Coiled tubing bottom seal dragging packer capable of effectively preventing blocking

Abstract

The invention relates to the technical field of oil and gas field development, in particular to a coiled tubing bottom seal dragging packer capable of effectively preventing clamping, which comprises a balance valve, a central pipe, a packing rubber sleeve and a locking component, and an upper lock nut and a lower lock nut are arranged on the outer side of the upper part of the central pipe at an interval up and down. The device is reasonable and compact in structure, when the device is used, the lower end of the center pipe is connected with an oil pipe, the upper end of the balance valve is sequentially connected with a tool string and a continuous oil pipe, after liquid is injected into the center pipe, the continuous oil pipe is lifted and put down, the locking assembly can be fixed to the inner wall of a sleeve, then the continuous oil pipe is put down, and the lower lock nut moves upwards relatively under the action of the locking assembly; the packer rubber barrel expands outwards under the combined action of the upper lock nut and the lower lock nut to achieve setting, during setting, the inner wall and the outer wall of the balance valve are communicated with each other, an upper flow channel and a lower flow channel of the packer are communicated, pressure is balanced, the stability during setting is improved, and under the condition of sand setting, a circulation channel can be established through the balance valve, effective sand washing and well washing operation is conducted, and the service life of the packer is prolonged. And the packer can be deblocked conveniently.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field development technology, and is a continuous tubing bottom seal drag packer that can effectively prevent jamming. Background Technology

[0002] Coiled tubing bottom-seal dragged reservoir stimulation technology is currently widely used in oil and gas field development. The main structure of current coiled tubing hydraulic jetting perforation fracturing tools consists of a release arm, centralizer, spray gun, and packer assembly. During bottom-seal dragged reservoir stimulation, problems frequently arise, such as large pressure differentials across the packer, difficulty in releasing the packer rubber seal, and sand buildup causing packer jamming and hindering the establishment of a sand-washing channel, severely impacting normal production operations. Adding appropriate functional tools to the tool string can easily lead to excessive tool string length and poor maneuverability. Summary of the Invention

[0003] This invention provides a bottom-sealed drag packer for coiled tubing that can effectively prevent jamming, overcoming the shortcomings of the prior art. It can effectively solve the problems of large pressure difference between the top and bottom of the packer, difficulty in unsealing the packer rubber, and sand jamming of the packer caused by sediment, which makes it difficult to establish a sand flushing and well washing channel.

[0004] The technical solution of the present invention is achieved through the following measures: a continuous tubing bottom seal drag packer that can effectively prevent jamming, comprising a balance valve, a central tube, a packer sleeve, and a locking assembly. An upper lock nut and a lower lock nut are spaced apart on the upper outer side of the central tube. A packer sleeve is positioned on the outer side of the central tube corresponding to the position between the upper and lower lock nuts. A locking assembly is provided on the lower outer side of the central tube, capable of reciprocating and being fixed to the inner side of the casing. When the locking assembly moves upward, it can push the lower lock nut upward to squeeze the packer sleeve and cause the middle part of the packer sleeve to expand outward. A balance valve is installed at the upper end of the central tube, capable of switching between an open and closed state. When the balance valve is in the open state, the inner and outer walls of the balance valve are interconnected, and the lower end of the balance valve is interconnected with the upper end of the central tube. When the balance valve is in the closed state, the inner and outer walls of the balance valve are interconnected, and the lower end of the balance valve is not interconnected with the upper end of the central tube.

[0005] The following are further optimizations and / or improvements to the above-mentioned technical solution: The outer side of the aforementioned sealing tube may be provided with several outward-facing deformable ring grooves at intervals. A spring ring is installed in the deformable ring groove. The inner side of the sealing tube between each pair of adjacent deformable ring grooves is provided with an inward-facing V-shaped fixing ring groove. A matching and fixedly installed convex ring is provided in the fixing ring groove and is fixedly installed on the outer side of the central tube.

[0006] The aforementioned balancing valve may include a lower connector, an upper connector, an upper valve body, a lower valve body, a valve stem, a valve core, and a sealing assembly. The outer side of the upper end of the central tube is fixedly installed together with the inner side of the lower end of the lower connector. The outer side of the upper end of the lower connector is fixedly installed together with the inner side of the lower end of the tubular outer shell. Several radially penetrating external connecting holes are distributed circumferentially on the outer side of the lower part of the outer shell. A connecting sleeve is fixedly installed on the inner side of the upper part of the outer shell. The outer side of the lower part of the upper connector is slidably and sealingly installed on the inner side of the connecting sleeve. The lower end of the upper connector, corresponding to the position below the connecting sleeve, is fixedly fitted with an upper valve body inside the outer shell. The inner side of the lower end of the upper valve body is fixedly installed with... The valve has a valve stem, and several flow holes with internal and external communication are evenly distributed around the lower outer side of the upper valve body at the position above the valve stem. A valve seat is fixedly installed on the upper end of the lower connector and fitted inside the lower inner side of the outer shell. The valve seat has an internal communication hole with internal and external communication on the inner side corresponding to each external communication hole position. The upper inner side of the valve seat has a funnel-shaped switch hole that is larger at the top and smaller at the bottom. A limit ring platform is fixed on the outer side of the valve stem at the position above the valve seat. A valve core that matches the switch hole is installed on the outer side of the valve stem at the upper end of the limit ring platform. The upper inner side of the lower connector has a sealing component that can make sealing contact with the outer side of the valve stem.

[0007] The aforementioned sealing assembly may include a sealing spacer and a sealing ring. A sealing ring platform is fixed on the inner side of the upper part of the lower connector. A sealing ring is provided at the upper end of the sealing ring platform. Several sealing spacers are arranged sequentially from bottom to top on the upper end of the sealing ring.

[0008] The outer side of the lower part of the aforementioned central tube can be fixed with a supporting outer ring platform, and the inner side of the upper end of the lower lock nut is fixed with a supporting inner ring platform sitting on the outer side of the upper end of the supporting outer ring platform. The outer side of the lower part of the lower lock nut has a conical surface that is larger at the top and smaller at the bottom.

[0009] The aforementioned locking assembly may include a disassembly sleeve, an upper sliding sleeve, rivet catches, a reversing pin, and a pressing assembly. The lower outer side of the central tube has a mounting step surface. A disassembly sleeve is fixedly installed on the lower outer side of the central tube corresponding to the lower end of the mounting step surface. A grooved rotary guide rail extending to the mounting step surface is provided on the lower outer side of the central tube. An upper sliding sleeve is fitted onto the lower outer side of the central tube. An upper mounting sleeve fitted onto the outer side of the central tube is fixedly installed on the upper inner side of the upper sliding sleeve. A rivet catch fitted onto the outer side of the central tube is installed on the upper end of the upper mounting sleeve. The upper part of the rivet catch is locked along the lower edge. After the lower outer part of the mother expands outward, a fixed inner ring platform is fixed on the upper inner side of the upper sliding sleeve. A guide slider is installed between the upper end of the fixed inner ring platform and the lower end of the upper mounting sleeve. A reversing pin with its end slidably installed in a grooved rotary guide rail is fixedly installed on the inner side of the guide slider. A support sleeve fitted on the outside of the disassembly sleeve is fixedly installed on the inner side of the lower end of the upper mounting sleeve. A compression component that can abut against the inner wall of the sleeve is installed on the outer side of the middle part of the support sleeve. A connector is fixedly installed on the outer side of the lower part of the support sleeve corresponding to the position below the compression component. A connecting thread is provided on the outer side of the lower part of the connector.

[0010] The aforementioned extrusion assembly may include a friction block. The outer side of the support sleeve has a number of stepped mounting holes that are interconnected and have a larger outer diameter than an inner diameter. Each mounting hole contains a friction block that is thicker in the middle and thinner at the sides. The inner side of the middle of the friction block has an extrusion groove with an inward opening. The upper end of the connector is fixed with a lower limiting ring fitted on the outer side of the lower end of the friction block. The lower end of the upper mounting sleeve is fixed with an upper limiting ring fitted on the outer side of the upper end of the friction block.

[0011] The outer side of the aforementioned friction block may have several outward-facing grooves spaced vertically.

[0012] The lower outer side of the connector located between the corresponding connecting thread and the support sleeve may be provided with a disassembly groove.

[0013] This invention has a reasonable and compact structure. In use, the lower end of the central tube is connected to the tubing, and the upper end of the balance valve is connected to the tool string and the continuous tubing in sequence. After fluid is injected into the central tube, the continuous tubing is raised and lowered. The locking assembly can be fixed to the inner wall of the casing. Then the continuous tubing is lowered, and the lower lock nut moves upward relative to the upper lock nut under the action of the locking assembly. The packer expands outward under the combined action of the upper and lower lock nuts to achieve setting. During setting, the inner and outer walls of the balance valve are connected to each other, and the upper and lower flow channels of the packer are connected and the pressure is balanced, which improves the stability during setting. In the event of sand settling, a circulation channel can be established through the balance valve to carry out effective sand flushing and well washing operations, which facilitates the release of the packer. Attached Figure Description

[0014] Appendix Figure 1 These are schematic diagrams of the main cross-sectional structure of embodiments one to nine of the present invention.

[0015] Appendix Figure 2 This is a schematic diagram of the main sectional view of the balance valve in Embodiments 1 to 9 of the present invention.

[0016] Appendix Figure 3 This is a schematic diagram of the front sectional view of the upper part of the locking component in embodiments one to nine of the present invention.

[0017] Appendix Figure 4 This is a schematic diagram of the front cross-sectional structure of the lower half of the locking component in embodiments one to nine of the present invention.

[0018] The codes in the attached diagram are as follows: 1 for center tube, 2 for upper lock nut, 3 for lower lock nut, 4 for sealing rubber sleeve, 5 for deformable ring groove, 6 for spring ring, 7 for fixed ring groove, 8 for convex ring, 9 for lower connector, 10 for upper connector, 11 for outer shell, 12 for external connecting hole, 13 for connecting sleeve, 14 for upper valve body, 15 for valve stem, 16 for flow hole, 17 for valve seat, 18 for internal connecting hole, 19 for switch hole, 20 for limit ring platform, 21 for valve core, 22 for sealing spacer ring, and 23 for sealing ring. 24 is the sealing ring platform, 25 is the outer supporting ring platform, 26 is the inner supporting ring platform, 27 is the disassembly sleeve, 28 is the upper sliding sleeve, 29 is the rivet clip, 30 is the groove, 31 is the grooved rotary guide rail, 32 is the upper mounting sleeve, 33 is the fixed inner ring platform, 34 is the guide slider, 35 is the reversing pin, 36 is the support sleeve, 37 is the connector, 38 is the friction block, 39 is the mounting hole, 40 is the extrusion groove, 41 is the lower limit ring, 42 is the upper limit ring, and 43 is the disassembly groove. Detailed Implementation

[0019] 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.

[0020] 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.

[0021] The present invention will be further described below with reference to embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1 As shown, the continuously variable tubing bottom seal drag packer that effectively prevents jamming includes a balance valve, a central tube 1, a packer sleeve 4, and a locking assembly. An upper locking nut 2 and a lower locking nut 3 are spaced vertically apart on the upper outer side of the central tube 1. A packer sleeve 4 is positioned on the outer side of the central tube 1 corresponding to the position between the upper locking nut 2 and the lower locking nut 3. A locking assembly is provided on the lower outer side of the central tube 1, which can be fixed to the inner side of the casing after reciprocating movement. When the locking assembly moves upward, it can push the lower locking nut 3 upward, squeezing the packer sleeve 4 and causing the middle of the packer sleeve 4 to expand outward. A balance valve that can switch between an open and closed state is installed at the upper end of the central tube 1. When the balance valve is open, the inner and outer walls of the balance valve are connected, and the lower end of the balance valve is connected to the upper end of the central tube 1. When the balance valve is closed, the inner and outer walls of the balance valve are connected, and the lower end of the balance valve is not connected to the upper end of the central tube 1.

[0022] In use, connect the lower end of the central tube 1 to the tubing, and the upper end of the balance valve to the tool string and the coiled tubing in sequence. After injecting fluid into the central tube 1, lift and lower the coiled tubing. The locking assembly can be fixed to the inner wall of the casing. Then lower the coiled tubing. The lower lock nut 3 moves upward relative to the upper lock nut 3 under the action of the locking assembly. The packer sleeve 4 expands outward under the combined action of the upper lock nut 2 and the lower lock nut 3 to achieve setting. During setting, the inner wall and outer wall of the balance valve are connected to each other, and the upper and lower flow channels of the packer are connected and the pressure is balanced, which improves the stability during setting. In the event of sand settling, a circulation channel can be established through the balance valve to carry out effective sand flushing and well washing operations, which facilitates the release of the packer.

[0023] The aforementioned continuous tubing bottom seal drag packer, which effectively prevents jamming, can be further optimized and / or improved according to actual needs: Example 2: As an optimization of the above examples, as shown in the appendix. Figure 1 , 3 As shown, the outer side of the sealing tube 4 is provided with several outward-facing deformable ring grooves 5 at intervals. A spring ring 6 is installed in the deformable ring groove 5. The inner side of the sealing tube 4 between each pair of adjacent deformable ring grooves 5 is provided with an inward-facing V-shaped fixing ring groove 7. A matching and fixedly installed convex ring 8 is provided in the fixing ring groove 7 on the outer side of the central tube 1.

[0024] During use, the outer side of the packer tube 4 is provided with several outward-facing deformation annular grooves 5 at intervals. Between each pair of adjacent deformation annular grooves 5, the inner side of the packer tube 4 is provided with an inward-facing V-shaped fixing annular groove 7. The middle of the packer tube 4 has an M-shaped structure, which improves the internal stress distribution and contact stress with the sleeve wall. Depending on the requirements, the packer tube 4 adopts a multi-hardness integrated molding technology, with the hardness at both ends being greater than that in the middle. The high hardness at both ends provides support and auxiliary sealing. After compression, the middle of the packer tube 4 adheres tightly to the sleeve wall to achieve pressure sealing. Spring rings 6 are embedded in the deformation annular grooves 5, which improves the anti-protrusion performance at both ends of the packer tube 4 during compression, ensuring the sealing shape of the packer tube 4, improving sealing capacity and recovery force after unsealing, and facilitating packer setting and unsealing operations.

[0025] Example 3: As an optimization of the above examples, as shown in the appendix. Figure 1 , 2As shown, the balancing valve includes a lower connector 9, an upper connector 10, an upper valve body 14, a lower valve body, a valve stem 15, a valve core 21, and a sealing assembly. The outer side of the upper end of the central tube 1 is fixedly installed together with the inner side of the lower end of the lower connector 9. The outer side of the upper end of the lower connector 9 is fixedly installed together with the inner side of the lower end of the tubular outer shell 11. Several radially penetrating external connecting holes 12 are distributed circumferentially on the outer side of the lower part of the outer shell 11. A connecting sleeve 13 is fixedly installed on the inner side of the upper part of the outer shell 11. The outer side of the lower part of the upper connector 10 is slidably sealed on the inner side of the connecting sleeve 13. The lower end of the upper connector 10, corresponding to the position below the connecting sleeve 13, is fixedly fitted with an upper valve body 14 inside the outer shell 11. A valve core 21 is fixedly installed on the inner side of the lower end of the upper valve body 14. The valve stem 15 has several flow holes 16 evenly distributed around its lower outer side along the circumference on the upper valve body 14, which is located above the valve stem 15. A valve seat 17 is fixedly installed on the upper end of the lower connector 9 and fitted inside the lower part of the outer casing 11. The valve seat 17 has an inner connecting hole 18 that is connected inside and outside on the inner side of each outer connecting hole 12. The valve seat 17 has a funnel-shaped switch hole 19 that is larger at the top and smaller at the bottom on the inner side of the upper end. A limiting ring platform 20 is fixed on the outer side of the valve stem 15, which is located above the valve seat 17. A valve core 21 that matches the switch hole 19 is installed on the outer side of the valve stem 15, which is located at the upper end of the limiting ring platform 20. A sealing component that can make sealing contact with the outer side of the valve stem 15 is provided on the inner side of the upper end of the lower connector 9.

[0026] As required, a switch step surface is provided on the inner side of the middle part of the funnel-shaped switch hole 19. During use, with this setup, when the continuous tubing is raised or lowered, the balance valve is in the open state after the valve stem 15 moves upward, the valve core 21 and the valve seat 17 are separated, and the upper connector 10 and the center tube 1 are connected internally. This allows the upper and lower parts of the sealing sleeve 4, the tubing and the annulus to be connected. It also allows the upper and lower annulus to be reliably separated during perforation by the expanded sealing sleeve 4. When the valve stem 15 moves downward, the balance valve is in the closed state. After the valve stem 15 moves downward, it is inserted into the sealing assembly, so that the upper connector 10 and the center tube 1 are not connected internally. At the same time, the limiting ring platform 20 leaves a gap between the valve core 21 and the valve seat 17, so that the inner wall and the outer wall of the balance valve are connected. This allows for both reverse circulation and forward circulation. Reverse circulation can be achieved in the setting state. By setting the limiting ring platform 20, that is, always leaving a distance between the valve core 21 and the valve seat 17, forward circulation can be achieved when the continuous tubing is raised or lowered and encounters resistance.

[0027] Example 4: As an optimization of the above examples, as shown in the appendix. Figure 1 , 2 As shown, the sealing assembly includes a sealing spacer ring 22 and a sealing ring 23. A sealing ring platform 24 is fixed on the upper inner side of the lower connector 9. A sealing ring 23 is provided on the upper end of the sealing ring platform 24. Several sealing spacers 22 are arranged sequentially from bottom to top on the upper end of the sealing ring 23.

[0028] Depending on the requirements, the sealing ring 23 is a known existing technology, such as a Y-type sealing ring. During use, it facilitates the assembly and disassembly of the sealing component and also improves the sealing performance between the sealing component and the valve stem 15.

[0029] Example 5: As an optimization of the above examples, as shown in the appendix. Figure 1 , 3 As shown, a supporting outer ring platform 25 is fixed on the lower outer side of the central tube 1, and a supporting inner ring platform 26 is fixed on the upper inner side of the lower lock nut 3, which sits on the upper outer side of the supporting outer ring platform 25. The lower outer side of the lower lock nut 3 has a conical surface that is larger at the top and smaller at the bottom.

[0030] During use, the outer ring support 25 and the inner ring support 26 can limit the sliding of the lower lock nut 3, which facilitates the disassembly and maintenance of the sealing rubber tube 4. The lower outer side of the lower lock nut 3 is a conical surface that is larger at the top and smaller at the bottom. When the locking component slides upward, it can prevent excessive pressure on the sealing rubber tube 4, which could cause it to break.

[0031] Example 6: As an optimization of the above examples, as shown in the appendix Figure 1 , 3 As shown in Figure 4, the locking assembly includes a disassembly sleeve 27, an upper sliding sleeve 28, a rivet clip 29, a reversing pin 35, and a pressing assembly. The lower outer side of the central tube 1 has a mounting step surface. A disassembly sleeve 27 is fixedly installed on the lower outer side of the central tube 1 corresponding to the lower end of the mounting step surface. A grooved rotary guide rail 31 extending to the mounting step surface is provided on the lower outer side of the central tube 1. An upper sliding sleeve 28 is fitted onto the lower outer side of the central tube 1. An upper mounting sleeve 32, fitted onto the outer side of the central tube 1, is fixedly installed on the upper inner side of the upper sliding sleeve 28. A rivet clip 29, fitted onto the outer side of the central tube 1, is installed on the upper end of the upper mounting sleeve 32. The upper part of the rivet clip 29 extends along the lower... After the lower outer side of the lock nut 3 moves, it expands outward. The upper inner side of the upper sliding sleeve 28 is fixed with a fixed inner ring platform 33. A guide slider 34 is installed between the upper end of the fixed inner ring platform 33 and the lower end of the upper mounting sleeve 32. A reversing pin 35 with its end slidably installed in the grooved rotary guide rail 31 is fixedly installed on the inner side of the guide slider 34. A support sleeve 36 fitted on the outer side of the disassembly sleeve 27 is fixedly installed on the inner side of the lower end of the upper mounting sleeve 32. A pressing component that can abut against the inner wall of the sleeve is installed on the outer side of the middle part of the support sleeve 36. A connector 37 is fixedly installed on the outer side of the lower part of the support sleeve 36 corresponding to the position below the pressing component. A connecting thread is provided on the outer side of the lower part of the connector 37.

[0032] According to the requirements, the rivet slip 29 is a known technology. The upper outer side of the rivet slip 29 has slip teeth. The grooved rotary guide rail 31 is a known technology, such as the grooved rotary guide rail 31 in the positive and negative circulation internal blowout preventer device with announcement number CN211058759U. The end of the reversing pin 35 is located on the lower inner side of the lower short groove. The upper inner wall of the grooved rotary guide rail 31 and the inner side of the central tube 1 are provided with a cleaning hole that connects the inside and outside. This allows the grooved rotary guide rail 31 to be cleaned and lubricated. The outer side of the central tube 1 corresponding to the position of the rivet slip 29 is provided with several through holes that connect the inside and outside along the circumference. This allows the slip teeth of the rivet slip 29 and the conical surface of the lower lock nut 3 to be lubricated and cleaned.

[0033] During operation, the continuous tubing is lowered, propelling the central tube 1 and the extrusion assembly forward within the casing. Once the extrusion assembly reaches a predetermined depth, the liquid within the central tube 1 acts on the extrusion assembly, causing its outer side to abut against the inner wall of the casing. This allows the extrusion assembly to secure the rivet slip 29, support sleeve 36, and upper mounting sleeve 32 within the casing. After the continuous tubing is lifted, the upper mounting sleeve 32 and upper sliding sleeve 28 move the central tube 1 upwards. Then, the continuous tubing is lowered again, and the reversing pin 35 slides from the lower short groove of the grooved rotary guide rail 31 to the lower long groove, causing the lower locking nut 3 to press against the upper inner side of the rivet slip 29. This upward movement of the lower locking nut 3 then presses against the sealing rubber cylinder 4, causing the sealing rubber cylinder 4 to... After the middle part expands outward, it sits on the inner wall of the casing. At the same time, the upper part of the rivet slip 29 expands outward and can be fixed on the inner wall of the casing. This fixes the packer. When the coiled tubing is lowered, the upper mounting sleeve 32 and the upper sliding sleeve 28 rotate at a certain angle under the action of the reversing pin 35. Repeatedly raising and lowering the coiled tubing can set the fracturing nozzle in multiple positions, which is convenient for perforating the inner wall of the casing in multiple positions, thereby performing perforation operations on the formation. At the same time, during the process of lowering the coiled tubing, the lower locking nut 3 and the inner side of the upper part of the rivet slip 29 can also squeeze each other, so that the upper part of the rivet slip 29 expands outward and is fixed on the inner wall of the casing. This fixes the packer and facilitates subsequent perforation operations.

[0034] Example 7: As an optimization of the above examples, as shown in the appendix. Figure 1 , 4 As shown, the extrusion assembly includes a friction block 38. The support sleeve 36 has several stepped mounting holes 39 that are interconnected and have a larger outer diameter than the inner diameter, evenly distributed along the circumference on the outer side of the middle. Each mounting hole 39 contains a friction block 38 that is thicker in the middle and thinner at both sides. The inner side of the middle of the friction block 38 is provided with an extrusion groove 40 that opens inward. The upper end of the connector 37 is fixed with a lower limit ring 41 that is fitted onto the outer side of the lower end of the friction block 38. The lower end of the upper mounting sleeve 32 is fixed with an upper limit ring 42 that is fitted onto the outer side of the upper end of the friction block 38.

[0035] During use, by setting the upper limit ring 42 and the lower limit ring 41, the friction block 38 and the support sleeve 36 can be prevented from separating from each other, and the disassembly and assembly of the friction block 38 and the support sleeve 36 can be facilitated, reducing subsequent maintenance costs. By setting the stepped mounting hole 39 with a larger outer diameter and a smaller inner diameter, the fluid in the central tube 1 can act on the inner side of the friction block 38 through the mounting hole 39, so that the outer side of the friction block 38 can abut against the inner wall of the casing, reducing the use of elastic elements. This can increase the force between the outer side of the friction block 38 and the inner wall of the casing, making the friction block 38 fixed and stable, which is convenient for subsequent setting and sealing operations and the opening and closing state of the balance valve when the coiled tubing is raised and lowered. The inner side of the friction block 38 is provided with a squeezing groove 40, so that the fluid in the central tube 1 flows into the squeezing groove 40 after passing through the mounting hole 39, and acts on the inner side of the friction block 38, so that the outer side of the friction block 38 can abut against the inner wall of the casing, improving the setting efficiency.

[0036] Example 8: As an optimization of the above examples, as shown in the appendix Figure 1 , 4 As shown, the friction block 38 has several outward-facing grooves 30 spaced vertically on its outer side.

[0037] Depending on the requirements, the groove 30 can be rectangular or arc-shaped. During use, the arc-shaped groove makes it easier to fix the friction block 38 to the inner wall of the sleeve.

[0038] Example 9: As an optimization of the above examples, as shown in the appendix Figure 1 , 4 As shown, a disassembly groove 43 is provided on the lower outer side of the connector 37, which is located between the connecting thread and the support sleeve 36. This design facilitates the disassembly and assembly of the support sleeve 36, connector 37, and oil pipe during use.

[0039] The above technical features constitute the 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.

[0040] The preferred embodiment of the present invention is as follows: The following components are assembled sequentially: release mechanism, centralizer, spray gun, coiled tubing bottom seal packer (effectively preventing jamming), and wellhead tool string; the reversing pin 35 is positioned in the lower short groove of the grooved rotary guide rail 31 and smoothly lowered into the well; after reaching the set position, the coiled tubing is raised and lowered, causing the reversing pin 35 to slide from the lower short groove of the grooved rotary guide rail 31 into the lower long groove. During the lowering process, the friction block 38 generates an upward frictional force against the inner wall of the casing, thus... The slip teeth of the rivet slip 29 open and push the lower lock nut 3 upward, eventually causing the packer sleeve 4 to expand and seal the annulus of the oil sleeve; at the same time, the lower end of the valve stem 15 is inserted into the sealing assembly, so that the packer is sealed inside; then the perforation and fracturing operations are carried out; after the construction is completed, the coiled tubing is pulled up, the valve stem 15 is pulled out from the sealing assembly, so that the inner hole between the upper and lower joints 9 of the balance valve is completely connected, the pressure of the upper and lower parts of the packer sleeve 4 is connected, the packer sleeve 4 is reset, the packer is unsealed, and then the downhole tool string can be pulled out.

Claims

1. A continuously variable tubing bottom seal drag packer that can effectively prevent jamming, characterized in that... The device includes a balance valve, a central tube, a sealing rubber tube, and a locking assembly. An upper locking nut and a lower locking nut are spaced apart on the upper outer side of the central tube. A sealing rubber tube is positioned on the outer side of the central tube corresponding to the position between the upper and lower locking nuts. A locking assembly is located on the lower outer side of the central tube, capable of reciprocating and fixing to the inner side of a sleeve. When the locking assembly moves upward, it pushes the lower locking nut upward, squeezing the sealing rubber tube and causing the middle of the sealing rubber tube to expand outward. A balance valve is installed at the upper end of the central tube, capable of switching between an open and closed state. When the balance valve is open, its inner and outer walls are connected, and its lower end is connected to the upper end of the central tube. When the balance valve is closed, its inner and outer walls are connected, but its lower end is not connected to the upper end of the central tube.

2. The continuous tubing bottom seal drag packer that can effectively prevent jamming according to claim 1, characterized in that... The outer side of the sealing tube has several outward-facing deformable ring grooves at intervals. Spring rings are installed in the deformable ring grooves. The inner side of the sealing tube between each pair of adjacent deformable ring grooves has an inward-facing V-shaped fixing ring groove. The fixing ring groove has a matching convex ring that is fixedly installed on the outside of the central tube.

3. The continuous tubing bottom seal drag packer that can effectively prevent jamming according to claim 2, characterized in that... The balancing valve includes a lower connector, an upper connector, an upper valve body, a lower valve body, a valve stem, a valve core, and a sealing assembly. The outer side of the upper end of the central tube is fixedly installed together with the inner side of the lower end of the lower connector. The outer side of the upper end of the lower connector is fixedly installed together with the inner side of the lower end of the tubular outer shell. Several radially penetrating external connecting holes are distributed circumferentially on the outer side of the lower part of the outer shell. A connecting sleeve is fixedly installed on the inner side of the upper part of the outer shell. The outer side of the lower part of the upper connector is slidably sealed within the connecting sleeve. The lower end of the upper connector, corresponding to the position below the connecting sleeve, is fixedly fitted with an upper valve body inside the outer shell. A valve core is fixedly installed on the inner side of the lower end of the upper valve body. The valve stem has several internally and externally connected flow holes evenly distributed around the circumference on the lower outer side of the upper valve body, corresponding to the position above the valve stem. A valve seat fitted inside the lower inner side of the outer shell is fixedly installed at the upper end of the lower connector. An internally connected hole is provided on the inner side of the valve seat corresponding to each externally connected hole. A funnel-shaped switch hole with a larger upper end and a smaller lower end is provided on the inner side of the upper end of the valve seat. A limit ring platform is fixed on the outer side of the valve stem corresponding to the position above the valve seat. A valve core matching the switch hole is installed on the outer side of the valve stem corresponding to the upper end of the limit ring platform. A sealing component that can make sealing contact with the outer side of the valve stem is provided on the inner side of the upper end of the lower connector.

4. The continuous tubing bottom seal drag packer that can effectively prevent jamming according to claim 3, characterized in that... The sealing assembly includes a sealing spacer ring and a sealing ring. A sealing ring platform is fixed on the inner side of the upper part of the lower connector. A sealing ring is provided at the upper end of the sealing ring platform. Several sealing spacer rings are arranged sequentially from bottom to top on the upper end of the sealing ring.

5. The continuous tubing bottom seal drag packer with effective anti-jamming capability according to claim 1, 2, 3, or 4, characterized in that... A supporting outer ring platform is fixed to the lower outer side of the central tube, and a supporting inner ring platform is fixed to the upper inner side of the lower lock nut, which sits on the upper outer side of the supporting outer ring platform. The lower outer side of the lower lock nut has a conical surface that is larger at the top and smaller at the bottom.

6. The continuously variable tubing bottom seal drag packer with effective anti-jamming capability according to claim 5, characterized in that... The locking assembly includes a disassembly sleeve, an upper sliding sleeve, rivet catches, a reversing pin, and a pressing assembly. The lower outer side of the central tube has a mounting step surface. A disassembly sleeve is fixedly installed on the lower outer side of the central tube corresponding to the lower end of the mounting step surface. A grooved rotary guide rail extending to the mounting step surface is provided on the lower outer side of the central tube. An upper sliding sleeve is fitted onto the lower outer side of the central tube. An upper mounting sleeve fitted onto the outer side of the central tube is fixedly installed on the upper inner side of the upper sliding sleeve. A rivet catch fitted onto the outer side of the central tube is installed on the upper end of the upper mounting sleeve. The upper part of the rivet catch is aligned with the lower lock nut. After the lower outer part moves, it expands outward. A fixed inner ring platform is fixed on the upper inner side of the upper sliding sleeve. A guide slider is installed between the upper end of the fixed inner ring platform and the lower end of the upper mounting sleeve. A reversing pin with its end slidably installed in the grooved rotary guide rail is fixedly installed on the inner side of the guide slider. A support sleeve fitted on the outside of the disassembly sleeve is fixedly installed on the inner side of the lower end of the upper mounting sleeve. A compression component that can abut against the inner wall of the sleeve is installed on the outer side of the middle part of the support sleeve. A connector is fixedly installed on the outer side of the lower part of the support sleeve corresponding to the position below the compression component. A connecting thread is provided on the outer side of the lower part of the connector.

7. The continuously variable tubing bottom seal drag packer that can effectively prevent jamming according to claim 6, characterized in that... The extrusion assembly includes a friction block. The outer side of the support sleeve has several stepped mounting holes that are interconnected and have a larger outer diameter than an inner diameter. Each mounting hole contains a friction block that is thicker in the middle and thinner at the sides. The inner side of the middle of the friction block has an extrusion groove with an inward opening. The upper end of the connector is fixed with a lower limit ring fitted on the outer side of the lower end of the friction block. The lower end of the upper mounting sleeve is fixed with an upper limit ring fitted on the outer side of the upper end of the friction block.

8. The continuous tubing bottom seal drag packer with effective anti-jamming capability according to claim 7, characterized in that... The friction block has several outward-facing grooves spaced at intervals on its outer side.

9. The continuously variable tubing bottom seal drag packer with effective anti-jamming capability according to claim 6, 7, or 8, characterized in that... A disassembly groove is provided on the lower outer side of the connector, which is located between the connecting thread and the support sleeve.

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