Casing coupling positioner and casing coupling positioning method

Abstract

The invention provides a casing coupling positioner and a casing coupling positioning method. The casing coupling positioner comprises a main body; the clamping pieces are in a strip shape and are distributed in the axial direction of the main body, and the clamping pieces are distributed in the peripheral area of the main body at intervals; the clamping part comprises an upper clamping part, a lower clamping part and a limiting part; the elastic piece is clamped between the limiting part and the main body; the upper limiting pipe is coaxially fixed on the peripheral side of the main body and used for limiting the upper clamping part to be separated from the main body, and a gap is reserved between the upper limiting pipe and the upper clamping part; the lower limiting pipe is coaxially fixed on the peripheral side of the main body and used for limiting the lower clamping part to be separated from the main body, and a gap is reserved between the lower limiting pipe and the lower clamping part; the limiting block is fixed to the side, close to the lower limiting pipe, of the lower clamping part, and the edge of the limiting block abuts against the inner wall of the lower limiting pipe; and the flexible pad is clamped in a gap between the lower clamping part and the main body and is used for filling the gap between the lower clamping part and the main body. According to the technical scheme, the accuracy of the clamping position of the positioner and the coupling is improved.

Description

Technical Field

[0001] The invention generally relates to the field of petroleum equipment, and in particular to a casing coupling locator and a casing coupling locating method. Background Art

[0002] The casing collar locator is a tool that plays an important role in oilfield operations. It mainly detects the position of the casing collar by induction or mechanical contact. When the casing string moves in the well, the locator can accurately identify the position of the collar and transmit the signal to the operator or related equipment. For example, the inductive locator uses the principle of electromagnetic induction. When the collar passes by, it will cause a change in the magnetic field and be detected; the mechanical contact locator determines the position by directly contacting the collar and triggering the corresponding mechanical structure. In oilfield drilling, completion and workover operations, it is crucial to accurately know the position of the casing collar. It can help operators ensure that the installation depth of the casing is accurate and improve the accuracy and efficiency of the operation.

[0003] The Chinese patent with publication number CN106285643B and name of casing coupling locator and casing coupling positioning method, the casing coupling locator comprises: a main body and a predetermined number of positioning pieces; the main body is a tubular body; the predetermined number of positioning pieces are arranged on the outer surface of the main body, and are arranged in a circular array with the axis of the main body as the array axis; the positioning pieces are provided with protrusions protruding in the direction away from the axis of the main body; the pipe wall of the main body between the positioning pieces is provided with a first sand-proof hole penetrating the pipe wall, the first sand-proof hole is used to guide the sand-carrying liquid in the casing into the main body to prevent the sand in the sand-carrying liquid from getting stuck in the casing coupling locator, and also includes: a compression spring piece, each of the compression spring pieces is provided between the positioning piece and the main body, the compression spring piece is arc-shaped, the middle part of the arc abuts against the main body, the two ends of the arc abut against the positioning piece, and the chord corresponding to the arc is parallel to the axis of the main body.

[0004] When the above-mentioned casing coupling locator is used, it is installed below the ball seat of the packer and moved down to the inside of the casing. The casing coupling locator is lifted and the lifting force of the casing coupling locator is detected. The position of the coupling is determined by the change of the pulling force. However, since the structure in the figure shows that there is movable space at both ends of the positioning piece, it has two movable ends when entering the casing. The protruding position is easy to be separated from the clamping of the coupling when the positioning piece is moved, thereby affecting the judgment of the staff on the state of the coupling.

[0005] Therefore, the inventor believes that the above method has at least the following defects: the positioning piece has multiple movable ends, which may easily cause the engagement state between the protruding position of the positioning piece and the coupling position to be unstable and easily disengaged from the engagement state, causing misjudgment by the staff. Summary of the invention

[0006] According to the present invention, in view of the problems existing in the above-mentioned prior art, a casing coupling locator is provided, comprising: a main body, which is a pipe body; a clamping piece, which is strip-shaped and distributed along the axial direction of the main body, and at least three of them are provided and are distributed at intervals in the peripheral area of ​​the main body; it comprises an upper clamping part, a lower clamping part, and a limiting part connected to the middle of the lower clamping part and the upper clamping part; an elastic piece, which is clamped between the limiting part and the main body; an upper clamping tube, which is coaxially fixed on the peripheral side of the main body, is used to limit the upper clamping part from being separated from the main body, and a gap is left with the upper clamping part; a lower limiting tube, which is coaxially fixed on the peripheral side of the main body, is used to limit the lower clamping part from being separated from the main body, and a gap is left with the lower clamping part; a limiting block, which is fixed on the side of the lower clamping part facing the adjacent lower limiting tube, and the edge of the limiting block abuts against the inner wall of the lower limiting tube; and also includes a flexible pad, which is clamped in the gap between the lower clamping part and the main body, and is used to fill the gap between the lower clamping part and the main body. By having the above-mentioned technical features, the limit block provides a support point between the lower limit tube, and the flexible pad provides a support between the back of the lower clamping part and the outer wall of the main body. When the clamping part is subjected to external pressure, it will drive the clamping part to rotate around the limit block and the support point of the lower limit tube as the axis. While the flexible pad plays a role in limiting and stabilizing the support for the clamping part, it also satisfies the activity space of the lower clamping part, thereby ensuring that only the upper clamping part area of ​​the clamping part is an elastic activity area, so as to ensure the stability of the limit part and the clamp limit clamp.

[0007] In some embodiments, the elastic member is an arc-shaped compression spring sheet, and the clamping member is provided with grooves for clamping the two ends of the compression spring sheet. Thus, the compression spring sheet has a sheet-like structure as a whole, which is simple in structure and cost-controllable, and can also exert elastic force to keep the limit portion in a protruding state at all times.

[0008] In some embodiments, the compression spring sheet includes a first arc-shaped portion, one end of which is clamped in the groove; a second arc-shaped portion, one end of which is clamped in the groove; and a deformation portion connected between the first arc-shaped portion and the second arc-shaped portion. Thus, through the mutual connection between the deformation zone and the first arc-shaped portion and the second arc-shaped portion, two support points are provided between the main body and the clamping part, ensuring the stability of the force support of the clamping part, and when the clamping part is subjected to force, the deformation zone deforms, driving the ends of the first arc-shaped portion and the second arc-shaped portion to approach each other, limiting the elastic deformation area of ​​the compression spring sheet, and further ensuring that the elastic support area of ​​the clamping part is controllable.

[0009] In some embodiments, the second arc is longer than the first arc, and the deformable portion is disposed away from the lower clamping portion. Thus, the compression spring sheet and the main body support area are located in an area away from the lower clamping portion, so that the clamping member is supported by three areas at the same time, ensuring support stability and more balanced force.

[0010] In some embodiments, the outer surface of the main body is provided with a strip-shaped limiting groove along the axial direction of the main body, the number of the limiting grooves corresponds to the number of the clamping parts, the limiting grooves are evenly arranged around the circumference of the main body, and the clamping parts are installed in the limiting grooves. Therefore, the limiting grooves limit the installation position of the clamping parts, ensuring the stability of the elastic rotation state of the clamping parts.

[0011] In some embodiments, the lower limit tube is composed of a plurality of arc-shaped pieces connected at the ends, the number of the arc-shaped pieces corresponds to the number of the clamping parts, the inner arc surface of each arc-shaped piece is convexly provided with a limit rib inserted along the lower edge of the limit groove, the end of the limit rib squeezes the flexible pad, and the arc-shaped piece is fixed to the main body by a pin; when the arc-shaped piece is fixed to the peripheral side of the main body, the limit block abuts against the inner wall of the arc-shaped piece. Thus, the arc-shaped piece plays a limiting role on the lower clamping part, limiting the separation of the lower clamping part from the main body, and the mutual insertion of the limit rib and the limit groove, on the one hand, limits the axial displacement of the arc-shaped piece along the main body; on the other hand, it abuts on the flexible pad, exerts pressure on the flexible pad, thereby playing a fixing role on the flexible pad; on the third hand, it squeezes the flexible pad, thereby leaving space on the back side of the lower clamping part, which is easy to rotate the clamping part, so that the staff can adjust the fixing tightness of the pin and adjust the force of the limit rib on the flexible pad to adjust the limit tightness of the lower clamping part.

[0012] In some embodiments, a limiting protrusion is convexly provided on the outer contour surface of the limiting portion, so that the protruding limiting protrusion can be frictionally engaged with the coupling area to play a hooking role.

[0013] In some embodiments, a sliding hole for penetrating the limiting part is provided at a position corresponding to the deformation zone in the limiting part and the compression spring sheet, a sliding block is slidably connected in the sliding hole, one end of the sliding block abuts against one side of the deformation zone of the compression spring sheet, and the other end of the sliding block is flush with the end of the limiting protrusion. Thus, as the sleeve and the positioner are plugged into each other, the sliding block will be driven to move into the inside of the slide groove and exert a force on the deformation zone of the compression spring sheet, thereby increasing the overall elastic force of the compression spring sheet. When the clamping part swings elastically, its elastic force is greater, and the clamping of the limiting protrusion and the gap area of ​​the coupling is more stable.

[0014] A casing collar positioning method, the method comprising: S1: Install the casing coupling locator below the ball seat of the packer; S2: displacing the packer to move the casing collar locator into the casing butt joint port; S3: lifting the casing coupling positioner and monitoring the lifting force of the casing coupling positioner; S4: When the upward pulling force becomes larger and larger, the position of the casing coupling locator is determined to be the connecting position.

[0015] Therefore, when the casing coupling locator is lifted, the positioning piece will be increased by the lifting force due to the gap in the coupling, and the operator can determine the coupling position by detecting the change in the lifting force, which solves the problem in the prior art that the magnetic locator needs to be lowered into the casing and the coupling position can only be determined based on the induced electromotive force, and the positioning process is relatively cumbersome and complicated. The effect of being able to directly determine the coupling position based on the lifting force when the packer is lifted normally is achieved.

[0016] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the overall structure of a casing coupling positioner provided by an embodiment of the present invention is shown; Figure 2 A cross-sectional view of a casing coupling locator provided by an embodiment of the present invention is shown; Figure 3 A schematic structural diagram of a clamping member in a casing coupling positioner provided by an embodiment of the present invention is shown; Figure 4 A schematic diagram of the split structure of a lower stop tube of a casing coupling locator provided by an embodiment of the present invention is shown; Figure 5 A flow chart of a positioning method for a casing coupling locator provided by an embodiment of the present invention is shown.

[0018] Explanation of symbols 1. Main body; 11. Limiting groove; 2. Clamping piece; 21. Upper locking part; 22. Lower locking part; 221. Limiting block; 222. Flexible pad; 23. Limiting part; 231. Limiting protrusion; 232. Sliding hole; 233. Sliding block; 234. Anti-slip block; 24. Groove; 3. Upper limiting tube; 4. Lower limiting tube; 41. Arc-shaped piece; 42. Limiting ridge; 5. Compression spring piece; 51. First arc-shaped part; 52. Second arc-shaped part; 53. Deformation part; 61. Positioner fixing; 62. Lowering and landing; 63. Lifting up and observing the pulling force; 64. Determining the position. DETAILED DESCRIPTION

[0019] Hereinafter, preferred embodiments (or implementation modes) of the present invention will be described in detail with reference to the accompanying drawings.

[0020] refer to Figure 1-Figure 5 A casing coupling locator and a casing coupling locating method of the present invention are described.

[0021] Figure 1 The overall structure diagram of a casing collar locator provided by an embodiment of the present invention is shown. Figure 1 As shown, a casing coupling locator provided in this embodiment includes a main body 1 and a plurality of clamping parts 2 arranged on the periphery of the main body 1. The main body 1 is a tubular component, and its upper half is provided with at least one tubular area with different diameters, which is plugged and fixed to adapt to different pipelines; in this embodiment, the upper half of the main body 1 is used to be plugged and fixed to the ball seat end area of ​​the packer; the lower half is also provided with a plurality of pipe diameter areas with different diameters, and the diameter of the middle part of the main body 1 decreases successively to the bottom area, so that the lower half of the main body 1 is arranged in a gradient, which plays a guiding role with the plug-in area on the one hand, and is also convenient for plugging in pipelines with different diameters on the other hand.

[0022] Figure 2 A cross-sectional view of a casing coupling locator provided by an embodiment of the present invention is shown. Figure 3 FIG. 2 is a schematic diagram showing the structure of a clamping member 2 in a casing coupling positioner provided by an embodiment of the present invention. Figure 2 , Figure 3 As shown, the clamping member 2 is a strip-shaped structure, which is distributed in the middle area of ​​the main body 1 along the axial direction of the main body 1, and at least three clamping members 2 are provided, and are evenly distributed along the circumference of the main body 1. In this embodiment, four clamping members 2 are taken as an example. Among them, the clamping member 2 includes an upper clamping portion 21, a lower clamping portion 22, and a limiting portion 23; the upper clamping portion 21, the upper clamping portion 21, and the limiting portion 23 are integrally arranged, and the limiting portion 23 is located in the middle area of ​​the upper clamping portion 21 and the lower clamping portion 22. A limiting protrusion 231 is convexly provided on the side of the limiting portion 23 away from the main body 1, and the limiting protrusion 231 is located in the connection area with the upper clamping portion 21.

[0023] In order to make the connection between the clamping member 2 and the main body 1 more stable, a plurality of limiting grooves 11 are provided in the middle area of ​​the main body 1. The number of limiting grooves 11 corresponds to the number of clamping members 2. Each limiting groove 11 is strip-shaped and distributed along the axial direction of the main body 1. Moreover, the plurality of limiting grooves 11 are evenly distributed on the circumference of the main body 1 with the axial direction of the main body 1 as the axis, and each clamping member 2 is installed in the corresponding limiting groove 11. An upper limit tube 3 is installed in the upper half area of ​​the main body 1. The inner wall diameter of the upper limit tube 3 is equal to the diameter of the outer wall of the middle part of the main body 1. The upper limit tube 3 can be threadedly connected to the circumference of the main body 1 or fixed to the circumference of the main body 1 by screws. Part of the upper limit tube 3 is blocked by the upper clamping part 21 of the clamping member 2, thereby limiting the separation of the upper clamping part 21 from the main body 1. A lower limit tube 4 is installed in the lower half area of ​​the main body 1. The inner wall diameter of the lower limit tube 4 is equal to the diameter of the outer wall of the middle part of the main body 1. When the lower stop tube 4 is fixed to the peripheral area of ​​the main body 1 , a part of the lower stop tube 4 is blocked by the lower locking portion 22 , thereby limiting the separation of the lower locking portion 22 from the main body 1 .

[0024] In order to reduce the movable end of the clamping member 2, a stopper 221 is convexly provided on the side of the lower clamping portion 22 away from the stopper groove 11, and a swing gap is left between the side of the lower clamping portion 22 facing the stopper groove 11 and the bottom wall of the stopper groove 11. In order to improve the stability of the clamping member 2 during the swinging process, the above gap is filled with a flexible pad 222, which can be made of rubber. While filling and stabilizing, it will not affect the normal swinging of the clamping member 2, so that the end of the stopper 221 abuts against the inner wall of the lower stopper tube 4. In order to reduce the friction between the stopper 221 and the inner wall of the lower stopper tube 4, the end face of the stopper 221 is an arc surface, thereby reducing the resistance of the clamping member 2 during the rotation process.

[0025] A groove 24 is provided on one side of the clamping member 2 facing the limiting groove 11, and an elastic member for applying elastic force to the clamping member 2 is clamped in the groove 24, and the elastic member can be a compression spring sheet 5, and the compression spring sheet 5 includes a first arc-shaped portion 51, a second arc-shaped portion 52, and a deformation portion 53, and the deformation portion 53 is located between the first arc-shaped portion 51 and the second arc-shaped portion 52, and the first arc-shaped portion 51, the second arc-shaped portion 52, and the deformation portion 53 are integrally arranged. The deformation portion 53 is an arc shape as a whole, and its overall arc region is opposite to the arc trend of the first arc-shaped portion 51 and the second arc-shaped portion 52. When the compression spring sheet 5 and the clip 2 are installed with each other, the ends of the first arc-shaped portion 51 and the second arc-shaped portion 52 are clamped at the edge of the groove 24, and the two ends of the deformation portion 53 are abutted against the bottom wall of the limiting groove 11. When the clip 2 and the main body 1 are installed with each other, the clip 2 is supported by three fulcrums of the flexible pad 222 and the ends of the deformation portion 532, thereby ensuring the stability of the initial state of the clip 2.

[0026] The lower locking portion 22 is supported by the limit block 221 and the flexible pad 222, so that the upper locking portion 21 is the movable end of the entire clamping member 2. In order to ensure the stability of the elastic force, the deformation portion 53 is located away from the lower locking portion 22, so that the second arc portion 52 is longer than the first arc portion 51. When the limiting portion 23 is subjected to external pressure, the first arc portion 51 and the second arc portion 52 are subjected to pressure, which drives the two ends of the deformation portion 53 to approach each other, so that the support of the compression spring sheet 5 to the clamping member 2 is more stable. Even if the two ends of the deformation portion 53 abut against each other, the first arc portion 51 and the second arc portion 52 can also be connected to each other to form a whole, thereby achieving the effect of applying an elastic force.

[0027] A limiting protrusion 231 is convexly provided on the side of the limiting portion 23 away from the limiting groove 11, the lower part of the limiting protrusion 231 is a guide surface, the upper part of the limiting protrusion 231 is a hook surface, and the angle between the guide surface and the axial direction of the main body 1 is smaller than the angle between the hook surface and the axial direction of the main body 1, so that when the positioner is pulled, the limiting protrusion 231 is more easily hooked in the gap area of ​​the casing coupling. Since the upper clamping portion 21 of the clamping member 2 is a movable end, the limiting protrusion 231 has no connection between the limiting portion 23 and the upper clamping portion 21, thereby increasing the clamping range of the limiting protrusion 231.

[0028] In order to improve the success rate of hooking, the limiting portion 23 of the clamping member 2 is located in the region of the deformation portion 53 of the compression spring sheet 5 and is horizontally provided with a sliding hole 232. A slider 233 is slidably connected in the sliding hole 232 and is abutted against the back side of the deformation portion 53. The slider 233 is fixed with an anti-slip block 234 at the end facing the deformation portion 53. The size of the anti-slip block 234 is larger than the size of the sliding hole 232. In the initial state, the anti-slip block 234 abuts against the back side of the deformation portion 53, and the end of the slider 233 is flush with the end of the initial state limiting protrusion 231, and a guide cut surface is provided below the end of the slider 233 to reduce hooking with the external environment. When the locator extends into the sleeve, the slider 233 first contacts the inner wall of the sleeve, and slides toward the inner direction of the sliding hole 232 under obstruction, and drives the deformation part 53 to undergo elastic deformation, and the limiting protrusion 231 is also hindered by the outside at the same time, driving the upper clamping part 21 to swing toward the inner direction of the limiting groove 11. During the swinging of the clamping part 2, the compression spring piece 5 will be driven to undergo elastic deformation. Due to the triggering of the slider 233, the deformation of the deformation part 53 of the compression spring piece 5 increases the elastic action of the deformation part 53, so that the overall elastic force of the compression spring piece 5 increases. When the locator is lifted, the end of the slider 233 and the limiting protrusion 231 simultaneously play a hooking role, and the compression spring piece 5 increases the overall resilience under the pressure deformation of the deformation part 53, so that the limiting protrusion 231 has a better hooking effect on the sleeve coupling area, which greatly improves the success rate of the hooking.

[0029] Figure 4The schematic diagram of the split structure of the lower stop tube 4 of the casing coupling locator provided by the embodiment of the present invention is shown. Figure 2 and Figure 4 As shown, the lower limiting tube 4 is composed of a plurality of arc-shaped pieces 41 of equal size, the number of the arc-shaped pieces 41 corresponds to the number of the clamping parts 2, each arc-shaped piece 41 is used to fix a separate clamping part 2, and a limiting ridge 42 is convexly provided on the inner arc surface of the arc-shaped piece 41, and the limiting ridge 42 is inserted into the limiting groove 11 along the lower edge of the limiting groove 11, and the end of the limiting ridge 42 is abutted against one side of the flexible pad 222, so that the upper part of the limiting ridge 42 is the end of the lower clamping part 22, and the lower part is the edge of the limiting groove 11, thereby limiting the arc-shaped piece 41. The displacement along the axial direction of the main body 1; on the one hand, the limiting ridge 42 abuts against the surface of the flexible pad 222 to realize the force on the flexible pad 222, increasing the friction between the flexible pad 222 and the bottom wall of the limiting groove 11, so that the flexible pad 222 and the limiting groove 11 are fixed more firmly; on the other hand, as the limiting ridge 42 abuts against the flexible pad 222, the area below the flexible pad 222 is deformed, so that the flexible pad 222 plays a filling role, and also vacates the space for the lower clamping part 22 to move, so that the activity of the clamping part 2 is more stable. Moreover, the arc-shaped piece 41 is fixed to the main body 1 by a pin. As the pin is screwed, the force of the limiting ridge 42 on the flexible pad 222 can be adjusted to adjust the flexibility of the activity of the clamping part 2.

[0030] Figure 5 The flowchart of a positioning method of a casing collar locator provided by an embodiment of the present invention is shown. Figure 5 As shown, a casing coupling locator positioning method provided in this embodiment includes the following steps: S1: Positioner fixing 61, the casing coupling positioner is installed below the ball seat of the packer; S2: moving down to the landing position 62, so that the packer is displaced to move the casing coupling positioner into the casing docking port; S3: lifting and observing the pulling force 63, lifting the casing coupling positioner, and monitoring the lifting pulling force of the casing coupling positioner; S4: Determine position 64. When the lifting force becomes larger and larger, determine that the position of the casing coupling locator is the connecting pipe position.

[0031] When lifting the casing coupling locator, the limiting protrusion 231 and the slider 233 on the clamping part 2 slide against the inner wall of the casing at the same time. When the limiting protrusion 231 slides to the coupling position, the limiting protrusion 231 will be stuck in the coupling gap, causing the lifting tension to increase sharply. If the limiting protrusion 231 is not stuck in the corresponding area, it can also be stuck by the slider 233; at this time, the sealing can be carried out, and the rubber ring of the packer will not be stuck in the coupling position of the casing during the sealing. When the lifting tension increases to greater than or equal to 2 tons, the limiting protrusion 231 will be pulled out of the coupling gap, and the lifting tension returns to normal.

[0032] In the description of this specification, the terms "connection", "installation", "fixation" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0033] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A casing coupling locator, characterized in that: include: The main body (1) is a tube body; The clamping member (2) is strip-shaped and distributed along the axial direction of the main body (1). At least three of the clamping members are provided and are spaced apart in the peripheral area of ​​the main body (1). The clamping member (2) comprises an upper clamping portion (21), a lower clamping portion (22), and a limiting portion (23) connected to the middle of the lower clamping portion and the upper clamping portion (21). An elastic member, sandwiched between the limiting portion (23) and the main body (1); An upper limit tube (3) is coaxially fixed on the circumference of the main body (1) and is used to limit the upper clamping portion (21) from being separated from the main body (1), and a gap is left between the upper clamping portion (21); A lower limiting tube (4) is coaxially fixed on the peripheral side of the main body (1) and is used to limit the lower locking portion (22) from being separated from the main body (1), and a gap is left between the lower locking portion (22); A limit block (221) is fixed to the side of the lower clamping portion (22) facing the lower limit tube (4), and the edge of the limit block (221) abuts against the inner wall of the lower limit tube (4); and further includes The flexible pad (222) is sandwiched in the gap between the lower clamping portion (22) and the main body (1) and is used to fill the gap between the lower clamping portion (22) and the main body (1).

2. A casing coupling locator according to claim 1, characterized in that: The elastic member is an arc-shaped compression spring sheet (5), and the clamping member (2) is provided with grooves (24) for clamping the two end portions of the compression spring sheet (5).

3. A casing coupling locator according to claim 2, characterized in that: The compression spring sheet (5) comprises A first arc-shaped portion (51), one end of which is clamped in the groove (24); A second arc-shaped portion (52), one end of which is clamped in the groove (24); and further comprising The deformation portion (53) is connected between the first arc-shaped portion (51) and the second arc-shaped portion (52).

4. A casing coupling locator according to claim 3, characterized in that: The second arc-shaped portion (52) is longer than the first arc-shaped portion (51), and the deformation portion (53) is arranged away from the lower locking portion (22).

5. A casing coupling locator according to claim 4, characterized in that: The outer surface of the main body (1) is provided with strip-shaped limiting grooves (11) along the axial direction of the main body (1), the number of the limiting grooves (11) corresponding to the number of the clamping parts (2), the limiting grooves (11) are evenly arranged around the circumference of the main body (1), and the clamping parts (2) are installed in the limiting grooves (11).

6. A casing coupling locator according to claim 5, characterized in that: The lower limiting tube (4) is composed of a plurality of arc-shaped pieces (41) connected at their ends, the number of the arc-shaped pieces (41) corresponding to the number of the clamping parts (2), the inner arc surface of each arc-shaped piece (41) being provided with a limiting ridge (42) inserted along the lower edge of the limiting groove (11), the end of the limiting ridge (42) pressing the flexible pad (222), the arc-shaped piece (41) being fixed to the main body (1) by a pin; When the arc-shaped piece (41) is fixed on the peripheral side of the main body (1), the limiting block (221) abuts against the inner wall of the arc-shaped piece (41).

7. A casing coupling locator according to claim 6, characterized in that: A limiting protrusion (231) is convexly provided on the outer contour surface of the limiting portion (23).

8. A casing coupling locator according to claim 7, characterized in that: A sliding hole (232) for penetrating the limiting portion (23) is provided at a position corresponding to the deformation zone in the compression spring sheet (5); a sliding block (233) is slidably connected in the sliding hole (232); one end of the sliding block (233) abuts against one side of the deformation zone of the compression spring sheet (5); and the other end of the sliding block (233) is flush with the end of the limiting protrusion (231).

9. A casing collar positioning method, characterized in that: For the casing coupling locator according to any one of claims 1 to 8, the method comprises: S1: Install the casing coupling locator below the ball seat of the packer; S2: displacing the packer to move the casing collar locator into the casing butt joint port; S3: lifting the casing coupling positioner and monitoring the lifting force of the casing coupling positioner; S4: When the upward pulling force becomes larger and larger, the position of the casing coupling locator is determined to be the connecting position.

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