Coiled tubing salvage accelerator

Abstract

The invention belongs to the technical field of screw drilling tools, and particularly relates to a coiled tubing salvage accelerator which comprises a transmission assembly and a hydraulic assembly. The transmission assembly comprises a spline mandrel and a spline transmission shell, and the spline mandrel and the spline transmission shell are in transmission connection through spline fit; the hydraulic assembly comprises a sealing shell, a sealing piston, a punching shaft and an inner punching pipe, the punching shaft is sleeved with the sealing piston, the sealing piston is in sliding sealing fit with the sealing shell, and the inner punching pipe is fixedly connected with the punching shaft and extends into the sealing shell. Through collaborative design of the transmission assembly and the hydraulic assembly, efficient transmission and enhancement of bidirectional jarring energy in the coiled tubing salvage process are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of screw drilling tools, and in particular relates to a coiled tubing salvage accelerator. Background Art

[0002] After the completion of the bridge plug drilling and grinding operation in shale gas wells, debris or tools and other debris are often left in the well, which need to be salvaged using continuous tubing. However, continuous tubing operations have inherent defects such as inability to rotate, limited lifting load, and large friction in the horizontal section, resulting in a low success rate of salvage. At present, the industry generally uses tools such as Venturi tubes and strong magnetic salvage devices to pre-treat the wellbore, and configures special tools such as jars and low-speed screw motors in the salvage pipe string to assist in fish top docking. When the drill is stuck due to resistance at the bottom of the well, it is mainly unblocked by repeatedly lifting / pressing the pipe string or activating the jar to generate impact force, but the energy of a single jar is often not enough to break through complex stuck points.

[0003] Although the existing technology can achieve basic jarring functions, it has significant limitations: the jarring force of conventional jars is limited by the elastic deformation capacity of the pipe string itself. When the strength of the stuck point exceeds the design threshold of the jar, additional energy-boosting tools are required to expand the impact energy. At present, there is a lack of efficient jarring energy-boosting devices that match the continuous oil pipe, and it is impossible to provide secondary energy supplement when the jar fails, resulting in low efficiency of the jamming operation. Therefore, there is an urgent need for an energy-boosting acceleration tool that works in conjunction with the jar to improve the success rate of jamming through a dynamic energy amplification mechanism. Summary of the invention

[0004] The purpose of the present invention is to provide a coiled tubing fishing accelerator to solve the problems existing in the background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a continuous tubing salvage accelerator, comprising a transmission assembly and a hydraulic assembly; the transmission assembly comprises a spline core shaft and a spline transmission housing, and the spline core shaft and the spline transmission housing are connected by a spline matching transmission; the hydraulic assembly comprises a sealing housing, a sealing piston, a punch shaft and an inner punch tube, the sealing piston is sleeved on the punch shaft and slidingly seals with the sealing housing, and the inner punch tube is fixedly connected to the punch shaft and extends to the inside of the sealing housing.

[0006] Preferably, the transmission assembly also includes an upper sealing joint and a limit sealing ring, the upper sealing joint is fixedly connected to the top end of the spline core shaft, and the limit sealing ring is installed inside the spline core shaft and cooperates with the spline transmission housing in a limited manner; a first high-pressure gasket O-ring and a first ordinary O-ring group are arranged in the upper sealing joint.

[0007] Preferably, the hydraulic assembly further comprises a lower joint, the lower joint being fixedly connected to the bottom end of the sealing housing, the inner flush pipe being connected to the external pipe column via the lower joint; a second common O-ring group is arranged in the lower joint.

[0008] Preferably, a second high-pressure gasketed O-ring group is provided on the sealing piston, and the sealing housing and the spline transmission housing are sealed and connected via a third common O-ring group.

[0009] Preferably, the punch shaft is fixedly connected to the spline core shaft via threads, and a fourth common O-ring is provided inside the punch shaft to achieve sealing with the spline core shaft.

[0010] Preferably, a third high-pressure gasket O-ring is provided on the inner punch pipe, and a fifth ordinary O-ring is provided on the limit sealing ring.

[0011] The beneficial effects of the present invention are as follows: the present invention realizes the efficient transmission and enhancement of bidirectional shock energy during the continuous tubing salvage process through the coordinated design of the transmission assembly and the hydraulic assembly. Its unique spline transmission structure ensures the stable transmission of torque, and the multi-stage high-pressure gasket seal design of the hydraulic sealing system significantly improves the sealing and reliability of the tool under complex working conditions. The integrated structure that does not require on-site adjustment allows it to be quickly adapted to existing salvage tools, and the compact layout takes into account both strength and corrosion resistance, effectively addressing the problems of high friction resistance in the horizontal section and difficulty in shock unblocking. When used in conjunction with a jar, the shock force can be amplified through the principle of hydraulic energy storage release, accelerating the efficiency of tubing unblocking, and significantly improving the success rate of salvage after drilling and grinding of shale gas well bridge plugs. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0013] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings and preferred embodiments.

[0014] like Figure 1 As shown, a continuous tubing salvage accelerator includes a transmission assembly and a hydraulic assembly; the transmission assembly includes a spline core shaft and a spline transmission housing. The spline core shaft 1 is a key component of the transmission assembly. Its top end is tightly connected to the upper sealing joint 2 through a thread, which ensures the stability and sealing of the connection and facilitates subsequent installation and disassembly operations. A position for installing a limit sealing ring 5 is provided inside the spline core shaft 1. The limit sealing ring 5 is fixed by a retaining ring or a step structure to prevent it from shifting during operation. The inner wall of the limit sealing ring 5 is installed with an eighth common O-ring 19, which fits tightly with the surface of the spline core shaft 1, which can not only effectively prevent fluid leakage, but also play a certain buffering role. The outer side of the spline core shaft 1 is splined with the spline transmission housing 4. This connection method can efficiently transmit torque and ensure stable power transmission.

[0015] The first high-pressure gasket O-ring 22, the first common O-ring 20 and the second common O-ring 21 are sequentially installed inside the upper sealing joint 2, which are respectively located in different sealing grooves to form a three-level sealing structure. This structure can effectively isolate the external fluid, ensure the internal sealing, and prevent the high-pressure liquid from leaking to the external environment.

[0016] The sealing plug 3 is installed at a specific hole position of the upper sealing joint 2, and is usually connected by a threaded connection. Its main function is to seal the hole position to prevent hydraulic oil or other media from leaking from the hole position. In addition to realizing the sealing function through the eighth common O-ring 19, the limit seal ring 5 can also limit the axial displacement of the spline transmission housing 4, ensure that the motion range of the spline transmission housing 4 on the spline core shaft 1 is in a reasonable range, and ensure the stability of the entire transmission system. The spline transmission housing 4 is sleeved on the outside of the spline core shaft 1, and torque transmission is achieved through spline matching. Its bottom end is connected to the top of the sealing housing 6 by a thread, and the fifth common O-ring 17 and the sixth common O-ring 18 are set at the connection, which effectively prevents hydraulic oil from leaking from the connection and ensures the normal operation of the hydraulic system. The top of the punch shaft 7 is fixedly connected to the spline core shaft 1 by a thread, and the seventh common O-ring 16 is installed at the connection part, which can prevent hydraulic oil from leaking from the connection between the punch shaft 7 and the spline core shaft 1, and ensure the sealing of the hydraulic system. The sealing piston 8 is sleeved on the middle part of the punch shaft 7, and needs to achieve good sliding sealing cooperation with the inner wall of the sealing housing 6. To this end, the second high-pressure gasket O-ring 14 and the third high-pressure gasket O-ring 15 are installed on the surface of the sealing piston 8. These two high-pressure gasket O-rings can withstand higher pressures to ensure that when the hydraulic system is working, there is no leakage between the sealing piston 8 and the sealing housing 6, ensuring the normal flow and pressure transmission of the hydraulic oil. The bottom end of the inner punch pipe 9 is fixedly connected to the punch shaft 7, and the top end extends to the inside of the sealing housing 6. The fourth high-pressure gasket O-ring 11 is installed on the surface of the inner punch pipe 9. The sealing ring fits tightly with the inner wall of the sealing housing 6 to form a high-pressure seal to prevent the high-pressure hydraulic oil from leaking from the gap between the inner punch pipe 9 and the sealing housing 6, ensuring the high-pressure stability of the hydraulic system. The sealing housing 6 provides a relatively closed working space for the hydraulic system, and its bottom end is connected to the lower joint 10 through a thread. The third common O-ring 12 and the fourth common O-ring 13 are installed in the lower joint 10, which can effectively prevent the fluid from leaking from the connection between the lower joint 10 and the sealing housing 6, and provide reliable sealing protection for connecting the external pipe string. The lower joint 10 is mainly used to connect the external pipe string. The third common O-ring 12 and the fourth common O-ring 13 inside it ensure the sealing of the connection with the external pipe string, prevent the fluid from leaking at the connection part, and ensure the normal connection and operation of the entire coiled tubing salvage accelerator with external equipment.

[0017] When the coiled tubing salvage accelerator encounters resistance when being lowered into the well, the operator can lift or press down the tubing string to make the sealing piston 8 slide on the punch shaft 7, compressing the hydraulic oil in the sealing housing 6 to increase the pressure of the hydraulic oil. The hydraulic oil with increased pressure is transmitted to the external tubing string through the inner punch pipe 9 to provide power for the salvage operation.

[0018] During the whole process, the spline structure between the spline transmission housing 4 and the spline core shaft 1 ensures the stable transmission of torque. When the jar is activated, the hydraulic energy stored in the sealing housing 6 is released instantly, and a bidirectional jarring force is applied to the pipe string through the punch shaft 7 and the inner punch pipe 9, which effectively helps to eliminate the jamming problem of the pipe string in the well.

[0019] The design of multi-stage sealing rings is crucial in the entire working process. They can effectively prevent the leakage of high-pressure fluids, ensure that the tool has good sealing and reliability under complex downhole working conditions, and ensure the normal operation of the coiled tubing salvage accelerator and the smooth progress of the salvage operation.

[0020] It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A coiled tubing salvage accelerator, characterized in that: The invention comprises a transmission assembly and a hydraulic assembly; the transmission assembly comprises a spline core shaft (1) and a spline transmission housing (4); the spline core shaft (1) and the spline transmission housing (4) are connected to each other through a spline matching transmission; the hydraulic assembly comprises a sealing housing (6), a sealing piston (8), a punch shaft (7) and an inner punch tube (9); the sealing piston (8) is sleeved on the punch shaft (7) and is matched with the sealing housing (6) in a sliding and sealing manner; the inner punch tube (9) is fixedly connected to the punch shaft (7) and extends into the interior of the sealing housing (6).

2. The coiled tubing salvage accelerator according to claim 1, characterized in that: The transmission assembly further comprises an upper sealing joint (2) and a limiting sealing ring (5); the upper sealing joint (2) is fixedly connected to the top end of the spline core shaft (1); the limiting sealing ring (5) is installed inside the spline core shaft (1) and is limitedly matched with the spline transmission housing (4); a first high-pressure gasket O-ring (22), a first common O-ring (20) and a second common O-ring (21) are arranged inside the upper sealing joint (2).

3. The coiled tubing salvage accelerator according to claim 1, characterized in that: The hydraulic assembly also includes a lower joint (10), the lower joint (10) is fixedly connected to the bottom end of the sealing housing (6), and the inner flush pipe (9) is connected to the external pipe column through the lower joint (10); a third common O-ring (12) and a fourth common O-ring (13) are arranged in the lower joint (10).

4. The coiled tubing salvage accelerator according to claim 1, characterized in that: The sealing piston (8) is provided with a second high-pressure gasket O-ring (14) and a third high-pressure gasket O-ring (15), and the sealing housing (6) and the spline transmission housing (4) are sealed and connected via a fifth common O-ring (17) and a sixth common O-ring (18).

5. The coiled tubing salvage accelerator according to claim 1, characterized in that: The punch shaft (7) is fixedly connected to the spline core shaft (1) via threads, and a seventh common O-ring (16) is arranged inside the punch shaft (7) to achieve sealing with the spline core shaft (1).

6. The coiled tubing salvage accelerator according to claim 1, characterized in that: A fourth high-pressure gasketed O-ring (11) is provided on the inner punch pipe (9), and an eighth common O-ring (19) is provided on the limit sealing ring (5).

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