Repeatable throwing and fishing type emergency shut-in valve for offshore platform and operation method of repeated throwing and fishing type emergency shut-in valve

Abstract

The invention discloses a repeatable throwing and fishing type emergency shut-in valve for an offshore platform and an operation method of the repeatable throwing and fishing type emergency shut-in valve. The repeatable throwing and fishing type emergency shut-in valve comprises a sliding sleeve body, a sliding sleeve connecting sleeve, a sliding sleeve valve, a sealing connecting sleeve, a feeding and recycling short section, an inserting core pipe, a plug and a lower connector. The upper end and the lower end of the sliding sleeve connecting sleeve are connected with the sealing connecting sleeve and the lower connector respectively, a sliding sleeve body is arranged on the inner side of the sliding sleeve connecting sleeve, a plug is arranged at the lower end of the sliding sleeve body, a first channel communicated with an inner cavity of the lower connector is formed in the side wall of the sliding sleeve body, and the sliding sleeve valve is arranged in the inner cavity of the sliding sleeve body. The feeding and recycling short section is connected with the sealing connecting sleeve through threads, an inserting core pipe is arranged at the lower end of the feeding and recycling short section, and the feeding and recycling short section drives the inserting core pipe to move axially so as to drive the sliding sleeve valve to move up and down to close and open the first channel. Opening and closing can be achieved by rotating the drill rod; the device is simple in structure, convenient to operate, reliable in sealing, reusable and suitable for emergency well shut-in requirements in offshore high-risk operation environments.

Description

Technical Field

[0001] This invention relates to the field of marine oil and gas drilling, completion and workover equipment technology, and in particular to a reusable emergency well sealing valve for offshore platforms and its operation method. Background Technology

[0002] In offshore drilling and workover operations, if a well kick, lost circulation, or other sudden pressure anomalies occur, effective measures must be taken immediately to control the wellhead pressure and prevent a blowout. The conventional approach is to rely on the blowout preventer assembly (BOP) for emergency shut-in, but in certain special conditions (such as when the tubing string is not fully retrieved or the testing tools are still in the well), complete shut-in is difficult to achieve.

[0003] Existing technologies include some downhole packers used in conjunction with well-sealing valves to establish temporary isolation barriers at specific depths. For example, after the packer is set, a well-sealing valve is installed above it to cut off the first fluid channel between the upper tubing and the lower formation, allowing for work stoppage or equipment replacement even with incomplete tripping out. However, existing well-sealing devices still have the following problems: complex operation: most rely on specialized tools or hydraulic control and cannot be directly switched on and off by rotating the drill pipe; non-reusable: some are designed as disposable structures, making recovery difficult and increasing operating costs; poor sealing reliability: prone to leakage under high pressure differential conditions, affecting well control safety; lack of controllable recovery mechanism: during the retrieval process, it is impossible to ensure synchronous control of annular and tubing pressure, posing a risk of pressure loss; low automation: the disconnection and reconnection processes rely on manual judgment, which is inefficient and prone to misoperation. In addition, most current well-sealing valves do not have a closed-loop capability of "insertion-disconnection-automatic closure-controllable recovery," limiting their application flexibility in complex offshore operations.

[0004] Therefore, there is an urgent need to develop an emergency well sealing valve that is simple in structure, easy to operate, and reusable, capable of quickly isolating the wellbore in an emergency and supporting recovery under controlled conditions, thereby improving the inherent safety level of offshore operations. Summary of the Invention

[0005] The purpose of this invention is to provide a reusable emergency well-sealing valve for offshore platforms and its operation method, aiming to solve the problems of inconvenient operation, non-reusability, unreliable sealing, and loss of control during the recovery process in the prior art.

[0006] The present invention solves its problems through the following technical solution: A reusable emergency well-sealing valve for offshore platforms includes a sliding sleeve body, a sliding sleeve connecting sleeve, a sliding sleeve valve, a sealing connecting sleeve, an insertion and recovery sub, an insertion core tube, a plug, and a lower connector. The upper and lower ends of the sliding sleeve connecting sleeve are connected to the sealing connecting sleeve and the lower connector, respectively. The sliding sleeve body is located inside the sliding sleeve connecting sleeve, and the plug is located at the lower end of the sliding sleeve body. The side wall of the sliding sleeve body has a first channel communicating with the inner cavity of the lower connector. The sliding sleeve valve is located in the inner cavity of the sliding sleeve body. The insertion and recovery sub is connected to the sealing connecting sleeve by threads. The insertion core tube is located at the lower end of the insertion and recovery sub. The insertion and recovery sub drives the insertion core tube to move axially to drive the sliding sleeve valve to move up and down to close and open the first channel.

[0007] Optionally, the upper end of the sliding valve is provided with an elastic claw suitable for radial extension and retraction, the upper end of the elastic claw is provided with a first protrusion extending radially outward, and the inner wall of the sliding body is provided with a first groove corresponding to the first protrusion.

[0008] Optionally, the upper end of the elastic claw is provided with a second protrusion extending radially inward, and the outer wall of the insertion core tube is provided with a second groove corresponding to the second protrusion.

[0009] Optionally, the second protrusion and the first protrusion are positioned correspondingly in the axial direction of the sliding valve.

[0010] Optionally, the sliding valve has a second channel on its side wall. When the sliding valve is in the position within the sliding sleeve body such that the second channel is connected to the first channel, the well sealing valve is in the open state. When the sliding valve is in the position within the sliding sleeve body such that the second channel is offset from the first channel, the well sealing valve is in the closed state.

[0011] Optionally, a retaining ring is provided between the inserted core tube and the feed-in recovery section.

[0012] Optionally, the feeding and recovery short section is provided with external threads, and the sealing connecting sleeve is provided with internal threads. The feeding and recovery short section and the sealing connecting sleeve are connected by rotation or disconnected by rotation.

[0013] An operating method for an emergency well sealing valve as described above includes the following steps: After connecting the recovery sub, insert core tube, and retaining ring, the sub is sent into the well via drill pipe. Rotate to tighten and engage the feeding and recovery section with the sealing connection sleeve; During the upper connection process, insert the core tube and press down the sliding sleeve valve to make its elastic claws retract and move downward, opening the well sealing valve; After completing the operation, rotate in the opposite direction to loosen the threaded connection between the inserted recovery section and the sealing connection sleeve; Raise the drill pipe to move the core tube and sliding sleeve valve upwards until the elastic claw of the sliding sleeve valve is embedded in the first groove of the sliding sleeve body, and close the well sealing valve; Continue lifting to disengage the insert core tube from the sliding valve, then remove and send in the recovery section, insert core tube, and retaining ring.

[0014] In summary, the technical effects and advantages of this invention are as follows: Simple operation: Switching can be achieved simply by rotating and moving the drill pipe up and down, without the need for additional hydraulic or cable control; Automatic shutdown: The sliding sleeve valve automatically locks and closes after the feed tool is disengaged, ensuring it does not fail in emergencies; Reusable: Supports multiple deployments and retrievals, reducing the cost per operation; Controllable pressure: Maintains independent sealing between the annulus and the tubing string during retrieval, facilitating pressure management; Strong compatibility: Can be used in combination with various packers and testing tools, adapting to different operational processes; Intrinsically safe: Reduces human intervention and improves the reliability of high-risk offshore operations. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the emergency well sealing valve in the open state according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the emergency well sealing valve in the closed state according to one embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the recycling component in one embodiment of the present invention; Figure 4 This is an isometric schematic diagram of the emergency well sealing valve in the open state according to an embodiment of the present invention.

[0017] The components are: 1. Sliding sleeve body; 2. Sliding sleeve connecting sleeve; 3. Sliding sleeve valve; 4. Sealing connecting sleeve; 5. Feed-in recovery short section; 6. Inserted core tube; 7. Retaining ring; 8. Plug; 9. Lower connector; 10. First channel; 11. Elastic claw; 12. First groove; 13. Second groove; 14. Second channel. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] This embodiment provides a reusable emergency well-sealing valve for offshore platforms, a downhole safety device used to quickly and temporarily seal off the well in case of abnormal situations during drilling, completion, or workover operations. The emergency well-sealing valve can be carried down via drill pipe, has an automatic closing function, and supports multiple deployments and retrievals. It is suitable for scenarios with extremely high well control safety requirements, such as high-pressure oil and gas wells, high-risk exploration wells, and unmanned platforms; and is used in scenarios requiring rapid establishment of a wellbore isolation barrier, such as temporary well sealing during offshore drilling, completion, or workover operations, pressure testing interruptions, and equipment replacements. Figures 1-4 As shown, the emergency well sealing valve includes a sliding sleeve body 1, a sliding sleeve connecting sleeve 2, a sliding sleeve valve 3, a sealing connecting sleeve 4, an infeed recovery sub 5, an insert core tube 6, a plug 8, and a lower connector 9. The upper and lower ends of the sliding sleeve connecting sleeve 2 are connected to the sealing connecting sleeve 4 and the lower connector 9, respectively. The lower connector 9 is used to connect to the packer below or other downhole tools to achieve integration with the downhole operation system. The inner side of the sliding sleeve connecting sleeve 2 is provided with the sliding sleeve body 1, and the sliding sleeve connecting sleeve 2 is used to connect the sliding sleeve body 1 to the upper tubing string. The lower end of the sliding sleeve 1 is provided with a plug 8, which serves as a bottom sealing end cap for the sliding sleeve 1. The side wall of the sliding sleeve 1 is provided with a first channel 10 communicating with the inner cavity of the lower connector 9. The sliding sleeve valve 3 is located in the inner cavity of the sliding sleeve 1. The feed-in and recovery short section 5 is connected to the sealing connecting sleeve 4 via threads. The sealing connecting sleeve 4 is used to transmit torque. The lower end of the feed-in and recovery short section 5 is provided with an insertion core tube 6. The upper end of the feed-in and recovery short section 5 is connected to the drill rod and enables rotational up-and-down operation. The feed-in and recovery short section 5 drives the insertion core tube 6 to move axially, thereby driving the sliding sleeve valve 3 to move up and down to close and open the first channel 10. The insertion core tube 6 is a central axially moving component that drives the sliding sleeve valve 3 to operate.

[0020] Specifically, the upper end of the sliding valve 3 is provided with an elastic claw 11 suitable for radial extension and retraction. The upper end of the elastic claw 11 is provided with a first protrusion extending radially outward, and the inner wall of the sliding body 1 is provided with a first groove 12 corresponding to the first protrusion. In this embodiment, the sliding body 1 is a main pressure-bearing structure, and the sliding body 1 has a first groove 12 inside to accommodate the first protrusion of the elastic claw 11. The sliding valve 3 is a movable valve core with an elastic claw 11, which can be opened and closed during up and down movement. The first protrusion of the elastic claw 11 can be embedded in the preset first groove 12 inside the sliding body 1 to achieve automatic locking and form a closed state.

[0021] Furthermore, the upper end of the elastic claw 11 is provided with a second protrusion extending radially inward, and the outer wall of the insertion core tube 6 is provided with a second groove 13 corresponding to the second protrusion. When the inserted recovery sub 5 is disengaged from the sealing connection sleeve 4 and lifted, the insertion core tube 6 drives the sliding valve 3 to move upward to the closed position and then automatically disengages, realizing the automatic closure of the well sealing valve and separation of the tool.

[0022] Furthermore, the second protrusion and the first protrusion are positioned correspondingly in the axial direction of the sliding valve 3.

[0023] Specifically, the sliding valve 3 has a second channel 14 on its side wall. When the sliding valve 3 is positioned inside the sliding body 1 such that the second channel 14 is connected to the first channel 10, the well sealing valve is in the open state. When the sliding valve 3 is positioned inside the sliding body 1 such that the second channel 14 is offset from the first channel 10, the well sealing valve is in the closed state.

[0024] Optionally, a retaining ring 7 is provided between the insertion core tube 6 and the delivery and recovery section 5. The retaining ring 7 is a limiting element to prevent the insertion core tube 6 from moving excessively upward.

[0025] Optionally, the feeding and recovery section 5 is provided with external threads, and the sealing connecting sleeve 4 is provided with internal threads. The feeding and recovery section 5 and the sealing connecting sleeve 4 are connected by rotation or disconnected by rotation.

[0026] In this embodiment, the sliding sleeve 1 is connected to the sliding sleeve connecting sleeve 2 by threads to form an outer cylinder structure; the sliding sleeve valve 3 is placed in the inner cavity of the sliding sleeve 1, and its outer circumference is provided with a set of radially retractable spring claws; the sealing connecting sleeve 4 is fixed to the upper end of the sliding sleeve 1, and has internal threads for docking with the feed-in recovery short section 5; the feed-in recovery short section 5 is inserted into the sealing connecting sleeve 4 by threads, and its lower end is connected to the insertion core tube 6; the insertion core tube 6 passes through the sealing connecting sleeve 4 and extends into the sliding sleeve 1, contacting the top of the sliding sleeve valve 3; the retaining ring 7 is welded to the outer wall of the insertion core tube 6 as an upward limit; the plug 8 is welded to the bottom of the sliding sleeve 1 to seal the lower end; the lower connector 9 is located at the bottommost end and is used to connect the packer or test tool string.

[0027] This embodiment also provides an operation method for the emergency well sealing valve as described above, including the following steps: After connecting the recovery sub 5, the core tube 6, and the retaining ring 7, the sub is sent into the well through the drill pipe. Rotate to tighten and engage the feeding and receiving short section 5 with the sealing connection sleeve 4; During the upper connection process, the inserted core tube 6 presses down the sliding sleeve valve 3, causing its elastic claw 11 to retract and move downward, opening the well sealing valve; After completing the operation, rotate in the opposite direction to loosen the threaded connection between the inserted recovery section 5 and the sealing connection sleeve 4; Raise the drill pipe to drive the core tube 6 and the sliding valve 3 upward until the elastic claw 11 of the sliding valve 3 is embedded in the first groove 12 of the sliding body 1, and close the well sealing valve. Continue lifting to disengage the insert core tube 6 from the sliding valve 3, then remove and send in the recovery section 5, insert core tube 6, and retaining ring 7.

[0028] The feed-in recovery assembly consists of the feed-in recovery sub 5, the insert core tube 6, and the retaining ring 7. In this embodiment, after the wellhead valve is closed, the upper operating tools can be safely recovered without disturbing the settling state of the downhole packer. The wellhead valve can be reopened by re-lowering the feed-in recovery assembly and rotating the top cap, allowing for multiple reuses.

[0029] Close workflow: Rotate the recovery section 5 and the sealing sleeve 4 to separate them; The drill rod is lifted, causing the core tube 6 and retaining ring 7 to move upwards; The inserted core tube 6 is pulled upward by the elastic claw 11 of the sliding valve 3; The first protrusion of the sliding valve 3 moves upward to the position of the first groove 12 of the sliding body 1, the elastic claw 11 is released, and the first protrusion is embedded in the first groove 12 to achieve locking. At this point, the core tube 6 is disengaged from the sliding valve 3, and the well sealing valve is in the closed state; Remove and send in the recycling section 5, insert the core tube 6 and retaining ring 7 assembly.

[0030] Start the workflow: The well sealing valve is re-inserted by sending in the recovery sub 5, inserting the core tube 6 and the retaining ring 7; Rotate to tighten and engage the feeding and receiving short section 5 with the sealing connection sleeve 4; During the upper buckling process, the insert core tube 6 pushes the sliding valve 3 downward, causing its elastic claw 11 to retract, and the second protrusion enters the second groove 13 on the insert core tube 6. When the sliding valve 3 moves downward, the second channel 14 connects with the first channel 10, the first channel 10 opens, and the well sealing valve resumes its flow state.

[0031] This structure achieves a complete cycle of "rotation disengagement → automatic closure → controllable recovery → re-engagement → rotation re-locking → reopening", meeting the high reliability and reusability requirements of offshore platforms for emergency well sealing systems.

[0032] Application scenario example: A certain offshore platform was conducting mid-course testing operations when a sudden well surge occurred, necessitating an emergency halt to the testing and the sealing of the well.

[0033] Initial state: The well sealing valve is lowered into the test tubing and is in the open state.

[0034] Decision to seal the well: The ground operator slowly lifts the drill pipe while simultaneously rotating it in the opposite direction to disengage the threaded connection between the feed recovery sub 5 and the sealing sleeve 4.

[0035] Automatic closing: Continue to lift, insert the core tube 6 to drive the sliding sleeve valve 3 upward. When the first protrusion of the elastic claw 11 is aligned with the first groove 12 of the sliding sleeve body 1, it automatically pops out and locks, the well sealing valve closes, and the wellbore is isolated.

[0036] Retrieve tools: Remove the infeed recovery sub 5, insert core tube 6 and retaining ring 7 from the tubing string, leaving the well sealing valve and packer in the well.

[0037] Subsequent handling: After the risk is eliminated, re-insert the recovery section 5, insert the core tube 6 and retaining ring 7, rotate the upper buckle, push the sliding valve 3 downward to open, restore the passage, and continue the operation or remove the whole unit.

[0038] The entire process does not require complete excavation, significantly reducing non-productive time and improving operational safety.

[0039] In summary, this embodiment is easy to operate: the switch can be operated simply by rotating and moving the drill pipe up and down, without the need for additional hydraulic or cable control; it automatically shuts off: the sliding valve automatically locks and closes after the feed tool is disengaged, ensuring it does not fail in emergencies; it is reusable: it supports multiple deployments and retrievals, reducing the cost per operation; it has controllable pressure: the annulus and tubing remain independently sealed during retrieval, facilitating pressure management; it is highly compatible: it can be used in combination with various packers and testing tools, adapting to different operational processes; and it is inherently safe: it reduces human intervention and improves the reliability of high-risk offshore operations.

[0040] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0041] Furthermore, the terms "a," "two," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0042] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A reusable emergency well-sealing valve for offshore platforms, characterized in that, The device includes a sliding sleeve body (1), a sliding sleeve connecting sleeve (2), a sliding sleeve valve (3), a sealing connecting sleeve (4), a feed and recovery short section (5), an insertion core tube (6), a plug (8), and a lower connector (9). The upper and lower ends of the sliding sleeve connecting sleeve (2) are connected to the sealing connecting sleeve (4) and the lower connector (9), respectively. The inner side of the sliding sleeve connecting sleeve (2) is provided with a sliding sleeve body (1), and the lower end of the sliding sleeve body (1) is provided with a plug (8). The side wall of the sliding sleeve body (1) is provided with a first channel (10) that communicates with the inner cavity of the lower connector (9). The sliding sleeve valve (3) is located in the inner cavity of the sliding sleeve body (1). The feed and recovery short section (5) is connected to the sealing connecting sleeve (4) by a thread. The lower end of the feed and recovery short section (5) is provided with an insertion core tube (6). The feed and recovery short section (5) drives the insertion core tube (6) to move axially to drive the sliding sleeve valve (3) to move up and down to close and open the first channel (10).

2. The reusable emergency well-sealing valve for offshore platforms according to claim 1, characterized in that, The upper end of the sliding valve (3) is provided with an elastic claw (11) suitable for radial extension and retraction. The upper end of the elastic claw (11) is provided with a first protrusion extending radially outward. The inner wall of the sliding body (1) is provided with a first groove (12) corresponding to the first protrusion.

3. The reusable emergency well-sealing valve for offshore platforms according to claim 2, characterized in that, The upper end of the elastic claw (11) is provided with a second protrusion extending radially inward, and the outer wall of the insertion core tube (6) is provided with a second groove (13) corresponding to the second protrusion.

4. The reusable emergency well-sealing valve for offshore platforms according to claim 3, characterized in that, The second protrusion and the first protrusion are positioned correspondingly in the axial direction of the sliding valve (3).

5. The reusable emergency well-sealing valve for offshore platforms according to claim 1, characterized in that, The sliding valve has a second channel (14) on its side wall. When the sliding valve (3) is in the position of the sliding body (1) such that the second channel (14) is connected to the first channel (10), the well sealing valve is in the open state. When the sliding valve (3) is in the position of the sliding body (1) such that the second channel (14) is offset from the first channel (10), the well sealing valve is in the closed state.

6. The reusable emergency well-sealing valve for offshore platforms according to claim 1, characterized in that, A retaining ring (7) is provided between the insert core tube (6) and the feed-in recovery section (5).

7. The reusable emergency well-sealing valve for offshore platforms according to claim 1, characterized in that, The feeding and recovery short section (5) is provided with external threads, and the sealing connecting sleeve (4) is provided with internal threads. The feeding and recovery short section (5) and the sealing connecting sleeve (4) are connected by rotation or disconnected by uncoupling.

8. A method for operating an emergency well-sealing valve as described in any one of claims 1-7, characterized in that, Includes the following steps: After connecting the feed recovery sub (5), insert core tube (6) and retaining ring (7), the feed sub is sent into the well through the drill pipe; Rotate to tighten the insertion and closing of the short section (5) and the sealing connection sleeve (4); During the upper connection process, the inserted core tube (6) presses down the sliding sleeve valve (3), causing its elastic claw (11) to retract and descend, opening the well sealing valve; After completing the operation, rotate in the opposite direction to loosen the threaded connection between the feed recovery short section (5) and the sealing connection sleeve (4); Raise the drill pipe to drive the core tube (6) and the sliding valve (3) upward until the elastic claw (11) of the sliding valve (3) is embedded in the first groove (12) of the sliding body (1) and the well sealing valve is closed. Continue to lift up to disengage the insert core tube (6) from the sliding valve (3), and remove the feed recovery short section (5), insert core tube (6) and retaining ring (7).

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