A casing collar locator and a casing collar location method

Abstract

The present invention provides a casing collar locator and a casing collar location method, comprising: a main body; a clamping member, which is strip-shaped and distributed along the axial direction of the main body, and at least three clamping members are provided and spaced apart in the circumferential region of the main body; the clamping member includes an upper clamping portion, a lower clamping portion, and a limiting portion; an elastic member, which is clamped between the limiting portion and the main body; an upper limiting tube, which is coaxially fixed on the circumference of the main body, is used to limit the upper clamping portion from separating from the main body, and has a gap with the upper clamping portion; a lower limiting tube, which is coaxially fixed on the circumference of the main body, is used to limit the lower clamping portion from separating from the main body, and has a gap with the lower clamping portion; a limiting block, which is fixed on the side of the lower clamping portion facing the adjacent lower limiting tube, and the edge of the limiting block abuts against the inner wall of the lower limiting tube; a flexible pad is further included, which is clamped in the gap between the lower clamping portion and the main body and is used to fill the gap between the lower clamping portion and the main body. This technical solution improves the accuracy of the clamping position between the locator and the collar.

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 inside of 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] In view of the problems existing in the above-mentioned prior art, the present invention provides a casing collar locator, including: a main body, which is a pipe body; a clamping member, which is strip-shaped and distributed along the axial direction of the main body, and at least 3 clamping members are provided and are spaced apart in the circumferential region of the main body; it includes an upper clamping portion, a lower clamping portion, and a limiting portion connected to the middle of the lower clamping portion and the upper clamping portion; an elastic member, which is clamped between the limiting portion and the main body; an upper limiting tube, which is coaxially fixed on the circumferential side of the main body, is used to limit the upper clamping portion from separating from the main body, and has a gap with the upper clamping portion; a lower limiting tube, which is coaxially fixed on the circumferential side of the main body, is used to limit the lower clamping portion from separating from the main body, and has a gap with the lower clamping portion; a limiting block, which is fixed on the side of the lower clamping portion facing the adjacent lower limiting tube, and the edge of the limiting block abuts against the inner wall of the lower limiting tube; a flexible pad is also included, which is clamped in the gap between the lower clamping portion and the main body, and is used to fill the gap between the lower clamping portion and the main body. With the above technical features, the limiting block provides a support point with the lower limiting tube, and the flexible pad provides a support between the back of the lower clamping portion and the outer wall of the main body. When the clamping member is subjected to an external pressure, it will drive the clamping member to rotate around the support point of the limiting block and the lower limiting tube. While the flexible pad plays a role in limiting and stably supporting the clamping member, it also satisfies the movement space of the lower clamping portion, so as to ensure that only the upper clamping portion area of the clamping member is the elastic activity area, so as to ensure the stability of the limiting portion and the clamping collar for limiting and clamping.

[0007] In some embodiments, the elastic member is an arc-shaped compression spring sheet, and the clamping member is provided with a groove for clamping the two end portions of the compression spring sheet. Thus, the compression spring sheet has a sheet structure as a whole, with a simple structure and controllable cost, and can also exert an elastic acting force to keep the limiting portion protruding all the time.

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

[0009] In some embodiments, the second arc-shaped portion is longer than the first arc-shaped portion, and the deformation portion is arranged away from the lower clamping portion. Thus, the compression spring piece and the main body support region are located in a region away from the lower clamping portion, so that the clamping member is supported by three regions at the same time, ensuring the support stability and more balanced force.

[0010] In some embodiments, a strip-shaped limiting groove is axially formed on the outer surface of the main body along the axis of the main body. The number of the formed limiting grooves corresponds to the number of the clamping members one by one, and the limiting grooves are evenly arranged around the circumferential side of the main body. The clamping members are installed in the limiting grooves. Thus, the limiting grooves limit the installation positions of the clamping members, ensuring the stability of the elastic rotation state of the clamping members.

[0011] In some embodiments, the lower limiting tube is composed of the ends of several arc-shaped pieces connected to each other. The number of the arc-shaped pieces corresponds to the number of the clamping members one by one. A limiting convex rib inserted along the lower edge of the limiting groove is convexly provided on the inner arc surface of each arc-shaped piece. The end of the limiting convex rib presses the flexible pad, and the arc-shaped piece is fixed to the main body through a pin; when the arc-shaped piece is fixed on the circumferential side of the main body, the limiting block abuts against the inner wall of the arc-shaped piece. Thus, the arc-shaped piece plays a role in limiting the lower clamping portion, restricting the separation of the lower clamping portion from the main body. The mutual insertion of the limiting convex rib and the limiting groove, on the one hand, restricts the axial displacement of the arc-shaped piece along the main body; on the other hand, it abuts against the flexible pad and applies pressure to the flexible pad, thereby playing a role in fixing the flexible pad; on the third hand, it presses the flexible pad, thereby leaving a space on the back side of the lower clamping portion, facilitating the rotation of the clamping member, so that the staff can adjust the acting force of the limiting convex rib on the flexible pad by adjusting the fixing tightness of the pin to adjust the limiting tightness of the lower clamping portion.

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

[0013] In some embodiments, a sliding hole penetrating the limiting portion is formed at a position corresponding to the deformation area in the limiting portion and the compression spring piece. A slider is slidably connected in the sliding hole. One end of the slider abuts against one side of the deformation area of the compression spring piece, and the other end of the slider is flush with the end of the limiting protrusion. Thus, with the mutual insertion of the casing and the locator, the slider will be driven to displace into the inner part of the sliding groove and apply an acting force to the deformation area of the compression spring piece, thereby increasing the overall elastic acting force of the compression spring piece. When the clamping member elastically swings, its elastic acting force is greater, and the limiting protrusion is more stably clamped with the collar gap area.

[0014] A method for positioning a casing collar, the method comprising:

[0015] S1: Install the casing collar locator below the ball seat of the packer;

[0016] S2: Shift the packer to move the casing collar locator into the casing docking port;

[0017] S3: Lift the casing collar locator and monitor the lifting force for lifting the casing collar locator;

[0018] S4: When the lifting force steadily increases, determine the position where the casing collar locator is located as the takeover position.

[0019] Thus, when the casing collar locator is lifted, the positioning piece will be affected by the collar gap to increase the lifting force. The operator can determine the collar position by detecting the change in the lifting force, solving the problem in the prior art that the magnetic locator needs to be lowered into the casing and the collar position can only be determined based on the induced electromotive force, and the positioning process is relatively cumbersome and complex; achieving the effect of being able to directly determine the collar position based on the lifting force when the packer is normally lifted.

[0020] It should be understood that the content described in the Summary of the Invention section is not intended to limit the key or important features of the embodiments of the present disclosure, nor is it used 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

[0021] Figure 1 Shows an overall structural schematic diagram of a casing collar locator provided by an embodiment of the present invention;

[0022] Figure 2 Shows a cross-sectional view of a casing collar locator provided by an embodiment of the present invention;

[0023] Figure 3 Shows a structural schematic diagram of a clamping member in a casing collar locator provided by an embodiment of the present invention;

[0024] Figure 4 Shows a split structural schematic diagram of a lower limit tube of a casing collar locator provided by an embodiment of the present invention;

[0025] Figure 5 Shows a flow chart of a positioning method for a casing collar locator provided by an embodiment of the present invention.

[0026] SYMBOL DESCRIPTION

[0027] 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

[0028] Hereinafter, preferred embodiments (or implementation modes) of the present invention will be described in detail with reference to the accompanying drawings.

[0029] refer to Figures 1 - 5 A casing coupling locator and a casing coupling locating method of the present invention are described.

[0030] 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.

[0031] 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.

[0032] 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 .

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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 lifted, 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.

[0037] 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 has a sliding hole 232 horizontally provided therein. A slider 233 abutting against the back side of the deformation portion 53 is slidably connected in the sliding hole 232. The slider 233 is fixedly connected 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 limiting protrusion 231 in the initial state, 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.

[0038] Figure 4Shows a schematic diagram of the split structure of a lower limit tube 4 of a casing collar locator provided by an embodiment of the present invention. Refer to Figure 2 and Figure 4 As shown, the lower limit tube 4 is composed of a plurality of equal-sized arc-shaped pieces 41. The number of arc-shaped pieces 41 corresponds one-to-one with the number of clamping members 2. Each arc-shaped piece 41 is used to fix a separate clamping member 2. A limiting convex rib 42 is protruded on the inner arc surface of the arc-shaped piece 41. The limiting convex rib 42 is inserted into the limiting groove 11 along the lower edge of the limiting groove 11, and the end of the limiting convex rib 42 abuts against one side of the flexible pad 222, so that the end of the lower clamping portion 22 is above the limiting convex rib 42, and the edge of the limiting groove 11 is below, thereby restricting the axial displacement of the arc-shaped piece 41 along the main body 1; on the other hand, the limiting convex rib 42 abuts against the surface of the flexible pad 222 to exert a force on the flexible pad 222, increasing the friction between the flexible pad 222 and the bottom wall of the limiting groove 11, thereby fixing the flexible pad 222 and the limiting groove 11 more firmly; on the third hand, as the limiting convex rib 42 abuts against the flexible pad 222, the area below the flexible pad 222 deforms, so that while the flexible pad 222 plays a filling role, it also creates a space for the lower clamping portion 22 to move, making the movement of the clamping member 2 more stable. Moreover, the arc-shaped piece 41 is fixed to the main body 1 through a pin. As the pin is screwed, the force exerted by the limiting convex rib 42 on the flexible pad 222 can be adjusted to adjust the flexibility of the movement of the clamping member 2.

[0039] Figure 5 Shows a flow chart of a positioning method of a casing collar locator provided by an embodiment of the present invention. Refer to Figure 5 As shown, a positioning method of a casing collar locator provided by this embodiment includes the following steps:

[0040] S1: Positioner fixation 61, install the casing collar locator below the ball seat of the packer;

[0041] S2: Lower movement and positioning 62, shift the packer to move the casing collar locator into the casing docking port;

[0042] S3: Lift and observe the pulling force 63, lift the casing collar locator and monitor the lifting pulling force for lifting the casing collar locator;

[0043] S4: Determine the position 64, when the lifting pulling force becomes stable and increases, determine the position where the casing collar locator is located as the connection pipe position.

[0044] When lifting the casing collar locator, the limit protrusion 231 and the slider 233 on the clamping member 2 are simultaneously abutted against the inner wall of the casing and slide. When the limit protrusion 231 slides to the position of the collar, the limit protrusion 231 will be stuck in the collar gap, causing the lifting tension to increase sharply. If the limit protrusion 231 is not set in the corresponding area, the slider 233 can also be used for positioning; at this time, setting can be performed, and the rubber ring of the packer will not be stuck at the collar position of the casing when setting. When the lifting tension increases to be greater than or equal to 2 tons, the limit protrusion 231 will be pulled out from the collar gap, and the lifting tension will return to normal.

[0045] In the description of this specification, terms such as "connection", "installation", "fixation", etc. should all be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0046] The above are only the preferred embodiments of this application and are not used to limit this application. For those skilled in the art, this application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims

1. A casing collar locator, characterized in that, Comprising: A main body (1), which is a pipe body; Clamping parts (2), which are strip-shaped and distributed along the axial direction of the main body (1). There are at least 3 clamping parts (2), and they are spaced apart and distributed in the circumferential area of the main body (1). It includes an upper clamping part (21), a lower clamping part (22), and a limiting part (23) connected to the middle of the lower clamping part and the upper clamping part (21); An elastic member, which is clamped between the limiting part (23) and the main body (1); An upper limiting pipe (3), which is coaxially fixed on the circumference of the main body (1) and is used to prevent the upper clamping part (21) from detaching from the main body (1), and there is a gap between the upper limiting pipe (3) and the upper clamping part (21); A lower limiting pipe (4), which is coaxially fixed on the circumference of the main body (1) and is used to prevent the lower clamping part (22) from detaching from the main body (1), and there is a gap between the lower limiting pipe (4) and the lower clamping part (22); A limiting block (221), which is fixed on the side of the lower clamping part (22) facing the adjacent lower limiting pipe (4), and the edge of the limiting block (221) abuts against the inner wall of the lower limiting pipe (4); Further comprising A flexible pad (222), which is clamped in the gap between the lower clamping part (22) and the main body (1) and is used to fill the gap between the lower clamping part (22) and the main body (1); The elastic member is an arc-shaped compression spring piece (5), and the clamping part (2) is provided with a groove (24) for clamping the two ends of the compression spring piece (5); The compression spring piece (5) includes A first arc-shaped part (51), one end of which is clamped in the groove (24); A second arc-shaped part (52), one end of which is clamped in the groove (24); Further comprising A deformation part (53), which is connected between the first arc-shaped part (51) and the second arc-shaped part (52); A limiting protrusion (231) protrudes from the outer contour surface of the limiting part (23); A sliding hole (232) penetrating the limiting part (23) is opened at the corresponding position of the deformation area between the limiting part (23) and the compression spring piece (5). A slider (233) is slidably connected in the sliding hole (232). One end of the slider (233) abuts against one side of the deformation area of the compression spring piece (5), and the other end of the slider (233) is flush with the end of the limiting protrusion (231).

2. The casing collar locator according to claim 1, wherein, The second arc-shaped part (52) is longer than the first arc-shaped part (51), and the deformation part (53) is arranged away from the lower clamping part (22).

3. The casing collar locator according to claim 2, characterized in that, A strip-shaped limiting groove (11) is axially opened on the outer surface of the main body (1). The number of the opened limiting grooves (11) corresponds to the number of the clamping parts (2) one by one. 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).

4. The casing collar locator according to claim 3, characterized in that, The lower limit tube (4) is composed of the ends of a plurality of arc-shaped pieces (41) connected to each other. The number of the arc-shaped pieces (41) corresponds to the number of the clamping members (2) one by one. A limit convex rib (42) inserted along the lower edge of the limit groove (11) protrudes from the inner arc surface of each arc-shaped piece (41). The end of the limit convex rib (42) presses the flexible pad (222). The arc-shaped piece (41) is fixed to the main body (1) by a pin; When the arc-shaped piece (41) is fixed on the circumference of the main body (1), the limit block (221) abuts against the inner wall of the arc-shaped piece (41).

5. A casing coupling positioning method, characterized in that, For the casing collar locator according to any one of claims 1 to 4, the method includes: S1: Install the casing collar locator below the ball seat of the packer; S2: Shift the packer to move the casing collar locator into the casing docking port; S3: Lift the casing collar locator and monitor the lifting force for lifting the casing collar locator; S4: When the lifting force steadily increases, determine that the position where the casing collar locator is located is the connection pipe position.

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