A safety valve forced opening tool

Abstract

The present invention provides a forced opening tool for a safety valve, belonging to the technical field of downhole tools for oil and gas field development, including a mandrel, an upper joint, an outer cylinder, a positioning mechanism, a pop-up mechanism, a support cylinder and a plug cap. The upper joint is arranged at the upper end of the mandrel, the outer cylinder is sleeved on the mandrel, and two sliding grooves are opened on the outer cylinder. The pop-up mechanism includes two shear sleeves arranged on the outer cylinder. A support cylinder is arranged between the two outer cylinder shear sleeves, and shear screws are arranged between the shear sleeves and the outer cylinder. The support cylinder is arranged between the two shear sleeves. When the mandrel moves downward in the present invention, the shear groove on the mandrel cuts off the shear screws. Under the elastic action of the support cylinder, the upper shear sleeve moves in the opposite direction of the lower shear sleeve. Under the elastic action, the support cylinder expands, and the outer part of the support cylinder jacks up the valve flap of the safety valve, realizing the permanent opening of the valve flap of the safety valve, thus solving the situation that the valve flap of the downhole safety valve cannot be opened.

Description

Technical Field

[0001] The present invention relates to the technical field of downhole tools for oil and gas field development, and particularly relates to a safety valve forced opening tool. Background Art

[0002] A downhole safety valve is an important tool for preventing blowouts and well kicks and ensuring the normal operation of oil and gas wells. During normal production, the downhole safety valve is open. In the event of a serious safety accident and the failure of surface wellhead control, the downhole safety valve pre-lowered through surface control can be used to cut off the fluid in the tubing and prevent the accident from expanding.

[0003] A typical structure for surface control of a downhole safety valve is to use a hydraulic control pipeline extending to the surface to realize the pressure (pressurization or decompression) of the liquid in the pipeline on the surface, thereby controlling the opening and closing state of the downhole safety valve.

[0004] Due to the harsh downhole environment, after the surface-controlled downhole safety valve has been working normally for a period of time, the hydraulic control pipeline may leak or for other reasons cause it to be unable to open, resulting in a failure of the downhole safety valve to open normally. Therefore, a safety valve forced opening tool is proposed to solve the above problems. Summary of the Invention

[0005] In view of this, the present invention provides a safety valve forced opening tool, which can support the expansion of the support cylinder under the action of elasticity, and jack up the valve flap of the safety valve outside the support cylinder, realizing the permanent opening of the valve flap of the safety valve, thus solving the situation where the valve flap of the downhole safety valve cannot be opened, and ensuring the original safety valve passage.

[0006] To solve the above technical problems, the present invention provides a safety valve forced opening tool, comprising:

[0007] A mandrel;

[0008] An upper joint for connecting with an external component to enable the forced opening tool to extend into the safety valve pipe, and the upper joint is arranged at the upper end of the mandrel;

[0009] An outer cylinder, the outer cylinder is sleeved on the mandrel, and two sliding grooves are opened on the outer cylinder;

[0010] A positioning mechanism for fixing the forced opening tool in the groove of the safety valve working cylinder to facilitate the overall operation of the forced opening tool;

[0011] A pop-up mechanism, the pop-up mechanism includes two shear sleeves arranged on the outer cylinder, and shear screws are arranged between the shear sleeves and the outer cylinder, and the shear sleeves are fixed on the outer cylinder by the shear screws;

[0012] The support tube is wound by a spring sheet and is arranged between two shear sleeves. The shear screw between the upper shear sleeve and the core shaft is cut off by the downward movement of the core shaft. The upper shear sleeve is pushed open by the elasticity of the support tube, so that the support tube is unfolded and the valve disc of the safety valve is permanently opened.

[0013] The plugging cap is arranged at one end of the outer tube away from the collet, so as to be used for pushing open the valve disc of the safety valve.

[0014] Furthermore, a shearing groove is provided on the core shaft, and the shearing screw passes through the shearing sleeve sliding groove in sequence and extends to the shearing groove, so that the shearing screw is sheared when the core shaft moves downward.

[0015] Furthermore, a limiting groove for limiting the position of the support tube is formed at the opposite ends of the two shear sleeves.

[0016] Furthermore, the positioning mechanism includes a collet mounted on the core shaft, the outer cylinder is arranged on the collet, two retaining rings are mounted on the collet, two key bodies are symmetrically arranged between the two retaining rings, the two retaining rings are used to limit the key body on the collet, and a force spring is arranged between the key body and the collet to apply pressure to the key body, so that the key body will contact the inner wall of the safety valve tube and limit the position of the forced opening tool.

[0017] Furthermore, a limiting protrusion and a triangular ring are respectively provided on the outer side of the key body, the limiting protrusion is located at the front section of the key body, and the triangular ring is located at the rear end of the key body. The triangular ring contacts the inner wall of the safety valve tube to compress the key body, and the limiting protrusion is limited in the groove on the inner wall of the installation valve pipe.

[0018] Furthermore, a guiding inclined surface is provided on a side of the limiting protrusion away from the triangular ring, so that the key body can be retracted when the forced opening tool is disassembled, so as to release the position limitation of the forced opening tool.

[0019] Furthermore, both ends of the key body are provided with limit blocks, and the opposite sides of the two retaining rings are provided with mounting grooves corresponding to the limit blocks.

[0020] Furthermore, the inner wall of the collet is provided with an inner ring platform, and the core shaft is provided with an outer convex step abutting against the inner ring platform to prevent the core shaft from being directly withdrawn from the outer barrel.

[0021] Furthermore, the force spring is a U-shaped spring, a circular hole is opened on the inner wall of the key body, and both ends of the force spring are arranged in the circular hole.

[0022] Furthermore, the plugging cap is arranged in a conical shape at one end away from the outer cylinder.

[0023] The beneficial effects of the above technical solution of the present invention are as follows:

[0024] 1. When the mandrel moves downward, the shear groove on the mandrel cuts off the upper shear screw. Under the elastic action of the support cylinder, the upper shear sleeve moves in the opposite direction to the lower shear sleeve. The distance between the two shear sleeves increases under the action of the support cylinder, and the shear screw on the shear sleeve moves in the chute. The support cylinder separates from the shear sleeve, and under the elastic action, the support cylinder unfolds, and the outside of the support cylinder jacks up the safety valve cap, realizing the permanent opening of the safety valve cap, thus solving the problem that the safety valve cap in the well cannot be opened and ensuring the original safety valve passage.

[0025] 2. The triangular ring contacts the inner wall of the safety valve pipe, and through the force-bearing spring, the two key bodies move relatively and compress, so that the key bodies penetrate into the safety valve pipe. When reaching the preset position, the force-bearing spring resets and jacks up the key bodies, so that the limit protrusions are limited in the inner wall grooves of the installation valve pipe, fixing the position of the collet and realizing the overall positioning of the forced opening tool.

[0026] 3. The key bodies are installed on the collet through two retaining rings to limit the positions of the key bodies. The cooperation between the limit blocks and the installation grooves can limit the movement range of the key bodies to prevent the key bodies from detaching from the collet.

[0027] 4. When disassembling the forced opening tool, the guiding inclined surface of the limit protrusion and the inclined surface of the triangular ring will compress the key bodies again, so that the key bodies disengage from the inner wall grooves of the installation valve pipe, and the forced opening tool is taken out from the installation valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic cross-sectional view of the structure of the forced opening tool of the present invention;

[0029] Figure 2 is a three-dimensional schematic view of the structure of the retaining ring of the present invention;

[0030] Figure 3 is a three-dimensional schematic view of the structure of the key body of the present invention;

[0031] Figure 4 is a three-dimensional schematic view of the structure of the force-bearing spring of the present invention;

[0032] Figure 5 is a three-dimensional schematic view of the structure of the outer cylinder of the present invention;

[0033] Figure 6 is a three-dimensional schematic view of the structure of the mandrel of the present invention;

[0034] Figure 7 is a three-dimensional schematic view of the structure of the shear sleeve of the present invention;

[0035] Figure 8 is a three-dimensional schematic view of the structure of the support cylinder of the present invention;

[0036] Figure 9It is a partial cross-sectional schematic diagram of the safety valve structure of the present invention.

[0037] In the figure: 1. upper joint; 2. collet; 3. retaining ring; 4. key body; 6. outer cylinder; 7. core shaft; 8. shear sleeve; 9. shear screw; 11. support cylinder; 13. plugging cap; 14. force spring; 18. slide groove; 19. shear groove; 20. limiting groove; 21. limiting protrusion; 22. guiding inclined surface; 23. triangular ring; 24. limiting block; 25. mounting groove; 26. inner ring platform; 27. outer convex step. DETAILED DESCRIPTION

[0038] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the following will be combined with the appended drawings of the embodiments of the present invention. Figures 1-9 , the technical scheme of the embodiment of the present invention is clearly and completely described. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention. Example

[0039] like Figure 1 As shown: a safety valve forced opening tool, including a core shaft 7, an upper joint 1, an outer tube 6, a positioning mechanism, a pop-up mechanism, a support tube 11 and a plugging cap 13, the upper joint 1 is installed on the upper end of the core shaft 7 by screws, the outer tube 6 is sleeved on the core shaft 7, and the plugging cap 13 is installed on the end of the outer tube 6 away from the collet 2 by screws. In the present invention, unless otherwise clearly specified and limited, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be a connection between the two elements or an interaction relationship between the two elements, Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to specific circumstances. The plugging cap 13 is conically set at one end away from the outer tube 6, which can facilitate the plugging cap 13 to quickly enter the safety valve pipeline. The forced opening tool is sent into the safety valve pipe through the upper joint 1 under the action of the tool string. After reaching the predetermined position, the plugging cap 13 opens the safety valve disc, and the positioning mechanism limits the position of the outer tube 6. Then the core shaft 7 moves to enable the pop-up mechanism to expand the support tube 11, and the safety valve disc is supported to realize the permanent opening of the safety valve disc, and the original safety valve channel can be guaranteed.

[0040] like Figure 1 and Figure 4As shown in the figure, the positioning mechanism includes a collet 2 sleeved on a mandrel 7. One end of an outer cylinder 6 close to the collet 2 is threadedly connected to the collet 2. Two retaining rings 3 are slidably sleeved on the collet 2. Two key bodies 4 are symmetrically arranged between the two retaining rings 3. Limiting blocks 24 are fixedly connected to both ends of the key body 4. Mounting grooves 25 corresponding to the limiting blocks 24 are formed on one side of the two retaining rings 3 facing each other. The key body 4 is mounted on the collet 2 through the two retaining rings 3 to limit the position of the key body 4. The cooperation between the limiting blocks 24 and the mounting grooves 25 can limit the movement range of the key body 4 to prevent the key body 4 from detaching from the collet 2. A force-bearing spring 14 is installed between the key body 4 and the collet 2. The force-bearing spring 14 is a U-shaped spring. A round hole is formed in the inner wall of the key body 4. Both ends of the force-bearing spring 14 are arranged in the round hole. The pressure generated by the force-bearing spring 14 presses the key body 4, causing the key body 4 to contact the inner wall of the safety valve pipe, limiting the position of the forced opening tool, preventing the forced opening tool from moving downward continuously, and facilitating the mandrel 7 to activate the ejection mechanism to deploy the support cylinder 11.

[0041] As Figure 2 shown, in one embodiment, limiting protrusions 21 and triangular rings 23 are respectively arranged on the outer side of the key body 4. The limiting protrusion 21 is located at the front section of the key body 4, and the triangular ring 23 is located at the rear section of the key body 4. The triangular ring 23 contacts the inner wall of the safety valve pipe, and through the force-bearing spring 14, the two key bodies 4 move relatively and compress, causing the key body 4 to penetrate into the safety valve pipe. When reaching the preset position, the force-bearing spring 14 resets and pushes up the key body 4, making the limiting protrusion 21 limited in the inner wall groove of the installation valve pipe, fixing the position of the collet 2, and realizing the overall positioning of the forced opening tool.

[0042] As Figure 2 and Figure 3 shown, a guiding inclined surface 22 is arranged on one side of the limiting protrusion 21 away from the triangular ring 23. When disassembling the forced opening tool, the guiding inclined surface 22 of the limiting protrusion 21 and the inclined surface of the triangular ring 23 will compress the key body 4 again, causing the key body 4 to disengage from the inner wall groove of the installation valve pipe and taking out the forced opening tool from the installation valve.

[0043] As Figure 1 and Figure 7 shown, the ejection mechanism includes two shear sleeves 8 arranged on the outer cylinder 6. A shear screw 9 is arranged between the shear sleeve 8 and the mandrel 7. The shear sleeve 8 is fixed on the outer cylinder 6 by the shear screw 9. A shear groove 19 is formed on the mandrel 7. The shear screw 9 sequentially passes through the chute 18 of the shear sleeve 8 and extends to the shear groove 19. When the mandrel 7 moves downward, the shear groove 19 on the mandrel 7 cuts off the shear screw 9.

[0044] As Figure 8As shown, the support cylinder 11 is formed by winding elastic pieces. The support cylinder 11 is arranged between two shear sleeves 8. A limiting groove 20 for limiting the support cylinder 11 is provided at one end of the two shear sleeves 8 facing each other. The limiting groove 20 can prevent the support cylinder 11 from unfolding in advance, resulting in the failure of the support cylinder 11 to support the safety valve cover. After the shear screw 9 is cut off, the upper shear screw 9 moves in the chute 18, and under the elastic action of the support cylinder 11, the upper shear sleeve 8 is pushed open. The upper shear sleeve 8 moves in the opposite direction to the lower shear sleeve 8. The distance between the two shear sleeves 8 increases under the action of the support cylinder 11, and the support cylinder 11 unfolds from the limiting groove 20, and the outside of the support cylinder 11 jacks up the safety valve cover to permanently open the safety valve cover.

[0045] As Figure 1 and Figure 6 As shown, an inner ring platform is provided on the inner wall of the collet 2, and an outer convex step abutting against the inner ring platform is provided on the mandrel 7 to limit the position of the mandrel 7, so that the mandrel 7 can only move downward to prevent the mandrel 7 from being directly pulled out of the outer cylinder 6.

[0046] The working method of the present invention:

[0047] During installation, one of the retaining rings 3 is sleeved on the collet 2, the key body 4 is installed with the force spring 14 and is installed at one end of one of the retaining rings 3, and the key body 4 is pressed tightly with the other retaining ring 3; the outer cylinder 5 is threadedly fixed on the collet 2, the mandrel 7 is passed through the outer cylinder 6, the collet 2 is connected to the outer cylinder 6, the upper joint 1 is connected to the mandrel 7, and the set screw is screwed on. The upper joint 1 is pulled upward to make the mandrel 7 abut against the collet 2. The upper joint 1 is rotated to align the shear groove 19 of the mandrel 7 with the chute 18 on the outer cylinder 6. One of the shear sleeves 8 is fixed with the shear screw 9. One end of the compressed support cylinder 11 is installed in the limiting groove 20 on the shear sleeve 8, and the other end of the support cylinder 11 is limited by another shear sleeve 8, and the shear screw 9 is screwed on. Finally, the plug cap 13 is screwed on, and an elastic dowel pin is driven into the plug cap 13.

[0048] In the case where the safety valve disc cannot be opened, it is connected to the tool string through the upper joint 1. Under the conveyance of the tool string, the outer cylinder 6 and the mandrel 7 are sent into the safety valve pipeline. During the movement, the plug cap 13 contacts the safety valve disc first and pushes open the safety valve disc. The plug cap 13 continues to move. When the key body 4 enters the safety valve pipeline, the two key bodies 4 are relatively compressed through the triangular ring 23, so that the key body 4 penetrates into the safety valve pipeline. When reaching the preset position, the force-bearing spring 14 resets and pushes up the key body 4, so that the limit protrusion 21 on the key body 4 is limited in the inner wall groove of the installation valve pipeline, realizing the positioning of the whole forced opening tool. When the positioning of the whole forced opening tool is completed, when the support cylinder 11 corresponds to the safety valve disc, then strike the upper joint 1. The upper joint 1 drives the mandrel 7 to move downward. The shear groove 19 on the mandrel 7 cuts off the shear screw 9. Under the elastic action of the support cylinder 11, the upper shear sleeve 8 moves in the opposite direction to the lower shear sleeve 8. The distance between the two shear sleeves 8 increases under the action of the support cylinder 11. The support cylinder 11 unfolds from the limiting groove 20, and the outside of the support cylinder 11 pushes up the safety valve disc, realizing the permanent opening of the safety valve disc;

[0049] When disassembling the forced opening tool, the mandrel 7 moves upward, driving the key body 4 to move upward. The guiding inclined surface 22 of the limit protrusion 21 on the key body 4 and the inclined surface of the triangular ring 23 will compress the key body 4 again, so that the key body 4 disengages from the inner wall groove of the installation valve pipeline, and the forced opening tool is taken out of the installation valve.

[0050] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A safety valve forced opening tool, characterized in that: Comprising: A mandrel (7); An upper joint (1) for connecting with an external component to enable a forced opening tool to extend into a safety valve tube. The upper joint (1) is arranged at the upper end of the mandrel (7); An outer cylinder (6) sleeved on the mandrel (7), and two sliding grooves (18) are formed in the outer cylinder (6); A positioning mechanism for fixing the forced opening tool in a groove of a safety valve working cylinder to facilitate the overall operation of the forced opening tool; A pop-up mechanism. The pop-up mechanism includes two shear sleeves (8) arranged on the outer cylinder (6). A shear screw (9) is arranged between the shear sleeve (8) and the outer cylinder (6), and the shear sleeve (8) is fixed on the outer cylinder (6) by the shear screw (9); A support cylinder (11) wound by elastic sheets. The support cylinder (11) is arranged between the two shear sleeves (8). When the mandrel (7) moves downward, the shear screw (9) between the upper shear sleeve (8) and the mandrel (7) is cut off. Under the elastic action of the support cylinder (11), the upper shear sleeve (8) is pushed open, and the support cylinder (11) is unfolded to permanently open the safety valve disc; A plug cap (13) arranged at one end of the outer cylinder (6) away from the collet (2) for pushing open the safety valve; 2. The safety valve forced opening tool according to claim 1, characterized in that: A shear groove (19) is formed in the mandrel (7). The shear screw (9) sequentially passes through the sliding groove (18) of the shear sleeve (8) and extends to the shear groove (19) to cut off the shear screw (9) when the mandrel (7) moves downward; 3. The safety valve forced opening tool according to claim 1, characterized in that: Limiting grooves (20) for limiting the position of the support cylinder (11) are formed at opposite ends of the two shear sleeves (8); 4. The safety valve forced opening tool according to claim 1, characterized in that: The positioning mechanism includes a collet (2) sleeved on the mandrel (7). The outer cylinder (6) is arranged on the collet (2). Two retaining rings (3) are sleeved on the collet (2). Two key bodies (4) are symmetrically arranged between the two retaining rings (3). The two retaining rings (3) are used to limit the key bodies (4) on the collet (2). A force-bearing spring (14) is arranged between the key bodies (4) and the collet (2) to apply pressure to the key bodies (4) so that the key bodies (4) are located in the grooves of the safety valve working cylinder to limit the position of the forced opening tool; 5. The safety valve forced opening tool according to claim 4, characterized in that: Limit protrusions (21) and triangular rings (23) are respectively arranged on the outer sides of the key bodies (4). The limit protrusions (21) are located at the front section of the key bodies (4), and the triangular rings (23) are located at the rear ends of the key bodies (4). When the triangular rings (23) contact the inner wall of the safety valve tube, the key bodies (4) are compressed, and the limit protrusions (21) are limited in the grooves of the installation valve working cylinder; 6. The safety valve forced opening tool according to claim 5, characterized in that: A guiding inclined surface (22) is arranged on one side of the limit protrusion (21) away from the triangular ring (23) to contract the key body (4) when the forced opening tool is disassembled, so as to facilitate releasing the position limitation of the forced opening tool; 7. The safety valve forced opening tool according to claim 4, characterized in that: Limit blocks (24) are arranged at both ends of the key body (4), and installation grooves (25) corresponding to the limit blocks (24) are formed on opposite sides of the two retaining rings (3).

8. The safety valve forced opening tool according to claim 4, characterized in that: The inner wall of the collet (2) is provided with an inner ring platform (26), and the mandrel (7) is provided with an outer convex step (27) that abuts against the inner ring platform to prevent the mandrel (7) from being directly pulled out of the outer cylinder (6).

9. The safety valve forced opening tool according to claim 5, characterized in that: The force-bearing spring (14) is a U-shaped spring. A round hole is formed in the inner wall of the key body (4), and both ends of the force-bearing spring (14) are arranged in the round hole.

10. The safety valve forced opening tool according to claim 1, characterized in that: One end of the plug cap (13) away from the outer cylinder (6) is tapered.

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