Sliding sleeve switch claw structure for half-way well cementation of oil and gas well and unlocking method

Abstract

The invention discloses a sliding sleeve opening and closing claw structure for oil and gas well half-way well cementation and an unlocking method, and belongs to the technical field of oil and gas exploitation, the sliding sleeve opening and closing claw structure comprises a casing string, a sliding sleeve, a slip assembly and an opening and closing claw assembly, an external groove is formed in the inner wall end of the casing string, the sliding sleeve is arranged in the external groove in a sliding mode, and the slip assembly comprises a front slip, a rear slip and a vacant groove; the front slip and the rear slip are coaxially arranged and fixedly connected, a vacant groove is formed between the front slip and the rear slip, and the switch claw assembly is movably arranged in the vacant groove and used for adjusting the position of the sliding sleeve in an external groove. The opening and closing states of the sliding sleeve in the casing string can be synchronously controlled, and when the sliding sleeve is clamped in the casing string, the built-in linkage structure can be used for automatic unlocking, so that the sliding sleeve assembly is prevented from being permanently clamped in the casing string.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil and gas extraction, and in particular relates to a sliding sleeve switch claw structure and an unlocking method for mid-stroke cementing of an oil and gas well. Background Art

[0002] The sliding sleeve used for mid-length cementing of oil and gas wells is usually called a cementing sleeve or a staged collar. It is a key tool for achieving staged cementing in cementing operations. It is especially important in the mid-length cementing scenario. It allows cementing operations to be carried out in stages, reducing the difficulty and risk of completing cementing of a long well section in one go.

[0003] When the wellbore is too long or the formation has low pressure bearing capacity, injecting all the cement slurry at one time may cause excessive annular pressure, fracturing weak formations and leading to leakage. It is difficult to advance the cement slurry in the long horizontal section, the displacement efficiency is low and the cementing quality is affected. After the cement slurry loses weight, the static column pressure on the oil and gas layer decreases, which may cause oil and gas to surge upward.

[0004] The casing string with cementing sleeve is lowered to the designed well depth. The position of the sleeve is usually designed to be at a position that requires half-length isolation. After the casing is lowered, the drilling fluid is circulated through the open state of the sleeve to adjust the mud performance. Common sleeve types include ball-dropping and pressure-holding type, hydraulic type and RFID wireless remote control type. Among them, the ball-dropping and pressure-holding type is the most common. The sleeve is driven to close and open the circulation hole by dropping the ball and holding the pressure to cut the pin. However, when the sleeve is stuck, dropping the ball is not only difficult to reset, but also easily leads to the scrapping of the casing string. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the embodiment of the present invention aims to provide a sliding sleeve switch claw structure and unlocking method for mid-stroke cementing of oil and gas wells, so as to solve the problems in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A sliding sleeve switch claw structure and unlocking method for mid-stroke cementing of oil and gas wells, comprising a casing string assembly, the casing string assembly comprising a casing string, an external groove and an external hole, the inner wall end of the casing string being provided with an external groove, and one end of the external groove being provided with a plurality of external holes;

[0008] A sliding sleeve assembly, the sliding sleeve assembly comprising a sliding sleeve and built-in holes, the sliding sleeve being slidably disposed in the external groove, and a plurality of built-in holes being arranged at one end of the sliding sleeve;

[0009] A slip assembly, comprising a front slip, a rear slip, a stop sleeve, an empty slot and a rear stop cylinder, wherein the front slip and the rear slip are coaxially arranged and fixedly connected, an empty slot is provided between the outer diameter ends of the front slip and the rear slip, a stop sleeve is fixedly assembled at one end of the empty slot, and a rear stop cylinder is provided at the other end of the empty slot;

[0010] A switch claw assembly is movably arranged in the vacant slot and is used to adjust the position of the sliding sleeve in the external slot.

[0011] As a further solution of the present invention, opposite first cylindrical step grooves and second cylindrical step grooves are provided at both ends of the external groove.

[0012] As a further solution of the present invention, opposite sliding sleeve first step grooves and sliding sleeve second step grooves are provided at both ends of the sliding sleeve.

[0013] As a further solution of the present invention, the switch claw assembly includes a switch claw body, a central claw, a front claw, a rear claw and an elastic member. The switch claw body is movably arranged in the empty slot, a central claw is provided in the middle of the switch claw body, and a front claw and a rear claw are respectively provided at both ends of the switch claw body. The front claw and the rear claw are respectively movably abutted against the stop sleeve and the rear stop cylinder, and an elastic member is also assembled between the switch claw body and the empty slot.

[0014] As a further solution of the present invention, the switch claw assembly also includes a latch member, a linkage member, a linkage rod and a trigger plate. The latch member is slidably arranged in the middle claw and is arranged toward one end of the front claw. One end of the linkage member is fixedly connected to the latch member, and the other end of the linkage member is fixedly connected to the linkage rod. The end of the linkage rod is fixedly connected to the trigger plate.

[0015] As a further solution of the present invention, the switch claw assembly also includes a blocking piece, a first linkage arm and a second linkage arm. The blocking piece is elastically inserted in the vacant slot and movably abuts against one end of the rear clamping claw to limit the radial sliding of the switch claw body. One end of the first linkage arm is rotatably assembled on the blocking piece, and the other end of the first linkage arm is rotatably assembled with the second linkage arm. The end of the second linkage arm is rotatably arranged on the trigger plate.

[0016] As a further solution of the present invention, two ends of the central clamping claw are provided with a first surface and a second surface opposite to each other.

[0017] In summary, the embodiments of the present invention have the following beneficial effects compared with the prior art:

[0018] The present invention can synchronously control the opening and closing state of the sliding sleeve in the casing string by controlling the sliding direction of the front slips and the rear slips in the sliding sleeve, and can automatically unlock the sliding sleeve by utilizing the built-in linkage structure when the sliding sleeve is stuck in the casing string to prevent the device from being completely stuck. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a partial cross-sectional view of a sliding sleeve switch claw structure for mid-stroke cementing of oil and gas wells provided in one embodiment of the present invention.

[0020] Figure 2 The present invention is a schematic structural diagram of a casing string assembly in a sliding sleeve switch claw structure for mid-stroke cementing of oil and gas wells provided in one embodiment of the present invention.

[0021] Figure 3 The figure is a schematic diagram of the assembly of a sleeve assembly and a slip assembly in a sleeve switch claw structure for mid-stroke cementing of oil and gas wells provided in one embodiment of the present invention.

[0022] Figure 4 The present invention is a schematic structural diagram of a sleeve assembly in a sleeve switch claw structure for mid-stroke cementing of oil and gas wells provided in one embodiment of the present invention.

[0023] Figure 5 The present invention is a schematic structural diagram of a slip assembly in a sleeve switch claw structure for mid-stroke cementing of oil and gas wells provided in one embodiment of the present invention.

[0024] Figure 6 for Figure 5 An enlarged schematic diagram of the figure marked A.

[0025] Figure 7 for Figure 5 An enlarged schematic diagram of the figure marked B.

[0026] Figure 8 for Figure 5 An enlarged schematic diagram of the figure marked C.

[0027] Figure markings: 1-casing string assembly, 101-casing string, 102-external groove, 103-external hole, 2-sleeve assembly, 201-sleeve, 202-internal hole, 3-slip assembly, 301-front slip, 302-rear slip, 303-stop sleeve, 304-empty groove, 305-rear stop cylinder, 4-switch claw assembly, 401-switch claw body, 402-middle clamping claw, 403-front clamping claw, 404-rear clamping claw, 405-elastic member, 406-latch member, 407-linkage member, 408-linkage rod, 409-trigger plate, 410-blocking member, 411-first linkage arm, 412-second linkage arm. DETAILED DESCRIPTION

[0028] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] See also Figures 1-8, a sliding sleeve switch claw structure and unlocking method for half-way cementing of oil and gas wells in an embodiment of the present invention, the sliding sleeve switch claw structure for half-way cementing of oil and gas wells has a relative first direction x, a second direction y and a third direction z, the sliding sleeve switch claw structure for half-way cementing of oil and gas wells includes a casing string assembly 1, the casing string assembly 1 includes a casing string 101, an external groove 102 and an external hole 103, the inner wall end of the casing string 101 is provided with an external groove 102, and one end of the external groove 102 is provided with a plurality of external holes 103; a sliding sleeve assembly 2, the sliding sleeve assembly 2 includes a sliding sleeve 201 and an internal hole 202, the sliding sleeve 201 is slidably provided in the external groove 102, and one end of the sliding sleeve 201 is provided with a plurality of internal holes 202; a slip assembly 3, the slip assembly 3 includes a front The front slip 301, the rear slip 302, the stop sleeve 303, the vacant slot 304 and the rear stop cylinder 305, the front slip 301 and the rear slip 302 are coaxially arranged and fixedly connected, an vacant slot 304 is provided between the outer diameter ends of the front slip 301 and the rear slip 302, one end of the vacant slot 304 is fixedly assembled with the stop sleeve 303, and the other end of the vacant slot 304 is provided with the rear stop cylinder 305; the switch claw assembly 4, the switch claw assembly 4 is movably arranged in the vacant slot 304, and is used to adjust the position of the sliding sleeve 201 in the external slot 102; the two ends of the external slot 102 are provided with a relative first step groove a1 of the cylinder and a second step groove a2 of the cylinder; the two ends of the sliding sleeve 201 are provided with a relative first step groove b1 of the sliding sleeve and a second step groove b2 of the sliding sleeve.

[0030] In actual application of this embodiment, the sliding sleeve switch claw structure for half-way cementing of oil and gas wells is arranged along the first direction x, and the sliding sleeve 201 is slidably assembled in the external groove 102 along the first direction x. When the internal hole 202 on the side of the sliding sleeve 201 is aligned with the external hole 103 on the side of the casing string 101, the outer cavity of the casing string 101 and the inner cavity of the sliding sleeve 201 are in a conductive state, so that the sliding sleeve 201 has a relative conductive position and a locked position in the first direction x, and the front slip 301 and the rear slip 302 slide along the first direction x. It is assembled on the inner cavity side of the sliding sleeve 201, and an empty groove 304 is arranged between the front slip 301 and the rear slip 302. The switch claw assembly 4 is movably arranged in the empty groove 304, so that when the slip assembly 3 moves in the positive and negative directions of the first direction x, the switch claw assembly 4 can be movably connected with the sliding sleeve 201, thereby driving the sliding sleeve 201 to move synchronously in the positive and negative directions of the first direction x, and then controlling the opening and closing of the sliding sleeve 201. The device can automatically adjust the opening and closing states of several sliding sleeve assemblies 2 by using the movement of the slip assembly 3.

[0031] See also Figure 6In a preferred embodiment of the present invention, the switch claw assembly 4 includes a switch claw body 401, a central claw 402, a front claw 403, a rear claw 404 and an elastic member 405. The switch claw body 401 is movably arranged in the vacant slot 304. The central claw 402 is provided in the middle of the switch claw body 401. The front claw 403 and the rear claw 404 are respectively provided at both ends of the switch claw body 401. The front claw 403 and the rear claw 404 are respectively movably abutted against the stop sleeve 303 and the rear stop cylinder 305. An elastic member 405 is further installed between the switch claw body 401 and the vacant slot 304. The two ends of the central claw 402 are provided with a first surface c1 and a second surface c2 that are opposite to each other.

[0032] In actual application of this embodiment, the switch claw body 401 is arranged in the vacant slot 304 for limited sliding along the first direction x, and the front claw 403 at one end of the switch claw body 401 is movably abutted against the stop sleeve 303, and the rear claw 404 at the other end of the switch claw body 401 is movably abutted against the rear stop cylinder 305, so that the switch claw body 401 can be movably assembled in the vacant slot 304 in the third direction z.

[0033] When the sliding sleeve needs to be locked, the front slip 301 and the rear slip 302 move in the positive direction of the first direction x. At this time, the second stepped groove b2 of the sliding sleeve located on the inner wall side of the sliding sleeve 201 abuts against the second surface c2, so that the second surface c2 pushes the second stepped groove b2 of the sliding sleeve to move synchronously, thereby driving the sliding sleeve 201 as a whole to move in the first direction x, so that the internal hole 202 slides away from the external hole 103, thereby switching the sliding sleeve to a locked state. When the sliding sleeve 201 slides close to the second stepped groove a2 of the cylinder, The rear clamping claw 404 preferably abuts against the second stepped groove a2 of the cylinder. The outer diameter of the rear clamping claw 404 is larger than the inner diameter of the second stepped groove a2 of the cylinder, so that when the rear clamping claw 404 abuts against the second stepped groove a2 of the cylinder, it pushes the switch claw body 401 to slide along the third direction z, and causes the switch claw body 401 to slide and shrink into the empty groove 304, so that the second surface c2 and the second stepped groove b2 of the sliding sleeve slide out, until the slip assembly 3 and the switch claw assembly 4 slide out along the casing string 101, thus completing the locking action of the sliding sleeve.

[0034] When the sliding sleeve needs to be opened, the front slip 301 and the rear slip 302 move in the negative direction of the first direction x. At this time, the first stepped groove b1 of the sliding sleeve located on the inner wall side of the sliding sleeve 201 abuts against the first surface c1, so that the first surface c1 pushes the first stepped groove b1 of the sliding sleeve to move synchronously, thereby driving the sliding sleeve 201 as a whole to move in the negative direction of the first direction x, so that the internal hole 202 slides close to the external hole 103, thereby switching the sliding sleeve to the open state. When the sliding sleeve 201 slides close to the first stepped groove a1 of the cylinder, When the front clamping claw 403 is in contact with the first stepped groove a1 of the cylinder, the outer diameter of the front clamping claw 403 is larger than the inner diameter of the first stepped groove a1 of the cylinder, so that when the front clamping claw 403 is in contact with the first stepped groove a1 of the cylinder, the switch claw body 401 is pushed to slide along the third direction z, and the switch claw body 401 is slid and retracted into the vacant groove 304, so that the first surface c1 and the first stepped groove b1 of the sliding sleeve are slid out, until the slip assembly 3 and the switch claw assembly 4 slide out along the casing string 101, and the opening action of the sliding sleeve is completed.

[0035] See also Figure 7 In a preferred embodiment of the present invention, the switch claw assembly 4 further includes a latch member 406, a linkage member 407, a linkage rod 408 and a trigger plate 409. The latch member 406 is slidably disposed in the middle claw 402 and is disposed toward one end of the front claw 403. One end of the linkage member 407 is fixedly connected to the latch member 406, and the other end of the linkage member 407 is fixedly connected to the linkage rod 408. The end of the linkage rod 408 is fixedly connected to the trigger plate 409.

[0036] In actual application of this embodiment, the latch member 406 is elastically slidably arranged in the central claw 402, and the latch member 406 is arranged on the side of the first surface c1. When the sliding sleeve is opened, the latch member 406 on the side of the first surface c1 movably abuts against the first stepped groove b1 of the sliding sleeve, and in the normally open state, the spring on one side of the latch member 406 is in a normal state of not being fully compressed. When the sliding sleeve is stuck during the opening process, the latch member 406 is pushed by the first stepped groove b1 of the sliding sleeve in the positive direction of the first direction x, so that the linkage member 407 synchronously drives the linkage rod 408 thereon to move in the first direction x, and then drives the trigger plate 409 to move in the positive direction of the first direction x, and at this time the switch claw body 401 remains stationary relative to the vacant groove 304.

[0037] See also Figure 8In a preferred embodiment of this embodiment, the switch claw assembly 4 further includes a blocking member 410, a first linkage arm 411, and a second linkage arm 412. The blocking member 410 is elastically inserted into the vacant slot 304 and movably abuts against one end of the rear clamping claw 404 to limit the radial sliding of the switch claw body 401. One end of the first linkage arm 411 is rotatably assembled on the blocking member 410, and the other end of the first linkage arm 411 is rotatably assembled with the second linkage arm 412. The end of the second linkage arm 412 is rotatably arranged on the trigger plate 409.

[0038] In actual application of this embodiment, when the sliding sleeve is stuck during the opening process, the latch member 406 is pushed by the first stepped groove b1 of the sliding sleeve in the positive direction of the first direction x, so that the linkage member 407 synchronously drives the linkage rod 408 thereon to move in the first direction x, thereby driving the trigger plate 409 to move in the positive direction of the first direction x. Since the blocking member 410 elastically arranged in the vacant groove 304 is used to limit the sliding of the switch claw body 401 in the first direction x, the trigger plate 409 links the first linkage arm 411 and the second linkage arm 412 during the movement, so that the blocking member 410 moves toward the front slip 301 One side of the outer wall moves, thereby causing the top of the blocking member 410 to slide and disengage from the switch claw body 401. At this time, the limit of the switch claw body 401 in the positive direction of the first direction x is released, so that the switch claw body 401 moves along the positive direction of the first direction x under the pushing action, and at this time, the rear clamping claw 404 slides and abuts against the rear blocking cylinder 305, thereby causing the switch claw body 401 to slide and shrink as a whole into the vacant groove 304, thereby causing the first surface c1 of the middle clamping claw 402 to disengage from the first stepped groove b1 of the sliding sleeve, thereby causing the slip assembly 3 and the switch claw assembly 4 to disengage from the stuck sliding sleeve 201, preventing the casing string from being stuck and scrapped.

[0039] The above-mentioned embodiment of the present invention provides a sliding sleeve switch claw structure and unlocking method for mid-stroke cementing of oil and gas wells. By controlling the sliding direction of the front slip 301 and the rear slip 302 in the sliding sleeve 201, the opening and closing state of the sliding sleeve 201 in the casing string 101 can be synchronously controlled. When the sliding sleeve 201 is stuck in the casing string 101, the built-in linkage structure can be used to automatically unlock to prevent the device from being completely stuck.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A sliding sleeve switch claw structure for mid-stroke cementing of oil and gas wells, characterized in that: The sliding sleeve switch claw structure for mid-stroke cementing of oil and gas wells includes: A casing string assembly, comprising a casing string, an external groove and external holes, wherein the inner wall end of the casing string is provided with an external groove, and one end of the external groove is provided with a plurality of external holes; A sliding sleeve assembly, the sliding sleeve assembly comprising a sliding sleeve and built-in holes, the sliding sleeve being slidably disposed in the external groove, and a plurality of built-in holes being arranged at one end of the sliding sleeve; A slip assembly, comprising a front slip, a rear slip, a stop sleeve, an empty slot and a rear stop cylinder, wherein the front slip and the rear slip are coaxially arranged and fixedly connected, an empty slot is provided between the outer diameter ends of the front slip and the rear slip, a stop sleeve is fixedly assembled at one end of the empty slot, and a rear stop cylinder is provided at the other end of the empty slot; A switch claw assembly is movably arranged in the vacant slot and is used to adjust the position of the sliding sleeve in the external slot.

2. The sliding sleeve switch claw structure for mid-stroke cementing of oil and gas wells according to claim 1 is characterized in that: Two ends of the external groove are provided with a first cylindrical step groove and a second cylindrical step groove which are opposite to each other.

3. The sliding sleeve switch claw structure for mid-stroke cementing of oil and gas wells according to claim 1 is characterized in that: Two ends of the sliding sleeve are provided with a first sliding sleeve stepped groove and a second sliding sleeve stepped groove which are opposite to each other.

4. The sliding sleeve switch claw structure for mid-stroke cementing of oil and gas wells according to claim 1 is characterized in that: The switch claw assembly includes a switch claw body, a middle claw, a front claw, a rear claw and an elastic member. The switch claw body is movably arranged in the empty slot. The middle part of the switch claw body is provided with a middle claw, and the two ends of the switch claw body are respectively provided with a front claw and a rear claw. The front claw and the rear claw are respectively movably abutted against the stop sleeve and the rear stop cylinder. An elastic member is also assembled between the switch claw body and the empty slot.

5. The sliding sleeve switch claw structure for mid-stroke cementing of oil and gas wells according to claim 1 is characterized in that: The switch claw assembly also includes a latch member, a linkage member, a linkage rod and a trigger plate. The latch member is slidably arranged in the middle claw and is arranged toward one end of the front claw. One end of the linkage member is fixedly connected to the latch member, and the other end of the linkage member is fixedly connected to the linkage rod. The end of the linkage rod is fixedly connected to the trigger plate.

6. The sliding sleeve switch claw structure for mid-stroke cementing of oil and gas wells according to claim 5 is characterized in that: The switch claw assembly also includes a blocking member, a first linkage arm and a second linkage arm. The blocking member is elastically inserted into the vacant slot and movably abuts against one end of the rear-mounted clamping claw to limit the radial sliding of the switch claw body. One end of the first linkage arm is rotatably assembled on the blocking member, and the other end of the first linkage arm is rotatably assembled with the second linkage arm. The end of the second linkage arm is rotatably arranged on the trigger plate.

7. The sliding sleeve switch claw structure for mid-stroke cementing of oil and gas wells according to claim 4 is characterized in that: The two ends of the central clamping claw are provided with a first surface and a second surface which are opposite to each other.

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