Removable sleeve plugging device

Abstract

The invention relates to a removable sleeve plugging device, and belongs to the technical field of oil field well repair tools. The removable casing pipe leakage stoppage device comprises a releasing structure used for being connected with a patching pipe in a hanging mode. The releasing structure comprises a clamping jaw pipe and a supporting pipe arranged in an axial through hole of the clamping jaw pipe in a sliding mode. A plurality of clamping jaws are formed on a clamping jaw part at the lower end of the clamping jaw pipe through an axial cutting groove penetrating through the end part, and the outer convex parts of the clamping jaws are used for fixing the patching pipe by being embedded into a ring groove in the inner circumferential surface of the patching pipe; the upper end of the supporting pipe is in sliding sealing fit with the inner circumferential surface of the sleeve part; the lower end of the supporting pipe is used for stopping the inner surface of the clamping jaw so that the outer protruding part of the clamping jaw can be kept in the annular groove in the inner circumferential face of the patching pipe. A receding part used for receding the clamping jaw so that the clamping jaw can retract in the radial direction is arranged above the supporting end. The sleeve part is fixed to the upper end of the supporting pipe in a shearable mode. By adopting the device to realize casing leakage stoppage, the inner drift diameter of the repaired casing cannot be reduced, the normal production of an oil-water well is ensured, meanwhile, the releasing mechanism delivery and extraction process is simple and safe, and the practicability of the device is improved.

Description

Technical Field

[0001] The invention relates to a removable casing plugging device, belonging to the technical field of oilfield well repairing tools. Background Art

[0002] With the deepening of oilfield development, the condition of casings in oil and water wells has gradually deteriorated. Due to factors such as corrosion, the casings have been perforated and leaked. As the service life of the casings increases, the leakage becomes more serious, affecting the normal production of oil and water wells, causing imperfections in the injection and production system, and seriously restricting the normal injection and production of oil and water wells. At present, the main technical means to solve casing leakage on site include replacement of casings, packer sealing and casing compensation. Among them, replacement of casings is expensive and takes a long time; the well circulation is limited by the packer sealing, and the sealing process is prone to failure in well washing. At the same time, due to the restrictions of the packer, the requirements for well entry tools are high and the combination of pipe strings is limited. Therefore, in actual applications, casing compensation technology is more practical.

[0003] Casing patching technology usually expands the expansion tube to the inner wall of the casing by hydraulic or mechanical means to patch the casing leakage to achieve the purpose of repairing the casing. The expansion requires a large pressure to achieve, but excessive pressure will cause the risk of permanent damage to some parts of the casing. The construction process is complicated. The inner diameter after patching will lose a certain thickness compared to the original casing, and the inner diameter is small, which limits the entry of subsequent operating tools into the well. The authorization announcement number is CN209976507U. The Chinese utility model patent authorization publication text discloses a high-pressure removable casing patching sealing anchoring device, including a patching pipe and upper and lower cone casings inserted at both ends of the patching pipe. The metal sealing ring is used for initial sealing to achieve the patching of the casing leakage section. The problems with this technology are: the blades of the upper and lower cone sleeves are inserted into the ports at both ends of the subsidy tube through the load provided by the power device, causing the two ends of the subsidy tube to expand. During this process, it is impossible to ensure that the two ends are subjected to uniform force, and the tube may not be inserted, resulting in a low process success rate; there is a risk of tool jamming on the blade of the lower cone sleeve; the use of grinding tools to grind the upper end of the subsidy tube cannot ensure that the upper end of the subsidy tube is milled cleanly, and the grinding process generates debris, which affects the subsequent pulling of the subsidy tube; the subsidy tube needs to be removed by grinding, salvaging, and grinding, and the process is complicated; the subsidy power device is its own gunpowder power source, which poses a risk. Summary of the invention

[0004] The purpose of the present invention is to provide a removable casing plugging device to solve the problems of low success rate of inserting a patching pipe into the casing and complex process of removing the patching pipe when plugging the casing of oil and water wells in the prior art.

[0005] To achieve the above objectives, the technical solutions and beneficial effects of the present invention include:

[0006] A removable casing leak plugging device of the present invention comprises a releasing structure for hanging a patching tube, the releasing structure comprising a claw tube and a support tube which cooperates with the inner peripheral surface of the axial through hole of the claw tube in a sliding seal; the claw tube comprises a claw portion at the lower end and a casing portion at the upper end, the claw portion forms a plurality of claws by an axial groove passing through the end portion; the lower end of the support tube has a supporting end for stopping the inner surface of the claw so that the outer protrusion of the claw remains in the annular groove on the inner peripheral surface of the patching tube; above the supporting end of the support tube, there is an avoiding portion for avoiding the claw so that the claw can withdraw from the annular groove on the inner peripheral surface of the patching tube when radially retracted; the support tube can be sheared and fixed on the claw tube so that the supporting end is in a position to stop the claw; the upper end of the support tube is provided with a ball seat for cooperating with a small ball to seal the center hole.

[0007] The beneficial effects of the above technical solution are as follows: the present invention sets the claw tube slidingly in the axial through hole of the support tube, opens a plurality of claw grooves in the claw part at the lower end of the claw tube, uses the support end at the lower end of the support tube and the circumferential annular groove in the subsidizing tube to stop the claw, so that the hand-release mechanism can send the subsidizing tube into the sleeve to plug the leak; when the hand-release mechanism is withdrawn, a steel ball is dropped into the claw tube, and after the steel ball falls into the ball seat at the upper end of the support tube, it forms a piston structure with the ball seat and the support tube, and at this time, the upper end of the support tube is pressed, so that the support tube cuts off the fixed structure between the support tube and the claw tube, and then the support tube drops. When the support tube drops to a certain position, the claw retracts radially to the avoidance part above the support tube, so that the subsidizing tube remains in the position of the sleeve to be subsidized. Using the hand-release mechanism designed by the present invention, it is relatively simple to realize the sending of the subsidizing tube and the safe and card-free withdrawal of the hand-release mechanism after the sending, thereby improving the success rate of the process.

[0008] As a further improvement to the solution, a drainage hole is opened on the tube wall of the sleeve portion, and when the support tube moves downward a certain distance from the fixed position, the drainage hole is connected with the axial through hole of the claw tube above the ball seat.

[0009] The beneficial effect of the above technical solution is that after the support tube moves downward and the hand is released, the drain hole opened on the inner wall of the sleeve is used to drain the liquid to balance the internal and external pressure difference.

[0010] As a further improvement to the solution, the inner circumferential surface of the sleeve portion is provided with an annular step for limiting the downward position of the support tube. When the support tube reaches the limit position of the annular step, the avoidance portion is located radially rearward of the claw.

[0011] The beneficial effect of the above technical solution is that when the upper end of the support tube is pressed downward, the annular step on the inner circumference of the sleeve portion is used to limit the position, thereby preventing the support tube from falling down indefinitely.

[0012] As a further improvement to the solution, the support tube includes a detachable piston section for slidingly sealing with the inner circumferential surface of the sleeve portion; the lower end surface of the piston section is used to stop with the annular step.

[0013] The beneficial effect of the above technical solution is that the support tube is sealed with the inner circumference of the claw tube through the detachable piston section, which facilitates the assembly of the casing leak plugging device of the present invention. When in use, the piston section is installed from the upper pipe opening of the claw tube, and the shear pin is screwed into the corresponding opening on the wall of the claw tube to complete the assembly of the shear pin. After the compensating tube is hung at the claw, the support section with the avoidance part and the support part of the support tube is extended from the lower pipe opening of the claw tube. After rotation, the support section is screwed onto the piston section through the thread to complete the assembly of the leak plugging device.

[0014] As a further improvement to the solution, the support end includes a tapered portion that is thin at the top and thick at the bottom and a cylindrical portion at the lower end of the tapered portion, the outer circumferential surface of the cylindrical portion contacts the inner wall of the patch tube, and the tapered surface of the tapered portion is stop-fitted with the inner surface of the claw.

[0015] The beneficial effect of the above technical solution is: through the outer circumferential surface of the cylindrical part contacting the inner wall of the patch tube, the conical surface of the conical part cooperates with the inner surface of the claw to achieve that when the release mechanism sends the patch tube into the sleeve, the claw will not shrink radially, thereby ensuring the safe delivery of the patch tube.

[0016] As a further improvement to the solution, a pin is further provided on the tube wall of the sleeve portion, and the pin cooperates with a long groove radially opened on the support tube to guide and stop rotation.

[0017] The beneficial effect of the above technical solution is: the sleeve part is matched with the support tube by using the pin, so that the support tube is restricted from rotating when moving.

[0018] As a further improvement to the solution, the avoidance portion is a circumferential annular groove opened at a corresponding position on the outer wall above the supporting end of the support tube.

[0019] The beneficial effect of the above technical solution is that the avoidance portion is set as a circumferential annular groove, and when each claw contracts radially, the clamping position of the claw is limited.

[0020] As a further improvement to the solution, the outer peripheral surface of the patching tube is provided with a circumferential annular groove on which a water-swellable rubber ring is sleeved.

[0021] The beneficial effects of the above technical solution are: a water-swellable rubber ring is sleeved in the annular groove on the outer periphery of the patching tube, and the rubber tube is expanded to provide a suspension force to anchor the seal on the casing. When removing it later, it is only necessary to apply an upward force that exceeds the friction force between the water-swellable rubber and the casing, so that the sealing tool can be directly salvaged and removed at one time, which is easy to construct.

[0022] As a further improvement to the solution, rubber protective bowls are also provided above and below the water-swellable rubber ring.

[0023] The beneficial effect of the above technical solution is that the rubber protective bowls arranged above and below the water-swellable rubber ring can prevent the water-swellable rubber ring from falling off due to external force.

[0024] As a further improvement to the solution, the lower end of the compensating tube is a trumpet-shaped opening for interference fit installation of the guide cone.

[0025] The beneficial effect of the above technical solution is that the trumpet-shaped opening at the lower end of the patch tube is installed with an interference fit with the guide cone to prevent the guide cone from falling off during guiding. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the removable casing leak plugging device of the present invention;

[0027] Figure 2 This is a schematic diagram of the multifunctional grabbing support of the present invention being opened;

[0028] Figure 3 This is a schematic diagram of the multifunctional claw of the present invention being repositioned and retracted;

[0029] Figure 4 It is a cross-sectional view of the multifunctional grasping and splitting petal structure of the present invention;

[0030] Figure 5 It is a schematic diagram of the sealing anchoring of the device of the present invention;

[0031] Figure 6 This is a schematic diagram of displacement caused by pitching and pressing of the present invention;

[0032] Figure 7 It is a schematic diagram of the delivery and withdrawal mechanism of the present invention.

[0033] The markings in the figure are: 1. Guide cone; 2. Rubber protective bowl; 3. Water-swellable rubber ring; 4. Substituting tube; 401. Annular groove; 402. Inner limit ring; 5. Adjustable lining cone; 501. Conical matching surface; 502. Limiting groove; 503. Vertical groove; 6. Multifunctional claw; 601. Split elastic claw; 602. Limiting step; 603. Drain hole; 7a. Pin; 7b. Shear pin; 8. Piston; 801. Annular groove; 802. Sealing groove; 9. O-ring; 10. Steel ball. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0035] The purpose of the present invention is to provide a removable casing plugging device, which can realize the delivery of the release mechanism by lowering the pipe column, shearing the pin after the ball is pressed, and the adjustable lining cone moves downward, the multifunctional claw loses support, and the oil pipe is lifted up to realize the withdrawal of the release mechanism, so as to solve the problems of low success rate of construction process, complex process and small internal diameter after repair when repairing the casing.

[0036] Embodiment of the removable casing plugging device:

[0037] like Figure 1 The removable casing plugging device shown includes a guide cone 1, a rubber protective bowl 2, a water-swellable rubber ring 3, a patching tube 4, an annular groove 401, an inner limit ring 402, an adjustable lining cone 5, a conical matching surface 501, a limit groove 502, a vertical groove 503, a multifunctional claw 6, a petal elastic claw 601, a limit step 602, a drain hole 603, a pin 7a, a shear pin 7b, a piston 8, an annular groove 801, a sealing groove 802, an O-ring 9, and a steel ball 10. Among them, the outer conical surface of the guide cone 1 is interference fit with the inner surface of the lower end of the subsidizing tube 4, and an annular groove 401 is formed on the outer tube wall of the subsidizing tube 4 to cooperate with the rubber protective bowl 2, the water-expandable rubber ring 3, and the rubber protective bowl 2. The lower end of the adjustable lining cone 5 as a support tube is placed inside the subsidizing tube 4, and the conical matching surface 501 and the limiting groove 502 as the avoidance part are in contact with the axial groove through the lower end of the multifunctional claw 6 (also referred to as: claw part) to form a plurality of claws, namely, the petal elastic claws 601, and the upper end of the adjustable lining cone 5 is connected with the piston 8 through a screw The multifunctional claw 6 is connected by a groove, and the petal elastic claw 601 at the lower end of the multifunctional claw 6 is placed in the annular groove on the inner circumference of the patch tube, that is, on the inner limit ring 402. The upper end of the multifunctional claw 6 is fixed on the annular groove 801 of the piston 8 by shearing the pin 7b, and cooperates with the vertical groove (that is, the annular step used to limit the downward position of the support tube) 503 in the adjustable liner cone 5 through the pin 7a. The upper end face of the piston 8 is in contact with the pressure-acting surface of the solid steel ball 10, and a sealing groove 802 is machined on the upper part of the outer end face of the piston 8, and the O-ring 9 is placed in the sealing groove 802.

[0038] Specifically, Figure 1 As shown, the guide cone 1 is a hollow structure, and is pressed on the front end of the patching tube 4 by mechanical interference fit, with an interference fit of about 0.02mm to 0.03mm, to guide the tool to go in, and the casing in the wellbore is not damaged during the lowering process, while protecting the patching tube 4; the material is a soluble material, which is dissolved later.

[0039] like Figure 1As shown, the subsidizing tube 4 is a tubular body, and the lower end is a trumpet-mouth structure, which does not affect the insertion of subsequent tools; there is an annular groove 401 on the outer tube wall of the subsidizing tube 4, and the rubber protective bowl 2 and the water-swellable rubber ring 3 are arranged on the annular groove 401 in the manner of rubber protective bowl 2-water-swellable rubber ring 3-rubber protective bowl 2, and the rubber protective bowls 2 on both sides are used to limit the unlimited longitudinal expansion of the water-swellable rubber ring 3 in the middle, and at the same time protect the water-swellable rubber ring 3; a circumferential annular groove for cooperating with the clamping claw to realize the hanging of the subsidizing tube is provided on the inner tube wall at the upper end of the subsidizing tube 4, that is, an inner limit ring 402, which cooperates with the petal elastic claw 601 in the propped-up state to limit the multi-functional claw.

[0040] like Figure 1 As shown, the lower end of the adjustable liner cone 5 is a conical matching surface, which is an inclined surface structure and does not self-lock.

[0041] like Figure 1 , Figure 2 , Figure 4 As shown, the multifunctional claw 6 is an elastic component, which has two forms: propping up and opening, and resetting and retracting. Figure 2 and Figure 5 As shown, when the multifunctional claw 6 is propped up and opened, the inner surface of the split elastic claw 601 contacts the conical mating surface 501, and the outer surface cooperates with the inner limit ring 402; Figure 3 and Figure 6 As shown, when the multifunctional claw 6 is reset and retracted, the split elastic claw 601 cooperates with the limiting groove 502 to play a limiting role.

[0042] like Figure 2-Figure 4 As shown, the petal elastic claw 601 is a petal structure, with twelve petals evenly arranged in the circumferential direction.

[0043] like Figure 1 As shown, the inner surface of the multifunctional claw 6 is provided with an annular step for limiting the downward movement of the support tube, namely, a limiting step 602, which limits the downward movement of the piston 8.

[0044] like Figure 1-Figure 3 As shown, the four holes of the pin 7a are evenly distributed, acting as splines in the vertical groove 503. The adjustable liner cone 5 and the piston 8 are connected through a threaded process. When the adjustable liner cone 5 moves upward, the pin 7a also slides upward in the vertical groove 503, which plays a role in limiting the rotation of the adjustable liner cone 5 when it moves.

[0045] like Figure 1-Figure 3 As shown, the twelve holes of the shear pin 7b are evenly distributed and cooperate with the annular groove 801. The shear pin 7b is disconnected by the ball throwing and pressing, and the piston 8 moves downward with the adjustable lining cone 5.

[0046] like Figure 1 As shown, an O-ring 9 is placed in the sealing groove 802 to achieve effective sealing between the piston 8 and the multifunctional claw 6.

[0047] like Figure 1-Figure 3 As shown, the four drain holes 603 are evenly distributed. After the shear pin 7b is disconnected, the piston 8 moves down, and the sealing mechanism composed of the sealing groove 802 and the O-ring 9 moves down to the bottom of the drain hole 603, the radial through hole opens, and the drain balances the internal and external pressure difference.

[0048] In this embodiment, the specific implementation steps of the device are as follows:

[0049] Step 1. Tool running: Connect the tool to the oil pipe and run it into the casing leak position in the wellbore.

[0050] Step 2. Sealing and anchoring: After the tool is lowered into the casing leakage position, the wellbore is filled with water, so that the water-swellable rubber ring 3 expands and anchors on the oil layer casing to seal the casing leakage point. Figure 5 shown.

[0051] Step 3. Ball injection: After the leak is sealed, a steel ball 10 is injected into the upper end of the piston 8 to inject pressure into the oil pipe, and the shear pin 7b is disconnected. The piston 8 moves downward with the adjustable liner cone 5, and displacement occurs between the adjustable liner cone 5 and the split elastic claw 601. Figure 6 shown.

[0052] Step 4. Exit of the release mechanism: the split elastic claw 601 loses support and is retracted, the piston 8 moves down to the limit step 602, the split elastic claw 601 cooperates with the limit groove 502, and is double-limited and fixed; at the same time, the sealing mechanism composed of the sealing groove 802 and the O-ring 9 is located below the drain hole 603, the radial through hole is opened, and the drain balances the internal and external pressure difference. At this time, the oil pipe is lifted up, and the mechanism is sent in and out to the wellhead to realize the exit of the release mechanism. Figure 7 shown.

[0053] Step 5. Removal of the plugging tool: When the anchoring sealing mechanism in the well needs to be removed for subsequent production and operation, a special retractable spear is lowered, and after the spear is fished out, friction is applied between the water-swellable rubber ring 3 and the casing in the wellbore.

[0054] The present invention utilizes the multifunctional claw of the release mechanism to hang the patching pipe, so as to realize the delivery of the patching pipe. When the release mechanism is withdrawn, the pin is sheared by throwing a ball to press, and the adjustable lining cone moves downward, so that the multifunctional claw loses support and the oil pipe is lifted up to realize the withdrawal of the release mechanism. The delivery and withdrawal mechanism process is simple. At the same time, a water-swelling rubber ring is sleeved in the annular groove on the outer wall of the patching pipe, and the expandable material is used to seal the leakage point, which does not affect the subsequent tool insertion and ensures the normal production of the oil and water wells. In addition, the expansion sealing anchoring principle of the expansion rubber cylinder is utilized, and the rubber cylinder is anchored and sealed on the casing by providing a suspension force after expansion. When it is taken out later, an upward lifting force exceeding the friction force between the water-swelling rubber and the casing is applied, so that the sealing tool can be directly salvaged and taken out at one time, which is easy to construct.

Claims

1. A removable casing plugging device, characterized in that: It comprises a releasing structure for hanging a patching tube, the releasing structure comprises a claw tube and a supporting tube which cooperates with the inner peripheral surface of the axial through hole of the claw tube in a sliding seal; the claw tube comprises a claw part at the lower end and a sleeve part at the upper end, the claw part forms a plurality of claws by an axial groove which passes through the end part; the lower end of the supporting tube comprises a supporting end for stopping the inner surface of the claw so that the outer protrusion of the claw is kept in the annular groove on the inner peripheral surface of the patching tube; above the supporting end of the supporting tube, there is an avoiding part for avoiding the claw so that the claw can withdraw from the annular groove on the inner peripheral surface of the patching tube when radially retracted; the supporting tube can be sheared and fixed on the claw tube so that the supporting end is in a position to stop the claw; the upper end of the supporting tube is provided with a ball seat for cooperating with a small ball to seal the center hole.

2. The removable casing leak plugging device according to claim 1, characterized in that: A drainage hole is provided on the tube wall of the sleeve portion. When the support tube moves downward a certain distance from a fixed position, the drainage hole is communicated with the axial through hole of the claw tube above the ball seat.

3. The removable casing leak plugging device according to claim 1, characterized in that: The inner circumferential surface of the sleeve portion is provided with an annular step for limiting the downward movement of the support pipe. When the support pipe reaches the limiting position of the annular step, the avoidance portion is located radially rearward of the claw.

4. The removable casing leak plugging device according to claim 3, characterized in that: The support tube comprises a detachable piston section for sliding and sealing cooperation with the inner peripheral surface of the sleeve portion; the lower end surface of the piston section is used to stop with the annular step.

5. The removable casing leak plugging device according to claim 1, characterized in that: The support end includes a tapered portion that is thin at the top and thick at the bottom and a cylindrical portion at the lower end of the tapered portion. The outer circumferential surface of the cylindrical portion contacts the inner wall of the patch tube, and the tapered surface of the tapered portion is stop-matched with the inner surface of the claw.

6. The removable casing leak plugging device according to claim 1, characterized in that: A pin is also provided on the tube wall of the sleeve portion, and the pin cooperates with a long groove radially opened on the support tube to guide and stop rotation.

7. The removable casing leak plugging device according to claim 1, characterized in that: The avoidance portion is a circumferential annular groove opened at a corresponding position on the outer wall above the supporting end of the supporting tube.

8. The removable casing leak plugging device according to claim 1, characterized in that: The outer peripheral surface of the patching tube is provided with a circumferential annular groove on which a water-swellable rubber ring is sleeved.

9. The removable casing leak plugging device according to claim 8, characterized in that: The water-expandable rubber ring is also provided with rubber protective bowls above and below.

10. The removable casing leak plugging device according to claim 1, characterized in that: The lower end of the patch tube is a trumpet-shaped opening for installing the guide cone through interference fit.

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