Casing centralizing, supplementing and cementing tool

Abstract

The invention relates to the technical field of underground casing repair, in particular to a casing centralizing, repairing and cementing tool. The casing centralizing, supplementing and cementing tool comprises a hydraulic expansion part and an eccentric channel finding part, the hydraulic expansion part comprises a lining arranged outside a mandrel in a sleeving mode, the mandrel comprises an upper-stage expansion device and a lower-stage expansion device which are of the same structure, each expansion device comprises a cylinder body arranged outside an inner connecting pipe in a sleeving mode, and a plurality of expansion holes are formed in the side wall of each cylinder body. An expansion ball is arranged in the expansion hole, a piston mechanism is arranged between the cylinder body and the inner connecting pipe to push the expansion ball to extrude the lining with the cementing channel for patching, and a blocking ring and a recycling ball are arranged at the bottom of the mandrel. According to the casing centralizing, supplementing and cementing tool, sealing of a liner pipe is not required in the pressure building expansion process, the liner pipe with a cementing channel can be used for supplementing, and cementing reinforcement can be conducted on a fracture in the follow-up process; the plugging ring and the recovery ball are matched for pressure building, rapid action is achieved, and the working efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of downhole casing repair, and particularly to a casing centralizing and connecting and cement injection tool. Background Art

[0002] In the later stage of water injection development in oil fields, due to geological and development reasons, the number of casing breakage wells is increasing day by day. After the casing breaks, it is divided into upper and lower sections, and there is an axial offset between the upper and lower sections of the casing. Generally, the method of expanding tube subsidy is used for repair, and the subsidy tube for repair is simultaneously expanded and connected with the upper and lower sections of the casing. In the prior art, due to the limitation of the equipment structure, when the expanding tube is subsidized, the subsidy tube needs to be completely sealed and pressure-bearing, so a passage for squeezing and injecting cement cannot be processed on the subsidy tube, and cement cannot be squeezed and injected outside the tube for reinforcement after the subsidy, and the subsidized casing is easily damaged again. Therefore, in view of the above deficiencies, a casing centralizing and connecting and cement injection tool is proposed. Summary of the Invention

[0003] (I) Technical Problems to be Solved Aiming at the deficiencies of the prior art, the present invention provides a casing centralizing and connecting and cement injection tool, which solves the problems that when the expanding tube is subsidized, the subsidy tube needs to be completely sealed and pressure-bearing, so a passage for squeezing and injecting cement cannot be processed, and cement cannot be squeezed and injected outside the tube for reinforcement after the subsidy, and the subsidized casing is easily damaged again.

[0004] (II) Technical Solutions To solve the above problems, the present invention provides a casing centralizing and connecting and cement injection tool, including: A hydraulic expansion part and an eccentric channel finding part, and the eccentric channel finding part can introduce the device downward into the casing at the breakage position to centralize the two sections of the casing; The hydraulic expansion part includes a mandrel and a bushing. The mandrel includes two upper and lower expansion devices with the same structure. Each expansion device includes an inner connecting pipe. A cylinder body is arranged outside the inner connecting pipe. A plurality of through expansion holes are evenly arranged circumferentially on the side wall of the cylinder body. An expansion ball is arranged in each expansion hole. A piston mechanism is arranged between the inner connecting pipe and the cylinder body. When the pressure in the inner connecting pipe increases, the piston mechanism acts to push the expansion ball outwards along the expansion hole. A blocking ring is arranged at the end of the inner connecting pipe of the lower expansion device. A recovery ball is arranged in the blocking ring. The lower surface of the inner wall of the blocking ring cooperates with the recovery ball, and the device can be blocked by inserting the recovery ball. The bushing is sleeved outside the mandrel, and its upper and lower edges respectively exceed the expansion holes of the upper and lower expansion mechanisms. When the pressure in the inner connecting pipe increases, the upper and lower expansion devices act to push the expansion balls outwards to squeeze the bushing, so that the bushing is fixed on the two broken casing pipes at the same time. Cement injection side holes are arranged on the bushing. After the mandrel is recovered, cement can be injected into the fracture of the casing through the cement injection side holes. A shear ring is arranged on the outer wall of the cylinder body of the lower expansion device. The lower edge of the bushing contacts the shear ring and is thus fixed outside the mandrel. Cutting the shear ring separates the mandrel and the bushing, and then the mandrel can be lifted and recovered.

[0005] Preferably, the piston mechanism includes a pushing piston and a pressure hole arranged on the side wall of the inner connecting pipe. The pushing piston can move up and down between the inner connecting pipe and the cylinder body. The outer wall of the pushing piston is an inclined surface that contracts downwards. The height of the pressure hole is above the pushing piston. After the pressure in the inner connecting pipe increases, the pushing piston is squeezed downwards through the pressure hole, and the pushing piston moves downwards and pushes the expansion ball outwards through the inclined surface of the outer wall.

[0006] Preferably, sealing rings are respectively arranged between the pushing piston and the inner connecting pipe and the cylinder body.

[0007] Preferably, an upper joint is arranged above the upper expansion device. The inner wall and the outer wall of the upper joint are respectively connected to the inner connecting pipe and the cylinder body of the upper expansion device.

[0008] Preferably, the upper expansion device and the lower expansion device are connected by a connecting short section. The upper and lower ends of the inner wall of the connecting short section are respectively connected to the inner connecting pipes of the upper and lower expansion devices, and the upper and lower ends of the outer wall of the connecting short section are respectively connected to the cylinder bodies of the upper and lower expansion devices.

[0009] Preferably, a centralizer sleeve is arranged at the bottom end of the inner connecting pipe of the upper expansion device. The bottom end of the centralizer sleeve is connected to the connecting short section, and the top end is connected to the inner connecting pipe in a stepped manner, which has a centralizing effect on the inner connecting pipe of the upper expansion device.

[0010] Preferably, an eccentric guide shoe is arranged at the bottom end of the eccentric channel finding part. The bottom end of the eccentric guide shoe is a tapered inclined surface that deviates to one side. After the pointed part of the cone extends into the lower broken casing, the casing is centralized and connected in series through the inclined surface.

[0011] Preferably, a plurality of positioning grooves are provided on the outer wall of the eccentric channel finding part, and a positioning block is provided in each positioning groove. The inner wall of the positioning groove is an upwardly expanding inclined surface, and when the device descends, the positioning block moves upward along the positioning groove to anchor the device.

[0012] (III) Beneficial effects The casing centralizing and patch cementing tool provided by the present invention drives the pushing piston to extrude the expansion ball to expand and fix the bushing by holding pressure in the space between the inner connecting pipe and the cylinder block. The bushing does not participate in the pressure holding process, so that the bushing can be processed as a subsidized bushing for the cement injection side hole for injecting cement. Through the cement injection channel, cement can be injected and fixed at the casing fracture after the mandrel is recovered; the recovery ball and the plug ring cooperate to realize ball throwing and pressure holding and local expansion, improve the safety of the device, speed up the action speed, and improve the work efficiency. Description of the drawings

[0013] Figure 1 is a schematic structural diagram of the casing centralizing and patch cementing tool of the present invention; Figure 2 is a schematic structural diagram of the hydraulic expansion part of the casing centralizing and patch cementing tool of the present invention; Figure 3 is a schematic structural diagram of the eccentric channel finding part of the casing centralizing and patch cementing tool of the present invention.

[0014] Among them, 1. upper joint; 2. centralizing sleeve; 3. connecting nipple; 4. cylinder block; 5. pushing piston; 6. expansion ball; 7. shear ring; 8. inner connecting pipe; 9. plug ring; 10. recovery ball; 11. positioning block; 12. eccentric guide shoe; 13. bushing. Embodiment

[0015] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0016] In the description of the present invention, it is necessary to understand that the orientation or positional relationship indicated by "upper", "lower", "inner", "outer", "top", "bottom", etc. is all based on the orientation or positional relationship shown in the drawings. The purpose is only to facilitate the description of the present invention and simplify the description, and does not indicate or imply that the components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0017] Such as Figures 1-3As shown in the figure, the present invention provides a casing centralizing and cementing tool for patching, which specifically includes a hydraulic expansion part and an eccentric channel finding part. The lower part of the hydraulic expansion part is connected to the eccentric channel finding part. The hydraulic expansion part carries a patch tube for repairing the casing. When the device reaches the patching position, the device is pressured and expanded inside to extrude the patch tube outward, so that the patch tube is connected and fixed to the casing. During the process of the eccentric channel finding part descending along the casing, the end is centered with the casing that is broken below and the two sections of the casing are connected in series, and then the device is anchored in the working position, facilitating the expansion and patching of the upper hydraulic expansion part.

[0018] As Figure 2 shown, the hydraulic expansion part includes a mandrel and a bushing 13. The bushing 13 serves as a patch sleeve for expanding and patching the casing. The mandrel is threaded inside the bushing 13 to drive the bushing 13 into the well and expand the bushing 13 from the inside to fix the bushing 13 to the casing. The mandrel includes two expansion devices with the same structure at the upper and lower levels. The expansion device includes an inner connecting pipe 8. An outer cylinder 4 is provided outside the inner connecting pipe 8. A plurality of expansion holes are provided on the outer wall of the cylinder 4. The expansion holes are evenly distributed circumferentially on the outer wall of the cylinder. An expansion ball 6 is provided in each expansion hole. When the expansion ball 6 is stressed, it moves outward along the expansion hole to extrude the outside.

[0019] Among them, the inner wall of the expansion hole is matched with the shape of the expansion ball 6, and the outer opening is smaller than the diameter of the expansion ball 6, preventing the expansion ball 6 from falling out along the expansion hole after being stressed, which may affect the normal operation of the subsequent casing.

[0020] It should be noted that the expansion ball 6 is generally a steel ball and can be replaced with other materials under the requirements of specific working environments or working contents.

[0021] In the present invention, a piston mechanism is provided between the inner connecting pipe 8 and the cylinder 4. After the pressure inside the inner connecting pipe 8 increases, the piston mechanism pushes the expansion ball 6 outward along the expansion hole under the action of the pressure to extrude the external components.

[0022] Among them, the piston mechanism includes a push piston 5 and a pressure hole provided on the side wall of the inner connecting pipe 8. The push piston 5 can move up and down between the inner connecting pipe 8 and the cylinder 4. The outer wall of the push piston 5 is a downwardly contracting inclined surface. When the push piston 5 moves downward, the inclined surface contacts the expansion ball 6 and extrudes the expansion ball 6 outward along the inclined surface.

[0023] It should be noted that sealing rings are provided between the push piston 5 and both the inner connecting pipe 8 and the cylinder 4 to maintain the seal between the push piston 5, the connecting pipe 8, and the cylinder 4, prevent pressure leakage due to poor sealing, improve the working efficiency of the piston mechanism, and achieve rapid operation. The position of the pressure hole is higher than the push piston 5. After the pressure inside the central pipe 8 increases, it can squeeze the push piston 5 downward through the pressure hole.

[0024] As shown Figure 2 in the figure, the bushing 13 is sleeved outside the mandrel, and its upper and lower edges respectively exceed the expansion holes of the upper and lower expansion mechanisms. When the device is inflated under pressure inside, the upper and lower expansion mechanisms act simultaneously. The expansion balls 6 of the two-stage expansion mechanism move outward along the expansion holes under the action of pushing the piston 5 at the same time, squeezing the bushing 13, so that the part of the bushing 13 in contact with the expansion balls 6 deforms and is fixed on the inner walls of the upper and lower ends of the casing after staggering to complete the expansion and repair. When the expansion and repair work is completed, the pressure in the inner connecting pipe 8 is relieved and then the core pipe is lifted. At this time, the expansion balls 6 move upward as the cylinder block 4 is lifted, contact the fixed liner 13, and move inward along the expansion holes under the extrusion of the liner 13 and push the piston 5 upward. At this time, the expansion balls 6 retract into the mandrel, and the device can be recovered smoothly. The liner 13 is provided with a cement injection channel. After the core pipe is recovered, cement can be injected into the casing port through the cement injection channel on the liner 13 to reinforce the casing after the expansion and repair, improve the stability of the repair work, and improve the work efficiency.

[0025] Among them, the upper and lower two-stage expansion devices are connected and fixed through the connecting short section 3. The connecting short section 3 is tubular, and the pressure liquid flows through the connecting short section 3 in the inner connecting pipe 8 of the upper and lower two-stage expansion devices. The top and bottom inner walls of the connecting short section 3 are respectively connected to the inner connecting pipes 8 of the upper expansion device and the lower expansion device, and the top and bottom outer walls of the connecting short section 3 are respectively connected to the cylinder blocks 4 of the upper expansion device and the lower expansion device.

[0026] It should be noted that the top of the upper expansion device is provided with an upper joint 1, which is connected to other devices through the upper joint 1. The inner and outer bottom walls of the upper joint 1 are respectively connected to the inner connecting pipe 8 and the cylinder block 4 of the upper expansion device. The bottom of the lower expansion device is provided with a plug ring 9. The top of the plug ring 9 is connected to the bottom end of the inner connecting pipe 8 of the lower expansion device. A recovery ball 10 is arranged in the plug ring 9. The shape of the bottom inner wall of the plug ring 9 matches that of the recovery ball 10. After the recovery ball 10 is dropped along the inner connecting pipe 8, the plug ring 9 seals to hold the pressure on the mandrel part above the plug ring 9, realizing partial pressure holding without affecting the components below. During the working process, the recovery ball 10 is not dropped when the device descends along the casing. At this time, the device is in a flowing state. When the device is fixed at the working position, the recovery ball 10 is dropped along the inner connecting pipe 8 to seal the plug ring 9, and the device starts to hold the pressure. Generally, the recovery ball 10 is a steel ball, and it can be replaced with other materials under the requirements of specific working environments or working contents.

[0027] In addition, in order to improve the stability of the device, a centralizer sleeve 2 is arranged between the connecting short section 3 and the inner connecting pipe 8 of the upper expansion device. The bottom end of the centralizer sleeve 2 is connected to the connecting short section 3, and the top end is connected to the bottom end of the inner connecting pipe 8, and the connecting part is a stepped structure to improve the stability of the device.

[0028] In the present invention, a shear ring 7 is provided on the outer wall of the cylinder block 4 of the lower expansion device. The bottom end of the bushing 13 is connected to the shear ring 7 and fixed outside the mandrel. After the device operates, through the process of pressure buildup and expansion, the bushing 13 is fixed on the casing. At this time, when the mandrel is lifted, when the shear stress received by the shear ring 7 is greater than the stress limit it can bear, the shear ring 7 is cut off. At this time, the mandrel is separated from the bushing 13, and continuous lifting can smoothly recover the mandrel.

[0029] As Figure 3 shown, an eccentric guide shoe 12 is provided at the bottom end of the eccentric channel finding part. The bottom end of the eccentric guide shoe 12 is a conical structure with an eccentric tip. During the process of the device descending along the casing, after the top end of the deflected guide shoe 12 is disengaged from the casing below the break, the tip is shot into the lower casing and continues to move downward. At this time, the lower casing gradually moves along the conical inclined surface and finally becomes concentric with the upper casing, playing a role in straightening.

[0030] Among them, a plurality of positioning grooves are provided on the outer wall of the eccentric guide shoe 12, positioning blocks 11 are arranged in the positioning grooves, the inner wall of the positioning grooves is an inclined surface that contracts downward, and the inner surface of the positioning block 11 matches the shape of the positioning grooves. Usually, the positioning block 11 is installed at the bottom of the positioning groove. When the device descends, the positioning block 11 rubs against the inner wall of the casing and slides upward along the positioning groove, and the positioning grooves and the inside of the casing gradually clamp the positioning block 11 to anchor the device in the working position. When the device is recovered, the mandrel is lifted. At this time, the pressure on the positioning block 11 decreases and it returns to the bottom of the positioning groove as the device rises. During the upward movement, due to the downward friction force, the positioning block 11 will not move upward and be set, and the equipment can be recovered normally.

[0031] Among them, a limit block is provided at the top end of the positioning groove. The limit block is used to limit the position of the positioning block 11 to prevent the positioning block 11 from moving upward along the positioning groove too far during the process of anchoring the device, resulting in the device being stuck in the casing.

[0032] The casing straightening and patching and cementing tool provided by the present invention can use a liner with a cementing channel as the patching pipe for expansion patching. After patching, cement can be squeezed into the fracture outside the casing through the cementing channel for reinforcement, improving the patching effect and extending the service life of the well. The specific operation process of this device is as follows: Step 1: Lower the device into the well along the sleeve.

[0033] Step 2: When the device reaches the fracture, adjust the angle of the device, extend the device into the lower casing, and continue to move downward to straighten the lower casing and anchor the device. During this process, the tip of the eccentric guide shoe first penetrates into the lower casing. After the device moves downward, the lower casing is pushed along the inclined surface of the eccentric guide shoe to straighten the lower casing. The positioning block moves upward along the positioning groove by friction with the inner wall of the lower casing below the fracture, increasing the pressure of the pipe wall on the device. Finally, the position of the device is anchored at the working position.

[0034] Step 3: Insert the recovery ball and perform expansion and patch. At this time, the expansion ball and the plug ring cooperate to seal the bottom of the device. The device is pressurized internally, and the upper and lower expansion devices act simultaneously. The pressure pushes the piston downward to move the expansion ball outwards along the expansion hole. The expansion ball extrudes the liner tube outwards, causing the liner tube to deform and be fixed on the inner walls of the upper and lower casings after the fracture.

[0035] Step 4: Release the pressure inside the mandrel and lift the mandrel to recover the device. During this process, when the pressure is greater than the stress limit that the shear ring can withstand, the shear ring is cut off, and the mandrel is separated from the liner tube. Continuing to lift the mandrel cylinder drives the expansion ball upward. Under the extrusion of the liner tube, the expansion ball retracts into the mandrel. The device moves upward. As the device moves upward, the positioning block in the anchored state contacts and sits back at the bottom of the positioning groove, and the mandrel is released from anchoring. The entire mandrel moves upward to withdraw from the casing for recovery.

[0036] Step 5: Inject cement into the cement injection channel inside the liner through the cement injection equipment, and inject the cement into the fracture outside the sleeve to reinforce the patched casing.

[0037] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A casing centralizer and cementing tool, characterized in that Comprising: A hydraulic expansion part and an eccentric channel finding part. The eccentric channel finding part can downwardly introduce the device into the casing at the offset part to straighten the two sections of the casing; The hydraulic expansion part includes a mandrel and a bushing (13). The mandrel includes upper and lower stages of expansion devices with the same structure. Each expansion device includes an inner connecting pipe (8). A cylinder block (4) is arranged outside the inner connecting pipe (8). A plurality of through expansion holes are circumferentially and uniformly arranged on the side wall of the cylinder block (4). An expansion ball (6) is arranged in each expansion hole. A piston mechanism is arranged between the inner connecting pipe (8) and the cylinder block (4). When the pressure in the inner connecting pipe (8) rises, the piston mechanism acts to push the expansion ball (6) outwards along the expansion hole. A plug ring (9) is arranged at the end of the inner connecting pipe (8) of the lower expansion device. A recovery ball (10) is arranged in the plug ring (9). The lower surface of the inner wall of the plug ring (9) cooperates with the recovery ball (10). The device can be blocked by inserting the recovery ball (10). The bushing (13) is sleeved outside the mandrel. Its upper and lower edges respectively exceed the expansion holes of the upper and lower expansion mechanisms. When the pressure in the inner connecting pipe (8) rises, the upper and lower expansion devices act to push the expansion balls (6) outwards to extrude the bushing (13) so that the bushing (13) is simultaneously fixed on the upper and lower offset casings. Cement injection side holes are arranged on the bushing (13). After the mandrel is recovered, cement can be injected into the fracture of the casing through the cement injection side holes. A shear ring (7) is arranged on the outer wall of the cylinder block (4) of the lower expansion device. The lower edge of the bushing (13) contacts the shear ring (7) to be fixed outside the mandrel. By cutting the shear ring (7), the mandrel and the bushing (13) can be separated and the mandrel can be lifted and recovered.

2. The casing centralizing and cementing tool according to claim 1, wherein The piston mechanism includes a push piston (5) and a pressure hole arranged on the side wall of the inner connecting pipe (8). The push piston (5) can move up and down between the inner connecting pipe (8) and the cylinder block (4). The outer wall of the push piston (5) is an inclined surface that contracts downwards. The height of the pressure hole is above the push piston (5). After the pressure in the inner connecting pipe (8) rises, it squeezes the push piston (5) downwards through the pressure hole. The push piston (5) moves downwards and pushes the expansion ball (6) outwards through the inclined surface of the outer wall.

3. The casing centralizing and cementing tool according to claim 2, characterized in that, Sealing rings are respectively arranged between the push piston (5) and the inner connecting pipe (8) and the cylinder block (4).

4. The casing centralizing and cementing tool according to claim 1, wherein, An upper joint (1) is arranged above the upper expansion device. The inner wall and the outer wall of the upper joint (1) are respectively connected to the inner connecting pipe (8) and the cylinder block (4) of the upper expansion device.

5. The casing centralizing and cementing tool according to claim 1, characterized in that, The upper expansion device and the lower expansion device are connected by a connecting short section (3). The upper and lower ends of the inner wall of the connecting short section (3) are respectively connected to the inner connecting pipes (8) of the upper and lower expansion devices. The upper and lower ends of the outer wall of the connecting short section (3) are respectively connected to the cylinder blocks (4) of the upper and lower expansion devices.

6. The casing centralizing and cementing tool according to claim 5, wherein, A centralizing sleeve (2) is arranged at the bottom end of the inner connecting pipe (8) of the upper expansion device. The bottom end of the centralizing sleeve (2) is connected to the connecting short section (3), and the top end is step-connected to the inner connecting pipe (8), which has a centralizing effect on the inner connecting pipe (8) of the upper expansion device.

7. The casing centralizer and cementing tool according to claim 1, characterized in that, An eccentric guide shoe (12) is provided at the bottom end of the eccentric channel finding part. The bottom end of the eccentric guide shoe (12) is a conical inclined surface that is biased to one side. After the tip of the cone extends into the offset casing below, the casing is straightened and connected in series through the inclined surface.

8. The casing centralizing and cementing tool according to claim 1, wherein A number of positioning grooves are provided on the outer wall of the eccentric channel finding part (13), and a positioning block (11) is provided in each positioning groove. The inner wall of the positioning groove is an upwardly expanding inclined surface. When the device descends, the positioning block (11) moves upward along the positioning groove to anchor the device.

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