Pressure release slip socket

Abstract

The utility model discloses a pressure release slip overshot which comprises an outer cylinder, a mandrel and a core cylinder, a slip is arranged at the bottom of the core cylinder, a guide shoe matched with the slip is arranged at the bottom of the outer cylinder, the core cylinder is sleeved on the mandrel in a vertically movable mode, an elastic piece tending to force the core cylinder to move downwards is arranged on the core cylinder, and the elastic piece is sleeved on the outer cylinder. A supporting edge is arranged at the bottom of the core shaft, a top edge is arranged on the core cylinder and above the supporting edge, a cavity is formed between the supporting edge and the top edge, the core shaft is hollow, a plurality of through holes leading to the cavity are formed in the side wall of the core shaft, and throttling nozzles are arranged at the bottoms of the through holes in the core shaft. After a fish enters the slip, high-pressure liquid can be introduced into the core shaft, the high-pressure liquid enters the cavity through the through hole, hydraulic pressure in the cavity is increased, the core cylinder is jacked up through the top edge, the slip is gradually separated from the fish along with the core cylinder, releasing of the fish is achieved, repeated fishing and releasing can be achieved, control operation is convenient, and flexibility is high.

Description

Technical Field

[0001] The utility model relates to the technical field of drilling tools, in particular to a pressure-releasing slip overshot tube. Background Art

[0002] During the drilling, repair and logging of oil and gas wells, due to various reasons, drilling tools, oil casing, packers, water distributors, production distributors and logging instruments often fall into the well. In order to ensure the completion of subsequent operations, it is necessary to lower the corresponding salvage tools to salvage them out of the well. In addition, during the salvage process, sometimes due to obstacles encountered during the salvage or due to process requirements, it is necessary to stop the salvage and release the fish. There are even cases where multiple salvage and release are required. Existing salvage tools mainly include three-ball salvage devices and slip salvage devices. Although the existing three-ball salvage devices also have a releasable structure, they are all shear-pin release methods, which can only achieve single salvage and release, and cannot be repeated. The existing slip salvage has good fish retractability and high stability of fish release, so it is a releasable slip salvage tool widely used in oil fields. Its release mode is divided into shear pin type and rotation type. The shear pin releasable slip salvage tube has the same release principle as the shear pin releasable three-ball salvage, both of which are released by pulling up and breaking the shear pin. Therefore, there is also the defect of non-repeatable release. The rotary releasable slip salvage is when releasing and exiting the fish, or it is necessary to rotate the drill tool forward, so as to achieve relative rotation and lifting between the salvage and the fish, and gradually drive the slip salvage to release and exit the fish in the well. In its application, it is required that the drilling instrument string cannot contain a rotating short section. If a rotating short section is connected, the slip salvage cannot be driven to rotate and release the fish. Therefore, the existing releasable slip salvage still has functional limitations, unreliable salvage and release, insufficient operation flexibility, and low salvage efficiency. Utility Model Content

[0003] The purpose of the utility model is to avoid the deficiencies of the prior art and provide a pressure release slip overshot, thereby effectively solving the deficiencies in the prior art.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a pressure-releasing cava salvage barrel, comprising an outer barrel, a core shaft and a core barrel, a cava is arranged at the bottom of the core barrel, a guide shoe is arranged at the bottom of the outer barrel in cooperation with the cava, the core barrel is movably sleeved on the core shaft, an elastic member tending to force the core barrel to move downward is arranged on the core shaft, a supporting edge is arranged at the bottom of the core shaft, a top edge is arranged on the core barrel at the upper part of the supporting edge, a cavity is present between the supporting edge and the top edge, the core shaft is hollow, a plurality of through holes leading to the cavity are opened on the side wall of the core shaft, and a throttling nozzle is arranged at the bottom of the through hole in the core shaft.

[0005] Furthermore, an upper joint is provided at the upper end of the outer cylinder, and the core shaft is connected to the upper joint.

[0006] Furthermore, the elastic member is a spring arranged between the upper joint and the core barrel.

[0007] Furthermore, the inner diameter of the bottom of the upper joint is smaller than the outer diameter of the core barrel.

[0008] Furthermore, the slips include a plurality of long claws arranged along the circumferential direction, and there are gaps between the long claws.

[0009] Further, the throttling nozzle is screwed to the bottom of the core shaft.

[0010] The above technical scheme of the utility model has the following beneficial effects: after the fallen fish enters the slip, the utility model can introduce high-pressure liquid into the core shaft, and the high-pressure liquid enters the cavity through the through hole. The hydraulic pressure in the cavity increases, and the core tube is lifted up through the top edge. The slip also gradually follows the core tube to separate from the fallen fish, thereby realizing the release of the fallen fish. The fish can be repeatedly salvaged and released, which is convenient for control operation and has high flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a cross-sectional schematic diagram of an embodiment of the utility model;

[0012] Figure 2 for Figure 1 Enlarged view of point A in the middle. DETAILED DESCRIPTION

[0013] The following is a detailed description of the preferred implementation of the present invention in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0014] In the description of the present utility model, unless otherwise specified, "multiple" means two or more than two; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0015] like Figure 1-2 As shown, a pressure release slip salvage barrel of the present embodiment comprises an outer barrel 1, a core shaft 2 and a core barrel 3, a slip 4 is arranged at the bottom of the core barrel 3, a guide shoe 5 is arranged at the bottom of the outer barrel 1 in cooperation with the slip 4, the core barrel 3 is sleeved on the core shaft 2 so as to be movable up and down, an elastic member 6 tending to force the core barrel 3 to move downward is arranged on the core shaft 2, a supporting edge 7 is arranged at the bottom of the core shaft 2, a top edge 8 is arranged on the core barrel 3 at the upper part of the supporting edge 7, a cavity 9 is arranged between the supporting edge 7 and the top edge 8, the core shaft 2 is hollow, a plurality of through holes 10 leading to the cavity 9 are opened on the side wall of the core shaft 2, and a throttling nozzle 11 is arranged at the bottom of the through hole 10 in the core shaft 2;

[0016] The working principle of this embodiment is as follows: during operation, the outer cylinder 1 and the core shaft 2 are connected to the drilling tool on the upper side, and the drilling tool on the upper side can drive the outer cylinder 1 to move up and down (not shown in the figure), and the salvage device is sent to the upper end of the fish in the well, and continues to be lowered, and the upper end of the fish enters the guide shoe 5 at the bottom of the outer cylinder 1, pushing the slip 4 to compress the elastic member 6 to move upward, and the slip 4 is separated from the matching position with the guide shoe 5 and then opens, and the upper end of the fish enters the slip 4. At this time, the outer cylinder 1 is lifted, and the fish and the slip 4 move downward (the fish moves downward due to gravity, and the slip 4 moves downward due to gravity and the elastic force of the elastic member 6), until the slip 4 contacts the inner cone surface of the guide shoe 5, forcing the slip 4 to contract and clamp the fish, and continuing to lift it up can achieve The fish is salvaged now; when the fish needs to be released for some reason, the outer tube 1 and the core shaft 2 are lowered again, and then the wellhead uses a mud pump or a pump truck to pump liquid into the core shaft 2 for circulation. Under the action of the throttling nozzle 11, high pressure is generated in the core shaft 2, and the high-pressure liquid enters the cavity 9 through the through hole 10. The hydraulic pressure in the cavity 9 increases, and the core tube 3 is lifted up through the top edge 8. The slip 4 also gradually moves upward with the core tube 3, and the upper end of the fish will hit the bottom of the core shaft 2 and cannot continue to move upward, so that the slip 4 gradually separates from the fish, and the fish is released. After the fish is released, the high-pressure liquid can be stopped. The salvage device can be repeatedly salvaged and released, which is convenient for control operation and has high flexibility.

[0017] Preferably, an upper joint 12 is provided at the upper end of the outer cylinder 1, and the mandrel 2 is connected to the upper joint 12. The upper joint 12 is used to connect to the drilling tool on the upper side (not shown in the figure). The upper joint 12 connects the outer cylinder 1 and the mandrel 2 so that they can move up and down at the same time. In this embodiment, the upper joint 12 is screwed on the outer cylinder 1, and the mandrel 2 is screwed on the upper joint 12.

[0018] Preferably, the elastic member 6 is a spring disposed between the upper joint 12 and the core barrel 3, and there is a gap between the upper joint 12 and the core shaft 2, and the spring can be disposed in the gap;

[0019] Preferably, the inner diameter of the bottom of the upper joint 12 is smaller than the outer diameter of the core tube 3. When the fish pushes against the slip 4 and moves upward, the upper end of the core tube 3 will push against the bottom of the upper joint 12, and the core tube 3 stops moving. At this time, the overshot tube is continuously lowered, so that the fish can push open the slip 4 and enter the slip 4.

[0020] Preferably, the slip 4 includes a plurality of long claws 13 arranged along the circumferential direction, and there are gaps between the long claws 13;

[0021] Preferably, the throttling nozzle 11 is screwed to the bottom of the core shaft 2 .

[0022] The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A pressure release slip overshot, characterized in that: It includes an outer tube, a core shaft and a core tube, a slip is provided at the bottom of the core tube, a guide shoe is provided at the bottom of the outer tube in coordination with the slip, the core tube is movably sleeved on the core shaft, an elastic member tending to force the core tube to move downward is provided on the core shaft, a supporting edge is provided at the bottom of the core shaft, a top edge is provided on the core tube at the upper part of the supporting edge, a cavity is provided between the supporting edge and the top edge, the core shaft is hollow, a plurality of through holes leading to the cavity are provided on the side wall of the core shaft, and a throttling nozzle is provided at the bottom of the through hole in the core shaft.

2. A pressure release slip overshot according to claim 1, characterized in that: An upper joint is arranged at the upper end of the outer cylinder, and the core shaft is connected to the upper joint.

3. A pressure release slip overshot according to claim 2, characterized in that: The elastic member is a spring arranged between the upper joint and the core barrel.

4. A pressure release slip overshot according to claim 2, characterized in that: The inner diameter of the bottom of the upper joint is smaller than the outer diameter of the core barrel.

5. A pressure release slip overshot according to claim 1, characterized in that: The slips include a plurality of long claws arranged along the circumferential direction, and gaps are provided between the long claws.

6. A pressure release slip overshot according to claim 1, characterized in that: The throttling nozzle is screwed on the bottom of the mandrel.

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