Oil and gas well repairing tool

Abstract

The invention belongs to the technical field of oil and gas well repair, and discloses an oil and gas well repair tool which comprises a hydraulic anchor, a backwater constant pressure device, a multi-stage power device and a ball pipe expander which are connected in sequence. The casing deformation area of the horizontal section of the oil and gas well can be rolled back to be round and recovered to be large in drift diameter through the ball pipe expander, and power can be provided for the ball pipe expander through the multi-stage power device. The hydraulic anchor can bear counter-acting force generated when the multi-stage power device applies thrust to the ball pipe expander, and the situation that the thrust acting on the ball pipe expander is insufficient is prevented. Stroke loss caused by synchronous work of the hydraulic anchor and the multi-stage power device under the working condition of the horizontal well can be avoided through the backwater constant pressure device, and the repairing difficulty of the horizontal oil and gas well is reduced; after construction is finished, liquid of the well entering pipe column can be effectively discharged through the water return constant pressure device in the process that the well entering pipe column is pulled out of the shaft through the water return constant pressure device, the effect that slurry is not sprayed when the well is pulled out is achieved, and the repairing efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas well repair, and particularly to an oil and gas well repair tool. Background Art

[0002] Workover operations are operations for maintaining the normal production of the wellbore during the entire life cycle of oil and gas wells following drilling and completion. They play a key role in extending the life cycle of oil and gas wells and also bear the responsibility of ensuring quality and quantity. They are indispensable and of great significance in the production process of oil and gas wells. With the development of oil and gas, there is a technical trend in workover operations towards deep wells, high-pressure wells, high-temperature wells, corrosive wells, horizontal wells, and thick-walled casing wells.

[0003] For oil and gas well construction using large-scale sand fracturing or volume fracturing, it is easy to cause formation dislocation or creep, resulting in casing deformation in the horizontal sections of a large number of gas wells, and a large proportion of wells have serious casing deformation. In the early stage, milling or reaming is mostly used for treatment, but this method has low efficiency. In the process of casing deformation treatment for many wells, the casing is worn through, and even new holes are drilled, which has a great impact on subsequent construction and leads to the abandonment of some wells. Currently, hydraulic shaping technology is often used to repair oil and gas wells with casing deformation. It utilizes the characteristics of liquids being easy to pressurize and remotely controllable. By lowering the downhole string into the oil and gas well, one end of the downhole string is connected to the ground pressure pumping equipment, and the other end is connected to the hydraulic shaping device. The ground pressure pumping equipment injects liquid into the downhole string, converts the liquid pressure into mechanical force, and acts on the ball expander to radially expand and roll the deformed casing, and rolls the deformed casing back to a circular shape through plastic deformation and restores it to a larger inner diameter. This technology does not sacrifice the casing thickness, but only expands and straightens the sunken and bent casing. However, currently, this technology mainly effectively shapes and repairs the deformed casings of vertical wells and deviated wells. However, due to the complex trajectory of horizontal wells and the increasing length of the horizontal section, it is more difficult to transmit the tension, compression, and torsion applied at the wellhead, further increasing the difficulty of shaping, fishing, drilling, and releasing stuck objects. Moreover, complex situations such as stuck, dropped objects, and casing deformation caused by workover operations are likely to cause the loss of stroke when the hydraulic anchor and the multi-stage power device work synchronously, resulting in incomplete repair of oil and gas wells with casing deformation. In addition, after the repair of oil and gas wells with casing deformation is completed, since the liquid in the downhole string cannot be drained, it causes the downhole string to spurt slurry when being pulled out of the well, increasing the safety hazards for operating personnel and reducing the construction efficiency.

[0004] Therefore, there is an urgent need for an oil and gas well repair tool to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide an oil and gas well repair tool to solve the problems of high repair difficulty, instability, and low efficiency in horizontal oil and gas wells.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] An oil and gas well repair tool includes a hydraulic anchor, a backwater constant pressure device, a multi-stage power device, and a ball expandable tube in sequence.

[0008] Preferably, the backwater constant pressure device includes:

[0009] A first connector, which is connected to the hydraulic anchor. The first connector is provided with shear pin holes, bypass holes, and drain holes at intervals. Shear pins are installed in the shear pin holes;

[0010] A sliding sleeve is slidably installed on the first connector. The sliding sleeve is provided with a fixing groove and a connecting channel. One end of the shear pin can be inserted into the fixing groove to fix the sliding sleeve. One end of the connecting channel communicates with the bypass hole, and the other end communicates with the drain hole;

[0011] A second connector, one end of which is connected to the multi-stage power device, and the other end is connected to the first connector. The second connector is provided with a pressure relief hole;

[0012] An overcurrent piston is slidably sleeved between the first connector and the second connector. The overcurrent piston is provided with an overcurrent groove and an overcurrent hole. An installation cavity and a communication cavity are provided between the overcurrent piston and the second connector. The installation cavity communicates with the outside through the pressure relief hole;

[0013] A return spring is installed in the installation cavity and abuts against the overcurrent piston.

[0014] Preferably, a first drill pipe connector and a second drill pipe connector are respectively provided on the first connector and the second connector. The first drill pipe connector is threadedly connected to the hydraulic anchor, and the second drill pipe connector is connected to the multi-stage power device.

[0015] Preferably, a first sealing ring is provided between the sliding sleeve and the first connector.

[0016] Preferably, a second sealing ring is provided between the first connector and the second connector.

[0017] Preferably, a third sealing ring is provided between the overcurrent piston and the second connector.

[0018] Preferably, the first connector and the second connector are threadedly connected.

[0019] Preferably, a fourth sealing ring is provided between the overcurrent piston and the first connector.

[0020] Advantages of the present invention:

[0021] The oil and gas well repair tool provided by the present invention can roll the casing deformation area in the horizontal section of the oil and gas well back into a circular shape and restore it to a larger inner diameter through a ball expanding tube device. A multi-stage power device can provide power for the ball expanding tube device so that the ball expanding tube device can roll the deformed casing area. A hydraulic anchor can withstand the reaction force generated when the multi-stage power device applies a thrust to the ball expanding tube device, preventing the thrust applied to the ball expanding tube device by the multi-stage power device from being insufficient. A backwater constant pressure device can avoid the stroke loss caused by the synchronous operation of the hydraulic anchor and the multi-stage power device under the conditions of a horizontal well, reducing the repair difficulty of the horizontal oil and gas well and ensuring a stable repair effect. After the construction is completed, the backwater constant pressure device can effectively discharge the liquid in the downhole string through the backwater constant pressure device during the process of lifting the downhole string out of the oil and gas well, so as to achieve the effect of no slurry spraying during tripping, improving the repair efficiency. Description of the Drawings

[0022] Figure 1 is the overall structural schematic diagram of the oil and gas well repair tool provided by the embodiment of the present invention;

[0023] Figure 2 is the overall structural schematic diagram of the backwater constant pressure device provided by the embodiment of the present invention;

[0024] Figure 3 is Figure 2 the A-A sectional view in

[0025] In the figure:

[0026] 100, hydraulic anchor; 200, multi-stage power device; 300, ball expanding tube device;

[0027] 1, backwater constant pressure device; 11, first connector; 111, shear pin hole; 112, bypass hole; 113, drain hole; 114, shear pin; 12, sliding sleeve; 121, fixing groove; 122, connecting channel; 13, second connector; 131, pressure relief hole; 14, flow-through piston; 141, flow-through groove; 142, flow-through hole; 15, installation cavity; 16, communication cavity; 17, return spring;

[0028] 2, first drill pipe joint; 3, second drill pipe joint; 4, first sealing ring; 5, second sealing ring; 6, third sealing ring; 7, fourth sealing ring. Detailed Embodiments

[0029] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only the parts related to the present invention are shown in the drawings, rather than all the structures.

[0030] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0031] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under", and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0032] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meanings.

[0033] As Figures 1 to 3 shown, this embodiment provides an oil and gas well repair tool, which includes a hydraulic anchor 100, a backwater constant pressure device 1, a multi-stage power device 200, and a ball expandable tube device 300 that are connected in sequence.

[0034] The oil and gas well repair tool provided in this embodiment can roll the casing deformation area in the horizontal section of the oil and gas well back into a circular shape and restore it to a larger through-diameter through the ball expandable tube 300. The multi-stage power device 200 can provide power for the ball expandable tube 300, enabling the ball expandable tube 300 to roll the deformed casing area. The hydraulic anchor 100 can withstand the reaction force generated when the multi-stage power device 200 applies a thrust to the ball expandable tube 300, preventing the thrust applied by the multi-stage power device 200 to the ball expandable tube 300 from being insufficient. The return water constant pressure device 1 can avoid the stroke loss caused by the synchronous operation of the hydraulic anchor 100 and the multi-stage power device 200 under the conditions of a horizontal well, reducing the repair difficulty of the horizontal oil and gas well and ensuring a stable repair effect. After the construction is completed, the return water constant pressure device 1 can effectively discharge the liquid in the downhole string through the return water constant pressure device 1 during the process of lifting the downhole string out of the oil and gas well, thereby achieving the effect of no slurry spraying during tripping and improving the repair efficiency.

[0035] Optionally, as Figure 2 and Figure 3 shown, the return water constant pressure device 1 includes a first connector 11, a sliding sleeve 12, a second connector 13, a flow-through piston 14, and a return spring 17. The first connector 11 is connected to the hydraulic anchor 100. The first connector 11 is provided with shear pin holes 111, bypass holes 112, and bleed holes 113 at intervals, and a shear pin 114 is installed in the shear pin hole 111. The sliding sleeve 12 is slidably installed on the first connector 11. The sliding sleeve 12 is provided with a fixing groove 121 and a connection channel 122. One end of the shear pin 114 can be inserted into the fixing groove 121 to fix the sliding sleeve 12. One end of the connection channel 122 communicates with the bypass hole 112, and the other end communicates with the bleed hole 113. One end of the second connector 13 is connected to the multi-stage power device 200, and the other end is connected to the first connector 11. The second connector 13 is provided with a pressure relief hole 131. The flow-through piston 14 is slidably sleeved between the first connector 11 and the second connector 13. The flow-through piston 14 is provided with a flow-through groove 141 and a flow-through hole 142. An installation cavity 15 and a communication cavity 16 are provided between the flow-through piston 14 and the second connector 13. The installation cavity 15 communicates with the outside through the pressure relief hole 131. The return spring 17 is installed in the installation cavity 15 and abuts against the flow-through piston 14.

[0036] Specifically, in this embodiment, in the initial state, the flow-through groove 141 does not communicate with the communication cavity 16, while the flow-through hole 142 communicates with the communication cavity 16. The shear pin 114 is inserted into the fixing groove 121 to fix the sliding sleeve 12, so that the sliding sleeve 12 blocks the bypass hole 112 and the bleed hole 113, and the inside of the first connector 11 does not communicate with the outside.

[0037] During the working state, the surface cement truck injects water and applies pressure to the oil and gas well repair tool through the well pipe string. The water enters the backwater constant pressure device 1 through the hydraulic anchor 100. The hydraulic pressure generated by the water acts on the flow-through piston 14. The flow-through piston 14 compresses the return spring 17. Since the installation cavity 15 is communicated with the outside through the pressure relief hole 131, the air in the installation cavity 15 can be discharged through the pressure relief hole 131, so that the flow-through piston 14 moves towards the multi-stage power device 200, thus making the flow-through groove 141 communicate with the communication cavity 16. The water can flow out of the backwater constant pressure device 1 and into the multi-stage power device 200 through the flow-through groove 141, the communication cavity 16 and the flow-through hole 142 in sequence, so that the multi-stage power device 200 can provide power for the ball expandable tube tool 300, enabling the hydraulic anchor 100 and the multi-stage power device 200 to work synchronously, solving the problem of stroke loss, effectively ensuring the repair effect of the oil and gas well with casing deformation, and reducing the repair difficulty.

[0038] After the work is completed, the surface increases the hydraulic pressure on the oil and gas well repair tool through the cement truck. The hydraulic pressure acts on the sliding sleeve 12, shearing and damaging the shear pin 114, so that the sliding sleeve 12 moves towards the multi-stage power device 200, making the side through hole 112 communicate with the inside of the first connector 11. The drain hole 113 can reduce the water pressure in the first connector 11, making the sliding sleeve 12 move towards the multi-stage power device 200 until the entire aperture of the side through hole 112 is completely communicated with the inside of the first connector 11, so that the water in the first connector 11 flows to the horizontal well through the side through hole 112. Then the cement truck stops injecting pressure. The flow-through piston 14 resets under the elastic force of the return compression spring. When the well pipe string is lifted out, the water in the well pipe string flows into the first connector 11 and then flows to the horizontal well through the side through hole 112, effectively solving the problem that the well pipe string cannot drain when tripping out, and improving the repair efficiency.

[0039] Specifically, it should be noted that the rated working pressure of the multi-stage power device 200 is 5 MPa, and the maximum working pressure is 30 MPa. The starting pressure of the backwater constant pressure device 1 is 5 MPa, and the maximum working pressure is 40 MPa. It can be understood that when the hydraulic pressure range is between 5 MPa and 30 MPa, the multi-stage power device 200 can work normally. Under this hydraulic pressure, when the hydraulic pressure acts on the sliding sleeve 12, one end of the shear pin 114 is inserted into the fixed groove 121 to fix the sliding sleeve 12, and the sliding sleeve 12 cannot slide. When the work is completed, the hydraulic pressure is increased to 30 MPa - 40 MPa to shear and damage the shear pin 114, so that the sliding sleeve 12 can move towards the multi-stage power device 200.

[0040] More specifically, the hydraulic anchor 100, the multi-stage power device 200 and the ball expandable tube tool 300 in this embodiment are prior arts, and their working principles will not be elaborated here.

[0041] Optionally, as shown in Figure 2 FIG. 1, a first drill pipe joint 2 and a second drill pipe joint 3 are respectively arranged on the first connector 11 and the second connector 13. The first drill pipe joint 2 is threadedly connected to the hydraulic anchor 100, and the second drill pipe joint 3 is connected to the multi-stage power device 200. This can make the connection between the hydraulic anchor 100 and the backwater constant pressure device 1 and the connection between the multi-stage power device 200 and the backwater constant pressure device 1 closer, ensuring the normal operation of the oil and gas well repair tool. Specifically, the first drill pipe joint 2 and the second drill pipe joint 3 in this embodiment are both API oil drill pipe joints, and the API oil drill pipe joints can withstand huge internal and external pressures, torsion, bending and vibration, ensuring the connection strength.

[0042] Optionally, as shown in Figure 2 FIG. 2, a first sealing ring 4 is arranged between the sliding sleeve 12 and the first connector 11. Thus, when the oil and gas well repair tool is working normally, it can prevent water from flowing into the bypass hole 112 and the drain hole 113 through the gap between the sliding sleeve 12 and the first connector 11, resulting in insufficient hydraulic pressure and insufficient output power of the multi-stage power device 200.

[0043] Optionally, as shown in Figure 2 FIG. 3, a second sealing ring 5 is arranged between the first connector 11 and the second connector 13. This can make the connection between the first connector 11 and the second connector 13 closer.

[0044] Optionally, as shown in Figure 2 FIG. 4, a third sealing ring 6 is arranged between the flow-through piston 14 and the second connector 13. Thus, when the oil and gas well repair tool is working normally, it can prevent water from flowing into the communication cavity 16 and the installation cavity 15 through the gap between the flow-through piston 14 and the second connector 13, resulting in insufficient hydraulic pressure and insufficient output power of the multi-stage power device 200, and can also effectively protect the return spring 17.

[0045] Optionally, as shown in Figure 2 FIG. 5, a fourth sealing ring 7 is arranged between the flow-through piston 14 and the first connector 11. This forms a sealing structure between the flow-through piston 14 and the first connector 11 to prevent liquid leakage.

[0046] Optionally, the first connector 11 and the second connector 13 are threadedly connected. In this embodiment, the first connector 11 and the second connector 13 are connected by metric threads to transmit tension and torque.

[0047] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An oil and gas well repair tool, characterized in that: The invention comprises a hydraulic anchor (100), a return water constant pressure device (1), a multi-stage power device (200) and a ball tube expander (300) which are connected in sequence.

2. The oil and gas well repair tool according to claim 1, characterized in that: The return water constant pressure device (1) comprises: a first connection head (11), the first connection head (11) being connected to the hydraulic anchor (100), the first connection head (11) being provided with a shear pin hole (111), a bypass hole (112) and a drain hole (113) at intervals, and a shear pin (114) being installed in the shear pin hole (111); a sliding sleeve (12) slidably mounted on the first connector (11); a fixing groove (121) and a connecting channel (122) are provided on the sliding sleeve (12); one end of the shear pin (114) can be inserted into the fixing groove (121) to fix the sliding sleeve (12); one end of the connecting channel (122) is communicated with the bypass hole (112), and the other end is communicated with the drain hole (113); a second connector (13), one end of the second connector (13) being connected to the multi-stage power device (200), and the other end of the second connector (13) being connected to the first connector (11), and a pressure relief hole (131) being provided on the second connector (13); A flow piston (14), the flow piston (14) is slidably mounted between the first connector (11) and the second connector (13), a flow groove (141) and a flow hole (142) are provided on the flow piston (14), an installation cavity (15) and a communication cavity (16) are provided between the flow piston (14) and the second connector (13), and the installation cavity (15) is communicated with the outside through the pressure relief hole (131); A return spring (17), wherein the return spring (17) is installed in the installation cavity (15) and abuts against the flow-through piston (14).

3. The oil and gas well repair tool according to claim 2, characterized in that: The first connecting head (11) and the second connecting head (13) are respectively provided with a first drill rod joint (2) and a second drill rod joint (3); the first drill rod joint (2) is threadedly connected to the hydraulic anchor (100), and the second drill rod joint (3) is threadedly connected to the multi-stage power device (200).

4. The oil and gas well repair tool according to claim 2, characterized in that: A first sealing ring (4) is provided between the sliding sleeve (12) and the first connecting head (11).

5. The oil and gas well repair tool according to claim 2, characterized in that: The first connecting head (11) is threadedly connected to the second connecting head (13).

6. The oil and gas well repair tool according to claim 5, characterized in that: A second sealing ring (5) is provided between the first connecting head (11) and the second connecting head (13).

7. The oil and gas well repair tool according to claim 2, characterized in that: A third sealing ring (6) is provided between the flow piston (14) and the second connecting head (13).

8. The oil and gas well repair tool according to claim 2, characterized in that: A fourth sealing ring (7) is provided between the flow piston (14) and the first connecting head (11).

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