Bidirectional anchor and using method thereof

Abstract

The invention discloses a bidirectional anchor and a using method thereof. The bidirectional anchor comprises an upper central pipe, an anchor setting locking mechanism, an anchoring mechanism and an anchor releasing mechanism, wherein the upper central pipe is sleeved with the anchor setting locking mechanism and the anchoring mechanism, and the anchor releasing mechanism is connected with the upper central pipe. The anchoring locking mechanism is used for moving downwards under the hydraulic effect and pushing the anchoring mechanism to expand in the radial direction to be anchored with an external sleeve. In the state that the upper central pipe is lifted upwards, the anchor releasing mechanism shears off an anchor releasing shear pin connecting the upper central pipe and the anchoring mechanism so as to release the limitation of the anchoring mechanism on the upper central pipe; or in the rotating state of the upper central pipe, the limiting sleeve of the anchor releasing mechanism is pushed to move downwards so as to release the limiting between the anchoring mechanism and the anchor releasing mechanism, and then the limiting of the upper central pipe is released; and after the upper central pipe is unlimited, the upper central pipe is lifted to drive the anchoring locking mechanism to move upwards, and then the anchoring mechanism and the casing pipe are driven to be unanchored. The two-way anchor is provided with more than one anchor releasing mode, and the clamping releasing reliability of the measure pipe column is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field exploration and development, and particularly relates to a two-way anchor and a using method thereof. Background Art

[0002] In oil and gas field development, anchoring tools such as two-way anchors and hydraulic anchors need to be supported for the string of measures such as separate layer water injection, so that the string of measures is anchored on the inner wall of the casing, preventing the string of measures from creeping repeatedly under the stress action of piston effect, expansion effect, temperature effect, etc. due to the influence of pressure and temperature fluctuations, and preventing the packer in the string of measures from creeping and failing.

[0003] The working principle of the two-way anchoring tool applied in the prior art is to push the piston and the connected cone block to move under the action of hydraulic pressure, force the two-way anchor tiles to be pushed out and stuck on the inner wall of the casing to achieve anchoring, and prevent the cone block from moving back and the two-way anchor tiles from retracting; during production, the up-pulling axial force generated by the string of measures due to stress actions such as expansion effect and temperature effect is transmitted to the two-way anchor tiles and the casing through the unlocking shear pin, avoiding the creeping of the string of measures and protecting the packer in the string of measures; during the later workover operation of pulling out the pipe string, a certain pulling force needs to be applied upwards, after cutting the unlocking shear pin, the piston and the connected cone block are driven to move upwards by pulling the central pipe upwards, creating space to make the two-way anchor tiles retract and release the anchoring. Summary of the Invention

[0004] The inventors of the present application found that when the axial force generated by the string of measures such as high-pressure water injection due to stress actions such as expansion effect and temperature effect is relatively large, in order to prevent the string of measures from creeping and failing due to insufficient anchoring force, the anti-shearing force of the unlocking shear pin needs to be set to a relatively large value accordingly. However, when unlocking, a sufficiently large pulling force is required to cut the unlocking shear pin. Due to the limited anti-pulling force of the workover derrick or the pipe string, it is difficult to cut the unlocking shear pin, which easily leads to the pipe string getting stuck or breaking, resulting in major repairs.

[0005] In view of the above problems, the present invention is proposed to provide a two-way anchor and a using method thereof that overcome the above problems or at least partially solve the above problems.

[0006] An embodiment of the present invention provides a two-way anchor, including: an upper central pipe, a setting and locking mechanism sleeved on the upper central pipe, an anchoring mechanism, and an unlocking mechanism connected to the upper central pipe;

[0007] The setting and locking mechanism is used to move downward under the action of hydraulic pressure and push the anchoring mechanism to expand radially to anchor with the external casing;

[0008] The unlocking mechanism is used to cut the unlocking shear pins connecting the upper central pipe and the anchoring mechanism in the state of lifting the upper central pipe, so as to release the limit of the upper central pipe by the anchoring mechanism; or in the state of rotating the upper central pipe, push the limit sleeve of the unlocking mechanism to move downward, so as to release the limit between the anchoring mechanism and the unlocking mechanism, and then release the limit of the upper central pipe;

[0009] After the limit of the upper central pipe is released, the upper central pipe is lifted to drive the setting and locking mechanism to move upward, and then drive the anchoring mechanism to release the anchoring with the casing.

[0010] In an optional embodiment, the unlocking mechanism includes: a lower central pipe, a connecting sleeve, a limit sleeve and a connecting sleeve;

[0011] The lower central pipe is connected to the lower end of the upper central pipe. The limit sleeve is sleeved on the lower central pipe and is threadedly connected to the lower central pipe. And the limit sleeve is circumferentially limited by the connecting sleeve to push the limit sleeve to move downward in the state of rotating the upper central pipe;

[0012] The upper end of the connecting sleeve is connected to the lower end of the upper central pipe through an unlocking shear pin. An elastic boss is arranged at the lower end of the connecting sleeve. And the elastic boss is limited by the limit sleeve and the limit groove of the anchoring mechanism and can be released from the limit after moving a preset distance relative to the limit sleeve.

[0013] In an optional embodiment, the unlocking mechanism is also used to cut the control shear pins connecting the upper central pipe and the anchoring mechanism in the state of ball plugging and pressure buildup inside the upper central pipe, so as to release the limit of the upper central pipe by the anchoring mechanism.

[0014] In an optional embodiment, an unlocking ball seat is arranged at one end of the lower central pipe close to the upper central pipe, and the upper central pipe and the lower central pipe are connected by a control shear pin.

[0015] In an optional embodiment, a limit boss is arranged at the lower end of the limit sleeve, and the elastic boss is limited by the limit boss and the limit groove;

[0016] A key strip protruding radially is arranged on the outer wall of the limit boss. Correspondingly, a key groove is formed on the inner wall of the connecting sleeve to circumferentially limit the limit sleeve through the cooperation of the key strip and the key groove.

[0017] In an optional embodiment, an annular space is formed by the anchoring mechanism, the upper central pipe, the lower central pipe and the connecting sleeve, and the connecting sleeve and the limit sleeve are arranged in the annular space;

[0018] And sealing elements are provided between the connecting sleeve and the lower central pipe and the anchoring mechanism, and between the upper central pipe and the anchoring mechanism and the lower central pipe;

[0019] The anchoring mechanism is provided with a grease injection hole, and the grease injection hole is sealed by a one-way sealing ring to inject a protective liquid into the annular space through the grease injection hole.

[0020] In an optional embodiment, the setting and anchoring locking mechanism includes: an outer cylinder, a piston, a piston seat, a lock block sleeve, and a coupling shaft that are arranged in the outer cylinder and sequentially sleeved on the upper central pipe, and the lock block sleeve is connected to the upper central pipe by a lock block;

[0021] The piston seat is provided with a flow-through hole communicating with the liquid inlet hole on the upper central pipe, and the coupling shaft is connected to the anchoring mechanism;

[0022] The piston is arranged in the annular space formed among the piston seat, the outer cylinder, and the lock block sleeve, and is connected to the piston seat by a setting and anchoring shear pin.

[0023] In an optional embodiment, a lock ring sleeve threadedly connected to the lower end of the outer cylinder is further provided on the outer cylinder, and a lock ring is provided on the lock ring sleeve;

[0024] Correspondingly, lock teeth are provided on the outer wall of the lower end of the coupling shaft to limit the upward movement of the coupling shaft through the cooperation of the lock teeth and the lock ring.

[0025] In an optional embodiment, the anchoring mechanism includes: an anchor tile housing, an upper support cone, a two-way anchor tile, and a lower support cone that are sequentially arranged in the anchor tile housing;

[0026] The upper support cone is connected to the anchor tile housing by a limit pin, its upper end is connected to the coupling shaft, and its lower end abuts against the upper end of the two-way anchor tile;

[0027] The two-way anchor tile is fixed in the anchor tile housing by a spring, and the anchor tile housing is provided with an anchor window for the radial extension of the two-way anchor tile. The lower end of the two-way anchor tile abuts against the upper end of the lower support cone, and the abutting surfaces of the two-way anchor tile with the upper support cone and the lower support cone are conical surfaces;

[0028] The lower end of the lower support cone is connected to the connecting sleeve, and forms the annular space with the connecting sleeve, the upper central pipe, and the lower central pipe. The grease injection hole and the limit groove are arranged on the lower support cone.

[0029] In an optional embodiment, the two-way anchor provided by the embodiment of the present invention further includes: an upper joint, a lifting sleeve, and a lower joint;

[0030] The upper sub is sealingly connected to the upper end of the upper central tube, and the lifting sleeve is sleeved on the upper sub and its lower end is connected to the piston seat;

[0031] The lower sub is sleeved on the lower central tube, and its upper end is sealingly connected to the connecting sleeve;

[0032] An anti - jamming locking ring is provided on the inner wall of the lower sub. Correspondingly, anti - jamming locking teeth adapted thereto are provided on the outer wall of the lower central tube to limit the upward movement of the lower sub relative to the lower central tube through the cooperation between the anti - jamming tooth ring and the anti - jamming locking teeth.

[0033] Based on the same inventive concept, an embodiment of the present invention provides a method for using the above - mentioned two - way anchor, which includes:

[0034] Control the pressure inside the central tube, and the hydraulic pressure acts on the setting - anchor locking mechanism, causing the setting - anchor locking mechanism to move downward and pushing the anchoring mechanism to expand radially to anchor with the external casing;

[0035] Lift the upper central tube or rotate the upper central tube to release the limit of the upper central tube by the releasing - anchor mechanism. After the releasing - anchor mechanism releases the limit of the upper central tube, lift the upper central tube to drive the setting - anchor locking mechanism to move upward, so that the anchoring mechanism is released from the anchor with the casing.

[0036] In an optional embodiment, the method for using the above - mentioned two - way anchor further includes:

[0037] Drop a ball to build up pressure inside the upper central tube, so that the releasing - anchor mechanism releases the limit of the upper central tube.

[0038] The beneficial effects of the above - mentioned technical solutions provided by the embodiments of the present invention at least include:

[0039] The two - way anchor provided by the embodiment of the present invention is provided with more than one releasing - anchor method. When releasing the anchor between the anchoring mechanism and the casing, the limit of the upper central tube by the releasing - anchor mechanism can be released by lifting the upper central tube or rotating the upper central tube, and the setting - anchor locking mechanism can be driven to move upward by lifting the central tube, thereby driving the anchoring mechanism to be released from the anchor with the casing; when the lifting force required to release the anchor by lifting the upper central tube is large, the method of rotating the upper central tube to release the anchor between the anchoring mechanism and the external casing can be selected to achieve the safe release of the pipe string when the anchoring tool has a large anchoring force; and the two releasing - anchor methods do not affect each other. In the case where one releasing - anchor method fails, it does not affect the implementation of the other releasing - anchor method, which can avoid the situation that the entire anchoring tool fails to release the anchor in the case of the failure of one releasing - anchor method, thus affecting the normal downhole operation, and increasing the anchoring safety and release - card reliability of the pipe string.

[0040] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention. The objectives and other advantages of the present invention may be realized and attained by the structure particularly pointed out in the written description, claims, as well as the drawings.

[0041] The technical solution of the present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0042] The drawings are used to provide a further understanding of the present invention, and constitute a part of the description. Together with the embodiments of the present invention, they are used to explain the present invention, but do not constitute a limitation to the present invention. In the drawings:

[0043] Figure 1 is a schematic structural diagram of a two-way anchor in an embodiment of the present invention;

[0044] Figure 2 is an enlarged schematic diagram of the anchor releasing assembly in an embodiment of the present invention.

[0045] Description of the Reference Numerals:

[0046] 100, sitting anchor locking mechanism; 200, anchoring mechanism; 300, anchor releasing mechanism; 1, upper joint; 2, lifting sleeve; 3, upper central tube; 4, liquid inlet hole; 5, piston seat; 6, piston; 7, sitting anchor shear pin; 8, lock block; 9, outer cylinder; 10, lock block sleeve; 11, connecting shaft; 12, locking teeth; 13, lock ring sleeve; 14, upper support cone; 15, anchor tile housing; 16, limit pin; 17, limit groove; 18, two-way anchor tile; 19, spring; 20, lower support cone; 21, housing sleeve; 22, anchor releasing ball seat; 23, lower central tube; 24, control shear pin; 25, grease injection hole; 26, one-way sealing ring; 27, anchor releasing shear pin; 28, connecting sleeve; 29, reverse rotation male thread; 30, limit sleeve; 31, reverse rotation female thread; 32, elastic boss; 33, limit groove; 34, limit boss; 35, connecting sleeve; 36, keyway; 37, anti-top lock ring; 38, anti-top locking teeth; 39, lower joint. Detailed Embodiments

[0047] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the drawings. Although the 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 by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0048] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0049] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0050] The inventors of the present application found that existing anchoring tools mainly rely on the force of the release shear pin to counteract stress effects such as piston effect, bulging effect, temperature effect, etc. and the upward force of the pipe string. For example, the anchoring packer disclosed in the patent application with the publication number CN113417595A, the magnitude of the shear force of the release shear pin in this structure determines the pressure-bearing capacity of the pipe string; if it is set too small, the pipe string will creep and fail under high pressure; if it is set too large, a large enough pulling force is required to cut the release shear pin, which is likely to cause the pipe string to get stuck or break, resulting in major repairs.

[0051] Moreover, there is also a situation where the existing anchoring tool causes the measure pipe string to be de-anchored due to temporary pressure relief or internal and external pressure balance, resulting in the creep failure of the packer tool under stress effects such as temperature effect. For example, the publication number CN115992661A discloses a long-term anchoring tool. When the pipe string is pressure-relieved or backwashed, the anchor claws retract and the anchoring is released, which will cause the packer tool to creep and fail under stress effects such as temperature effect.

[0052] Therefore, in order to solve the problems in measures such as high-pressure water injection, the measure string fails to be anchored due to the small designed anti-shearing force value of the unlocking shear pin of the anchoring tool and insufficient anchoring force, or the string is unanchored due to the balance of internal and external pressures, resulting in the failure of the string to creep; and when the designed anti-shearing force value of the unlocking shear pin of the anchoring tool is large, the required upward unlocking pulling force is too large, making it difficult to unlock, resulting in the inability to retract the anchor shoe, causing the string to get stuck or break; and due to the complex downhole working environment, the existing anchoring tools are easily affected by high salinity water quality, etc., and the unlocking components cannot move due to corrosion and scaling, resulting in the inability to unlock and causing string sticking accidents, etc. The embodiment of the present invention provides a two-way anchor, which realizes safe pipe unhooking through multiple unlocking methods, adapts to various complex well conditions, reduces the probability of string sticking accidents, improves the safety and reliability of the measure string, and reduces the construction operation cost.

[0053] It should be noted that in the embodiment of the present invention, when the two-way anchor is applied, the end connected to the measure string is called the upper end of the two-way anchor, and the end connected to downhole tools such as packers is called the lower end of the two-way anchor.

[0054] The two-way anchor provided by the embodiment of the present invention, referring to Figure 1 as shown, includes: an upper central tube 3, an anchoring and locking mechanism 100 sleeved on the upper central tube 3, an anchoring mechanism 200, and an unlocking mechanism 300 connected to the upper central tube 3;

[0055] The anchoring and locking mechanism 100 is used to move downward under hydraulic action and push the anchoring mechanism 200 to expand radially to anchor with the external casing;

[0056] The unlocking mechanism 300 is used to cut the unlocking shear pin connecting the upper central tube 3 and the anchoring mechanism 200 to release the limit of the anchoring mechanism 200 on the upper central tube 3 when the upper central tube 3 is lifted; or to push the limit sleeve of the unlocking mechanism 300 to move downward when the upper central tube 3 rotates, so as to release the limit between the anchoring mechanism 200 and the unlocking mechanism 300, and then release the limit of the upper central tube 3;

[0057] After the upper central tube 3 is released from the limit, the upper central tube 3 is lifted to drive the anchoring and locking mechanism 100 to move upward, and then drive the anchoring mechanism 200 to release the anchor with the casing.

[0058] The two-way anchor provided by the embodiment of the present invention is provided with more than one anchor release method. When releasing the anchor between the anchoring mechanism 200 and the casing, the upper central tube 3 can be lifted or the upper central tube 3 can be rotated to release the limit of the upper central tube 3 by the anchor release mechanism 300, and the setting anchor locking mechanism 100 can be driven to move upward by lifting the central tube, thereby driving the anchoring mechanism 200 to release the anchor from the casing; when the lifting force required to release the anchor of the anchoring mechanism 200 by lifting the upper central tube 3 is relatively large, the method of rotating the upper central tube 3 to release the anchor of the anchoring mechanism 200 from the external casing can be selected to achieve the safe release of the measure string when the anchoring tool is set with a large anchoring force; and the two anchor release methods do not affect each other. In the case where one anchor release method fails to be attempted, it does not affect the implementation of the other anchor release method, and it can be avoided that in the case where one anchor release method fails to release the anchor, the entire anchoring tool fails to release the anchor, thereby affecting the normal downhole operation, increasing the anchoring safety and release reliability of the measure string.

[0059] Optionally, referring to Figure 1 and Figure 2 As shown, the anchor release mechanism includes: a lower central tube 23, a connecting sleeve 28, a limiting sleeve 30, and a connecting sleeve 35;

[0060] The lower central tube 23 is connected to the lower end of the upper central tube 3. The limiting sleeve 30 is sleeved on the lower central tube and is threadedly connected to the lower central tube 23, and the limiting sleeve 30 is circumferentially limited by the connecting sleeve 35 so as to push the limiting sleeve 30 to move downward in the rotating state of the upper central tube 3;

[0061] The upper end of the connecting sleeve 28 is connected to the lower end of the upper central tube 3 through an anchor release shear pin 27. The lower end of the connecting sleeve 28 is provided with an elastic boss 32, and the elastic boss 32 is limited by the limiting sleeve 30 and the limiting groove 33 of the anchoring mechanism and can be released from the limit after moving a preset distance relative to the limiting sleeve 30.

[0062] Specifically, a reverse rotation male thread 29 can be provided on the outer side of the lower central tube 23, and a reverse rotation female thread 31 adapted to the reverse rotation male thread 29 can be provided on the inner side of the limiting sleeve 30. The limiting sleeve 30 is sleeved on the lower central tube 23 by the cooperation of the reverse rotation female thread 31 and the reverse rotation male thread 29 on the outer side of the lower central tube 23; the reverse rotation male thread 29 and the reverse rotation female thread 31 can specifically be trapezoidal threads. After the two cooperate, the required torque for rotation is small, and applying a small torque to one party will cause it to rotate, and an axial thrust will be generated to push the other party to move axially. Therefore, when rotating the upper central tube 3, only a small torque needs to be transmitted to the lower central tube 23 to drive the lower central tube 23 to rotate and generate an axial thrust to push the limiting sleeve 30 to move downward.

[0063] Further, the unlocking shear pin 27 is clamped in the lower slot of the upper central pipe 3 through the pin hole at the upper end of the connecting sleeve 28 to fixedly connect the lower end of the upper central pipe 3 and the upper end of the connecting sleeve 28, preventing the connecting sleeve 28 and the upper central pipe 3 from moving relatively up and down.

[0064] In an alternative embodiment, the anchoring mechanism is further configured to cut the control shear pin connecting the upper central pipe and the anchoring mechanism under the condition of ball plugging and pressure buildup inside the upper central pipe, so as to release the limitation of the anchoring mechanism on the upper central pipe.

[0065] Further, an unlocking ball seat 22 is provided at one end of the lower central pipe close to the upper central pipe, and the upper central pipe 3 and the lower central pipe 23 are connected by a control shear pin.

[0066] Specifically, the control shear pin 24 fixes the lower central pipe 23 inside the upper central pipe 3, preventing the lower central pipe 23 and the upper central pipe 3 from moving relatively up and down. The unlocking ball seat 22 is provided at the top end of the lower central pipe 23 and can be used in cooperation with a metal ball to form a seal, blocking the pressure in the upper central pipe 3 from being transmitted to the lower central pipe 23.

[0067] Optionally, referring to Figure 1 As shown, a limiting boss 34 is provided at the lower end of the limiting sleeve 30, and the elastic boss 32 is limited by the limiting boss 34 and the limiting groove;

[0068] A key strip protruding radially is provided on the outer wall of the limiting boss 34. Correspondingly, a key groove is provided on the inner wall of the connecting sleeve, so as to circumferentially limit the limiting sleeve 30 through the cooperation of the key strip and the key groove.

[0069] Specifically, the elastic boss 32 at the lower end of the connecting sleeve 28 is an elastic structure and can expand and contract radially. The elastic boss 32 is clamped in the limiting groove 33 of the anchoring mechanism, preventing the connecting sleeve 28 and the lower support cone 20 from moving relatively up and down. The upper end of the limiting boss 34 contacts the elastic boss 32, restricting the elastic boss 32 from radially contracting and disengaging from the limiting groove 33. When the limiting sleeve 30 moves up or down a preset distance relative to the connecting sleeve 28, the limiting boss 34 and the elastic boss 32 are disengaged from contact, and the elastic boss 32 radially contracts and disengages from the limiting groove 33. At this time, when the upper central pipe 3 is lifted, the unlocking mechanism can be driven to move upward together, that is, the limitation of the upper central pipe is released.

[0070] Further, an annular space is formed among the anchoring mechanism 200, the upper central pipe 3, the lower central pipe 23 and the connecting sleeve 35, and the connecting sleeve 28 and the limiting sleeve 30 are arranged in the annular space;

[0071] Sealing elements are provided between the connecting sleeve 35 and the lower central pipe 23 and the anchoring mechanism 200, and between the upper central pipe 3 and the anchoring mechanism 200 and the lower central pipe 23;

[0072] The anchoring mechanism 200 is provided with a grease injection hole 25, and the grease injection hole 25 is sealed by a one-way sealing ring 26 to inject a protective liquid into the annular space through the grease injection hole 25.

[0073] Specifically, the grease injection hole 25 is sealed by a screw and a one-way sealing ring 26, allowing liquid to be injected into the annular closed space formed by the anchoring mechanism, the upper central tube, the lower central tube, and the connecting sleeve through the grease injection hole 25, but preventing the liquid from flowing out of the closed annular space through the grease injection hole 25. When the two-way anchor is applied, liquids with anti-corrosion and lubrication functions such as engine oil, edible oil, and anti-corrosion lubricant can be injected into the closed annular space through the grease injection hole 25, thereby preventing the movable parts in the anchor releasing mechanism, such as the lower central tube 23, the anchor releasing shear pin 27, the limit sleeve 30, the elastic boss 32, the limit boss 34, etc., from being unable to move relative to each other due to corrosion and scaling, resulting in anchor release failure and the two-way anchor tile 18 being unable to radially contract, causing a stuck well accident.

[0074] Optionally, the setting and locking mechanism 100 of the two-way anchor provided by the embodiment of the present invention includes: an outer cylinder 9, a piston 6, a piston seat 5, a lock block sleeve 10, and a coupling shaft 11 that are arranged in the outer cylinder 9 and sequentially sleeved on the upper central tube 3, and the lock block sleeve 10 is connected to the upper central tube 3 through a lock block 8;

[0075] The piston seat 5 is provided with a flow-through hole channel communicating with the liquid inlet hole 4 on the upper central tube 3, and the coupling shaft 11 is connected to the anchoring mechanism;

[0076] The piston 6 is arranged in the annular space formed among the piston seat 5, the outer cylinder 9, and the lock block sleeve 10, and is connected to the piston seat 5 through an anchoring shear pin 7 to prevent the piston 6 from moving relative to the piston seat 5. Only after the anchoring shear pin 7 is cut can the piston 6 move relative to the piston seat 5.

[0077] During the anchoring process of the two-way anchor, the pressure in the central tube is transmitted through the liquid inlet hole 4 provided on the upper central tube 3 and the corresponding flow-through hole channel on the piston seat 5, so that the pressure acts on the piston 6.

[0078] Specifically, the inner side of the piston seat 5 and the upper central tube 3 are sealed with a sealing ring, and the outer side of the lower end is fixedly connected to the outer cylinder 9 by a thread and is sealed with a sealing ring; the inner side of the piston 6 is also provided with a groove, and the inner side of the piston 6 and the lock block sleeve 10 are sealed with a sealing ring, and the outer side is sealed with the outer cylinder 9 with a sealing ring; both the upper and lower end faces of the inner side of the lock block 8 are inclined planes, which are stuck in the semi-circular clamping groove of the upper central tube 3 and the lock block sleeve 10 to prevent the lock block sleeve 10 from moving relative to and rotating relative to the upper central tube 3. The outer side of the lock block 8 contacts the inner side of the piston 6. The upper end of the outer cylinder 9 is fixedly connected to the piston seat 5 by a thread, and the inner side of the lock block sleeve 10 and the upper central tube 3 are sealed with a sealing ring, and the lower end of the lock block sleeve 10 is fixedly connected to the coupling shaft 11 by a thread.

[0079] Furthermore, a lock ring sleeve 13 threadedly connected to the lower end of the outer cylinder 9 is provided, and a lock ring (not shown in the figure) is provided on the lock ring sleeve 13;

[0080] Correspondingly, locking teeth 12 are provided on the outer wall of the lower end of the coupling shaft 11 to limit the upward movement of the coupling shaft 11 through the cooperation of the locking teeth 12 and the lock ring.

[0081] After the locking teeth 12 are in contact with and locked by the lock ring, the coupling shaft 11 can only move downward under the push of the piston 6 and the lock block sleeve 10, and cannot move upward after the thrust disappears, preventing the upper support cone 14 and the double - acting anchor housing 15 from moving upward when the internal and external pressures are balanced after the anchoring mechanism is anchored to the external casing, that is, when the hydraulic action disappears, resulting in the weakening or disappearance of the extrusion force of the lower end face of the upper support cone 14 and the upper end face of the lower support cone 20 on the double - acting anchor 18, leading to the failure of the anchoring of the measure string.

[0082] In an alternative embodiment, the anchoring mechanism includes: an anchor housing 15, and an upper support cone 14, a double - acting anchor 18, and a lower support cone 20 sequentially arranged within the anchor housing 15;

[0083] The upper support cone 14 is connected to the anchor housing 15 through a limit pin 16, its upper end is connected to the coupling shaft 11, and its lower end abuts against the upper end of the double - acting anchor 18;

[0084] The double - acting anchor 18 is fixed within the anchor housing by a spring 19, and an anchor window for the radial protrusion of the double - acting anchor 18 is provided on the anchor housing. The lower end of the double - acting anchor 18 abuts against the upper end of the lower support cone 20, and the abutting surfaces of the double - acting anchor 18 with the upper support cone 14 and the lower support cone 20 are conical surfaces;

[0085] The lower end of the lower support cone 20 is connected to a connection sleeve, and forms an annular space with the connection sleeve, the upper central tube 3, and the lower central tube. A grease injection hole and a limit groove 33 are provided on the lower support cone 20.

[0086] Specifically, the upper end face of the upper support cone 14 contacts the coupling shaft 11, and the lower end face is conical with a limit groove 17 thereon; the two-way anchor shell 15 is provided with a pin hole, and the limit pin 16 is stuck in the limit groove 17 through the pin hole on the anchor shell 15, so that the anchor shell 15 and the upper support cone 14 can move relatively up and down within the range restricted by the limit groove 17; the upper end of the two-way anchor 18 is suspended on the upper support cone 14, and the lower end is fixedly connected to the shell sleeve 21 by threads. Both the upper and lower end faces of the two-way anchor 18 are conical surfaces, which are respectively in contact with the lower end face of the upper support cone 14 and the upper end face of the lower support cone 20, and are restricted within the two-way anchor shell 15 under the action of the spring 19; the upper end face of the lower support cone 20 is conical in shape and is suspended on the shell sleeve 21. A sealing ring is provided between the inner side of the upper end of the lower support cone 20 and the outer side of the upper center tube 3, and the outer side of the lower end is fixedly connected to the inner side of the connecting sleeve 35 by threads and is provided with a sealing ring for sealing.

[0087] Optionally, referring to Figure 1 As shown, the two-way anchor provided by the embodiment of the present invention further includes: an upper joint 1, a lifting sleeve 2, and a lower joint 39;

[0088] The upper joint 1 is hermetically connected to the upper end of the upper center tube 3, and the lifting sleeve 2 is sleeved on the upper joint 1 and the lower end is connected to the piston seat 5;

[0089] The lower joint 39 is sleeved on the lower center tube 23, and its upper end is hermetically connected to the connecting sleeve;

[0090] An anti-jamming lock ring is provided on the inner wall of the lower joint. Correspondingly, anti-jamming lock teeth 12 adapted to the anti-jamming lock ring are provided on the outer wall of the lower center tube 23 to limit the upward movement of the lower joint relative to the lower center tube through the cooperation of the anti-jamming tooth ring and the anti-jamming lock teeth 12. Specifically, the anti-top lock ring 37 can be provided in the inclined groove on the inner side of the upper end of the lower center tube 23 and the outer side of the upper end of the lower joint 39, and the upper end of the lower joint 39 is fixedly connected to the lower end of the connecting sleeve 35 by threads for sealing. The lower end is used to connect downhole tools such as oil pipes or packers. When the upper center tube 3 drives the lower center tube 23 to move upward first during the lifting and unlocking of the measure string, the anti-top lock teeth 38 on the lower center tube 23 move upward to contact and lock with the anti-top lock ring 37, preventing the lower joint 39, the connecting sleeve 35, the lower support cone 20, and the two-way anchor 18 from being jacked up under the inertia of the measure string movement during the process of replacing the lifting clamp of the measure string, resulting in the two-way anchor 18 expanding outward from the two-way anchor shell 15 under the extrusion force of the lower end face of the upper support cone 14 and the upper end face of the lower support cone 20 and getting stuck on the inner wall of the casing, causing the measure string to get stuck during lowering and affecting the operation efficiency of replacing the lifting clamp and removing a single joint.

[0091] When the bi-directional anchor provided by the embodiment of the present invention is applied, the bi-directional anchor configured for the string of measures such as separate layer water injection is arranged above downhole tools such as packers. The following provides an exemplary description of the detailed process of the bi-directional anchor from being run in to being anchored and released as follows:

[0092] During the process of running in the string of measures, the upper end of the upper sub 1 is connected to the tubing, and the lower end of the lower sub 39 is connected to the string with downhole tools such as packers. Since the upper sub 1 is threadedly and fixedly connected to the upper central tube 3, and the lifting sleeve 2 is suspended on the upper sub 1, the lifting sleeve 2 and the outer cylinder 9 are respectively threadedly and fixedly connected to the piston seat 5, the setting anchor shear pin 7 fixes the piston seat 5 and the piston 6, the piston 6 prevents the locking block 8 from disengaging from the semi-circular slot of the upper central tube 3, the locking block 8 is stuck in the semi-circular slot of the upper central tube 3 and the locking block sleeve 10, so that the locking block sleeve 10 is fixed on the upper central tube 3, and the locking block sleeve 10, the coupling shaft 11, and the upper support cone 14 are sequentially threadedly and fixedly connected, so the positions of the lifting sleeve 2, the outer cylinder 9, the piston seat 5, the piston 6, the locking block sleeve 10, the coupling shaft 11, and the upper support cone 14 are all kept fixed. The bi-directional anchor tile housing 15 is suspended on the upper support cone 14, the bi-directional anchor tile housing 15 is threadedly and fixedly connected to the housing sleeve 21, the lower support cone 20 is suspended on the housing sleeve 21, and the positions of the upper support cone 14 and the lower support cone 20 are kept relatively fixed, so that the upper and lower end cones of the bi-directional anchor tile 18 are not supported by the upper support cone 14 and the lower support cone 20, and the spring 19 restricts the bi-directional anchor tile 18 in the bi-directional anchor tile housing 15 to ensure the safe running in of the string of measures; also because the lower support cone 20, the connecting sleeve 35, and the lower sub 39 are sequentially threadedly and fixedly connected, the load of the string with downhole tools such as packers acts on the upper central tube 3 through the lower sub 39, the connecting sleeve 35, the lower support cone 20, the housing sleeve 21, the bi-directional anchor tile housing 15, the upper support cone 14, the coupling shaft 11, the locking block sleeve 10, and the locking block 8, rather than directly acting on the upper central tube 3 through the lower sub 39, the connecting sleeve 35, the lower support cone 20, the connecting sleeve 28, and the releasing anchor shear pin 27, protecting the releasing anchor shear pin 27 from being stressed and preventing the releasing anchor shear pin 27 from being fatigued and fractured or having the shear strength reduced due to repeated alternating loads or being easily released during operation and resulting in the failure of the string anchoring.

[0093] Meanwhile, since the locking block 8 is stuck in the semi-circular slot of the upper central tube 3 and the locking block sleeve 10, the locking block sleeve 10 is fixed on the upper central tube 3, preventing relative rotational movement between the upper central tube 3 and the locking block sleeve 10, thereby preventing the upper central tube 3 from driving the lower central tube 23 to rotate relative to the limit sleeve 30, and preventing the phenomenon that the limit boss 34 moves and disengages from the contact with the elastic boss 32, resulting in the elastic boss 32 radially contracting and disengaging from the limit groove 33 during operation and causing the failure of the anchoring.

[0094] After the measure string is lowered to the designed position, the pressure is gradually increased from the tubing. The hydraulic pressure enters through the liquid inlet holes 4 on the upper central pipe 3 and the flow-through hole channels corresponding to the liquid inlet holes 4 on the piston seat 5, and acts on the piston 6 and the lock block sleeve 10. When the hydraulic pressure increases to a certain value, the setting anchor shear pin 7 is cut off, and the piston 6 is pushed to move downward, so that the groove inside the piston 6 moves to the outside of the lock block 8. At the same time, the lock block sleeve 10 pushes the lock block 8 to move downward under the action of the hydraulic pressure. The reaction force of the inner inclined surface of the lock block 8 pushes the lock block 8 to move radially outward, disengages from the semi-circular clamping groove of the upper central pipe 3 and falls into the groove inside the piston 6, so that the lock block sleeve 10 is released from the fixation with the upper central pipe 3. At this time, the load of the string with downhole tools such as packers acts directly on the upper central pipe 3 through the lower joint 39, the connecting sleeve 35, the lower support cone 20, the connecting sleeve 28, and the releasing anchor shear pin 27; the piston 6 and the lock block sleeve 10 move downward together under the action of the hydraulic pressure, pushing the coupling shaft 11 and the upper support cone 14 to move downward, so that the locking teeth 12 on the coupling shaft 11 move to contact and lock with the locking rings on the locking ring sleeve 13; at the same time, the upper support cone 14 pushes the bi-directional anchor housing 15 and the bi-directional anchor 18 to move downward through the limit pin 16. The lower support cone 20 cannot move downward because it is fixed by the elastic boss 32 on the connecting sleeve 28 fixed to the upper central pipe 3 through the releasing anchor shear pin 27. Therefore, the bi-directional anchor 18 expands outward from the bi-directional anchor housing 15 under the extrusion action of the lower end surface of the upper support cone 14 and the upper end surface of the lower support cone 20, and is stuck on the inner wall of the casing to realize the anchoring of the measure string; after the locking teeth 12 on the coupling shaft 11 are locked with the locking rings on the locking ring sleeve 13, the coupling shaft 11 can only move downward under the push of the piston 6 and the lock block sleeve 10, and cannot move upward after the hydraulic pressure disappears, preventing the upper support cone 14 and the bi-directional anchor housing 15 from moving upward, resulting in the weakening or disappearance of the extrusion action of the lower end surface of the upper support cone 14 and the upper end surface of the lower support cone 20 on the bi-directional anchor 18, and causing the anchoring failure of the measure string.

[0095] During the production with measures such as separate layer water injection, the measure string is subjected to the internal and external pressure differences and the pressure differences above and below the lower packer tool. Since the two-way anchor anchors the measure string on the inner wall of the casing and restricts the creep of the measure string, the measure string is stressed due to bulging effect, piston effect, etc. under the internal and external, upper and lower pressure differences. When the internal pressure is greater than the external pressure, a bulging effect that shortens the string is generated, causing an upward tensile force on the measure string. This upward tensile force acts on the upper central tube 3 through the measure string and the upper joint 1, and then is transmitted to the two-way anchor shoe 18 and the inner wall of the casing through the anchor release shear pin 27, the connecting sleeve 28, the elastic boss 32, and the lower support cone 20; when the internal pressure is less than the external pressure, a reverse bulging effect that elongates the string is generated, causing a downward pressure on the measure string. This downward pressure acts on the piston seat 5 through the measure string and the upper joint 1, and then is transmitted to the two-way anchor shoe 18 and the inner wall of the casing through the outer cylinder 9, the lock ring sleeve 13, the coupling shaft 11, and the upper support cone 14; when the downward pressure of the lower packer tool is greater than the upward pressure, the measure string is subjected to an upward thrust due to the piston effect. This upward thrust acts on the lower joint 39 through the measure string, and then is transmitted to the two-way anchor shoe 18 and the inner wall of the casing through the connecting sleeve 35 and the lower support cone 20; when the downward pressure of the lower packer tool is less than the upward pressure, the measure string is subjected to a downward tensile force due to the piston effect. This downward tensile force acts on the lower joint 39 through the measure string, and then is transmitted to the two-way anchor shoe 18 and the inner wall of the casing through the connecting sleeve 35, the lower support cone 20, the elastic boss 32, the connecting sleeve 28, the anchor release shear pin 27, the upper central tube 3, the upper joint 1, the piston seat 5, the outer cylinder 9, the lock ring sleeve 13, the coupling shaft 11, and the upper support cone 14; when the internal pressure is greater than the external pressure or the downward pressure of the lower packer tool is less than the upward pressure, that is, during operations such as high-pressure water injection, the stress of the measure string is transmitted to the two-way anchor shoe 18 and the inner wall of the casing through the anchor release shear pin 27, preventing the creep failure of the measure string.

[0096] In measures such as high-pressure water injection, under the action of large internal and external, upper and lower pressure differences, the measure string is subjected to large stress due to expansion effect, piston effect, etc. To prevent the problem that the measure string is stressed greatly and the anchor release shear pin 27 is sheared, resulting in the failure of the measure string anchoring, the anti-shear force value of the anchor release shear pin 27 can be increased.

[0097] When pulling up the measure string during workover operations, the pulling force is transmitted to the two-way anchor shoe 18 and the inner wall of the casing through the upper joint 1, the upper central tube 3, the anchor release shear pin 27, the connecting sleeve 28, the elastic boss 32, and the lower support cone 20. Since the two-way anchor shoe 18 is anchored on the inner wall of the casing and does not move, a suitable anchor release method needs to be selected when moving the pipe string during workover operations, so that the upper central tube 3 is disengaged from the indirect fixation with the lower support cone 20 through the connecting sleeve 28, and pulling up the measure string can drive the upper joint 1 and the upper central tube 3 to move upward to further release the anchoring of the measure string.

[0098] When releasing the anchoring of the measure string, there are the following three anchor release methods:

[0099] Method 1: Lift the measure string, increase the lifting force, cut off the anchor release shear pin 27, so that the upper central tube 3 is disengaged from the fixing of the connecting sleeve 28, and further disengaged from the indirect fixing with the lower support cone 20. The upper joint 1 and the upper central tube 3 move up with the lifting measure string.

[0100] Method 2: Drop a metal ball into the measure string. The metal ball falls from the upper central tube 3 onto the anchor release ball seat 22 to form a seal, so that the upper central tube 3 is not connected to the lower central tube 23. Pressurize the measure string. The hydraulic pressure acts on the metal ball and the anchor release ball seat 22, cuts off the control shear pin 24 and pushes the lower central tube 23 downward. The lower central tube 23 drives the limit sleeve 30 to move downward, so that the limit boss 34 moves downward and disengages from the contact with the elastic boss 32. Lift the measure string. After the elastic boss 32 loses the restriction of the limit boss 34, it radially contracts under the lifting force and disengages from the limit groove 33, so that the connecting sleeve 28 is disengaged from the fixing with the lower support cone 20, and further the upper central tube 3 is disengaged from the indirect fixing with the lower support cone 20. The upper joint 1 and the upper central tube 3 move up with the lifting measure string.

[0101] Method 3: Rotate the measure string clockwise, driving the upper joint 1, the upper central tube 3 and the lower central tube 23 to rotate clockwise together. Since the reverse external thread 29 on the lower central tube 23 cooperates with the reverse internal thread 31 on the limit sleeve 30 and the keyway 36 on the connecting sleeve 35 catches the key strip on the outer side of the lower end of the limit boss 34, preventing the limit boss 34 and the limit sleeve 30 from rotating. The clockwise rotation movement of the lower central tube 23 generates a downward force to push the reverse internal thread 31 by the reverse external thread 29, pushing the limit sleeve 30 downward, so that the limit boss 34 moves downward and disengages from the contact with the elastic boss 32. Lift the measure string. After the elastic boss 32 loses the restriction of the limit boss 34, it radially contracts under the lifting force and disengages from the limit groove 33, so that the connecting sleeve 28 is disengaged from the fixing with the lower support cone 20, and further the upper central tube 3 is disengaged from the indirect fixing with the lower support cone 20. The upper joint 1 and the upper central tube 3 move up with the lifting measure string.

[0102] After the upper lifting measure string drives the upper sub 1 and the upper central tube 3 to move upward, the upper sub 1 further drives the lifting sleeve 2, the fixed piston seat 5, the outer cylinder 9, the lock block sleeve 10, the coupling shaft 11 and the upper support cone 14 to move upward, so that the lower conical surface of the upper support cone 14 disengages from the bi-directional anchor shoe 18; the upper support cone 14 drives the bi-directional anchor shoe housing 15 to move upward, and the bi-directional anchor shoe housing 15 drives the bi-directional anchor shoe 18 and the housing sleeve 21 to move upward. Since the lower sub 39, the connecting sleeve 35 and the lower support cone 20 are sequentially threadedly fixed and connected, before the upper end of the housing sleeve 21 moves upward to contact the lower support cone 20, the lower support cone 20 remains stationary, and the upward movement of the bi-directional anchor shoe 18 will disengage from the upper conical surface of the lower support cone 20; after the upper and lower conical surfaces of the bi-directional anchor shoe 18 are disengaged from the lower conical surface of the upper support cone 14 and the upper conical surface of the lower support cone 20 respectively, and lose the supporting force of the upper support cone 14 and the lower support cone 20, it radially contracts into the bi-directional anchor shoe housing 15 under the push of the spring 19 and the bi-directional anchor shoe housing 15, disengages from the inner wall of the casing, and releases the anchoring of the measure string. Continuing to lift the measure string, the housing sleeve 21 hooks the lower support cone 20, pulls the lower support cone 20, the connecting sleeve 35, the lower sub 39 and some other strings to move upward, and the upper central tube 3 or the connecting sleeve 35 also drives the limit sleeve 30 and the lower central tube 23 to move upward, and finally the entire measure string is taken out.

[0103] The bi-directional anchor provided by the embodiment of the present invention is provided with an anchor release shear pin mechanism, a rotary anchor release mechanism and a ball dropping and pressure applying anchor release mechanism, and can be released by any one of the three methods of directly lifting the string, rotating the string with a small torque, and dropping the ball and applying pressure. When one anchor release method fails to be attempted, it does not affect the implementation of other anchor release methods, realizing the safe release of the measure string when the anchoring tool is set with a large anchoring force, ensuring the safety of the measure string anchoring and the reliability of the anchor release, and solving the problems that in measures such as high-pressure water injection, the measure string fails to be anchored due to the small anti-shearing force value design of the anchor release shear pin of the anchoring tool and insufficient anchoring force, or the pipe string is released from the anchor due to the internal and external pressure balance, resulting in the creep failure of the pipe string, and the large anti-shearing force value design of the anchor release shear pin of the anchoring tool makes the upward pull for anchor release too large, resulting in difficult anchor release, pipe string sticking or fracture; at the same time, the key moving parts for anchor release are concentrated in a closed space, and a liquid with anti-corrosion and lubrication functions can be injected for protection, isolating contact with the injected water and formation water with high salinity, avoiding the occurrence of anchor release failure and stuck well accidents caused by the inability of the key moving parts for anchor release to move due to corrosion and scaling in corrosion and scaling wells, being applicable to separate injection and other measures in various complex well conditions including deep inclined wells and corrosion and scaling wells, reducing the probability of stuck well accidents, improving the safety and reliability of the measure string, and reducing the construction operation cost.

[0104] Based on the same inventive concept, an embodiment of the present invention further provides a method for using the above-mentioned bi-directional anchor, including: pressurizing the inside of the central pipe, and the hydraulic pressure acts on the anchor setting and locking mechanism, causing the anchor setting and locking mechanism to move downward, and pushing the anchoring mechanism to expand radially to anchor with the external casing;

[0105] Lifting or rotating the upper central pipe to enable the anchor releasing mechanism to release the limit on the upper central pipe. After the anchor releasing mechanism releases the limit on the upper central pipe, lifting the upper central pipe drives the anchor setting and locking mechanism to move upward, so that the anchoring mechanism is released from the casing.

[0106] In an optional embodiment, the method for using the bi-directional anchor provided by the embodiment of the present invention further includes:

[0107] Throwing a ball to build up pressure inside the upper central pipe, so that the anchor releasing mechanism releases the limit on the upper central pipe.

[0108] Regarding the method for using the bi-directional anchor in the above embodiment, the specific manner has been described in detail in the embodiment related to the bi-directional anchor, and will not be elaborated here.

[0109] 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 can be rearranged without departing from the protection scope of the present disclosure. The appended method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy recited.

[0110] In the above detailed description, various features are combined in a single embodiment to simplify the present disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, the present invention lies in a state less than all the features of the single disclosed embodiment. Therefore, the appended claims are hereby expressly incorporated into the detailed description, where each claim stands alone as a separate preferred embodiment of the present invention.

[0111] The foregoing description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but those of ordinary skill in the art should recognize that the various embodiments can be further combined and arranged. Accordingly, the embodiments described herein are intended to embrace all such changes, modifications, and variations that fall within the scope of the appended claims. Further, with respect to the term "comprising" used in the specification or claims, the manner in which this term is encompassed is similar to the term "including" as interpreted when "including," is used as a transitional word in a claim. Further, any use of the term "or" in a claim of the specification is to mean "non-exclusive or."

Claims

1. A two-way anchor, characterized in that, Comprising: an upper central tube, an anchor setting and locking mechanism sleeved on the upper central tube, an anchoring mechanism, and an anchor releasing mechanism connected to the upper central tube; the anchor setting and locking mechanism is used to move downward under hydraulic action and push the anchoring mechanism to expand radially to anchor with an external casing; the anchor releasing mechanism is used to cut the anchor releasing shear pins connecting the upper central tube and the anchoring mechanism to release the limit of the upper central tube by the anchoring mechanism when the upper central tube is in the state of being lifted; or to push the limit sleeve of the anchor releasing mechanism to move downward when the upper central tube is in the state of being rotated to release the limit between the anchoring mechanism and the anchor releasing mechanism, and further release the limit of the upper central tube; after the upper central tube is released from the limit, the upper central tube is lifted to drive the anchor setting and locking mechanism to move upward, and further drive the anchoring mechanism to release the anchor with the casing.

2. The two-way anchor according to claim 1, characterized in that, the anchor releasing mechanism includes: a lower central tube, a connecting sleeve, a limit sleeve, and a connecting sleeve tube; the lower central tube is connected to the lower end of the upper central tube, the limit sleeve is sleeved on the lower central tube and is threadedly connected to the lower central tube, and the limit sleeve is circumferentially limited by the connecting sleeve tube so as to push the limit sleeve to move downward when the upper central tube is in the state of being rotated; the upper end of the connecting sleeve is connected to the lower end of the upper central tube by an anchor releasing shear pin, an elastic boss is arranged at the lower end of the connecting sleeve, and the elastic boss is limited by the limit sleeve and a limit groove of the anchoring mechanism and can be released from the limit after moving a preset distance relative to the limit sleeve.

3. The two-way anchor according to claim 2, characterized in that, the anchor releasing mechanism is also used to cut the control shear pins connecting the upper central tube and the anchoring mechanism when the upper central tube is in the state of having a ball injected into the tube to build up pressure, so as to release the limit of the upper central tube by the anchoring mechanism.

4. The two-way anchor according to claim 3, characterized in that, a release ball seat is arranged at one end of the lower central tube close to the upper central tube, and the upper central tube and the lower central tube are connected by control shear pins.

5. The two-way anchor according to claim 2, characterized in that, a limit boss is arranged at the lower end of the limit sleeve, and the elastic boss is limited by the limit boss and the limit groove; a radially protruding key strip is arranged on the outer wall of the limit boss, and correspondingly, a key groove is formed on the inner wall of the connecting sleeve tube to circumferentially limit the limit sleeve through the cooperation of the key strip and the key groove.

6. The two-way anchor according to claim 2, characterized in that, an annular space is formed among the anchoring mechanism, the upper central tube, the lower central tube and the connecting sleeve tube, and the connecting sleeve and the limit sleeve are arranged in the annular space; and sealing elements are arranged between the connecting sleeve tube and the lower central tube and the anchoring mechanism, and between the upper central tube and the anchoring mechanism and the lower central tube; a grease injection hole is arranged on the anchoring mechanism, and the grease injection hole is sealed by a one-way sealing ring to inject a protective liquid into the annular space through the grease injection hole.

7. The two-way anchor according to claim 6, characterized in that, the anchor setting and locking mechanism includes: an outer cylinder, a piston, a piston seat, a lock block sleeve, and a coupling shaft which are arranged in the outer cylinder and are sequentially sleeved on the upper central tube, and the lock block sleeve is connected to the upper central tube by a lock block; a flow-through hole communicating with a liquid inlet hole on the upper central tube is arranged on the piston seat, and the coupling shaft is connected to the anchoring mechanism; The piston is arranged in the annular space formed among the piston seat, the outer cylinder and the lock block sleeve, and is connected with the piston seat through the setting anchor shear pin.

8. The two-way anchor according to claim 7, characterized in that, A lock ring sleeve connected with the outer cylinder through thread is further arranged at the lower end of the outer cylinder, and a lock ring is arranged on the lock ring sleeve; Correspondingly, lock teeth are arranged on the outer wall of the lower end of the connecting shaft to limit the upward movement of the connecting shaft through the cooperation of the lock teeth and the lock ring.

9. The two-way anchor according to claim 7, characterized in that, The anchoring mechanism comprises: an anchor tile housing, an upper support cone body, a two-way anchor tile and a lower support cone body which are sequentially arranged in the anchor tile housing; The upper support cone body is connected with the anchor tile housing through a limit pin, the upper end of the upper support cone body is connected with the connecting shaft, and the lower end of the upper support cone body abuts against the upper end of the two-way anchor tile; The two-way anchor tile is fixed in the anchor tile housing through a spring, an anchor window for the two-way anchor tile to radially extend out is arranged on the anchor tile housing, the lower end of the two-way anchor tile abuts against the upper end of the lower support cone body, and the abutting surfaces of the two-way anchor tile with the upper support cone body and the lower support cone body are conical surfaces; The lower end of the lower support cone body is connected with the connecting sleeve, and forms the annular space with the connecting sleeve, the upper central pipe and the lower central pipe, and the grease injection hole and the limit groove are arranged on the lower support cone body.

10. The two-way anchor according to claim 8, characterized in that, It further comprises: an upper sub, a lifting sleeve and a lower sub; The upper sub is hermetically connected with the upper end of the upper central pipe, the lifting sleeve is sleeved on the upper sub and the lower end of the lifting sleeve is connected with the piston seat; The lower sub is sleeved on the lower central pipe, and the upper end of the lower sub is hermetically connected with the connecting sleeve; An anti-sticking lock ring is arranged on the inner wall of the lower sub, and correspondingly, anti-sticking lock teeth matched with the anti-sticking lock ring are arranged on the outer wall of the lower central pipe to limit the upward movement of the lower sub relative to the lower central pipe through the cooperation of the anti-sticking lock ring and the anti-sticking lock teeth.

11. A method for using the two-way anchor according to any one of claims 1-10, characterized in that, It comprises: Controlling the pressurization inside the central pipe, the hydraulic pressure acts on the setting anchor locking mechanism to enable the setting anchor locking mechanism to move downward, and pushes the anchoring mechanism to expand radially to anchor with the external casing; Lifting or rotating the upper central pipe to enable the releasing mechanism to release the limit on the upper central pipe. After the releasing mechanism releases the limit on the upper central pipe, lifting the upper central pipe drives the setting anchor locking mechanism to move upward so that the anchoring mechanism releases the anchor with the casing.

12. The usage method according to claim 11, characterized in that, It further comprises: Throwing a ball to cause the pressure buildup inside the upper central pipe, so that the releasing mechanism releases the limit on the upper central pipe.

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