Multi-stage releasing mechanism for packer

Abstract

The invention belongs to the field of petroleum and natural gas exploitation, and discloses a multistage releasing mechanism for a packer, a central pipe is used as an inner supporting structure of the device, a spring, a supporting body and a cone are sleeved outside the central pipe, a pressing cap and a tightening ring are installed at two ends of the central pipe and are tightly connected through threads, and the supporting body and the cone are connected through threads. The releasing pressure of the releasing mechanism is controlled by adjusting the number of rotation turns of threads of the pressing cap and the tightening ring and adjusting the pressing degree of the spring, the sealing rings are installed on the inner surface and the outer surface of the cone, sealing between the cone and the working barrel and sealing between the cone and the central pipe are achieved, and the supporting body is clamped on the inner inclined face of the working barrel. The cone acts on the supporting body to prevent springback, and the whole body is tightly attached together through the elastic force of the spring. The releasing problem of the multi-stage packer is effectively solved, multiple times of ball throwing is not needed, the number of releasing stages is not limited theoretically, and the multi-stage packer releasing device can be matched with multiple types of packers for releasing in the aspect of tubular column matching.

Description

Technical Field

[0001] The invention belongs to the field of oil and natural gas exploitation and relates to a multi-stage release mechanism for a packer. Background Art

[0002] As oilfield exploitation enters the middle and late stages, the application of various technological measures has led to an increasing use of downhole tools. As a commonly used downhole tool in oilfields, the types of packers are increasing with the advancement of on-site needs and technology.

[0003] At present, the conventional sealing methods of packers are divided into lifting and releasing the pipe string, rotating the pipe string, self-sealing, hydraulic pressure and lowering tools. Hydraulic sealing has the advantages of controllable release pressure, strong anchoring performance and convenient later salvage, and is widely used. The commonly used release mechanism of hydraulic sealing packers is the ball throwing type, which is limited by the number of stages and cannot be used on multi-stage packer strings. Summary of the invention

[0004] The purpose of the present invention is to invent a novel packer release mechanism to solve the problem of multi-stage packer release.

[0005] In the design of the tubing, a working cylinder needs to be installed at each release position, and the release mechanism cooperates with the working cylinder of each level to achieve hierarchical release.

[0006] The above object of the present invention is achieved through the following technical solutions:

[0007] A multi-stage release mechanism for a packer comprises a pressure cap, a spring, a central tube, a support body, a cone, a sealing ring and a tightening ring.

[0008] The center tube serves as the internal support structure of the device. The three components of the spring, the support body and the cone are sleeved outside the center tube. The pressure cap and the tightening ring are installed at both ends of the center tube and are tightly connected by threads.

[0009] The releasing pressure of the releasing mechanism is controlled by adjusting the number of rotations of the threads of the pressing cap and the tightening ring and adjusting the degree of compression of the spring.

[0010] The sealing ring is installed on the inner and outer surfaces of the cone to achieve sealing between the cone and the working cylinder, and between the cone and the center tube.

[0011] The support body is clamped on the inner inclined surface of the working cylinder, and the cone acts on the support body to prevent rebound. The whole body is tightly fitted together by the elastic force of the spring.

[0012] An operating method for a multi-stage release mechanism for a packer, wherein a working cylinder is installed at each release position, an inner bevel is machined in the working cylinder, and when the packer needs to release, a pipe line is connected at the wellhead, and positive pressure is applied through the oil pipe. The hydraulic pressure acts on the end face of the center pipe and the end face of the cone, and the cone overcomes the elastic force of a spring and moves downward, leaving the support position of a support body. The support body contracts, the release mechanism leaves the working cylinder position, the pressure inside the oil pipe drops, the release of this stage is successful, the release mechanism falls downward, enters the tool cylinder of the next release position, and waits for the next release operation.

[0013] The beneficial effects of the present invention compared with the prior art are:

[0014] The present invention effectively solves the problem of multi-stage packer loss without multiple drops. Theoretically, there is no limit to the number of loss stages. In terms of pipe string matching, multiple types of packers can be lost together. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0016] Figure 1 It is a schematic diagram of the overall structure;

[0017] Figure 2 It is a schematic diagram of the inner inclined surface of the working cylinder;

[0018] Figure 3 A cross-sectional view for cooperation with the working cylinder;

[0019] Figure 4 This is a cross-sectional view of the device being separated from the working cylinder after the device is released;

[0020] Figure 5 A schematic diagram of the support body.

[0021] Among them: 1 pressure cap, 2 spring, 3 center tube, 4 support body, 5 cone, 6 sealing ring, 7 tightening ring. DETAILED DESCRIPTION

[0022] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical scheme of the present invention is now described in detail in conjunction with the following specific embodiments, but it should not be understood as limiting the applicable scope of the present invention.

[0023] Example 1

[0024] The utility model discloses a multi-stage release mechanism for a packer.

[0025] The invented multi-stage release mechanism for a packer comprises a pressure cap 1, a spring 2, a central tube 3, a support body 4, a cone 5, a sealing ring 6, and a tightening ring 7.

[0026] The central tube 3 serves as the internal supporting structure of the device. The spring 2, the supporting body 4 and the cone 5 are sleeved outside the central tube 3. The pressure cap 1 and the tightening ring 7 are installed at both ends of the central tube 3 and are tightly connected by threads.

[0027] The releasing pressure of the releasing mechanism is controlled by adjusting the number of rotations of the threads of the pressing cap 1 and the tightening ring 7 and adjusting the degree of compression of the spring 2.

[0028] The sealing ring 6 is installed on the inner and outer surfaces of the cone 5 to achieve sealing between the cone 5 and the working cylinder, and between the cone 5 and the central tube 3.

[0029] The support body 4 is clamped on the inner inclined surface of the working cylinder, and the cone acts on the support body 4 to prevent rebound. The whole body is tightly fitted together by the elastic force of the spring.

[0030] Operation example: In the design of the tubing, a working barrel needs to be installed at each release position, and an inner bevel is machined inside the working barrel. When the packer needs to be released, the pipe line is connected at the wellhead, and the oil pipe is positively pressurized, and the hydraulic pressure acts on the end face of the center pipe 3 and the end face of the cone 5. The cone 5 overcomes the elastic force of the spring 2 and moves downward, leaving the support position of the support body 4. The support body 4 shrinks, the release mechanism leaves the working barrel position, the pressure inside the oil pipe drops, and the release of this level is successful. The release mechanism falls down and enters the tool barrel of the next release position, waiting for the next release operation.

[0031] The above-described embodiments are only preferred embodiments of the present invention, but not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A multi-stage release mechanism for a packer, characterized in that: The utility model comprises a pressure cap (1), a spring (2), a central tube (3), a support body (4), a cone (5), a sealing ring (6), and a tightening ring (7).

2. The multi-stage release mechanism for a packer according to claim 1, characterized in that: The central tube (3) serves as the internal supporting structure of the device. The three components, namely the spring (2), the supporting body (4) and the cone (5), are sleeved outside the central tube (3). The pressure cap (1) and the tightening ring (7) are installed at both ends of the central tube (3) and are tightly connected by threads.

3. The multi-stage release mechanism for a packer according to claim 1, characterized in that: The release pressure is adjusted by adjusting the number of rotations of the threads of the pressure cap (1) and the tightening ring (7), thereby adjusting the degree of compression of the spring (2) and achieving control of the release pressure.

4. The multi-stage release mechanism for a packer according to claim 1, characterized in that: The sealing ring (6) is installed on the inner and outer surfaces of the cone (5) to achieve sealing between the cone (5) and the working cylinder, and between the cone (5) and the central tube (3).

5. The multi-stage release mechanism for a packer according to claim 1, characterized in that: The support body (4) has an inner inclined surface that is clamped in the working cylinder, and the cone acts on the support body (4) to prevent rebound, and the whole body is tightly fitted together by relying on the elastic force of the spring.

6. The method for operating the multi-stage release mechanism for a packer according to claim 1, characterized in that: A working cylinder is installed at each release position, and an inner bevel is machined inside the working cylinder. When the packer needs to be released, a pipe line is connected at the wellhead, and positive pressure is applied through the oil pipe. The hydraulic pressure acts on the end surface of the center pipe (3) and the end surface of the cone (5). The cone (5) overcomes the elastic force of the spring (2) and moves downward, leaving the support position of the support body (4). The support body (4) contracts, the release mechanism leaves the working cylinder position, the pressure inside the oil pipe drops, the release of this stage is successful, the release mechanism falls downward, enters the tool cylinder of the next release position, and waits for the next release operation.

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