Casing releasing tool for lower horizontal section of coal bed gas horizontal well

Abstract

The utility model provides a coal bed gas horizontal well lower horizontal section casing releasing tool which comprises a connecting pipe, the rear section of the connecting pipe is an upper connector used for being connected with a drill rod, the upper connector is provided with an upper connector inner ring, the front end of the upper connector is provided with a conical spring claw, a central pipe is arranged in the connecting pipe, and a sliding sleeve is arranged on the periphery of the central pipe. The rear portion of the sliding sleeve is fixed on the central pipe through a pin, an inner hole in the front portion of the sliding sleeve abuts against the central pipe, the periphery of the sliding sleeve expands the spring claw, an expanded molded opening is in butt joint with a glass fiber reinforced plastic screen pipe female buckle, the middle of the sliding sleeve and the central pipe form an inner cavity, a radial hole is formed in the central pipe and communicated with the inner cavity, and a conical inner opening is formed in the rear end of the central pipe. A spacer sleeve is arranged at the front end of the center pipe, a sealing ring is arranged between the spacer sleeve and the center pipe, a hole is formed in the front end of the spacer sleeve, and a ball socket capable of containing a steel ball is arranged at the rear end of the hole. The situation that tension bearing parts and releasing shear stress parts of a releasing tool are the same is avoided, reliability of the tool is guaranteed, releasing pressure is easier to control, and operation difficulty and cost are reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the coal bed gas horizontal well equipment technical field, concretely relates to a coal bed gas horizontal well down horizontal section casing release tool. BACKGROUND

[0002] With the continuous optimization of coal bed gas development well type, L type horizontal well, multi-branch horizontal well and other complex well types are widely applied. In the completion process of such well types, the glass steel screen pipe becomes the commonly used pipe material for horizontal section completion due to the low friction coefficient, high strength, corrosion resistance and other characteristics. Especially in the injection-production conversion, well passing, well washing and other operations of coal bed gas, the glass steel screen pipe can effectively improve the pipe string running-in efficiency and ensure the passage stability.

[0003] In the running-in process of the glass steel screen pipe, the release tool needs to be connected with the drill string, and is released safely after the pipe string is lowered to the target position. The traditional release tool has the following problems in structure: 1. unable to transmit torque, no structure for reliable connection with the screen pipe thread, leading to difficult screen pipe rotary running-in; 2. unreasonable structure stress, multiple key structures simultaneously bearing tensile force and shear force, easy to cause fatigue damage or failure; 3. unstable release operation, dependent on artificial control or single stress element, inaccurate release, with the risk of jamming or failure; 3. poor adaptability, difficult to adapt to glass steel screen pipes of different sizes and structures, insufficient universality. Therefore, developing a release tool with reasonable structure stress, torque transmission, reliable release and simple operation is of great significance to ensure the smooth implementation of the coal bed gas horizontal well section completion operation. UTILITY MODEL CONTENTS

[0004] To solve the above technical problems, the utility model provides a coal bed gas horizontal well down horizontal section casing release tool.

[0005] The utility model adopts the technical scheme, a coal bed gas horizontal well down horizontal section casing release tool, including the connecting pipe, the rear section of connecting pipe is the upper joint for connecting the drill pipe, the upper joint is equipped with the upper joint inner ring, the front end of upper joint is equipped with the tapered spring claw, the center pipe is arranged in the connecting pipe, the outer periphery of center pipe is equipped with the sliding sleeve, the rear part of sliding sleeve is fixed on the center pipe through the pin, the front part inner hole of sliding sleeve abuts against the center pipe, the outer periphery props open the spring claw, the type mouth after prop opening is connected with the glass steel screen pipe female buckle, the middle part of sliding sleeve forms the inner chamber with the center pipe, the inner chamber is connected with the inner chamber through the radial hole in the center pipe, the rear end of center pipe is equipped with the tapered inner mouth, the front end of center pipe is equipped with the retaining sleeve, the sealing ring is arranged between the retaining sleeve and the center pipe, the front end of retaining sleeve is equipped with the hole, the rear end of the hole is equipped with the ball socket that can hold the steel ball.

[0006] Further, the upper joint inner ring is a tapered hole, which gradually narrows from outside to inside.

[0007] Further, a convex stopper is arranged at the front end of the upper joint in the circumferential direction, and a check ring is arranged in the convex stopper.

[0008] Further, the inner wall of the sliding sleeve is protruded to the center at the front part to form an inner hole.

[0009] Further, the outer diameter of the rear section of the center tube is larger than that of the front section, and the rear part of the sliding sleeve is fixed to the front side of the rear end of the center tube through a pin.

[0010] Further, an annular seal is arranged between the inner hole and the center tube.

[0011] The coal bed gas horizontal well lower horizontal section casing releasing tool has the following beneficial effects:

[0012] 1. Torque transmission can be realized, the spring claw structure of the tool is provided with a car-made public buckle, can be reliably connected with the female buckle of the glass steel screen pipe, axial bearing can be realized, and rotating torque can be transmitted, and the working condition requirement of the rotating running of the glass steel screen pipe is met.

[0013] 2. The releasing action is stable and reliable, the sliding sleeve slides along the axial direction under the action of liquid force and releases the spring claw, so that the spring claw is retracted to complete the disengagement, the action process is clear and the control is simple, the releasing behavior is clear and controllable, and the operation error is reduced.

[0014] 3. The structure stress is optimized, the tool structure reasonably shares the tension and shear force through the sliding sleeve, the pin and the retainer, the same component is avoided from bearing complex force, the structure fatigue risk is reduced, and the use reliability is improved.

[0015] 4. The tool has good tensile strength and pressure bearing capacity, is suitable for the operation environment with large well depth, high well inclination and strong friction, can improve the overall operation efficiency while ensuring the releasing stability.

[0016] 5. Modular design, convenient maintenance, clear component structure, convenient assembly and disassembly, simple post-maintenance and fault troubleshooting, and the safety and reliability of on-site operation are improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 is a front view of the utility model;

[0018] Fig. 2 is a structural schematic view of the utility model;

[0019] Fig. 3 is a sectional view of the utility model.

[0020] In the drawing: 1, upper joint; 2, upper joint inner ring; 3, spring claw; 4, center tube; 5, sliding sleeve; 6, pin; 7, retainer; 8, sealing ring; 9, steel ball; 10, check ring. DETAILED DESCRIPTION

[0021] To better understand the purpose, structure, and function of this utility model, the following description, in conjunction with the accompanying drawings, provides a more detailed description of a casing release tool for horizontal sections of coalbed methane wells.

[0022] like Figs. 1-3 As shown, a casing release tool for a horizontal section of a coalbed methane well includes a connecting pipe. The rear section of the connecting pipe is an upper connector 1 for connecting the drill pipe. The upper connector 1 has an inner ring 2 and a tapered spring claw 3 at its front end. A central pipe 4 is installed inside the connecting pipe. A sliding sleeve 5 is installed on the outer periphery of the central pipe 4. The rear part of the sliding sleeve 5 is fixed to the central pipe 4 by a pin 6. The inner hole of the front part of the sliding sleeve 5 abuts against the central pipe 4. The outer periphery expands the spring claw 3, and the expanded opening aligns with the female thread of the fiberglass screen pipe. The middle part of the sliding sleeve 5 forms an inner cavity with the central pipe 4. A radial hole is provided inside the central pipe 4 to communicate with the inner cavity. A tapered inner opening is provided at the rear end of the central pipe 4. A retainer 7 is provided at the front end of the central pipe 4. A sealing ring 8 is provided between the retainer 7 and the central pipe 4. A hole is provided at the front end of the retainer 7, and a ball socket for accommodating a steel ball 9 is provided at the rear end of the hole.

[0023] In this embodiment, a circumferential convex stop is provided at the front end of the upper connector 1, and a retaining ring 10 is provided in the convex stop. The inner ring 2 of the upper connector is a tapered hole, which gradually narrows from the outside to the inside.

[0024] The inner wall of the sliding sleeve 5 protrudes towards the center to form an inner hole, and an annular seal is provided between the inner hole and the central tube 4. The outer diameter of the rear section of the central tube 4 is larger than that of the front section, and the rear part of the sliding sleeve 5 is fixed to the front side of the rear end of the central tube 4 by a pin 6.

[0025] The upper connector 1 of the drop tool connects to the Ø73mm drill pipe, and the tapered spring claw 3 of the lower connector connects to the Ø89mm fiberglass screen. Through the cooperation of the drill string and the drop tool, the fiberglass screen is lowered to the desired well depth. At this point, the drop position is at the second landing point, 5m deep. The drop operation begins. After the tubing string is in place, a displacement circulation is performed, the suspended weight is tested, the entire tubing string is rotated, and the rotation torque is recorded.

[0026] A steel ball 9 is thrown into the inner hole of the release tool. The steel ball 9 falls to the position of the retaining sleeve 7. The sliding sleeve 5 is fixed to the central tube 4 by the pin 6. The pump is turned on at 13 MPa. Under the action of hydraulic force, the pin 6 breaks and the sliding sleeve 5 slides down. As the sliding sleeve 5 slides down, the spring claw 3 of the release tool begins to retract. When the pin 6 breaks, the sliding sleeve 5 slides down to the retaining sleeve 7 under the action of hydraulic force. The spring claw 3 retracts to complete the release operation. Then, the drill string is lifted to observe the change of the drill string suspension weight on the drilling rig instrument panel. After confirming that it has been completed, the drill string is pulled up. The entire release operation is successfully completed.

[0027] This utility model avoids the commonality of tensile and shear stress-bearing parts in the release tool's structural design, ensuring the tool's reliability and making the release pressure easier to control. It features high tensile strength, strong pressure-bearing capacity, the ability to transmit large torques, and suitability for wells with large inclinations and deep well operations. When applied to horizontal well operations, this tool simplifies the tubing string structure, reduces operational difficulty and cost, and improves operational efficiency.

[0028] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A tool for releasing casing in the horizontal section of a coalbed methane well, characterized in that, The system includes a connecting pipe, the rear section of which is an upper connector (1) for connecting the drill rod. The upper connector (1) is provided with an upper connector inner ring (2). The front end of the upper connector (1) is provided with a tapered spring claw (3). A central tube (4) is provided inside the connecting pipe. A sliding sleeve (5) is provided on the outer periphery of the central tube (4). The rear part of the sliding sleeve (5) is fixed to the central tube (4) by a pin (6). The inner hole of the front part of the sliding sleeve (5) abuts against the central tube (4). The outer periphery expands the spring claw (3). The expanded opening is connected to the fiberglass screen tube female thread. The middle part of the sliding sleeve (5) and the central tube (4) form an inner cavity. A radial hole is provided inside the central tube (4) to connect to the inner cavity. A tapered inner opening is provided at the rear end of the central tube (4). A retainer (7) is provided at the front end of the central tube (4). A sealing ring (8) is provided between the retainer (7) and the central tube (4). A hole is provided at the front end of the retainer (7). A ball socket that can accommodate a steel ball (9) is provided at the rear end of the hole.

2. The casing release tool for horizontal sections of coalbed methane wells according to claim 1, characterized in that, The inner ring (2) of the upper connector is a tapered hole, which gradually narrows from the outside to the inside.

3. The casing release tool for horizontal sections of coalbed methane wells according to claim 1, characterized in that, The front end of the upper connector (1) is provided with a circumferential convex stop, and a retaining ring (10) is provided in the convex stop.

4. The casing release tool for horizontal sections of coalbed methane wells according to claim 1, characterized in that, The inner wall of the sliding sleeve (5) protrudes towards the center to form an inner hole.

5. The casing release tool for horizontal sections of coalbed methane wells according to claim 4, characterized in that, The outer diameter of the rear section of the central tube (4) is larger than that of the front section, and the rear part of the sliding sleeve (5) is fixed to the front side of the rear end of the central tube (4) by a pin (6).

6. The casing release tool for horizontal sections of coalbed methane wells according to any one of claims 1 to 5, characterized in that, An annular seal is provided between the inner hole and the central tube (4).

Images