin gland; 18. nylon pin; 19. limit ring; 20. adjustment ring; 21. axial tension ring; 22. connecting ring; 23. torsion spring; 24. double rubber cylinder connecting ring; 25. axial friction ring; 26. locking rotation unsealing mechanism; 27. bypass hole; 28. lifting unsealing device; 29. ​​copper sulfide ring. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Embodiment 1:

[0040] according to Figure 1-Figure 10 The double-release plugging and isolation tool connected to a drill column as shown comprises a central axis 1, an upward lifting and releasing device 28, a rubber cylinder mechanism, a sliding sleeve 2, an outer cylinder body 7, a static sleeve 4, a ball seat 12, a ball seat cavity 13, a lower joint 14, a shear pin 15 and a locking and rotating releasing mechanism 26; the central axis 1 is connected to the lower end of the upward lifting and releasing device 28; the outer side wall of the central axis 1 is connected with a rubber cylinder mechanism, a sliding sleeve 2, an outer cylinder body 7 and a locking and rotating releasing mechanism 26 in sequence from top to bottom; a static sleeve 4 is connected between the outer cylinder body 7 and the central axis 1, and a bypass hole 27 is provided at the upper part of the connection position between the central axis 1 and the static sleeve 4; the lower joint 14 is connected to the lower end of the central axis 1 through the ball seat cavity 13; the ball seat 12 is connected to the upper part of the ball seat cavity 13 through the shear pin 15.

[0041] In actual use, the double-release plugging and isolation tool connected to the drill column is lowered to the regular wellbore section above the leaking layer. The pump is opened and pressurized by dropping a ball on the ground. The drilling fluid pushes the piston to move upward along the axial direction, squeezes the rubber tube mechanism, expands the rubber tube in the rubber tube mechanism, and fits the well wall to achieve sealing; the locking and rotating unsealing mechanism 26 is locked to keep the rubber tube mechanism in the sealing state and isolate the upper and lower well walls of the leaking layer. When the pressure continues to increase to a certain value, the ball seat 12 moves downward to form a liquid flow channel, and the plugging slurry enters the leaking layer to implement plugging. After the plugging is completed, the drill tool is lifted, and the lifting and unsealing device 28 is activated to release the locking state; the unlocking ring in the rubber tube mechanism moves upward under the action of the rebound force of the rubber tube 3, and the rubber tube 3 is reset to achieve unsealing. Or the drill tool is rotated, and the fixed teeth 8 and the sliding teeth 9 in the locking and rotating unsealing mechanism 26 rotate relative to each other, cancel the meshing, and the sliding teeth 9 move downward under the action of the rebound force of the rubber tube mechanism, and the rubber tube mechanism is reset to achieve unsealing.

[0042] The locking and rotating unsealing mechanism 26 of the present invention has a light structure and is suitable for small-sized wellbores.

[0043] Embodiment 2:

[0044] according to Figure 1-Figure 6 The double-release plugging and isolation tool connected to a drill column as shown is different from the first embodiment in that: the lifting and unsealing device 28 includes an unlocking ring 5, an upper joint 6, a rotating pin 16, a rotating pin pressure cover 17 and a torsion spring 23; the rotating pin pressure cover 17 is fixed to the lower end of the upper joint 6; the unlocking ring 5 is connected to the lower part of the upper joint 6 through the rotating pin 16 and is placed in the rotating pin pressure cover 17, and a conical annular groove is provided at the upper end of the inner wall of the unlocking ring 5; the torsion spring 23 is placed between the rotating pin 16 and the rotating pin pressure cover 17; and an annular groove is provided on the end surface of the unlocking ring 5 facing the rubber cylinder mechanism.

[0045] Furthermore, the upper joint 6 is a conical cylinder with large diameters at both ends and a small diameter in the middle.

[0046] In actual use, the working process of the lifting and unsealing device 28 is as follows: when the tool enters the well and reaches the plugging stage, the rotating pin 16 placed in the rotating pin pressure cap 17 is stuck in the conical ring groove at the upper end of the inner wall of the unlocking ring 5, and the rotating pin 16 remains locked under the action of the downward force of the upper joint 6. After the plugging is completed, the drilling tool is lifted, the upper joint 6 and the central axis 1 move upward, and the rubber cylinder 3 and the axial tension ring 21 do not produce relative movement under the action of the static friction force of the well wall. The connecting ring 22 and the upper joint 6 move axially upward with respect to the unlocking ring 5. The rotating pin 16 between the upper joint 6 and the unlocking ring 5 is actuated, and the rotating pin 16 is separated from the unlocking ring 5 to release the locking relationship. The elastic force of the torsion spring 23 is released to prevent the pin shaft from rotating in the opposite direction. The unlocking ring 5 moves upward under the action of the rebound force of the rubber cylinder 3, and the rubber cylinder 3 is reset to achieve unsealing.

[0047] The upper joint 6 adopts the above technical solution. When the tool is connected at the wellhead, the small diameter part is the position of the hanging card buckle, which is convenient for hanging, lifting and lowering the tool.

[0048] Embodiment three:

[0049] according to Figure 1-Figure 8 The double-release plugging and isolation tool connected to a drill column as shown is different from the first embodiment in that: the rubber cylinder mechanism includes two upper and lower rubber cylinders 3, an adjustment ring 20, an axial tension ring 21 and a connecting ring 22; a connecting ring 22 is connected between the upper rubber cylinder 3 and the lifting and unsealing device 28; the axial tension ring 21 is connected to the end face of the upper rubber cylinder 3 and is placed inside the connecting ring 22 and contacts the connecting ring 22; an adjustment ring 20 is connected to the lower end of the lower rubber cylinder 3, and the adjustment ring 20 contacts the upper end face of the sliding sleeve 2; a double rubber cylinder connecting ring 24 is connected between the upper rubber cylinder 3 and the lower rubber cylinder 3.

[0050] When plugging leaks, a certain length of drilling tools is connected as needed, and then the double-release plugging and isolation tools are connected, and then lowered into the regular section of the wellbore above the leaking layer. By pumping the ball on the ground to increase the pressure, the plugging slurry enters the bypass hole 27 on the central axis 1 between the central axis 1 and the static sleeve 4 and the sliding sleeve 2, pushing the sliding sleeve 2 to move upward along the axial direction of the central axis 1, squeezing the rubber tube 3, so that the rubber tube 3 expands and fits the well wall. The two ends of the inner side of the rubber tube 3 have small apertures, and the middle part has a large aperture. When deformed by pressure, only a bulge is generated from the thinnest part of the rubber tube wall, ensuring a better fit with the well wall and better sealing and pressure-bearing effect. The copper sulfide ring 29 embedded in the rubber tube groove reduces the friction when the rubber tube slides on the center rod under compression. The sliding sleeve 2 drives the outer cylinder 7 to activate the locking and rotating unlocking mechanism 26, locking to achieve the seat seal, and the rubber tube 3 remains in the seat seal state to isolate the upper and lower well walls. When the pressure is continuously increased to the set value, the shear pin 15 connecting the ball seat 12 and the ball seat cavity 13 is cut off, and the ball seat 12 moves downward to the upper end of the lower joint 14. A liquid flow channel is formed between the ball seat 12 and the lower joint 14, and the plugging slurry enters the leaking layer. After the plugging is completed, the drill bit is lifted, the upper joint 6 and the central axis 1 move upward, the rubber cylinder 3 and the axial tension ring 21 do not produce relative movement under the action of the static friction force of the well wall, and the connecting ring 22 and the unlocking ring 5 produce a small displacement movement in the axial direction. The lifting and unsealing device 28 is activated, and the unlocking ring 5 moves upward under the action of the rebound force of the rubber cylinder 3, and the rubber cylinder 3 is reset to achieve unsealing. When another unsealing method is used, the drill bit is first rotated, and the upper joint 6 drives the central axis 1 to rotate. The rubber cylinder 3, the adjustment ring 20, the sliding sleeve 2, and the outer cylinder 7 are kept stationary by the static friction between the rubber cylinder 3 and the well wall. The locking and rotating unsealing mechanism is activated to release the locking state, and the rubber cylinder 3 is reset to achieve unsealing.

[0051] Embodiment 4:

[0052] according to Figure 1-Figure 8The double-release plugging and isolation tool with a lower drill column connection shown in the figure is different from the third embodiment in that: a limit ring 19 is connected between the adjustment ring 20 and the sliding sleeve 2; the double rubber tube connecting ring 24 is a circular ring structure, and a plurality of rectangular slots are opened on its side wall; through holes for connecting with the upper rubber tube 3 and the lower rubber tube 3 are opened along the axial direction on the end faces of both ends of the double rubber tube connecting ring 24; the two rubber tubes 3 are both short cylindrical structures that are symmetrical on the left and right, the apertures at the two ends of the inner side of the rubber tube 3 are small, and the apertures in the middle part are large, grooves are provided on the inner walls at both ends of the rubber tube 3, and copper sulfide rings 29 are embedded in the grooves.

[0053] In actual use, after the ball is thrown to build up pressure, the sliding sleeve 2 moves upward along the axial direction of the central axis 1 under the pressure of the drilling fluid, and stops when the inner step surface of the sliding sleeve 2 contacts the limit ring 19 to control the compression amount of the rubber cylinder 3 within the set range.

[0054] The double rubber tube connecting ring 24 adopts the above technical solution. During the plugging operation, the double rubber tubes are used in combination to increase the effective sealing area and ensure that the rubber tubes are fully fitted to the well wall.

[0055] Embodiment five:

[0056] according to Figure 1-Figure 8 The double-release plugging and isolation tool connected to a drill column as shown is different from the third embodiment in that an annular groove is opened on the opposite surface of the axial tension ring 21 and the upper lifting and unsealing device 28, and an axial friction ring 25 made of polytetrafluoroethylene is connected in the annular groove; there is a gap between the opposite surfaces of the axial tension ring 21 and the upper lifting and unsealing device 28.

[0057] The working process in actual use is as follows: during rotational unsealing, the axial friction ring 25 is used to release the torque between the unlocking ring 5 and the axial tension ring 21, separating the rotation work of the upper joint 6, the unlocking ring 5, and the center shaft 1 from the rubber cylinder 3. The upper joint 6, the unlocking ring 5 and the center rod rotate freely, and the rubber cylinder 3 remains stationary to prevent the rubber cylinder 3 from rotating with the drilling tool due to failure to seal with the well wall or insufficient friction with the well wall, thereby causing the rotational unsealing device to fail.

[0058] Embodiment six:

[0059] according to Figure 1-Figure 8 The double-release plugging and isolation tool connected to a drill column as shown is different from the first embodiment in that: the locking rotation unsealing mechanism 26 includes a fixed tooth mechanism, a sliding tooth 9, a tooth sleeve 10, a spring 11 and a nylon pin 18; the tooth sleeve 10 is fixed on the inner wall of the outer cylinder 7; the sliding tooth 9 is connected to the tooth sleeve 10; the fixed tooth mechanism is fixedly connected to the tooth sleeve 10 through the nylon pin 18, and is meshed with the sliding tooth 9; the spring 11 is placed between the sliding tooth 9 and the outer cylinder 7, and is used for full meshing of the fixed tooth mechanism with the sliding tooth 9.

[0060] Furthermore, the fixed tooth mechanism is a circular ring structure, and three groups of fixed teeth 8 are evenly arranged axially on its outer wall; each group of fixed teeth 8 corresponds to a group of sliding teeth 9 to form a locking device; the sliding teeth 9 and fixed teeth 8 are both meshing one-way teeth.

[0061] The locking and rotating unsealing mechanism 26 in this embodiment is of a three-petal type, and the three sets of locking devices are evenly distributed radially along the central axis 1 at an angle of 120° to each other.

[0062] In actual use, the sliding teeth 9 are mounted on the gear sleeve 10 and mesh with the fixed teeth 8. The spring leaf 11 is placed between the sliding teeth 9 and the outer cylinder 7, and pressure is applied to fully mesh the fixed teeth 8 with the sliding teeth 9. The fixed teeth 8 and the gear sleeve 10 are fixed with nylon pins 18 to prevent relative rotation between the fixed teeth 8 and the gear sleeve 10 during the drilling process, which would cause locking failure.

[0063] Working process: After the ball is thrown to start the pump and the pressure is built up, the sliding sleeve 2 is pushed by the high-pressure drilling fluid flowing in through the bypass hole 27 on the central axis 1, driving the outer cylinder 7 to move upward in the axial direction, thereby driving the gear sleeve 10 fixed on the outer cylinder, the sliding teeth 9 fixed on the gear sleeve 10, and the spring 11 placed between the sliding teeth 9 and the outer cylinder 7 to move upward relative to the fixed teeth 8. Both the fixed teeth 8 and the sliding teeth 9 are one-way teeth, so that the locking device is locked to achieve seat sealing.

[0064] Embodiment seven:

[0065] according to Figure 1-Figure 8 The double-release plugging and isolation tool connected to the drill column shown is different from the first embodiment in that the ball seat 12 is a hollow cylinder with a six-claw structure at one end and a through hole penetrating the side wall perpendicular to the axis for connecting the shear pin 15.

[0066] In actual use, the working process is as follows: after the rubber cylinder 3 is sealed, the pressure is continuously held, the shear pin 15 between the ball seat 12 and the ball seat cavity 13 is sheared off, the ball seat 12 moves downward together with the ball seated therein, and falls into the upper part of the lower joint 14, and the drilling fluid passes through the through hole on the ball seat 12 and the gap between the ball seat claws, and enters the leaking layer through the lower joint 14 and the lower drill pipe to implement the leak plugging operation.

[0067] Embodiment eight:

[0068] according to Figure 1-Figure 8The double-release plugging and sealing tool with a lower connection to a drill column shown in the figure is different from the first embodiment in that: the lifting and unsealing device 28 includes an unlocking ring 5, an upper joint 6, a rotating pin 16, a rotating pin pressure cover 17 and a torsion spring 23; the rotating pin pressure cover 17 is fixed to the lower end of the upper joint 6; the unlocking ring 5 is connected to the lower part of the upper joint 6 through the rotating pin 16 and is placed in the rotating pin pressure cover 17, and a conical annular groove is opened on the upper end of the inner wall of the unlocking ring 5; the torsion spring 23 is placed between the rotating pin 16 and the rotating pin pressure cover 17, and an annular groove is opened on the end surface of the unlocking ring 5 facing the rubber cylinder mechanism; the upper joint 6 is a conical cylinder with large diameters at both ends and a small diameter in the middle part; the rubber cylinder mechanism includes two upper and lower rubber cylinders 3, an adjusting The integral ring 20, the axial tension ring 21 and the connecting ring 22; the connecting ring 22 is connected between the upper rubber cylinder 3 and the lifting and unsealing device 28; the axial tension ring 21 is connected to the end face of the upper rubber cylinder 3, and is placed inside the connecting ring 22, and contacts with the connecting ring 22; the lower end of the lower rubber cylinder 3 is connected with an adjustment ring 20, and the adjustment ring 20 contacts with the upper end face of the sliding sleeve 2; a double rubber cylinder connecting ring 24 is connected between the upper rubber cylinder 3 and the lower rubber cylinder 3; the rubber cylinder 3 is a short cylindrical structure with left-right symmetry, the two ends of the inner side of the rubber cylinder 3 have small apertures, and the middle part has a large aperture, grooves are arranged on the inner walls at both ends of the rubber cylinder 3, and copper sulfide rings 29 are embedded in the grooves; a limiting ring is connected between the adjustment ring 20 and the sliding sleeve 2 19; the double rubber cylinder connecting ring 24 is a circular ring structure, and a plurality of rectangular slots are opened on its side wall; through holes for connecting with the upper rubber cylinder 3 and the lower rubber cylinder 3 are opened along the axial direction on the end faces of both ends of the double rubber cylinder connecting ring 24; annular grooves are opened on the opposite surfaces of the axial tension ring 21 and the unlocking ring 5, and the annular grooves on the unlocking ring 5 and the axial tension ring 21 are correspondingly arranged, and the axial friction ring 25 made of polytetrafluoroethylene is placed in the correspondingly arranged groove; there is a gap between the opposite surfaces of the axial tension ring 21 and the lifting and unsealing device 28; the locking and rotating unsealing mechanism 26 includes a fixed tooth mechanism, a sliding tooth 9, a tooth sleeve 10, a spring leaf 11 and a nylon pin 18; the tooth sleeve 10 is fixed on the outer cylinder body 7 On the inner wall; the sliding tooth 9 is connected to the tooth sleeve 10; the fixed tooth mechanism is fixedly connected to the tooth sleeve 10 through a nylon pin 18, and is meshed with the sliding tooth 9; the spring leaf 11 is placed between the sliding tooth 9 and the outer cylinder 7, and is used for the full meshing of the fixed tooth mechanism and the sliding tooth 9; the fixed tooth mechanism is a circular ring structure, and three groups of fixed teeth 8 are evenly arranged on its outer wall along the axial direction; each group of fixed teeth 8 corresponds to a group of sliding teeth 9, forming a group of locking devices; the sliding teeth 9 and the fixed teeth 8 are both meshable one-way teeth; the ball seat 12 is a hollow cylinder, one end of which is a six-claw structure, and the side wall of the other end is perpendicular to the axis and has a through hole penetrating the side wall for connecting the shear pin 15.

[0069] In actual use, the double-release plugging and isolation tool connected to the drill column is lowered to the regular wellbore section above the leaking layer; the pump is turned on by throwing a ball on the ground to increase the pressure, and the plugging slurry enters between the central axis 1 and the static sleeve 4 and the sliding sleeve 2 from the bypass hole 27 of the central axis 1, pushing the sliding sleeve 2 to move upward along the axial direction of the central axis 1, squeezing the rubber cylinder 3 in the rubber cylinder mechanism, so that the rubber cylinder 3 expands and fits the well wall; the sliding sleeve 2 drives the outer cylinder 7 to activate the locking and rotating unlocking mechanism 26, locking to achieve the seat seal, and the rubber cylinder mechanism maintains the seat seal state to isolate the upper and lower well walls; thereafter, when the pressure is continuously increased to the set value, the shear pin 15 connecting the ball seat 12 and the ball seat cavity 13 is sheared off, the ball seat 12 moves downward to the upper end of the lower joint 14, and a liquid flow channel is formed between the ball seat 12 and the lower joint 14, and the plugging slurry enters the leaking layer to plug the leak. After plugging, the drill tool is lifted, and the upper joint 6 and the central axis 1 in the lifting and unsealing device 28 move upward. The upper rubber cylinder 3 and the axial tension ring 21 in the rubber cylinder mechanism do not produce relative movement under the action of the static friction force of the well wall, and the connecting ring 22 and the unlocking ring 5 produce a small displacement movement in the axial direction; then, the lifting and unsealing device 28 is activated, and the unlocking ring 5 moves upward under the action of the rebound force of the two rubber cylinders 3 in the rubber cylinder mechanism, and the two rubber cylinders 3 are reset to achieve unsealing. Unsealing can also be implemented in the following way: rotating the drill tool, the upper joint 6 drives the central axis 1 to rotate, and the two rubber cylinders 3, the adjustment ring 20, the sliding sleeve 2, and the outer cylinder 7 are kept stationary by the static friction between the rubber cylinder and the well wall; the locking and rotating unsealing mechanism 26 is activated to release the locking state, and the two rubber cylinders 3 are reset to achieve unsealing.

[0070] The present invention overcomes the problems of the prior art of single unsealing method, poor sealing pressure bearing effect of the rubber tube, and large size of the locking and locking mechanism, and has two unsealing methods of rotation and lifting to ensure the success rate of unsealing. The locking, rotating and unlocking mechanism 26 of the present invention is small, so that it has a wide range of applications, especially for small-sized wellbores.

[0071] Embodiment nine:

[0072] Reference Figure 1-Figure 8 A plugging method for a double-release plugging and isolation tool connected to a drill column, comprising the following steps:

[0073] Step 1: lower the double-release plugging and isolation tool connected to the drill string to the regular wellbore section above the leaking layer;

[0074] Step 2: Pressurize the pump by throwing a ball on the ground, and the plugging slurry enters between the central shaft 1 and the static sleeve 4 and the sliding sleeve 2 through the bypass hole 27 of the central shaft 1, pushing the sliding sleeve 2 to move upward along the axial direction of the central shaft 1, squeezing the rubber cylinder 3 in the rubber cylinder mechanism, so that the rubber cylinder 3 expands and fits the well wall;

[0075] Step 3: The sliding sleeve 2 drives the outer cylinder 7 to activate the locking and rotating unlocking mechanism 26, and the locking is performed to achieve the seat seal, and the rubber cylinder mechanism maintains the seat seal state to seal the upper and lower well walls;

[0076] Step 4: When the pressure is continuously increased to the set value, the shear pin 15 connecting the ball seat 12 and the ball seat cavity 13 is cut off, and the ball seat 12 moves downward to the upper end of the lower joint 14, a liquid flow channel is formed between the ball seat 12 and the lower joint 14, and the plugging slurry enters the leaking layer to plug the leak;

[0077] Step 5: After plugging, the drill tool is lifted, and the lifting and unsealing device 28 and the central axis 1 are moved upward. The upper rubber cylinder 3 and the axial tension ring 21 in the rubber cylinder mechanism do not produce relative movement under the action of the static friction force of the well wall, and the connecting ring 22 and the unlocking ring 5 are displaced in the axial direction;

[0078] Step six, the lifting and unsealing device 28 is activated, and the unlocking ring 5 moves upward under the action of the rebound force of the two rubber tubes 3 in the rubber tube mechanism, and the two rubber tubes 3 are reset to achieve unsealing; or the drill bit is rotated, and the upper joint 6 drives the central axis 1 to rotate, and the two rubber tubes 3, the adjusting ring 20, the sliding sleeve 2, and the outer cylinder 7 are kept stationary by the static friction between the rubber tube 3 and the well wall; the locking and rotating unsealing mechanism 26 is activated to release the locking state, and the two rubber tubes 3 are reset to achieve unsealing.

[0079] The present invention has two unsealing modes, namely, rotation and lifting, which overcomes the problem of single unsealing mode in the prior art and greatly increases the success rate of unsealing.

[0080] The rubber cylinder structure of the present invention is composed of two upper and lower rubber cylinders, an adjustment ring, an axial tension ring and a connecting ring, so that the sealing effect is better.

[0081] The locking and rotating unsealing mechanism of the present invention is organically composed of a fixed tooth mechanism, a sliding tooth, a tooth sleeve, a spring and a nylon pin. The mechanism is compact and space-saving, and its application range is expanded. It is more suitable for small-sized wellbores.

[0082] In the absence of conflicts, technicians in this field can combine the relevant technical features in the above examples according to actual conditions to achieve corresponding technical effects. The specific combinations are not described here one by one.

[0083] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0084] In addition, the descriptions of "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0085] The above are only preferred embodiments of the present invention. The present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein. Any simple modification, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A double-release plugging and isolation tool connected to the drill string. Features: It comprises a central shaft (1), a lifting and unsealing device (28), a rubber cylinder mechanism, a sliding sleeve (2), an outer cylinder body (7), a static sleeve (4), a ball seat (12), a ball seat cavity (13), a lower joint (14), a shear pin (15) and a locking and rotating unsealing mechanism (26); the central shaft (1) is connected to the lower end of the lifting and unsealing device (28); the outer wall of the central shaft (1) is connected with the rubber cylinder mechanism, the sliding sleeve (2), the outer cylinder body (7) and the locking and rotating unsealing mechanism (26) in sequence from top to bottom; the static sleeve (4) is connected between the outer cylinder body (7) and the central shaft (1), and a bypass hole (27) is provided at the upper part of the connection position between the central shaft (1) and the static sleeve (4); the lower joint (14) is connected to the lower end of the central shaft (1) through the ball seat cavity (13); the ball seat (12) is connected to the upper part of the ball seat cavity (13) through the shear pin (15).

2. A double-release plugging and isolation tool connected to a drill string as claimed in claim 1, Features: The lifting and unsealing device (28) comprises an unlocking ring (5), an upper joint (6), a rotating pin (16), a rotating pin pressure cover (17) and a torsion spring (23); the rotating pin pressure cover (17) is fixed to the lower end of the upper joint (6); the unlocking ring (5) is connected to the lower part of the upper joint (6) through the rotating pin (16) and is placed in the rotating pin pressure cover (17); a conical annular groove is formed at the upper end of the inner wall of the unlocking ring (5); the torsion spring (23) is placed between the rotating pin (16) and the rotating pin pressure cover (17); and an annular groove is formed on the end surface of the unlocking ring (5) facing the rubber cylinder mechanism.

3. A double-release plugging and isolation tool connected to a drill string as claimed in claim 2, Features: The upper joint (6) is a conical column with large diameters at both ends and a small diameter in the middle.

4. A double-release plugging and isolation tool connected to a drill string as claimed in claim 1, Features: The rubber cylinder mechanism comprises two upper and lower rubber cylinders (3), an adjustment ring (20), an axial tension ring (21) and a connecting ring (22); a connecting ring (22) is connected between the upper rubber cylinder (3) and the lifting and unsealing device (28); the axial tension ring (21) is connected to the end face of the upper rubber cylinder (3) and is placed inside the connecting ring (22) and contacts the connecting ring (22); an adjustment ring (20) is connected to the lower end of the lower rubber cylinder (3), and the adjustment ring (20) contacts the upper end face of the sliding sleeve (2); a double rubber cylinder connecting ring (24) is connected between the upper rubber cylinder (3) and the lower rubber cylinder (3).

5. A double-release plugging and isolation tool connected to a drill string as claimed in claim 4, Features: A limit ring (19) is connected between the adjustment ring (20) and the sliding sleeve (2); the double rubber tube connecting ring (24) is a circular ring structure, and a plurality of rectangular slots are formed on its side wall; through holes for connecting with the upper rubber tube (3) and the lower rubber tube (3) are formed on the end faces of both ends of the double rubber tube connecting ring (24) along the axial direction; the two rubber tubes (3) are both short cylindrical structures that are symmetrical on both sides, with small apertures at the two ends of the inner side of the rubber tube and large apertures in the middle part; grooves are formed on the inner walls of both ends of the rubber tube, and copper sulfide rings (29) are embedded in the grooves.

6. A double-release plugging and isolation tool connected to a drill string as claimed in claim 4, Features: An annular groove is formed on the opposing surfaces of the axial tension ring (21) and the lifting and unsealing device (28), and an axial friction ring (25) made of polytetrafluoroethylene is connected in the annular groove; there is a gap between the opposing surfaces of the axial tension ring (21) and the lifting and unsealing device (28).

7. A double-release plugging and isolation tool connected to a drill string as claimed in claim 1, Features: The locking and rotating unsealing mechanism (26) comprises a fixed tooth mechanism, a sliding tooth (9), a tooth sleeve (10), a spring leaf (11) and a nylon pin (18); the tooth sleeve (10) is fixed on the inner wall of the outer cylinder (7); the sliding tooth (9) is connected to the tooth sleeve (10); the fixed tooth mechanism is fixedly connected to the tooth sleeve (10) through the nylon pin (18) and meshed with the sliding tooth (9); the spring leaf (11) is placed between the sliding tooth (9) and the outer cylinder (7) to ensure full meshing of the fixed tooth mechanism with the sliding tooth (9).

8. A double-release plugging and isolation tool connected to a drill string as claimed in claim 7, Features: The fixed tooth mechanism is a circular ring structure, and three groups of fixed teeth (8) are evenly arranged on its outer wall along the axial direction; each group of fixed teeth (8) corresponds to a group of sliding teeth (9), forming a group of locking devices; the sliding teeth (9) and the fixed teeth (8) are both meshing one-way teeth.

9. A double-release plugging and isolation tool connected to a drill string as claimed in claim 1, Features: The ball seat (12) is a hollow cylinder, one end of which is a six-claw structure, and the side wall of the other end is provided with a through hole penetrating the side wall and being used to connect the shear pin (15) perpendicular to the axis.

10. A plugging method for a double-release plugging and isolation tool connected to a drill string as claimed in any one of claims 1 to 9, Features: The following steps are included: Step 1: lower the double-release plugging and isolation tool connected to the drill string to the regular wellbore section above the leaking layer; Step 2: By pumping a ball on the ground to increase pressure, the plugging slurry enters between the central shaft (1) and the static sleeve (4) and the sliding sleeve (2) through the bypass hole (27) of the central shaft (1), pushing the sliding sleeve (2) to move upward along the axial direction of the central shaft (1), squeezing the rubber cylinder (3) in the rubber cylinder mechanism, so that the rubber cylinder (3) expands and fits against the well wall; Step 3: The sliding sleeve (2) drives the outer cylinder (7) to activate the locking and rotating unlocking mechanism (26), thereby locking and achieving the seat seal, and the rubber cylinder mechanism maintains the seat seal state to seal the upper and lower well walls; Step 4: When the pressure is continuously increased to a set value, the shear pin (15) connecting the ball seat (12) and the ball seat cavity (13) is sheared off, the ball seat (12) moves downward to the upper end of the lower joint (14), a liquid flow channel is formed between the ball seat (12) and the lower joint (14), and the plugging slurry enters the leaking layer to plug the leak; Step 5: After plugging, the drilling tool is lifted, and the lifting and unsealing device (28) and the central axis (1) are moved upward. The upper rubber cylinder (3) and the axial tension ring (21) in the rubber cylinder mechanism do not produce relative movement under the action of the static friction force of the well wall, and the connecting ring (22) and the unlocking ring (5) are displaced in the axial direction; Step six, the lifting and unsealing device (28) is activated, and the unlocking ring (5) moves upward under the action of the rebound force of the two rubber cylinders (3) in the rubber cylinder mechanism, and the two rubber cylinders (3) are reset to achieve unsealing; or the drilling tool is rotated, and the upper joint (6) drives the central axis (1) to rotate, and the two rubber cylinders (3), the adjustment ring (20), the sliding sleeve (2), and the outer cylinder (7) are kept stationary by the static friction between the rubber cylinders (3) and the well wall; the locking and rotating unsealing mechanism (26) is activated to release the locking state, and the two rubber cylinders (3) are reset to achieve unsealing.

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