A type of coiled tubing end fitting

Abstract

This utility model relates to the field of downhole oil and gas tubing cable joint technology, specifically a continuous tubing end joint, including an outer tube connection assembly, an inner tube connection assembly, and a cable crossing connector. The outer tube connection assembly includes a shear pin safety device, a reverse circulation valve, a cup packer, and a union connector. The shear pin safety device includes a shear seat and a shear cap. The upper end of the shear seat is connected to a quick-release ratchet outer cylinder, and the lower end of the cup packer is connected to the base of the cable crossing connector's adapter socket via a union connector. The inner tube connection assembly includes an extended inner tube and a non-pressure-bearing plug. The upper end of the extended inner tube is connected to the inner tube of the upper-level composite tubing cable, and the lower end is connected to the upper end of the non-pressure-bearing plug. The lower end of the non-pressure-bearing plug is connected to the second inner tube of the cable crossing connector's adapter socket. This utility model is applicable to composite continuous tubing with built-in cables, enabling quick access and disassembly of downhole tools while ensuring reliable sealing and rapid disposal after tool damage.

Description

Technical Field

[0001] This utility model relates to the field of downhole oil and gas pipeline technology, specifically a continuous tubing end connector. Background Technology

[0002] In downhole oil production operations, coiled tubing is typically used to transport oil and gas. To facilitate control of underground equipment, cables are often installed inside the coiled tubing, creating a composite coiled tubing structure. Currently, for this type of composite coiled tubing with cables inside, the end connectors (connecting downhole tools) require rapid deployment and retrieval of the tools during use. In some extreme environments, rapid disposal is also necessary if downhole tools are damaged. Because the structure of composite coiled tubing differs significantly from previous methods, new requirements have been placed on the design of the end connectors to meet these needs. Utility Model Content

[0003] In response to the problems raised in the background art, the purpose of this utility model is to provide a continuous tubing end connector, which is suitable for composite continuous tubing with built-in cables, enabling quick access and disassembly of downhole tools, while ensuring reliable sealing, and also has the function of quick disposal after downhole tool damage.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A continuous tubing end fitting includes an outer tubing connection assembly, an inner tubing connection assembly, and a cable crossing connector. The outer tubing connection assembly includes a shear pin safety device, a reverse circulation valve, a cup packer, and a union connector. The shear pin safety device includes a shear seat and a shear cap. The shear seat is a tubular structure. The upper end of the shear seat is connected to a quick-release ratchet outer cylinder. The shear cap is fitted in the middle of the shear seat and connected to the shear seat via a shear pin. The lower end of the shear cap is connected to the inlet of the reverse circulation valve via an expanded outer cylinder. The outlet of the reverse circulation valve is connected to the upper end of the cup packer. The lower end of the cup packer is connected to the base of the adapter socket of the cable crossing connector via a union connector. The inner tubing connection assembly includes an extended inner tubing and a non-pressure-bearing plug. The extended inner tubing is located inside the outer tubing assembly. The upper end of the extended inner tubing is connected to the inner tubing of the upper-level composite cable, and the lower end is connected to the upper end of the non-pressure-bearing plug. The lower end of the non-pressure-bearing plug is connected to the second inner tubing of the adapter socket of the cable crossing connector. The adapter of the cable crossing connector connects to the downhole tool. The fluid collected by the downhole tool enters the cable crossing connector through the central channel of the adapter, and the cable of the downhole tool enters the cable crossing connector through the cable channel of the adapter.

[0005] The upper end of the shear seat is provided with a first ratchet tooth; the lower end of the quick-release ratchet outer cylinder has an annular slot with a lower opening, the inner side wall of the annular slot is threadedly connected to the inner wall of the upper end of the shear seat, and the outer side wall of the annular slot is slidably sealed to the outer wall of the upper end of the shear seat; a ratchet is provided inside the annular slot, the lower end of the ratchet has a second ratchet tooth, and a spring is provided between the upper end of the ratchet and the top wall of the annular slot; the outer side wall of the annular slot is provided with multiple waist-shaped through slots, and multiple protrusions are connected to the outer circumference of the ratchet, each protrusion being inserted into a waist-shaped through slot.

[0006] The shear cap is an overall annular structure. The upper end of the inner hole of the shear cap is in clearance fit with the shear seat. The lower end of the inner hole of the shear cap is provided with a first annular stepped groove. The first annular stepped groove is threadedly connected to the upper end of the expanded diameter outer cylinder. The lower end of the outer wall of the shear seat is provided with a sealing ring. The upper end of the expanded diameter outer cylinder is also slidably sealed to the outer wall of the shear seat.

[0007] The inlet of the reverse circulation valve is provided with an external thread, and the outlet of the reverse circulation valve is provided with an internal thread; the inlet of the reverse circulation valve is threadedly connected to the lower end of the expanded outer cylinder, and the outlet of the reverse circulation valve is threadedly connected to the upper end of the cup packer.

[0008] The union connector includes a union sealing seat and a union outer cylinder. The union sealing seat is a tubular structure with external threads on its upper outer wall and a first annular boss on its lower outer wall. The union outer cylinder has a second annular boss on its upper inner wall. The upper end of the union sealing seat is threadedly connected to the lower end of the cup packer. The upper end of the union outer cylinder is fitted onto the lower end of the union sealing seat, and the second annular boss of the union outer cylinder is slidably and sealingly connected to the union sealing seat. The lower end of the union outer cylinder is threadedly connected to the base of the adapter socket of the cable passing through the connector.

[0009] The non-pressure-bearing plug is located inside the union connector. The upper end of the non-pressure-bearing plug is fixedly connected to the extension inner tube, and the lower end is welded to the upper end of the second inner tube of the adapter socket of the cable crossing connector. The lower end of the non-pressure-bearing plug has a insertion groove, and the upper end of the second inner tube of the adapter socket of the cable crossing connector has a plug. The plug is inserted into the corresponding insertion groove.

[0010] This invention offers the following advantages: It enables continuous composite transmission of the central cable and downhole fluid, suitable for coiled tubing with built-in cables. The shear pin safety device allows for rapid connection to the upper tubing and can disconnect the connection while preserving the equipment above the safety device in case the lower tool jams. The reverse circulation valve design facilitates cleaning of the tubing annular cavity wall, and the cup packer ensures downhole fixation of the entire coiled tubing end joint. The cable crossing connector transfers the cable from the center of the tubing to the annular space, while simultaneously transferring the downhole fluid from the annular space to the central channel, making connection to downhole tools convenient and quick, particularly suitable for connection with submersible pumps (SPMPs). Attached Figure Description

[0011] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0012] Figure 2 This is a front view of the overall structure of this utility model.

[0013] Figure 3 for Figure 2 AA view.

[0014] Figure 4 for Figure 3 Enlarged view of part B.

[0015] Figure 5 for Figure 3 Enlarged view of part C.

[0016] Figure 6 for Figure 3 Enlarged view of part D.

[0017] Figure 7 This is a front view of the shear pin safety device.

[0018] Figure 8 This is a three-dimensional schematic diagram of the inner tube connection assembly.

[0019] Figure 9 This is a three-dimensional schematic diagram of the union joint and the extended inner tube.

[0020] Figure 10 This is a three-dimensional schematic diagram of a non-pressure-bearing plug.

[0021] Figure 11 This is a three-dimensional diagram of a cable crossing connector.

[0022] In the diagram: 1-Shear pin safety device, 2-Reverse circulation valve, 3-Pouch sealer, 4-Union connector, 5-Cable pass-through connector, 6-Quick release ratchet outer cylinder, 7-Expanded outer cylinder, 8-Extended inner tube, 9-Non-pressure-bearing plug; 11-Shear seat, 12-Shear cap, 13-Shear pin; 41-Union sealing seat, 42-Union outer cylinder, 43-Locking nut, 44-Anti-loosening nut; 51-Adapter socket, 52-Adapter; 511-Base, 512-Second inner tube; 61- Circular slot, 62- Ratchet, 63- Spring, 64- Waist-shaped through slot, 65- Protrusion; 111 - Sealing ring. Detailed Implementation

[0023] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0024] like Figure 1-11 As shown, this utility model provides a continuous tubing end connector, including an outer tube connection assembly, an inner tube connection assembly, and a cable passage connector 5. The outer tube connection assembly includes a shear pin safety device 1, a reverse circulation valve 2, a cup packer 3, and a union connector 4. The shear pin safety device 1 includes a shear seat 11 and a shear cap 12. The shear seat 11 is a tubular structure. The upper end of the shear seat 11 is connected to a quick-release ratchet outer cylinder 6. The shear cap 12 is fitted in the middle of the shear seat 11 and connected to the shear seat 11 through a shear pin 13. The lower end of the shear cap 12 is connected to the inlet of the reverse circulation valve 2 through an expanded diameter outer cylinder 7. The outlet of the reverse circulation valve 2 is connected to the upper end of the cup packer 3. The lower end of device 3 is connected to the base 511 of the adapter socket 51 of cable crossing connector 5 via a union connector 4. The inner tube connection assembly includes an extended inner tube 8 and a non-pressure-bearing plug 9. The extended inner tube 8 is disposed inside the outer tube assembly. The upper end of the extended inner tube 8 is connected to the inner tube of the upper-level composite cable, and the lower end is connected to the upper end of the non-pressure-bearing plug 9. The lower end of the non-pressure-bearing plug 9 is connected to the second inner tube 512 of the adapter socket 51 of cable crossing connector 5. The adapter 52 of cable crossing connector 5 is connected to the downhole tool. The fluid collected by the downhole tool enters the cable crossing connector 5 through the central channel of adapter 52, and the cable of the downhole tool enters the cable crossing connector 5 through the cable channel of adapter 5. Here, the cable crossing connector 5 adopts the inventor's prior patent application (a downhole cable crossing connector, patent number: 202511102083X). Based on this patent, this utility model is particularly suitable for connection with submersible electric pumps.

[0025] The upper end of the shear seat 11 is provided with a first ratchet tooth; the lower end of the quick-release ratchet outer cylinder 6 is provided with an annular slot 61 with a lower opening, the inner side wall of the annular slot 61 is threadedly connected to the inner wall of the upper end of the shear seat 11, and the outer side wall of the annular slot 61 is slidably sealed to the outer wall of the upper end of the shear seat 11; a ratchet 62 is provided inside the annular slot 61, the lower end of the ratchet 62 is provided with a second ratchet tooth, and a spring 63 is provided between the upper end of the ratchet 62 and the top wall of the annular slot 61; the outer side wall of the annular slot 61 is provided with a plurality of waist-shaped through grooves 64, and a plurality of protrusions 65 are connected to the outer periphery of the ratchet 62, each protrusion 65 being inserted into a waist-shaped through groove 64. The upper end of this utility model is connected to a composite coiled tubing (with a three-core power cable, a five-core signal cable, and an optical fiber passing through the center, and downhole fluid passing through the annular cavity). The lower end of the outer tube of the composite coiled tubing is equipped with a quick-release ratchet outer cylinder 6, which contains a spring 63. Pushing the protrusion 65 on the quick-release ratchet outer cylinder 6 compresses the spring 63, which can achieve quick disassembly. When the spring 63 is released, the spring 63 rebounds, causing the ratchet 62 to engage, which can prevent the threads from disengaging.

[0026] The shear cap 12 is an overall annular structure. The upper end of the inner hole of the shear cap 12 is clearance-fitted with the shear seat 11. The lower end of the inner hole of the shear cap 12 has a first annular stepped groove, which is threaded to the upper end of the expanded diameter outer cylinder 7. The lower end of the outer wall of the shear seat 11 has a sealing ring 111, and the upper end of the expanded diameter outer cylinder 7 is also slidably sealed to the outer wall of the shear seat 11. The shear pin safety device 1 can cut off the shear pin 13 by applying tension at the upper end when the lower tool gets stuck, discarding the stuck tool and keeping the equipment above the shear pin safety device.

[0027] The inlet of the reverse circulation valve 2 is provided with an external thread, and the outlet of the reverse circulation valve 2 is provided with an internal thread. The inlet of the reverse circulation valve 2 is threadedly connected to the lower end of the expanded outer cylinder 7, and the outlet of the reverse circulation valve 2 is threadedly connected to the upper end of the cup packer 3. The lower end of the shear pin type safety device 1 consists of the reverse circulation valve 2 and the cup packer 3 in sequence. Both the reverse circulation valve 2 and the cup packer 3 are existing technologies. The reverse circulation valve 2 can be referenced in patent CN 207750062U, and the cup packer 3 can be referenced in patent CN223330528U. Therefore, their specific structures are not detailed in the figure, and their functions will not be described in detail.

[0028] The union connector 4 includes a union sealing seat 41 and a union outer cylinder 42. The union sealing seat 41 is a tubular structure with external threads on its upper outer wall and a first annular boss on its lower outer wall. The union outer cylinder 42 has a second annular boss on its upper inner wall. The upper end of the union sealing seat 41 is threadedly connected to the lower end of the cup sealer 3. The upper end of the union outer cylinder 42 is fitted onto the lower end of the union sealing seat 41, and the second annular boss of the union outer cylinder 42 is slidably and sealingly connected to the union sealing seat 41. The lower end of the union outer cylinder 42 is threadedly connected to the base 511 of the adapter socket 51 of the cable passing connector 5.

[0029] The non-pressure-bearing plug 9 is disposed inside the union connector 4. The upper end of the non-pressure-bearing plug 9 is fixedly connected to the extension inner tube 8, and the lower end is welded to the upper end of the second inner tube 512 of the adapter socket 51 of the cable passage connector 5. The lower end of the non-pressure-bearing plug 9 has a insertion groove, and the upper end of the second inner tube 512 of the adapter socket 51 of the cable passage connector 5 has a connector, which is inserted into the insertion groove. Specifically, the lower outer wall of the non-pressure-bearing plug 9 has a stepped groove, which is inserted into the second inner tube 512 and slides in a sealed manner with the second inner tube 512.

[0030] The lower end of the union connector 4 is equipped with a cable crossing connector 5, which can transfer the power cable, signal cable and optical fiber in the center of the pipeline to the annular space, and at the same time transfer the downhole fluid in the annular space to the central channel to facilitate the rapid connection of subsequent tools.

[0031] The parts of this utility model not described in detail are existing technologies.

Claims

1. A coiled tubing end fitting comprising an outer pipe connection assembly, an inner pipe connection assembly and a cable passage fitting (5), characterized in that: The outer tube connection assembly includes a shear pin safety device (1), a reverse circulation valve (2), a cup packer (3), and a union connector (4). The shear pin safety device (1) includes a shear seat (11) and a shear cap (12). The shear seat (11) is a tubular structure. The upper end of the shear seat (11) is connected to the quick-release ratchet outer cylinder (6). The shear cap (12) is fitted in the middle of the shear seat (11) and connected to the shear seat (11) through a shear pin (13). The lower end of the shear cap (12) is connected to the inlet of the reverse circulation valve (2) through an expanded diameter outer cylinder (7). The reverse circulation valve ( 2) The outlet is connected to the upper end of the cup seal (3), and the lower end of the cup seal (3) is connected to the base (511) of the adapter socket (51) of the cable crossing connector (5) through the union joint (4); the inner tube connection assembly includes an extended inner tube (8) and a non-pressure-bearing plug (9). The extended inner tube (8) is set inside the outer tube assembly. The upper end of the extended inner tube (8) is connected to the inner tube of the upper composite cable, and the lower end is connected to the upper end of the non-pressure-bearing plug (9). The lower end of the non-pressure-bearing plug (9) is connected to the second inner tube (512) of the adapter socket (51) of the cable crossing connector (5). The adapter (52) of the cable crossing connector (5) is connected to the downhole tool. The fluid collected by the downhole tool enters the cable crossing connector (5) through the central channel of the adapter (52), and the cable of the downhole tool enters the cable crossing connector (5) through the cable channel of the adapter (52).

2. The coiled tubing end fitting according to claim 1, characterized in that: The upper end of the shear seat (11) is provided with a first ratchet tooth; the lower end of the quick-release ratchet outer cylinder (6) is provided with an annular slot (61) with a lower opening, the inner side wall of the annular slot (61) is threadedly connected to the inner wall of the upper end of the shear seat (11), and the outer side wall of the annular slot (61) is slidably sealed to the outer wall of the upper end of the shear seat (11); a ratchet (62) is provided inside the annular slot (61), the lower end of the ratchet (62) is provided with a second ratchet tooth, and a spring (63) is provided between the upper end of the ratchet (62) and the top wall of the annular slot (61); the outer side wall of the annular slot (61) is provided with multiple waist-shaped through grooves (64), and multiple protrusions (65) are connected to the outer periphery of the ratchet (62), each protrusion (65) being inserted into a waist-shaped through groove (64).

3. A coiled tubing end fitting according to claim 1, characterized in that: The shear cap (12) is an overall ring structure. The upper end of the inner hole of the shear cap (12) is in clearance fit with the shear seat (11). The lower end of the inner hole of the shear cap (12) is provided with a first annular stepped groove. The first annular stepped groove is threadedly connected to the upper end of the expanded diameter outer cylinder (7). The lower end of the outer wall of the shear seat (11) is provided with a sealing ring (111). The upper end of the expanded diameter outer cylinder (7) is also slidably sealed to the outer wall of the shear seat (11).

4. A coiled tubing end fitting according to claim 1, characterized in that: The inlet of the reverse circulation valve (2) is provided with an external thread, and the outlet of the reverse circulation valve (2) is provided with an internal thread; the inlet of the reverse circulation valve (2) is threaded to the lower end of the expanded outer cylinder (7), and the outlet of the reverse circulation valve (2) is threaded to the upper end of the cup packer (3).

5. A coiled tubing end fitting according to claim 1, characterized in that: The union connector (4) includes a union sealing seat (41) and a union outer cylinder (42). The union sealing seat (41) is a tubular structure with an external thread on its upper outer wall and a first annular boss on its lower outer wall. The union outer cylinder (42) has a second annular boss on its upper inner wall. The upper end of the union sealing seat (41) is threaded to the lower end of the cup sealer (3). The upper end of the union outer cylinder (42) is fitted onto the lower end of the union sealing seat (41), and the second annular boss of the union outer cylinder (42) is slidably sealed to the union sealing seat (41). The lower end of the union outer cylinder (42) is threaded to the base (511) of the adapter socket (51) of the cable through connector (5).

6. A coiled tubing end fitting according to claim 1, characterized in that: The non-pressure-bearing plug (9) is located inside the union connector (4). The upper end of the non-pressure-bearing plug (9) is fixedly connected to the extension inner tube (8), and the lower end is welded to the upper end of the second inner tube (512) of the adapter socket (51) of the cable crossing connector (5). The lower end of the non-pressure-bearing plug (9) has a plug groove, and the upper end of the second inner tube (512) of the adapter socket (51) of the cable crossing connector (5) has a plug connector. The plug connector is inserted into the plug groove.

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