An asynchronous disconnection device and control method of an oil-water well casing blowout prevention tool

Abstract

The application discloses an asynchronous disengaging device of an oil-water well casing blowout preventer and a control method, wherein the asynchronous disengaging device of the oil-water well casing blowout preventer comprises a retractable spring claw, an expanding spring claw, a disengaging cylinder, a retraction limiting mechanism, an expansion limiting mechanism and a reset mechanism; the outer wall of the retractable spring claw is provided with a first convex edge, and the inner wall of the expanding spring claw is provided with a second convex edge matched with the first convex edge; the retractable spring claw is internally provided with the retraction limiting mechanism; the expanding spring claw is located inside the disengaging cylinder, the inner wall of the disengaging cylinder is provided with the expansion limiting mechanism near the top position; and the retractable spring claw and the disengaging cylinder are connected with the reset mechanism. The problems that no special fishing tool is used for fishing the blowout preventer, the existing fishing tool cannot realize repeated disengaging function, the success rate of fishing is low, the fishing operation time is prolonged, the construction efficiency is reduced and the labor cost is increased are solved.

Description

Technical Field

[0001] This invention relates to the field of oil production engineering, specifically to an asynchronous disconnection device and control method for blowout preventer tools for oil and water well casings. Background Technology

[0002] During downhole operations in oil and water wells, high formation pressure often leads to oil and casing overflows, causing environmental pollution. Disposable blowout preventers (BOPs) such as sliding sleeve switches, valves, bridge plugs, and packers are commonly used to achieve non-pressure blowout prevention. However, during secondary operations, these downhole BOPs are typically retrieved using a sliding retrieval spear, as there are no dedicated retrieval tools. Existing retrieval tools cannot achieve repeated disengagement, resulting in a low retrieval success rate, prolonged retrieval time, reduced construction efficiency, and increased labor costs. Summary of the Invention

[0003] In view of this, the present invention provides an asynchronous disconnection device and control method for blowout preventer tools for oil and water well casings, in order to solve the problems that in the past, when retrieving blowout preventer tools, there was no dedicated retrieval tool, and the existing retrieval tools could not achieve repeated disconnection function, resulting in a low success rate of retrieval, prolonging the retrieval operation time, reducing construction efficiency and increasing labor costs.

[0004] In a first aspect, the present invention provides a device comprising: a retractable spring claw, an expandable spring claw, a disengagement cylinder, a retractable limiting mechanism, an expandable limiting mechanism, and a reset mechanism;

[0005] The retractable spring claw has a first protruding edge on its outer wall, and the expandable spring claw has a second protruding edge on its inner wall that mates with the first protruding edge.

[0006] The retractable spring claw has a retraction limiting mechanism inside, and the retractable spring claw is connected to the retraction limiting mechanism. The retraction limiting mechanism is used to prevent the bottom sidewall of the retractable spring claw from retracting inward.

[0007] The expandable spring claw is located inside the disconnecting cylinder. The inner wall of the disconnecting cylinder near the top has an expansion limiting mechanism. The expansion limiting mechanism is used to prevent the top sidewall of the expandable spring claw from expanding outward. In the initial position, the top of the expandable spring claw is located at the expansion limiting mechanism.

[0008] A reset mechanism is connected between the retractable spring claw and the disengagement cylinder. The reset mechanism is used to bring the expandable spring claw to its initial position in a natural state.

[0009] Preferably, the contraction limiting mechanism includes: a mandrel;

[0010] The mandrel is located inside the retractable spring claw. When the bottom end of the mandrel is located near the bottom of the retractable spring claw, the outer wall of the bottom end of the mandrel is in contact with the inner wall of the retractable spring claw.

[0011] The outer wall of the mandrel has a third protrusion, and the inner wall of the retractable spring claw near the top has a fourth protrusion that mates with the third protrusion.

[0012] The mandrel and the retractable spring claw are connected by a pin, which is used to fix the bottom end of the mandrel inside the retractable spring claw near the bottom.

[0013] Preferably, the expansion limiting mechanism includes:

[0014] The inner wall of the disconnecting cylinder has a first protrusion near the top. When the top of the expanding spring claw is in the disconnecting cylinder near the top, the outer wall of the top of the expanding spring claw fits against the side wall of the first protrusion.

[0015] Preferably, the area between the sidewall of the first protrusion and the inner sidewall of the lower disconnect cylinder is an inclined slope.

[0016] The inner wall of the disconnecting cylinder, located above the first protrusion, has a second protrusion. When the top of the expanding spring claw is in a position near the top inside the disconnecting cylinder, the bottom surface of the second protrusion contacts the top surface of the expanding spring claw.

[0017] Preferably, the reset mechanism includes: a reset spring;

[0018] The reset spring is sleeved on the outside of the bottom end of the expandable spring claw. One end of the reset spring is connected to the bottom of the disconnect cylinder, and the other end is connected to the expandable spring claw.

[0019] Preferably, it further includes: an anti-corrosion ring;

[0020] The anti-corrosion ring is fitted onto the outside of the retractable spring claw;

[0021] The anti-corrosion ring is made of aluminum alloy.

[0022] Secondly, the present invention provides an asynchronous disconnection control method for blowout preventer tools in oil and water well casings, comprising:

[0023] When it is necessary to asynchronously disengage the expanding spring claw from the retractable spring claw, the retractable limiting mechanism is controlled to move upward, and the retractable limiting mechanism moves away from the bottom end of the retractable spring claw.

[0024] When the retractable limiting mechanism moves, it drives the retractable spring claw to move upward. The bottom side wall of the retractable spring claw retracts inward due to the obstruction of the second protrusion, until the retractable spring claw moves away from the expanding spring claw, thereby completing the asynchronous disengagement.

[0025] When it is necessary for the expanding spring claw to dock with the retractable spring claw, the retractable spring claw is controlled to move downward. When the bottom end of the retractable spring claw moves to contact the expanding spring claw, the expanding spring claw is pushed downward. When the top of the expanding spring claw moves away from the expansion limit mechanism, the top side wall of the expanding spring claw expands outward, allowing the retractable spring claw to insert into the interior of the expanding spring claw.

[0026] The reset mechanism drives the expansion spring claw to move upward. When the top of the expansion spring claw moves to the expansion limit mechanism, the side wall of the top of the expansion spring claw retracts inward. The expansion limit mechanism prevents the side wall of the top of the expansion spring claw from expanding outward, thereby completing the docking.

[0027] The present invention has the following beneficial effects:

[0028] This invention provides an asynchronous disconnection device and control method for blowout preventer (BOP) tools in oil and water well casings. By setting retractable and expandable spring claws, along with corresponding retraction and expansion limiting mechanisms, a repeatable disconnection function of the two-stage spring claws is achieved. The operation is simple and fast, improving work efficiency and reducing labor costs. It solves the problems of low success rates, prolonged retrieval time, reduced construction efficiency, and increased labor costs associated with the previous retrieval of BOPs due to the lack of dedicated retrieval tools and the inability of existing retrieval tools to achieve repeatable disconnection. Attached Figure Description

[0029] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0030] Figure 1 This is a schematic diagram of the asynchronous disconnection device of an oil and water well casing blowout preventer according to an embodiment of the present invention.

[0031] In the diagram, 1-upper connector, 2-anti-corrosion ring, 3-anti-rotation pin, 4-retractable spring claw, 401-first protrusion, 402-fourth protrusion, 5-spindle, 501-third protrusion, 6-pin, 7-disconnect sleeve, 8-expanding spring claw, 801-second protrusion, 9-spring center tube, 10-reset spring, 11-connector, 12-first protrusion, 13-second protrusion, 14-retractable spring claw, 15-expanding spring claw. Detailed Implementation

[0032] The present invention will now be described based on embodiments, but it is worth noting that the present invention is not limited to these embodiments. In the following detailed description of the invention, certain specific details are described in detail. However, those skilled in the art will fully understand the invention for the parts not described in detail.

[0033] Furthermore, those skilled in the art should understand that the accompanying drawings are provided only to illustrate the purpose, features, and advantages of the present invention, and are not actually drawn to scale.

[0034] Furthermore, unless the context explicitly requires it, the words "comprising," "including," and similar terms throughout the specification and claims should be interpreted as including rather than exclusive or exhaustive; that is, meaning "including but not limited to."

[0035] Figure 1 This is a schematic diagram of the asynchronous disconnection device for an oil / water well casing blowout preventer according to an embodiment of the present invention. Figure 1 As shown, an asynchronous disconnection device for an oil and water well casing blowout preventer includes: a retractable spring claw 4, an expanding spring claw 8, a disconnection cylinder 7, a retraction limiting mechanism, an expanding limiting mechanism, and a reset mechanism; the retractable spring claw 4 has a first protruding edge 401 on its outer wall, and the expanding spring claw 8 has a second protruding edge 801 on its inner wall that mates with the first protruding edge 401; the retractable spring claw 4 has the retraction limiting mechanism inside, and the retractable spring claw 4 is connected to the retraction limiting mechanism, which is used to prevent the retraction... The bottom sidewall of the retractable spring claw 4 retracts inward; the expandable spring claw 8 is located inside the disconnecting cylinder 7, and the inner wall of the disconnecting cylinder 7 near the top has an expansion limiting mechanism, which is used to prevent the top sidewall of the expandable spring claw 8 from expanding outward. In the initial position, the top of the expandable spring claw 8 is located at the expansion limiting mechanism; a reset mechanism is connected between the retractable spring claw 4 and the disconnecting cylinder 7, which is used to keep the expandable spring claw 8 in the initial position in its natural state.

[0036] In this embodiment of the invention, the retractable spring claw 4 is hollow inside with an open bottom; the expandable spring claw 8 is hollow inside with an open top. The bottom of the retractable spring claw 4 and the top of the expandable spring claw 8 each have multiple claw plates, with gaps between adjacent claw plates. Specifically, the top surface of the first convex edge 401 from the side away from the retractable spring claw 4 to the side near the retractable spring claw 4 is an upwardly sloping surface, and / or the bottom surface of the second convex edge 801 from the side away from the expandable spring claw 8 to the side near the expandable spring claw 8 is a downwardly sloping surface.

[0037] In the initial state, the bottom end of the retractable spring claw 4 is inserted into the interior of the expanding spring claw 8 through the top opening; the bottom end of the retraction limiting mechanism is located near the bottom of the retractable spring claw 4; the top end of the expanding spring claw 8 is located near the top of the disengagement cylinder 7. The retraction limiting mechanism prevents the retractable spring claw claw 14 from retracting inward, and the expansion limiting mechanism prevents the expanding spring claw claw 15 from expanding outward. At this time, the bottom surface of the second protrusion 801 of the expanding spring claw 8 contacts the top surface of the first protrusion 401 of the retractable spring claw 4, thereby engaging the expanding spring claw 8 and the retractable spring claw 4 together.

[0038] In use, the top of the retractable limiting mechanism is connected to the tubing string via the upper connector 1, and the bottom of the disengagement sleeve 7 is connected to the blowout preventer (BOP) via the connector 11. The tubing string, retractable spring claw 4, expanding spring claw 8, disengagement sleeve 7, and BOP are lowered into the well. When they reach the predetermined position, the tubing string is pulled up until the BOP is set. After the BOP is set, the retractable limiting mechanism is controlled to move upwards. The bottom of the retractable limiting mechanism gradually moves away from the retractable spring claw's claw plate 14. When the retractable limiting mechanism moves close to the inner top of the retractable spring claw 4, it will drive the retractable spring claw 4 upwards. At this time, as the retractable spring claw 4 moves upwards, the first protrusion 401 also moves upwards. Due to the obstruction of the second protrusion 801 and the fact that the retractable limiting mechanism has moved away from the bottom of the retractable spring claw 4, the retractable spring claw's claw plate 14 retracts inwards. The retractable spring claw 4 continues to move upwards until it is completely separated from the expanding spring claw 8, completing the disengagement. The top surface of the first protruding edge 401 and the bottom surface of the second protruding edge 801 are inclined slopes. This is to allow the first protruding edge 401 to slide upward along the inclined slope when the retractable spring claw 4 moves upward, preventing the first protruding edge 401 from getting stuck under the second protruding edge 801, which would prevent the retractable spring claw 4 from moving upward and separating from the expanding spring claw 8.

[0039] When retrieving a blowout preventer (BOP), a retrieval string is lowered into the well. The retrieval string includes a retractable spring claw 4, a retraction limiting mechanism, and an upper connector 1. The upper connector 1 connects to the retrieval string, and at this point, the bottom end of the retraction limiting mechanism is inside the retractable spring claw 4, near its bottom. The retractable spring claw 4, the retraction limiting mechanism, and the upper connector 1 are lowered into the well via the retrieval string. When the retractable spring claw 4 reaches above the expanding spring claw 8, its bottom end contacts the top end of the expanding spring claw 8. Due to the action of the retraction limiting mechanism, the retractable spring claw's claw plate 14 cannot retract inward, preventing the retractable spring claw 4 from inserting into the expanding spring claw 8, thus pushing the expanding spring claw 8 downward. After the top end of the expanding spring claw 8 moves downward away from the expanding limiting mechanism, the expanding spring claw's claw plate 15 expands outward, allowing the bottom end of the retractable spring claw 4 to insert downward into it. As the retractable spring claw 4 continues to move downwards to the bottom of the expanding spring claw 8, pressure is applied to the expanding spring claw 8 through the retractable spring claw 4. This pressure is transmitted to the bottom end of the blowout preventer through the connector 11, causing the unsealing pin at the bottom end of the blowout preventer to break. The blowout preventer is then unsealed, and the tubing is lifted. The retractable spring claw 4 no longer applies downward pressure to the expanding spring claw 8. At this time, the reset mechanism connecting the expanding spring claw 8 and the disconnect sleeve 7 will drive the expanding spring claw 8 to move upwards until the top of the expanding spring claw 8 moves to a position near the top inside the disconnect sleeve 7, i.e., at the expansion limiting mechanism. The expanding spring claw claw piece 15 then retracts inwards to return to its initial state, and the expansion limiting mechanism prevents the expanding spring claw claw piece 15 from expanding outwards. Continue lifting the tubing string, causing the retractable spring claw 4 to move upward. Through the locking engagement of the first protrusion 401 and the second protrusion 801, the retractable spring claw 4 will drive the expanding spring claw 8 and the disconnecting cylinder 7 upward. The disconnecting cylinder 7 will drive the blowout preventer upward through the connector 11, completing the retrieval.

[0040] In this invention, the retractable limiting mechanism includes: a spindle 5; the spindle 5 is located inside the retractable spring claw 4, and when the bottom end of the spindle 5 is located near the bottom of the retractable spring claw 4, the outer side wall of the bottom end of the spindle 5 is in contact with the inner wall of the retractable spring claw 4; the outer side wall of the spindle 5 has a third protrusion 501, and the inner wall of the retractable spring claw 4 near the top has a fourth protrusion 402 that cooperates with the third protrusion 501; the spindle 5 and the retractable spring claw 4 are connected by a pin 6, and the pin 6 is used to fix the position of the bottom end of the spindle 5 near the bottom of the retractable spring claw 4.

[0041] In this embodiment of the invention, the retractable spring claw 4 has a through hole at its top. During installation, the top end of the mandrel 5 is inserted upwards into the retractable spring claw 4 from its bottom opening until it passes through the top of the retractable spring claw 4. In the initial state, the outer wall of the bottom end of the mandrel 5 is in contact with the inner wall of the retractable spring claw 14 to prevent the claw from retracting inwards. The pin 6 is used to position the bottom end of the mandrel 5 in the retractable spring claw 4 near the bottom in the initial state, that is, the bottom end of the mandrel 5 is located at the position of the retractable spring claw 14. The top end of the mandrel 5 is inserted into the upper connector 1, and the anti-rotation pin 3 fixes the top end of the mandrel 5 inside the upper connector 1.

[0042] When it is necessary to disengage the retractable spring claw 4 from the expanding spring claw 8, the tubing is lifted, and the tubing applies upward tension to the mandrel 5. When the load exceeds 10 tons, the pin 6 is sheared, and the mandrel 5 is driven upward by the tubing. When the third protrusion 501 on the outer wall of the mandrel 5 moves to below the fourth protrusion 402 near the top of the inner wall of the retractable spring claw 4, the third protrusion 501 is stuck below the fourth protrusion 402. The continued upward movement of the mandrel 5 will drive the retractable spring claw 4 to move upward. Because the bottom end of the mandrel 5 is now away from the retractable spring claw 14, the retractable spring claw 14 can retract inward. The bottom end of the retractable spring claw 4 moves upward until it separates from the expanding spring claw 8.

[0043] When it is necessary to mate the retractable spring claw 4 with the expanding spring claw 8, return the mandrel 5 to its initial position, that is, the bottom end of the mandrel 5 is in the retractable spring claw 4 near the bottom. Fix the mandrel 5 and the retractable spring claw 4 together. The fixed connection is used to prevent the mandrel 5 from moving upward in the retractable spring claw 4 when it is lifted. The fixed connection can be made by inserting pins 6 into the pin holes of the retractable spring claw 4 and the mandrel 5. At this time, the pins 6 used can be larger diameter pins 6, or the number of pins 6 can be increased to two or more, so that they can withstand the pulling force of the release cylinder 7, the expanding spring claw 8 and the blowout preventer when the tube is lifted without breaking. Alternatively, other methods can be used to connect and fix the mandrel 5 and the retractable spring claw 4 to ensure that the position of the mandrel 5 in the retractable spring claw 4 remains unchanged when the tube is lifted.

[0044] During docking, the mandrel 5 and retractable spring claw 4 are lowered into the well via the tubing string. After reaching the top of the expanding spring claw 8, the expanding spring claw 8 is pushed downwards. As the expanding spring claw 8 moves downwards, its top claw expands, and the bottom end of the retractable spring claw 4 inserts into the expanding spring claw 8. The retractable spring claw 4 continues to move downwards, pushing the expanding spring claw 8, the release sleeve 7, the connector 11, and the blowout preventer (BOP) downwards. This causes the bottom unsealing pin of the BOP to shear off, rendering the BOP anchoring ineffective. Lifting the tubing string and mandrel 5 moves the retractable spring claw 4 upwards. The retractable spring claw 4 no longer applies downward pressure, and the reset mechanism pushes the expanding spring claw 8 upwards to reset and complete the docking. Continuing to lift the tubing string, the tubing string moves the mandrel 5 and the retractable spring claw 4 upwards. The retractable spring claw 4, through the engagement of the first protrusion 401 and the second protrusion 801, moves the expanding spring claw 8 upwards, thereby moving the release sleeve 7 and the BOP upwards, completing the retrieval.

[0045] In this invention, the expansion limiting mechanism includes: a first protrusion 12 on the inner wall of the disengagement cylinder 7 near the top position; when the top end of the expansion spring claw 8 is in the disengagement cylinder 7 near the top position, the outer wall of the top end of the expansion spring claw 8 is in contact with the side wall of the first protrusion 12.

[0046] In this embodiment of the invention, the first protrusion 12 is an annular convex edge on the inner wall of the disengagement cylinder 7 near the top. When the top of the expansion spring claw 8 is in the disengagement cylinder 7 near the top, that is, when the top side wall of the expansion spring claw 8 overlaps with the first protrusion 12, the outer side wall of the expansion spring claw claw piece 15 is in contact with the side wall of the annular convex edge, thereby preventing the top claw piece of the expansion spring claw 8 from expanding outward.

[0047] In this invention, the sidewall of the first protrusion 12 is inclined to the inner sidewall of the lower disconnecting cylinder 7; the inner wall of the disconnecting cylinder 7 above the first protrusion 12 has a second protrusion 13, and when the top of the expanding spring claw 8 is in the position near the top inside the disconnecting cylinder 7, the bottom surface of the second protrusion 13 contacts the top surface of the expanding spring claw 8.

[0048] In this embodiment of the invention, the bottom surface of the first protrusion 12 is an inclined slope, which is used to prevent the top of the expanding spring claw 8 from getting stuck under the first protrusion 12 and unable to reset when the expanding spring claw 8 is pushed downward by the retractable spring claw 4 to move downward and reset by the reset mechanism.

[0049] The second protrusion 13 is an annular convex edge on the inner wall between the first protrusion 12 and the top inside the disengagement cylinder 7. The height of the second protrusion 13 is greater than the height of the first protrusion 12. It is used to make the top of the expansion spring claw 8 stuck below the second protrusion 13 to prevent the expansion spring claw 8 from coming out of the disengagement cylinder 7.

[0050] In this invention, the reset mechanism includes a reset spring 10; the reset spring 10 is sleeved on the outside of the bottom end of the expandable spring claw 8, one end of the reset spring 10 is connected to the bottom of the disconnect cylinder 7, and the other end is connected to the expandable spring claw 8.

[0051] In this embodiment of the invention, the bottom end of the expanding spring claw 8 has a spring center tube 9, and the return spring 10 is sleeved on the outside of the spring center tube 9. When the retractable spring claw 4 pushes the expanding spring claw 8 downward, the return spring 10 is compressed. When the bottom end of the retractable spring claw 4 enters the interior of the expanding spring claw 8, the return spring 10 rebounds and pushes the expanding spring claw 8 upward until the top end of the expanding spring claw 8 overlaps with the position of the first protrusion 12.

[0052] The invention also includes: an anti-corrosion ring 2; the anti-corrosion ring 2 is sleeved on the outside of the retractable spring claw 4; the anti-corrosion ring 2 is made of aluminum alloy.

[0053] In this embodiment of the invention, the top of the retractable spring claw 4, the connection between the mandrel 5 and the upper connector 1 are all located inside the anti-corrosion ring 2. The anti-corrosion ring 2 is used to prevent the mandrel 5 and the expandable spring claw 8 from being electrochemically corroded, thereby improving the reliability of each component during secondary operations. The anti-corrosion ring 2 is made of aluminum alloy (2A12), which is characterized by its resistance to deformation and oxidation.

[0054] The corrosion-resistant ring 2 is also used when the blowout preventer is being retrieved. When the spindle 5 moves downward, it drives the corrosion-resistant ring 2 downward. When the corrosion-resistant ring 2 moves downward until its bottom surface contacts the top surface of the release cylinder 7, the spindle 5 is controlled to continue downward, generating a downward thrust on the release cylinder 7. The release cylinder 7 pushes the blowout preventer downward, causing the release pin at the bottom of the blowout preventer to be sheared off.

[0055] The present invention also provides an asynchronous disengagement control method for blowout preventer tools for oil and water well casings, including the asynchronous disengagement device as described above, specifically including the following steps: Step 1: When it is necessary to asynchronously disengage the expanding spring claw 8 from the contracting spring claw 4, the contraction limiting mechanism is controlled to move upward, and the contraction limiting mechanism is moved away from the bottom end of the contracting spring claw 4.

[0056] In this embodiment of the invention, the top end of the mandrel 5 of the retractable limiting mechanism is connected to the tubing string via the upper connector 1, and the bottom of the disconnecting cylinder 7 is connected to the blowout preventer via the connector 11. The tubing string, the asynchronous disconnecting device of the oil / water well casing blowout preventer, and the blowout preventer are lowered into the well. At this time, the bottom end of the mandrel 5 of the limiting mechanism is located inside the retractable spring claw 4 near the bottom. During the secondary operation, i.e., when it is necessary to asynchronously disconnect the expanding spring claw 8 from the retractable spring claw 4, the tubing string is controlled to move upward, and the tubing string applies a pulling force to the mandrel 5. When the pulling force is greater than the maximum load that the pin 6 can withstand, the pin 6 is sheared, and the tubing string drives the mandrel 5 to move upward, with the bottom end of the mandrel 5 moving away from the bottom of the retractable spring claw 4.

[0057] Step 2: When the retractable limiting mechanism moves, it drives the retractable spring claw 4 to move upward. The bottom side wall of the retractable spring claw 4 retracts inward due to the obstruction of the second protrusion 801 until the retractable spring claw 4 moves away from the expanding spring claw 8, thereby completing the asynchronous disengagement.

[0058] In this embodiment of the invention, after the pin 6 is cut off, the tube column drives the mandrel 5 to continue moving upward. When the third protrusion 501 on the outer wall of the mandrel 5 moves to below the fourth protrusion 402 at the top of the retractable spring claw 4, the third protrusion 501 is stuck below the fourth protrusion 402, thereby causing the mandrel 5 to drive the retractable spring claw 4 to move upward until the bottom end of the retractable spring claw 4 is completely separated from the expanding spring claw 8.

[0059] Step 3: When it is necessary for the expanding spring claw 8 to dock with the retractable spring claw 4, control the retractable spring claw 4 to move downward. When the bottom end of the retractable spring claw 4 moves to contact the expanding spring claw 8, push the expanding spring claw 8 to move downward. When the top of the expanding spring claw 8 moves away from the expansion limiting mechanism, the top side wall of the expanding spring claw 8 expands outward, so that the retractable spring claw 4 is inserted into the interior of the expanding spring claw 8.

[0060] In this embodiment of the invention, the retractable spring claw 4 is driven downward by the tubing column. At this time, the bottom end of the mandrel 5 is located near the bottom of the retractable spring claw 4. When the bottom end of the retractable spring claw 4 moves to the top of the expanding spring claw 8, it pushes the expanding spring claw 8 downward. The reset spring 10 of the reset mechanism at the bottom of the expanding spring claw 8 is compressed. When the top end of the expanding spring claw 8 moves away from the first protrusion 12 of the expansion limiting mechanism inside the disengagement cylinder 7, the claw piece 15 of the expanding spring claw expands outward, so that the bottom end of the retractable spring claw 4 is inserted into the interior of the expanding spring claw 8. After the retractable spring claw 4 continues to move downward to the bottom of the expanding spring claw 8, it pushes the expanding spring claw 8, the disengagement cylinder 7, and the blowout preventer connected to the bottom of the disengagement cylinder 7 downward. When the blowout preventer moves downward, the release pin is sheared, and the blowout preventer is released.

[0061] Step 4: The reset mechanism drives the expansion spring claw 8 to move upward. When the top of the expansion spring claw 8 moves to the expansion limit mechanism, the top side wall of the expansion spring claw 8 retracts inward. The expansion limit mechanism prevents the top side wall of the expansion spring claw 8 from expanding outward, thereby completing the docking.

[0062] In this embodiment of the invention, after the blowout preventer is unsealed, the control spindle 5 moves upward, causing the retractable spring claw 4 to move upward. After the retractable spring claw 4 no longer applies downward pressure, the reset spring 10 of the reset mechanism pushes the expanding spring claw 8 upward during its rebound until the top of the expanding spring claw 8 moves to a position near the top inside the disengagement cylinder 7, i.e., overlapping with the first protrusion 12, thus completing the docking. After docking, the mandrel 5 and the retractable spring claw 4 move upward through the tubing column. The first protrusion 401 of the retractable spring claw 4 moves upward and, by being caught below the second protrusion 801, drives the expanding spring claw 8, the disengagement cylinder 7, and the blowout preventer upward, thereby completing the retrieval.

[0063] This invention features a third protruding edge 501 on the sidewall of the mandrel 5, which, when moving upwards, can asynchronously drive the retractable spring claw 4 upwards. A first protruding edge 401 is located at the bottom of the retractable spring claw 4, which cooperates with the second protruding edge 801 of the expanding spring claw 8 for limiting movement. The retractable spring claw 4 and the expanding spring claw 8 cooperate to form a two-stage spring claw structure, ensuring repeatable disengagement. By placing the expansion limiting mechanism inside the disengagement cylinder 7 near the top, the expanding spring claw 8 can expand internally when moving downwards, ensuring smooth docking with the retractable spring claw 4. This invention has a simple and reasonable structure, achieves repeatable disengagement, has high reliability in dropping and retrieving, and is reusable. It is suitable for casing blowout prevention during oil and water well operations, solving the environmental pollution problem caused by casing overflow during the running-in and running-out of tubing in oil and water wells.

[0064] The embodiments described above are merely illustrative of implementation methods of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications, equivalent substitutions, and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. An asynchronous disconnection device for blowout preventer tools in oil and water well casings, characterized in that, include: Retractable spring claw (4), expandable spring claw (8), disconnecting cylinder (7), retractable limiting mechanism, expandable limiting mechanism and reset mechanism; The retractable spring claw (4) has a first protruding edge (401) on its outer wall, and the expandable spring claw (8) has a second protruding edge (801) on its inner wall that cooperates with the first protruding edge (401). The retractable spring claw (4) has a retraction limiting mechanism inside, and the retractable spring claw (4) is connected to the retraction limiting mechanism. The retraction limiting mechanism is used to prevent the bottom sidewall of the retractable spring claw (4) from retracting inward. The retraction limiting mechanism includes: a spindle (5); the spindle (5) is inside the retractable spring claw (4). When the bottom end of the spindle (5) is in the retractable spring claw (4) near the bottom, the outer sidewall of the bottom end of the spindle (5) fits against the inner wall of the retractable spring claw (4); the outer sidewall of the spindle (5) has a third protrusion (501), and the inner wall of the retractable spring claw (4) near the top has a fourth protrusion (402) that cooperates with the third protrusion (501); the spindle (5) and the retractable spring claw (4) are connected by a pin (6), and the pin (6) is used to fix the position of the bottom end of the spindle (5) in the retractable spring claw (4) near the bottom. The expandable spring claw (8) is located inside the disconnecting cylinder (7). The inner wall of the disconnecting cylinder (7) near the top has an expansion limiting mechanism. The expansion limiting mechanism is used to prevent the top sidewall of the expandable spring claw (8) from expanding outward. When the expandable spring claw (8) is in the initial position, its top position is at the expansion limiting mechanism. The expansion limiting mechanism includes: a first protrusion (12) on the inner wall of the disconnecting cylinder (7) near the top. When the top of the expandable spring claw (8) is in the disconnecting cylinder (7) near the top, the outer wall of the top of the expandable spring claw (8) is in contact with the sidewall of the first protrusion (12). The side wall of the first protrusion (12) and the inner side wall of the lower disconnect cylinder (7) are inclined slopes; the inner wall of the disconnect cylinder (7) above the first protrusion (12) has a second protrusion (13). When the top of the expanding spring claw (8) is in the position close to the top inside the disconnect cylinder (7), the bottom surface of the second protrusion (13) contacts the top surface of the expanding spring claw (8). A reset mechanism is connected between the retractable spring claw (4) and the disconnect cylinder (7), the reset mechanism being used to bring the expandable spring claw (8) to the initial position in its natural state.

2. The asynchronous disconnection device for the blowout preventer tool for oil and water well casing according to claim 1, characterized in that, The reset mechanism includes: a reset spring (10); The reset spring (10) is sleeved on the outside of the bottom end of the expansion spring claw (8). One end of the reset spring (10) is connected to the bottom of the disconnect cylinder (7), and the other end is connected to the expansion spring claw (8).

3. The asynchronous disconnection device for the blowout preventer tool for oil and water well casing according to claim 1, characterized in that, Also includes: Anti-corrosion ring (2); The anti-corrosion ring (2) is sleeved on the outside of the retractable spring claw (4); The anti-corrosion ring (2) is made of aluminum alloy.

4. An asynchronous disconnection control method for blowout preventer tools in oil and water well casings based on the device described in claim 1, characterized in that, include: When it is necessary to asynchronously disengage the expanding spring claw (8) from the retracting spring claw (4), the retracting limiting mechanism is controlled to move upward, and the retracting limiting mechanism moves away from the bottom end of the retracting spring claw (4); When the retractable limiting mechanism moves, it drives the retractable spring claw (4) to move upward. The bottom side wall of the retractable spring claw (4) retracts inward due to the obstruction of the second protrusion (801) until the retractable spring claw (4) moves away from the expanding spring claw (8), thereby completing the asynchronous disengagement. When it is necessary for the expanding spring claw (8) to dock with the retractable spring claw (4), the retractable spring claw (4) is controlled to move downward. When the bottom end of the retractable spring claw (4) moves to contact the expanding spring claw (8), the expanding spring claw (8) is pushed downward. When the top of the expanding spring claw (8) moves away from the expansion limiting mechanism, the top side wall of the expanding spring claw (8) expands outward, so that the retractable spring claw (4) is inserted into the interior of the expanding spring claw (8). The resetting mechanism drives the expansion spring claw (8) to move upward. When the top of the expansion spring claw (8) moves to the expansion limiting mechanism, the top side wall of the expansion spring claw (8) retracts inward. The expansion limiting mechanism prevents the top side wall of the expansion spring claw (8) from expanding outward, thereby completing the docking.

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