Self-rotating circulating unblocking and shearing retrieval cylinder capable of detecting fish tops

Abstract

This invention relates to the field of fishing cylinder technology, specifically a self-rotating, circulating, unblocking, and shearing fishing cylinder capable of detecting the top of a fish. It comprises an upper connector, a detection outer cylinder, a slip outer cylinder, and a fork, all threaded together from left to right. The detection outer cylinder houses a fish-top detection mechanism that can move left and right and can block the cavity of the upper connector. A positive circulation channel is located on the outer side of the fish-top detection mechanism. The slip outer cylinder contains a clamping slip and a clamping slip seat. The right end of the clamping slip has a split structure that can tighten inwards and has serrations on its inner side. The right end of the clamping slip is located within the clamping slip seat. A guide shoe is installed on the outer side of the fork. This invention has a reasonable and compact structure and is easy to use. By using the left and right movement of the fish-top detection mechanism to block the cavity of the upper connector, and observing the ground pump pressure to confirm whether the fallen fish has entered the effective area within the fishing cylinder, the tubing string is then lifted for retrieval, improving the success rate of coiled tubing fishing cylinder retrieval.

Description

Technical Field

[0001] This invention relates to the field of fishing cylinder technology, and is a self-rotating, cyclical, unblocking, and shearing fishing cylinder capable of detecting the top of a fish. Background Technology

[0002] Coiled tubing retrieval technology is safe, environmentally friendly, and efficient, and is currently widely used in handling abnormal operating conditions in the oil and gas development field. Coiled tubing retrieval tubes are commonly used retrieval tools, but currently suffer from the following main problems: First, because the top axis of the fallen fish usually deviates from the casing axis, and the coiled tubing used in well drilling is in a bent state within the casing, lacking centering and unable to rotate, it is difficult for various retrieval tubes to successfully guide the fallen fish into an effective retrieval position inside the retrieval tool; Second, during the retrieval operation, it is impossible to accurately determine whether the fallen fish has entered an effective position inside the retrieval tube, resulting in the inability to effectively grasp the fallen fish or its accidental detachment after grasping; Third, after grasping the fallen fish, it is impossible to effectively unclog the lower tubing string and tools through effective fluid circulation, making effective retrieval impossible; Fourth, the clamping components are not secure, causing the fallen fish to slip off; Fifth, when it is impossible to unstick the fallen fish for various reasons and effective shearing, segmented retrieval, or other subsequent operations are required, the current retrieval tubes have a low shearing success rate. The existence of the above problems seriously reduces the retrieval efficiency of coiled tubing retrieval cylinders, prolongs the production downtime, and increases the risk of secondary accidents.

[0003] The invention patent with publication number CN110644941A discloses a continuous tubing rotary introduction retrieval device, including an upper connector, a conversion connector, an outer cylinder, retrieval slips, slip seats, shear pins, shear slips, a guide rail inner cylinder, pins, a guide rail outer cylinder, and a guide shoe. The lower outer side of the upper connector is fixedly installed with the upper inner side of the conversion connector. The lower outer side of the conversion connector is fixedly installed with the upper inner side of the outer cylinder. The lower outer side of the outer cylinder is fixedly installed with the upper inner side of the guide rail inner cylinder. The guide rail outer cylinder is fitted onto the lower outer side of the guide rail inner cylinder. A limiting ring platform is provided on the upper outer side of the guide rail inner cylinder. The upper end of the guide rail outer cylinder abuts against the lower end of the limiting ring platform. The guide rail inner cylinder and the guide rail outer cylinder are fixedly installed together by pins. A passageway is provided on the middle outer side of the guide rail inner cylinder. A grooved rotary guide rail rotates by means of pin displacement. At least two pins with their inner ends engaged in the grooved rotary guide rail are fixedly installed on the outer cylinder of the guide rail. The lower outer side of the outer cylinder is fixedly installed to the upper inner side of the guide shoe. Two downward-facing V-shaped notches are evenly distributed along the circumference of the lower end of the guide shoe. A vertically penetrating cutting channel is provided in the middle of the outer cylinder, comprising a first straight hole, a first conical hole, and a second straight hole connected sequentially from top to bottom. The first conical hole is wider at the top and narrower at the bottom. A slip seat is fixedly installed in the first straight hole corresponding to the upper inner side of the outer cylinder by a shear pin. The slip seat has a vertically penetrating second conical hole in its middle, also wider at the top and narrower at the bottom. A lower end seat is provided on the upper inner side of the outer cylinder, resting on the upper part of the second conical hole. The salvage slips on the side can expand radially outward when the upper inner side of the salvage slip is subjected to outward compressive force, and can contract radially inward when the lower outer side of the salvage slip is subjected to inward compressive force. The salvage slips have annular teeth on their inner side. A shearing slip with its lower end seated on the inner side of the upper part of the first conical hole, corresponding to the lower inner side of the outer cylinder, can contract radially inward when the lower outer side of the shearing slip is subjected to inward compressive force. The shearing slip has shearing teeth on its lower inner side. The shearing slip is located below the slip seat, and the outer diameter of the upper end of the shearing slip is larger than the inner diameter of the lower end of the slip seat. Upper gear rings can be distributed on the outer wall of the inner cylinder of the guide rail above the grooved rotary guide rail, and upper gear rings can be distributed on the outer wall of the inner cylinder of the guide rail below the grooved rotary guide rail. The device has a lower gear ring, and a grooved rotary guide rail is formed between the upper and lower gear rings. The upper gear ring includes upper ratchet teeth that are continuously and evenly distributed around the circumference with their tips pointing downwards. The upper ratchet teeth on the front side include an upper slope surface and an upper vertical surface that are higher on the left and lower on the right. The right end of the upper slope surface and the lower end of the adjacent upper vertical surface are connected together to form the tip of the upper ratchet teeth. The lower gear ring includes lower ratchet teeth that are continuously and evenly distributed around the circumference with their tips pointing upwards. The lower ratchet teeth on the front side include a lower slope surface and a lower vertical surface that are lower on the left and higher on the right. The right end of the lower slope surface and the upper end of the adjacent lower vertical surface are connected together to form the tip of the lower ratchet teeth. The upper and lower ratchet teeth are staggered, with the tip of each lower ratchet tooth located in the middle of the corresponding upper slope surface and the tip of each upper ratchet tooth located in the middle of the corresponding lower slope surface. This patent addresses the problems of poor centering of the coiled tubing and difficulty in introducing the fish head by designing a retrieval device structure consisting of an inner guide rail cylinder, an outer guide rail cylinder, and a rotating guide shoe.The tool uses a lifting and lowering of the tubing string to drive a pin that moves within a ratchet groove, achieving relative rotation of the outer cylinder of the guide rail. Combined with a guide shoe featuring a V-shaped notch, the contact position is adjusted multiple times to guide the fish head into the tool. It also integrates retrieval slips and shearing slips, combining gripping and shearing functions. The fish is clamped by squeezing the slips through a conical hole. While this patent achieves the rotational introduction function, it lacks a detection mechanism for the effective position of the fish head. During operation, the operator must rely on experience to judge the weight change of the tubing string. In complex conditions such as heavy oil blockage and annular sedimentation, the weight signal is easily distorted, still posing a risk of "false fish entry" leading to grip failure or detachment. Furthermore, the tool lacks an internal liquid circulation channel. If the lower tubing string becomes stuck after the fish is caught, it cannot be unblocked by pumping liquid; only forced lifting can be used, increasing the probability of the fish slipping and potentially causing secondary tubing breakage. This fails to address the core problem of "ineffective cyclic unblocking." Summary of the Invention

[0004] This invention provides a self-rotating circulating unblocking shearing retrieval cylinder capable of detecting the top of a fish, overcoming the shortcomings of the prior art. It can effectively solve the problems of fish slippage and secondary breakage of the tubing caused by the inability of existing continuous tubing retrieval cylinders to accurately determine whether a fish has entered the effective position inside the retrieval cylinder, as well as the inability to release the obstruction of the lower tubing string and tools.

[0005] The technical solution of this invention is achieved through the following measures: a self-rotating circulating unblocking and shearing retrieval cylinder capable of detecting the top of a fish, comprising an upper connector, a detection outer cylinder, a slip outer cylinder, and a fork connected sequentially from left to right by threads; a fish top detection mechanism is provided inside the detection outer cylinder, which can move left and right and can block the cavity of the upper connector; a positive circulation channel is provided on the outside of the fish top detection mechanism; a clamping slip and a clamping slip seat are installed inside the slip outer cylinder; the right end of the clamping slip has a split structure that can tighten inward and has serrations on the inner side. The right end of the clamping slip is located inside the clamping slip seat, and a guide shoe is installed on the outside of the fork; the fish top detection mechanism is a one-way valve, and the right side of the valve body of the one-way valve has several flow channels along the circumference, and the left end of the valve body can block the upper connector cavity; the middle side of the valve body of the one-way valve has a conical surface that can seal with the upper connector; it also includes a sealing mechanism, and the right end of the clamping slip seat is equipped with a sealing mechanism, which includes a rubber core and a shear pin seat. The right end of the clamping slip seat is equipped with a rubber core, and the right end of the rubber core is equipped with a shear pin seat, which is connected to the outer cylinder of the slip through a shear pin.

[0006] The following are further optimizations and / or improvements to the above-mentioned technical solution:

[0007] Preferably, it also includes a shearing slip assembly, which includes a shearing slip and a shearing slip seat. The shearing slip seat is installed inside the slip outer cylinder on the left side of the shift fork. The shearing slip seat is installed together with the slip outer cylinder by a pin. The shearing slip is provided inside the slip outer cylinder on the left side of the shearing slip seat. The right end of the shearing slip has a segmented structure, and each segment has an inwardly pointed protrusion on its inner side.

[0008] Preferably, a guide shoe is mounted on the outer side of the shift fork via a thrust bearing, and the guide shoe can rotate relative to the shift fork.

[0009] Preferably, a sealing ring is installed between the outer right side of the shift fork and the inner side of the guide shoe, a sealing ring is installed between the upper connector and the outer probe cylinder, and a sealing ring is installed between the outer probe cylinder and the outer slip cylinder; an anti-rotation pin is installed between the upper connector and the outer probe cylinder, and an anti-rotation pin is installed between the outer probe cylinder and the outer slip cylinder.

[0010] This invention features a reasonable and compact structure and is easy to use. It uses a self-rotating guide shoe to smoothly introduce the fish into the retrieval tube. The fish-top detection mechanism moves left and right to block the cavity of the upper connector. The ground pump pressure is observed to confirm whether the fish has entered the effective part of the retrieval tube. Once it has entered the effective part, the tubing is lifted for retrieval. The sealing device enables effective liquid circulation to release the obstruction of the lower tubing and tools. If the obstruction cannot be released, the fish can be effectively sheared, improving the success rate of coiled tubing retrieval. Attached Figure Description

[0011] Appendix Figure 1 This is a schematic diagram of the front cross-sectional structure according to an embodiment of the present invention.

[0012] Appendix Figure 2 This is a cross-sectional view of the fish-top detection mechanism entering the upper connector cavity.

[0013] Appendix Figure 3 This is a cross-sectional schematic diagram of the fish-top detection mechanism extending out of the upper connector cavity.

[0014] Appendix Figure 4 This is a cross-sectional view of the fish top detection mechanism and the unsealed upper connector, indicating that the fish has not entered the effective position.

[0015] Appendix Figure 5 This indicates the direction of liquid flow during the positive circulation after the fish enters the retrieval tube.

[0016] Appendix Figure 6 This indicates the direction of liquid flow during reverse circulation after the fish falls into the retrieval tube.

[0017] Appendix Figure 7 For the appendix Figure 1 Enlarged structural diagram on the left.

[0018] Appendix Figure 8 For the appendix Figure 1 Enlarged structural diagram of the right side.

[0019] Appendix Figure 9 For the appendix Figure 1 Enlarged cross-sectional view of section AA.

[0020] The codes in the attached diagram are as follows: 1 is the upper connector, 2 is the outer cylinder of the probe, 3 is the outer cylinder of the slip, 4 is the shift fork, 5 is the one-way valve, 6 is the flow channel, 7 is the conical surface, 8 is the rubber core, 9 is the upper connector cavity, 10 is the shear pin seat, 11 is the clamping slip, 12 is the clamping slip seat, 13 is the serration, 14 is the guide shoe, 15 is the shear pin, 16 is the shearing slip, 17 is the shearing slip seat, 18 is the pointed protrusion, 19 is the thrust bearing, 20 is the sealing ring, and 21 is the anti-rotation pin. Detailed Implementation

[0021] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0022] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as front, back, top, bottom, left, right, etc. The positional relationships are determined based on the layout direction of the attached diagram in the instruction manual.

[0023] The present invention will be further described below with reference to embodiments and accompanying drawings:

[0024] Example 1: As shown in the attached document Figure 1-9 As shown, the self-rotating circulating unblocking and shearing retrieval cylinder capable of detecting fish tops includes an upper connector 1, a detection outer cylinder 2, a slip outer cylinder 3, and a fork 4, which are threaded together from left to right. The detection outer cylinder 2 houses a fish top detection mechanism that can move left and right and can block the upper connector cavity 9. A positive circulation channel is provided on the outside of the fish top detection mechanism. The slip outer cylinder 3 houses a clamping slip 11 and a clamping slip seat 12. The right end of the clamping slip 11 has a split structure that can tighten inwards and has serrations 13 on its inner side. The right end of the clamping slip 11 is located at the clamping slip seat 12. Inside 2, a guide shoe 14 is installed on the outer side of the shift fork 4; the fish top detection mechanism is a one-way valve 5, and the right side of the valve body of the one-way valve 5 is provided with several flow channels 6 along the circumference, and the left end of the valve body can block the upper connector cavity 9; the middle outer side of the valve body of the one-way valve 5 has a conical surface 7 that can seal with the upper connector 1; it also includes a sealing mechanism, and a sealing mechanism is installed on the right end of the clamping slip seat 12. The sealing mechanism includes a rubber core 8 and a shear pin seat 10. The right end of the clamping slip seat 12 is provided with a rubber core 8, and the right end of the rubber core 8 is provided with a shear pin seat 10. The shear pin seat 10 is connected to the outer cylinder of the slip 3 through a shear pin 15.

[0025] By setting the sealing cone surface 7, a tighter seal can be achieved when the valve body contacts the inner side of the upper connector 1.

[0026] When the one-way valve 5 is not sealed with the upper connector 1, during ground pressurization, the liquid flows to the right from the upper connector cavity 9 through the flow channel 6 on the outside of the valve body, thus achieving positive circulation. During reverse circulation well washing, high-pressure liquid is injected from the annulus of the oil casing, enters the pipe from the guide shoe 14, and then flows to the left from the one-way valve 5. Therefore, the one-way valve 5 can not only be used as a tool to determine whether the fish has entered the effective retrieval position, but also form positive and reverse circulation channels, which is beneficial for tool unblocking.

[0027] When the clamping slip 11 captures and lifts the fish, the clamping slip seat 12 moves downward. As the pumping pressure inside the pipe increases, the downward squeezing force of the clamping slip seat 12 increases, squeezing the rubber core 8 to effectively seal the outer surface of the fish, allowing the positive circulation liquid to flow from the inside of the fish to the right, cleaning the annulus, and facilitating the unblocking operation of the lower part of the fish.

[0028] The usage process is as follows: 1. Select the appropriate retrieval cylinder based on the outer diameter of the fish to be retrieved;

[0029] 2. Lower the retrieval tube. After the guide shoe 14 at the bottom of the retrieval tube contacts the fallen fish, it guides the fish into the inner cavity of the retrieval tube.

[0030] 3. Continue lowering the retrieval tube. Once the fish enters the effective position inside the retrieval tube, it will push the fish-top detection mechanism, causing its top to enter the upper connector cavity 9. Figure 2 The lifting tube string applies a pre-tightening force to the clamping slip 11. After the clamping slip 11 grips the fish, the fish top detection mechanism will retract a certain distance from the inner cavity of the upper connector 1. Figure 3 (If the water level remains high but the water level is low, a pressure seal test is performed using ground-based pumping equipment. If there is no significant pressure loss, it indicates the fish has entered a valid location, and the next retrieval operation can proceed. If significant pressure loss occurs, it indicates the fish has not entered a valid location.) Figure 4 As shown;

[0031] 4. Raise the retrieval string. If the fish is not severely stuck in the well, the fish can be lifted directly to the wellhead to complete the retrieval operation.

[0032] 5. If the fish becomes stuck and further lifting of the retrieval string to the predetermined tonnage fails to release the stuck fish, the clamping slip 11 reliably clamps the fish (coiled tubing, etc.) that has entered the retrieval cylinder's inner cavity. The retrieval string moves to the left, while the stuck fish moves to the right relative to the retrieval cylinder. During continuous pressure testing, the fish-top detection device retracts from the upper connector cavity 9, detaching from the fish. The positive circulation channel 6 of the fluid inside the pipe opens, allowing the release fluid to be pumped through ground pumping equipment. After clearing the annular obstruction, the retrieval operation can proceed. Figure 5 As shown;

[0033] 6. If reverse circulation well washing is required due to special operating conditions, the unblocking fluid can be pumped from the annulus through a surface pumping device. At this time, the channel within the fish-top detection mechanism opens, allowing the tool to perform reverse circulation. Figure 6 As shown.

[0034] The fork 4 inside the guide shoe 14 of this invention can assist in guiding the fallen object into the effective grasping range of the retrieval tool, improving the success rate of retrieval. When the fallen object is tilted or partially buried near the well wall, the fork 4 can move the fallen object, changing its position so that the retrieval tool can accurately grasp it. The fish-top detection mechanism determines whether the upper connector 1 is sealed under the push of the fallen fish to determine whether the fallen fish has entered the effective retrieval position in the retrieval tube, thereby determining whether to start retrieval or restart the fish introduction. The tubing string can only be lifted for retrieval after the fallen fish reaches the designated position, improving the success rate of coiled tubing retrieval and reducing production downtime. By setting internal channels, positive and reverse circulation well washing can be realized, relieving the jamming of the lower tubing string and tools and reducing operational risks.

[0035] The above-mentioned self-rotating circulating unblocking and shearing retrieval cylinder capable of detecting fish tops can be further optimized and / or improved according to actual needs:

[0036] Example 2: As shown in the attached document Figure 1 , 8 As shown, it also includes a shear slip 16 assembly, which includes a shear slip 16 and a shear slip seat 17. The shear slip seat 17 is installed inside the slip outer cylinder 3 on the left side of the shift fork 4. The shear slip seat 17 is installed together with the slip outer cylinder 3 by a pin. The shear slip 16 is provided inside the slip outer cylinder 3 on the left side of the shear slip seat 17. The right end of the shear slip 16 has a split structure, and each split has an inwardly pointed protrusion 18 on its inner side.

[0037] When the fish gets stuck in the wellbore, if the axial tension reaches the shearing tonnage set by the shearing pin 15 but still cannot release the fish as the lifting load increases, the tubing string will continue to be lifted. The clamping slips 11, clamping slip seat 12 and sealing device will move to the right along with the fish, pushing the shearing slips 16 into the shearing slip seat 17, causing the shearing slips 16 to contract and cut off the fish, thus retrieving the cut upper continuous tubing.

[0038] Example 3: As shown in the attached document Figure 1 , 8As shown, a guide shoe 14 is mounted on the outer side of the shift fork 4 via a thrust bearing 19, allowing the guide shoe 14 to rotate relative to the shift fork 4. By connecting the guide shoe 14 to the thrust bearing 19, it can withstand both axial and rotational forces. During contact between the guide shoe 14 and the fish, the axial thrust acting on the guide shoe 14 generates a radial component along the guide shoe 14, allowing it to rotate freely around its axis. The guide shoe 14 is mounted on the far right of the tool, and its front cutting edge facilitates the pulling of the fish, which is obliquely attached to the inner wall of the casing, into the inner cavity of the guide shoe 14 during rotation, thus facilitating the introduction of the fish into the inner cavity of the retrieval cylinder.

[0039] Example 4: As shown in the appendix Figure 1 , 7 As shown in Figure 8, a sealing ring 20 is installed between the outer right side of the shift fork 4 and the inner side of the guide shoe 14; a sealing ring 20 is installed between the upper connector 1 and the outer probe cylinder 2; and a sealing ring 20 is installed between the outer probe cylinder 2 and the outer slip cylinder 3. An anti-rotation pin 21 is installed between the upper connector 1 and the outer probe cylinder 2, and between the outer probe cylinder 2 and the outer slip cylinder 3. An O-ring seal 20 is installed between the guide shoe 14 and the shift fork 4, which prevents impurities from entering the joint and allows adjustment of the tightness of the guide shoe 14 during rotation. By setting the anti-rotation pin 21, the problem of relative rotation and disengagement caused by factors such as column vibration can be avoided, ensuring the stability of the connection.

[0040] The above technical features constitute various embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A self-rotating, circulating, unblocking, shearing, and retrieval cylinder capable of detecting the top of a fish, characterized in that... The components, from left to right, are a top connector, a probe outer cylinder, a slip outer cylinder, and a fork, all threaded together. The probe outer cylinder houses a fish-top detection mechanism, which can move left and right and block the upper connector cavity. A positive circulation channel is located on the outside of the fish-top detection mechanism. The slip outer cylinder contains a clamping slip and a clamping slip seat. The right end of the clamping slip has a split structure that can tighten inwards and has serrations on its inner side. The right end of the clamping slip is located within the clamping slip seat. A guide shoe is installed on the outside of the fork. The fish-top detection mechanism is a one-way valve. The right side of the valve body has several flow channels along its circumference on the outer side. The left end of the valve body can... The upper connector cavity is sealed; the outer side of the valve body of the one-way valve has a conical surface that can seal with the upper connector; it also includes a sealing mechanism, and the right end of the clamping slip seat is equipped with a sealing mechanism, which includes a rubber core and a shear pin seat. The right end of the clamping slip seat is provided with a rubber core, and the right end of the rubber core is provided with a shear pin seat. The shear pin seat is connected to the outer cylinder of the slip through a shear pin. When the one-way valve is not sealed with the upper connector, when the surface is pressurized, the liquid flows to the right from the upper connector cavity through the flow channel on the outside of the valve body to achieve positive circulation. When the well is cleaned by reverse circulation, high-pressure liquid is injected from the annulus of the casing, enters the pipe from the guide shoe, and then flows out to the left from the one-way valve.

2. The self-rotating, circulating, unblocking, shearing, and retrieval cylinder capable of detecting the top of a fish as described in claim 1, characterized in that... It also includes a shear slip assembly, which includes a shear slip and a shear slip seat. The shear slip seat is installed inside the outer cylinder of the slip on the left side of the shift fork. The shear slip seat is installed together with the outer cylinder of the slip by a pin. The shear slip is provided inside the outer cylinder of the slip on the left side of the shear slip seat. The right end of the shear slip has a segmented structure, and each segment has an inwardly pointed protrusion on its inner side.

3. The self-rotating, circulating, unblocking, shearing, and retrieval cylinder capable of detecting the top of a fish as described in claim 1 or 2, characterized in that... A guide shoe is mounted on the outside of the shift fork via a thrust bearing, and the guide shoe can rotate relative to the shift fork.

4. The self-rotating, circulating, unblocking, shearing, and retrieval cylinder capable of detecting the top of a fish as described in claim 3, characterized in that... A sealing ring is installed between the outer right side of the shift fork and the inner side of the guide shoe; a sealing ring is installed between the upper connector and the outer probe cylinder; a sealing ring is installed between the outer probe cylinder and the outer slip cylinder; an anti-rotation pin is installed between the upper connector and the outer probe cylinder; and an anti-rotation pin is installed between the outer probe cylinder and the outer slip cylinder.

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