Hydraulic rotary cutting and fishing device and fishing method

Abstract

The invention relates to the technical field of cutting and salvaging of coiled tubing for well workover, in particular to a hydraulic rotary cutting and salvaging device and a salvaging method.The hydraulic rotary cutting and salvaging device comprises an outer cylinder, a tool bit, a push broach ring, a slip bowl, a slip insert, a limiting sleeve and a throttling assembly, and a fixed ring table is fixed to the inner side of the lower portion of the outer cylinder; a plurality of radial through mounting holes are uniformly distributed in the inner side of the lower part of the fixed ring table along the circumference at intervals. The continuous oil pipe fish cutting device is reasonable and compact in structure, high-pressure fluid is pumped into the outer cylinder by arranging the taper sleeve-shaped throttling assembly, the fluid forms pressure difference on the outer side and the inner side of the upper end of the throttling assembly, so that the throttling assembly is driven to move downwards, the slip insert can clasp continuous oil pipe fish for the first time, and the continuous oil pipe fish can be conveniently cut; by arranging the limiting sleeve, after the coiled tubing fish is cut off, the outer cylinder is lifted upwards, the limiting sleeve can extrude the slip insert again, the slip insert further holds the coiled tubing fish tightly, and the coiled tubing fish is smoothly lifted out by lifting the outer cylinder upwards.

Description

Technical Field

[0001] The invention relates to the technical field of continuous oil pipe cutting and salvaging for well repair in the petroleum industry, and relates to a hydraulic rotary cutting and salvaging device and a salvaging method. Background Art

[0002] In the field of oil industry, accidents of coiled tubing getting stuck in underground operations are common. When the drill is stuck, the coiled tubing needs to be unstuck in time. If the unstuck is ineffective, the coiled tubing has to be cut off, causing the coiled tubing and tool string to fall into the well, which has a serious impact on subsequent production operations. At present, in the complex treatment of coiled tubing salvage in horizontal well sections, thickened tubing outside the drill tool or tubing with a lifting and pulling cutting tool is usually used for through-hole salvage. The salvage principle is to convert the longitudinal pulling force of the drill tool into the transverse bite cutting method of the mechanical cutting tool to cut the coiled tubing to achieve cutting and salvage.

[0003] The above-mentioned salvage method has a good salvage effect in the coiled tubing salvage of vertical wells, but in horizontal wells, due to the friction resistance of the horizontal well deflection section, part of the lifting load of the workover rig cannot be fully transmitted to the tool cutting mechanism, the salvage success rate is low, and the possibility of salvage drilling tools breaking off is high. If the salvage drilling tools break off, it will further complicate the engineering accident. Therefore, it is necessary to study new horizontal well coiled tubing salvage technology and break through the key technology of long horizontal well section coiled tubing salvage. Summary of the invention

[0004] The present invention provides a hydraulic rotary cutting and salvaging device and a salvaging method, which overcome the shortcomings of the above-mentioned prior art and can effectively solve the problems that part of the pulling load of the well repair machine in the horizontal well section cannot be completely transmitted to the tool cutting mechanism, the salvage success rate is low, and the possibility of the salvage drill bit breaking is high in the existing lifting and pulling cutting and salvaging operations used in continuous oil pipe salvage operations.

[0005] One of the technical solutions of the present invention is achieved through the following measures: a hydraulic rotary cutting and salvaging device, including an outer cylinder, a cutter head, a push cutter ring, a slip seat, a slip tooth, a limit sleeve and a throttling assembly, a fixed ring platform is fixed to the inner side of the lower part of the outer cylinder, a plurality of radially penetrating mounting holes are evenly distributed along the circumference on the inner side of the lower part of the fixed ring platform, a rotating shaft is rotatably mounted in each mounting hole, a vertical fixed block is fixedly mounted on the outer side of each rotating shaft, a cutter head with an upper end located on the inner side of the fixed ring platform is fixed on the upper side of each fixed block, a limit plate is fixed to the inner side of the lower part of each mounting hole, and a device is provided between the lower part of each fixed block and the inside of the mounting hole so that the outer side of the lower part of the fixed block and the inner side of the limit plate can be aligned A first elastic reset member is arranged on the inner side of the lower part of the outer cylinder corresponding to the position above the fixed ring stage, a push knife ring is mounted on the inner side of the lower part of the outer cylinder corresponding to the position above the fixed ring stage, a sealing ring stage is fixed on the outer side of the upper end of the push knife ring and is in sealing contact with the inner side of the outer cylinder, a second elastic reset member is arranged between the lower end of the sealing ring stage and the upper end of the fixed ring stage, a cava seat is mounted on the inner side of the upper part of the outer cylinder corresponding to the position above the sealing ring stage, a plurality of cava teeth are distributed at intervals along the circumference at the lower end of the cava seat, a limiting sleeve is fixedly installed on the inner side of the outer cylinder corresponding to the position between the cava teeth and the sealing ring stage, and the limiting sleeve can make the lower ends of the plurality of cava teeth radially contract after moving upward, and a conical sleeve-shaped throttling component with a small upper part and a large lower part is installed on the upper part of the push knife ring corresponding to the position below the limiting sleeve.

[0006] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: The above-mentioned throttling assembly may include a petal piston and an elastic hoop. A plurality of petal pistons are evenly distributed along the circumference of the upper end of the push knife ring. When the plurality of petal pistons are close to each other, a conical tube with a small upper part and a large lower part is formed. The elastic hoop is sleeved on the outer side of the upper part of the conical tube. A plurality of limit screws fixedly installed with the inner side of the outer tube are evenly distributed along the circumference on the outer side of the lower part of the conical tube. A plurality of first connecting holes communicating with the inside and the outside are evenly distributed along the circumference on the outer side of the outer tube corresponding to the position above the sealing ring platform and the position below the sealing ring platform.

[0007] The upper end of the push knife ring can be evenly distributed with four petal pistons along the circumference, and the upper end of the push knife ring corresponding to the lower middle part of each petal piston is provided with a mounting groove which is small at the top and large at the bottom and opens inward, and each mounting groove is installed with a connecting block whose upper end is fixed to the lower end of the corresponding petal piston, and two of the opposite petal pistons are provided with overlapping grooves on both sides, and overlapping plates matching the overlapping grooves are fixed on both sides of the other two petal pistons, and the overlapping plates of each petal piston are installed in the overlapping grooves of adjacent petal pistons.

[0008] The inner side of the above-mentioned limit sleeve may be provided with a first tapered hole, a straight hole and a second tapered hole that are connected in sequence from top to bottom. The first tapered hole is a cone with a larger top and a smaller bottom. A number of radially penetrating second connecting holes are evenly distributed along the circumference on the inner wall of the straight hole. A third connecting hole that is connected inside and outside is provided on the outer side of the outer cylinder corresponding to the position of each first connecting hole. Each third connecting hole is provided with a connecting screw whose end is screwed into the corresponding first connecting hole.

[0009] A guide shoe can be fixedly installed on the inner side of the lower end of the outer cylinder, and a plurality of grinding and milling sheets are evenly distributed along the circumference of the inner side of the guide shoe.

[0010] The inner side of the slip tooth may be provided with a plurality of serrated anti-skid grooves at intervals in the upper and lower parts.

[0011] An upper joint may be fixedly mounted on the upper end of the outer cylinder.

[0012] A centralizer can be installed on the inner side of the lower part of the outer cylinder at the position corresponding to the guide shoe and the fixed ring platform. The centralizer includes an upper fixed ring and a lower fixed ring which are spaced apart and mounted on the inner side of the lower part of the outer cylinder. A number of centralizer springs are evenly distributed along the circumference between the lower end of the upper fixed ring and the upper end of the lower fixed ring, and the middle part of each centralizer spring is arched inward.

[0013] The second technical solution of the present invention is achieved by the following measures: a salvage method, comprising the following steps: Step 1: Connect the upper joint to the pipe string and lower it into the well; Step 2: Continue to lower the tubing string so that the coiled tubing fish head passes through the push cutter ring, the split piston, the limit sleeve and the slip teeth in sequence; Step 3, continue to lower the pipe string to the position where the coiled tubing is to be cut; Step 4: Make the outer cylinder rotate and start the pump to inject high-pressure fluid into the outer cylinder. A pressure difference is formed between the outer and inner sides of the upper end of the split piston. The split piston pushes the push cutter ring downward. The push cutter ring continues to move downward to push the cutter head to swing inward and abut against the outer side of the coiled tubing fish. The cutter head rotates circumferentially under the drive of the outer cylinder to cut the coiled tubing fish. Step 5: After the coiled tubing is cut, the outer tube stops rotating and the circulation pump is turned off; Step six: lift the tubing string to complete the salvage of the fish dropped in the coiled tubing.

[0014] The following is a further optimization and / or improvement of the second technical solution of the above invention: The above step 1 includes: connecting the upper joint with the pipe string and lowering it into the well, when the top of the coiled tubing fish fish contacts the guide shoe, the outer tube rotates, the milling piece trims the top of the coiled tubing fish fish fish, and the outer tube stops rotating after the trimming is completed.

[0015] The structure of the present invention is reasonable and compact. By setting a conical sleeve-shaped throttling component that is small at the top and large at the bottom, high-pressure fluid is pumped into the outer cylinder. The fluid forms a pressure difference between the outer side and the inner side of the upper end of the throttling component, thereby driving the throttling component to move downward. The slip teeth can initially hold the continuous oil tubing fish, which is convenient for cutting the continuous oil tubing fish. By setting a limiting sleeve, after the continuous oil tubing fish is cut off, the outer cylinder is lifted up, and the limiting sleeve can squeeze the slip teeth again, so that the slip teeth further hold the continuous oil tubing fish, and the continuous oil tubing fish is smoothly lifted out by lifting the outer cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attached Figure 1 It is a schematic diagram of the front cross-sectional structure of the first embodiment.

[0017] Attached Figure 2 It is a schematic diagram of the top view of the throttling assembly in Example 1.

[0018] Attached Figure 3 It is a schematic diagram of the three-dimensional structure of the throttling assembly in Example 1.

[0019] Attached Figure 4 It is a schematic diagram of the three-dimensional structure of the cutter head in the first embodiment.

[0020] Attached Figure 5 It is a schematic diagram of the three-dimensional structure of the kava tooth in Example 1.

[0021] The codes in the accompanying drawings are: 1 is an outer cylinder, 2 is a cutter head, 3 is a push cutter ring, 4 is a slip seat, 5 is a slip tooth, 6 is a limit sleeve, 7 is a fixed ring platform, 8 is a mounting hole, 9 is a rotating shaft, 10 is a fixed block, 11 is a first elastic reset member, 12 is a sealing ring platform, 13 is a second elastic reset member, 14 is a limit plate, 15 is a petal piston, 16 is an elastic hoop ring, 17 is a limit screw, 18 is a first connecting hole, 19 is a connecting block, 20 is a lap plate, 21 is a first tapered hole, 22 is a straight hole, 23 is a second tapered hole, 24 is a connecting screw, 25 is a guide shoe, 26 is a grinding and milling sheet, 27 is an anti-skid groove, 28 is an upper joint, 29 is an upper fixed ring, 30 is a lower fixed ring, and 31 is a straightening spring. DETAILED DESCRIPTION

[0022] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0023] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached Figure 1 The positional relationships such as front, back, top, bottom, left, and right are described according to the layout directions of the drawings in the specification.

[0024] The present invention will be further described below in conjunction with embodiments and drawings: Embodiment 1: As shown in the attached Figures 1 to 5 As shown, the hydraulic rotary cutting and salvaging device includes an outer cylinder 1, a cutter head 2, a push cutter ring 3, a slip seat 4, a slip tooth 5, a limit sleeve 6 and a throttling assembly. A fixed ring platform 7 is fixed to the inner side of the lower part of the outer cylinder 1. A plurality of radially penetrating mounting holes 8 are evenly distributed along the circumference on the inner side of the lower part of the fixed ring platform 7. A rotating shaft 9 is rotatably mounted in each mounting hole 8. A vertical fixed block 10 is fixedly mounted on the outer side of each rotating shaft 9. A cutter head 2 with an upper end located on the inner side of the fixed ring platform 7 is fixed on the upper side of each fixed block 10. A limit plate 14 is fixed to the inner side of the lower part of each mounting hole 8. A first elastic reset member 11 is provided between the lower part of each fixed block 10 and the inside of the mounting hole 8, which can make the outer side of the lower part of the fixed block 10 abut against the inner side of the limit plate 14. A push knife ring 3 is sleeved on the inner side of the lower part of the outer cylinder 1 corresponding to the position above the fixed ring platform 7, and a sealing ring platform 12 is fixed on the outer side of the upper end of the push knife ring 3, which is in sealing contact with the inner side of the outer cylinder 1. A second elastic reset member 13 is provided between the lower end of the sealing ring platform 12 and the upper end of the fixed ring platform 7. A slip seat 4 is sleeved on the inner side of the upper part of the outer cylinder 1 corresponding to the position above the sealing ring platform 12, and a plurality of slip teeth 5 are distributed along the circumference at intervals at the lower end of the slip seat 4. A limiting sleeve 6 is fixedly installed on the inner side of the outer cylinder 1 corresponding to the position between the slip teeth 5 and the sealing ring platform 12. After the limiting sleeve 6 moves upward, the lower ends of the plurality of slip teeth 5 can be radially contracted. A conical sleeve-shaped throttling component with a small upper part and a large lower part is installed on the upper part of the push knife ring 3 corresponding to the position below the limiting sleeve 6.

[0025] According to the needs, the outer side of the upper part of the cutter head 2 is in an arc shape with an opening facing inward, so that the push ring 3 can press the cutter head 2 after moving downward so that the cutter head 2 can swing inward and resist the outer side of the continuous oil pipe fish. The first elastic reset member 11 is an existing well-known torsion spring, and the second elastic reset member 13 is an existing well-known compression spring. During use, the outer tube 1 is connected to the tubing string and then lowered into the well. The top of the coiled tubing fish fish passes through the fixed ring platform 7, the pusher ring 3, the throttling assembly, and the limit sleeve 6 from bottom to top. When the top of the coiled tubing fish fish contacts the slip teeth 5, the slip teeth 5 expand outward after elastic deformation. At this time, all the slip teeth 5 hold the outer side of the upper part of the coiled tubing fish fish, and continue to lower the tubing string to the position where the coiled tubing fish fish is to be cut. At this time, the turntable is turned on, and the turntable drives the outer tube 1 to rotate through the tubing string. At the same time, the pump circulation is started, and the fluid flows downward to the upper end of the throttling assembly. The inner side of the upper end of the throttling assembly is close to the outer side of the coiled tubing fish fish. The fluid forms a pressure difference between the outer and inner sides of the upper end of the throttling assembly, causing the throttling assembly to move downward, thereby driving the pusher ring 3 to move downward, and the lower end of the pusher ring 3 moves to After moving downward, the outer side of the cutter head 2 is squeezed so that the inner side of the cutter head 2 is against the outer side of the continuous tubing fish. At this time, the rotation of the turntable drives the outer cylinder 1 to rotate. When the outer cylinder 1 rotates, it drives the cutter head 2 to cut the continuous tubing fish. After completing the continuous tubing fish cutting operation, the turntable stops rotating so that the outer cylinder 1 stops rotating. At the same time, the circulating pump is turned off. The second elastic reset member 13 resets and drives the push cutter ring 3 to move up. After the push cutter ring 3 moves up, the cutter head 2 swings outward with the fixed block 10 under the action of the first elastic reset member 11 and separates from the continuous tubing fish. At this time, the pipe string is slowly lifted, and the limiting sleeve 6 fixed in the outer cylinder 1 moves up accordingly. The cava tooth 5 enters the limiting sleeve 6 and is gradually contracted, thereby further clamping the continuous tubing fish. The pipe string continues to be lifted to complete the salvage of the continuous tubing fish.

[0026] By setting the slip teeth 5, the coiled tubing fish can be initially held tightly, which facilitates the cutting operation of the coiled tubing fish. By setting the limiting sleeve 6, after the coiled tubing fish is cut off, the outer tube 1 is lifted up, and the limiting sleeve 6 can squeeze the slip teeth 5 again, so that the slip teeth 5 further hold the coiled tubing fish, and the coiled tubing fish is smoothly lifted out by lifting the outer tube 1. By setting the limiting plate 14, the fixed block 10 can be prevented from being located outside the outer tube 1 under the action of the first elastic reset member 11, which not only reduces the difficulty of lowering the outer tube 1 into the well, but also shortens the swing amplitude of the cutter head 2, thereby improving the cutting efficiency. With this arrangement, the push cutter ring 3 can act on the outer side of the upper part of the cutter head 2 after moving downward, so that the cutter head 2 can swing inward and abut against the outer side of the continuous oil pipe fish, which is convenient for cutting operations. By setting a conical sleeve-shaped throttling component with a small upper part and a large lower part, high-pressure fluid is pumped into the outer cylinder 1, and a pressure difference is formed between the outer and inner sides of the upper end of the throttling component, thereby driving the throttling component to move downward. By setting a second elastic reset member 13, after the cutting operation is completed and the high-pressure fluid is stopped from being pumped into the outer cylinder 1, the second elastic reset member 13 can make the push cutter cylinder reset after moving upward, so that the cutter head 2 can reset after swinging outward, which can protect the cutter head 2.

[0027] The above-mentioned hydraulic rotary cutting and salvaging device can be further optimized and / or improved according to actual needs: Embodiment 2: As an optimization of the above embodiment, as shown in the attached Figure 1 , 2 As shown in Figure 3, the throttling assembly includes a petal piston 15 and an elastic hoop 16. A plurality of petal pistons 15 are evenly distributed along the circumference of the upper end of the push knife ring 3. When the plurality of petal pistons 15 are close to each other, a conical tube with a small upper part and a large lower part is formed. The elastic hoop 16 is sleeved on the outer side of the upper part of the conical tube. A plurality of limit screws 17 fixedly installed with the inner side of the outer tube 1 are evenly distributed along the circumference on the outer side of the lower part of the conical tube. A plurality of first connecting holes 18 communicating with the inside and the outside are evenly distributed along the circumference on the outer side of the outer tube 1 corresponding to the position below the sealing ring platform 12.

[0028] During use, by setting the limit screw 17, it is possible to prevent the split piston 15 from getting stuck after contacting the limit sleeve 6 after moving upward, so that the cutter head 2 cannot contact the inner side of the continuous oil pipe. By setting the first connecting hole 18, the top of the continuous oil pipe fish drop passes through the upper end of the split piston 15 and is fixed by the cava tooth 5, and the fluid is pumped into the outer tube 1. The fluid forms a pressure difference between the upper and lower ends of the split piston 15, so that the split piston 15 drives the sealing ring platform 12 and the push knife ring 3 to move downward. In this way, the fluid at the lower end of the sealing ring platform 12 and the outside of the push knife ring 3 can be discharged to the outside of the outer tube 1 through the first connecting hole 18, so that the push knife ring 3 can move downward smoothly and make the cutter head 2 contact the outside of the continuous oil pipe fish drop, which is convenient for subsequent cutting operations.

[0029] Embodiment 3: As an optimization of the above embodiment, as shown in the attached Figure 1 , 2 As shown in Figure 3, four petal pistons 15 are evenly distributed along the circumference of the upper end of the push knife ring 3, and a mounting groove with a small upper part and a large lower part and an opening facing inward is provided on the upper end of the push knife ring 3 corresponding to the lower middle part of each petal piston 15. A connecting block 19 is installed in each mounting groove, and the upper end and the lower end of the corresponding petal piston 15 are fixed together. Two of the opposite petal pistons 15 are provided with overlapping grooves on both sides, and overlapping plates 20 matching the overlapping grooves are fixed on both sides of the other two petal pistons 15, and the overlapping plates 20 of each petal piston 15 are installed in the overlapping grooves of adjacent petal pistons 15.

[0030] According to the requirements, a groove is provided on the outer side of the upper part of each split piston 15, and the elastic hoop 16 is installed in the groove. The installation groove and the connecting block 19 are both in an inverted T shape, which can prevent the elastic hoop 16 from falling off and improve the stability during use. By setting the connecting block 19 and the lap plate 20, the disassembly and assembly between the split pistons 15 and between the split pistons 15 and the push knife ring 3 are facilitated. At the same time, the upper end of the split piston 15 can be opened outward to adapt to the continuous oil pipe fishing of various specifications.

[0031] Embodiment 4: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, the inner side of the limiting sleeve 6 is provided with a first tapered hole 21, a straight hole 22 and a second tapered hole 23 which are connected in sequence from top to bottom. The first tapered hole 21 is in a tapered shape which is larger at the top and smaller at the bottom. A plurality of radially penetrating second connecting holes are evenly distributed along the circumference on the inner wall of the straight hole 22. A third connecting hole which is connected inside and outside is provided on the outer side of the outer cylinder 1 corresponding to the position of each first connecting hole 18. A connecting screw 24 whose end is screwed into the corresponding first connecting hole 18 is provided in each third connecting hole.

[0032] According to the requirements, the outer side of the lower end of each slip tooth 5 is chamfered. In the process of use, such a setting facilitates the fixing of the limit sleeve 6. At the same time, after the outer cylinder 1 is lifted up, the slip seat 4 drives the slip teeth 5 to move downward under the gravity of the coiled tubing, so that the lower end of the slip teeth 5 moves downward into the first tapered hole 21. The inner wall of the first tapered hole 21 continuously squeezes the slip teeth 5, so that the slip teeth 5 are tightened and hold the coiled tubing fish, so that the coiled tubing fish can be smoothly lifted out.

[0033] Embodiment 5: As an optimization of the above embodiment, as shown in the attached Figure 1As shown, a guide shoe 25 is fixedly installed on the inner side of the lower end of the outer cylinder 1, and a plurality of grinding and milling discs 26 are evenly distributed along the circumference of the inner side of the guide shoe 25. According to the requirements, the guide shoe 25 is an existing well-known technology, and four fixed grooves with openings inward are evenly distributed along the circumference on the inner cone surface of the guide shoe 25, and the grinding and milling discs 26 are fixedly installed in the fixed grooves. During use, by setting the guide shoe 25, it is convenient to introduce the top of the continuous tubing fish into the outer cylinder 1, so as to cut the continuous tubing fish. By setting the grinding and milling discs 26, the top of the continuous tubing fish can be trimmed to ensure that the size of the top of the continuous tubing fish is uniform, and the one-time shaping of the top of the continuous tubing fish can be achieved, and it is also convenient for the continuous tubing fish to be fixed after the lower end of the slip tooth 5 is approached.

[0034] Embodiment 6: As an optimization of the above embodiment, as shown in the attached Figure 1 , 5 As shown, a plurality of serrated anti-skid grooves 27 are provided at intervals on the inner side of the slip teeth 5. In use, through such a setting, when the lower ends of the slip teeth 5 are close to each other, the friction between the slip teeth 5 and the coiled tubing fish to be cut can be increased, which is convenient for fixing the coiled tubing fish and facilitating the subsequent cutting operation of the coiled tubing fish.

[0035] Embodiment 7: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, an upper joint 28 is fixedly mounted on the upper end of the outer tube 1. In the process of use, such an arrangement facilitates the connection between the outer tube 1 and the pipe column, and is convenient for assembly and disassembly.

[0036] Embodiment 8: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a centralizer is installed on the inner side of the lower part of the outer cylinder 1 corresponding to the position between the guide shoe 25 and the fixed ring platform 7. The centralizer includes an upper fixed ring 29 and a lower fixed ring 30 which are spaced apart and sleeved on the inner side of the lower part of the outer cylinder 1. A plurality of centralizer springs 31 are evenly spaced along the circumference between the lower end of the upper fixed ring 29 and the upper end of the lower fixed ring 30. The middle part of each centralizer spring 31 is arched inward. During use, through such a setting, after the upper end of the coiled tubing fish fish passes through the centralizer, the centralizer can make the coiled tubing fish fish coaxial with the outer cylinder 1, thereby facilitating the coaxiality of the cutter head 2 during rotation and improving the cutting efficiency.

[0037] Embodiment 9: As an optimization of the above embodiment, as shown in the attached Figures 1 to 5 As shown, a salvage method comprises the following steps: Step 1: Connect the upper joint 28 to the pipe string and lower it into the well. When the top of the coiled tubing fish fish contacts the guide shoe 25, the outer tube 1 rotates, and the milling sheet 26 trims the top of the coiled tubing fish fish fish. After the trimming is completed, the outer tube 1 stops rotating. Step 2: Continue to lower the pipe string so that the top of the coiled tubing passes through the push cutter ring 3, the split piston 15, the limit sleeve 6 and the slip teeth 5 in sequence; Step 3, continue to lower the pipe string to the position where the coiled tubing is to be cut; Step 4: Make the outer cylinder 1 rotate, and start the pump to inject high-pressure fluid into the outer cylinder 1. A pressure difference is formed between the outer and inner sides of the upper end of the split piston 15. The split piston 15 pushes the push cutter ring 3 downward. The push cutter ring 3 continues to move downward to push the cutter head 2 to swing inward and abut against the outer side of the coiled tubing fish. The cutter head 2 rotates circumferentially under the drive of the outer cylinder 1 to cut the coiled tubing fish. Step 5: After the coiled tubing is cut, the outer tube 1 stops rotating and the circulation pump is turned off; Step six: lift the tubing string to complete the salvage of the fish dropped in the coiled tubing.

[0038] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

[0039] The use process of the best embodiment of the present invention: During operation, first, connect the upper joint 28 and the pipe string and then lower it into the well. When the top of the coiled tubing fish contacts the guide shoe 25, turn on the turntable to drive the outer tube 1 and the guide shoe 25 to rotate, slowly rotate and trim the top of the coiled tubing fish, use the guide shoe 25 to introduce the top of the coiled tubing fish into the outer tube 1, and weld four grinding and milling discs 26 on the inner cone surface of the guide shoe 25. The grinding and milling discs 26 trim the top of the coiled tubing fish to ensure that the size of the fish top is uniform. After the shaping of the coiled tubing fish top is completed, the turntable is closed to stop the outer cylinder 1 from rotating, and the pipe string is continued to be lowered so that the coiled tubing fish top passes through the stabilizer, the pusher ring 3, the split piston 15, the limit sleeve 6 and the slip teeth 5 in sequence. When the coiled tubing fish top contacts the slip teeth 5, the slip teeth 5 are elastically deformed and expanded outward. The deformed slip teeth 5 hold the coiled tubing fish, and the pipe string is continued to be lowered to the position where the coiled tubing fish is to be cut. The turntable is turned on to rotate the outer cylinder 1, and the pump is started to circulate at the same time. A pressure difference is formed between the outer and inner sides of the upper ends of the split piston 15. The split piston 15 pushes the push cutter ring 3 downward, and the second elastic reset member 13 is gradually compressed. The push cutter ring 3 continues to move downward to push the cutter head 2 to swing inward and abut against the outer side of the continuous tubing fish. The cutter head 2 is driven by the outer cylinder 1 to rotate circumferentially to cut the continuous tubing fish. After the continuous tubing fish cutting is completed, the turntable stops rotating to stop the outer cylinder 1, and the circulating pump is turned off at the same time. The second elastic reset member 13 resets and drives the push cutter ring 3 upward. After the push cutter ring 3 and the cutter head 2 are separated from each other, the cutter head 2 is reset under the action of the first elastic reset member 11. At this time, the pipe column is slowly lifted, and the limit sleeve 6 fixed on the outer cylinder 1 moves upward accordingly. The cava teeth 5 and the continuous tubing fish move downward under the action of gravity. The lower end of the cava teeth 5 moves into the first tapered hole 21 of the limit sleeve 6 and then gradually contracts, which further clamps the continuous tubing fish. The pipe column is continued to be lifted to complete the salvage of the continuous tubing fish.

Claims

1. A hydraulic rotary cutting and salvaging device, characterized in that It includes an outer cylinder, a cutter head, a push cutter ring, a slip seat, a slip tooth, a limit sleeve and a throttling assembly. A fixed ring platform is fixed on the inner side of the lower part of the outer cylinder. A plurality of radially penetrating mounting holes are evenly distributed along the circumference on the inner side of the lower part of the fixed ring platform. A rotating shaft is rotatably mounted in each mounting hole. A vertical fixed block is fixedly mounted on the outer side of each rotating shaft. A cutter head with an upper end located on the inner side of the fixed ring platform is fixed on the upper side of each fixed block. A limit plate is fixed on the inner side of the lower part of each mounting hole. A first elastic reset member is provided between the lower part of each fixed block and the inside of the mounting hole, which can make the outer side of the lower part of the fixed block abut against the inner side of the limit plate. The first elastic reset member corresponding to the upper part of the fixed ring platform A push knife ring is mounted on the inner side of the lower part of the outer cylinder at the position, and a sealing ring platform is fixed on the outer side of the upper end of the push knife ring and is in sealing contact with the inner side of the outer cylinder, and a second elastic reset part is provided between the lower end of the sealing ring platform and the upper end of the fixed ring platform, and a cava seat is mounted on the inner side of the upper part of the outer cylinder corresponding to the position above the sealing ring platform, and a plurality of cava teeth are distributed at intervals along the circumference at the lower end of the cava seat, and a limiting sleeve is fixedly installed on the inner side of the outer cylinder corresponding to the position between the cava teeth and the sealing ring platform, and the limiting sleeve can make the lower ends of the plurality of cava teeth radially contract after moving upward, and a conical sleeve-shaped throttling component with a small upper part and a large lower part is installed on the upper part of the push knife ring corresponding to the position below the limiting sleeve.

2. The hydraulic rotary cutting and salvaging device according to claim 1, characterized in that The throttling assembly includes a petal piston and an elastic hoop. A plurality of petal pistons are evenly distributed along the circumference of the upper end of the push knife ring. When the plurality of petal pistons are close to each other, a conical tube with a small upper part and a large lower part is formed. The elastic hoop is sleeved on the outer side of the upper part of the conical tube. A plurality of limit screws fixedly installed with the inner side of the outer tube are evenly distributed along the circumference on the outer side of the lower part of the conical tube. A plurality of first connecting holes communicating with the inside and the outside are evenly distributed along the circumference on the outer side of the outer tube corresponding to the position above the sealing ring platform and the position below the sealing ring platform.

3. The hydraulic rotary cutting and salvaging device according to claim 2, characterized in that There are four petal pistons evenly distributed along the circumference of the upper end of the push knife ring. The upper end of the push knife ring corresponding to the lower middle part of each petal piston is provided with a mounting groove which is small at the top and large at the bottom and opens inward. A connecting block is installed in each mounting groove, the upper end of which is fixed to the lower end of the corresponding petal piston. Two of the opposite petal pistons are provided with overlapping grooves on both sides, and overlapping plates matching the overlapping grooves are fixed on both sides of the other two petal pistons. The overlapping plates of each petal piston are installed in the overlapping grooves of adjacent petal pistons.

4. The hydraulic rotary cutting and salvaging device according to claim 1, 2 or 3, characterized in that The inner side of the limit sleeve is provided with a first tapered hole, a straight hole and a second tapered hole which are connected in sequence from top to bottom. The first tapered hole is in the shape of a cone which is larger at the top and smaller at the bottom. A number of radially penetrating second connecting holes are evenly distributed along the circumference on the inner wall of the straight hole. A third connecting hole which is connected inside and outside is provided on the outer side of the outer cylinder corresponding to the position of each first connecting hole. Each third connecting hole is provided with a connecting screw whose end is screwed into the corresponding first connecting hole.

5. The hydraulic rotary cutting and salvaging device according to claim 1, 2 or 3, characterized in that A guide shoe is fixedly installed on the inner side of the lower end of the outer cylinder, and a plurality of milling blades are evenly distributed along the circumference of the inner side of the guide shoe; a plurality of serrated anti-skid grooves are arranged at intervals up and down on the inner side of the slip tooth; or / and, an upper joint is fixedly installed on the upper end of the outer cylinder.

6. The hydraulic rotary cutting and salvaging device according to claim 4, characterized in that A guide shoe is fixedly installed on the inner side of the lower end of the outer cylinder, and a plurality of milling blades are evenly distributed along the circumference of the inner side of the guide shoe; a plurality of serrated anti-skid grooves are arranged at intervals up and down on the inner side of the slip tooth; or / and, an upper joint is fixedly installed on the upper end of the outer cylinder.

7. The hydraulic rotary cutting and salvaging device according to claim 5, characterized in that A centralizer is installed on the inner side of the lower part of the outer cylinder corresponding to the position between the guide shoe and the fixed ring platform. The centralizer includes an upper fixed ring and a lower fixed ring which are spaced apart and mounted on the inner side of the lower part of the outer cylinder. A number of centralizer springs are evenly distributed along the circumference between the lower end of the upper fixed ring and the upper end of the lower fixed ring, and the middle part of each centralizer spring is arched inward.

8. The hydraulic rotary cutting and salvaging device according to claim 6, characterized in that A centralizer is installed on the inner side of the lower part of the outer cylinder corresponding to the position between the guide shoe and the fixed ring platform. The centralizer includes an upper fixed ring and a lower fixed ring which are spaced apart and mounted on the inner side of the lower part of the outer cylinder. A number of centralizer springs are evenly distributed along the circumference between the lower end of the upper fixed ring and the upper end of the lower fixed ring, and the middle part of each centralizer spring is arched inward.

9. A salvaging method using the hydraulic rotary cutting and salvaging device as claimed in any one of claims 1 to 8, characterized in that The steps include: Step 1: Connect the upper joint to the pipe string and lower it into the well; Step 2: Continue to lower the tubing string so that the coiled tubing fish head passes through the push cutter ring, the split piston, the limit sleeve and the slip teeth in sequence; Step 3, continue to lower the pipe string to the position where the coiled tubing is to be cut; Step 4: Make the outer cylinder rotate and start the pump to inject high-pressure fluid into the outer cylinder. A pressure difference is formed between the outer and inner sides of the upper end of the split piston. The split piston pushes the push cutter ring downward. The push cutter ring continues to move downward to push the cutter head to swing inward and abut against the outer side of the coiled tubing fish. The cutter head rotates circumferentially under the drive of the outer cylinder to cut the coiled tubing fish. Step 5: After the coiled tubing is cut, the outer tube stops rotating and the circulation pump is turned off; Step six: lift the tubing string to complete the salvage of the fish dropped in the coiled tubing.

10. The salvage method according to claim 9, characterized in that Step one includes: connecting the upper joint to the pipe string and lowering it into the well, when the top of the coiled tubing fish fish contacts the guide shoe, the outer tube rotates, the milling piece trims the top of the coiled tubing fish fish fish, and the outer tube stops rotating after the trimming is completed.

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