Retrievable Sealing Hanging Device and Cementing Method

Abstract

The present invention belongs to the technical field of oil and gas exploitation, and discloses a retrievable sealing and hanging device and a cementing method. The retrievable sealing and hanging device includes an outer casing, a central pipe, a releasing sub, a slip assembly and an expansion sealing assembly. The central pipe is disposed through the outer casing. One end of the releasing sub is detachably connected to an upper connecting pipe. The slip assembly is arranged on the outer casing, and the slip assembly can radially abut against the inner wall of the upper casing. The expansion sealing assembly includes an actuating structure and a rubber barrel. The actuating structure is arranged on the outer casing corresponding to an expansion through hole, and the rubber barrel is arranged around the outer casing and axially abuts against the actuating structure. When the central pipe is lifted, the actuating structure can move axially along the outer casing under the action of the liquid pressure of the displacement water in the outer casing, so that the rubber barrel is compressed and deformed and elastically abuts against the inner wall of the upper casing. The retrievable sealing and hanging device can improve the annular cementing quality and solve the problem of poor cementing quality caused by the loss of cementing fluid or the backflow of fluid due to the poor formation pressure bearing capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploitation, and particularly relates to a retrievable sealing suspension device and a cementing method. Background Art

[0002] During the development of oil and gas fields, the staged fracturing technology for horizontal wells is one of the effective production-increasing measures. Practice has proved that in view of the existing problems in the current exploitation of old horizontal wells, after the wellbore is reconstructed and refractured, the fracture penetration zone is communicated with the remaining oil and gas distribution area, an effective oil and gas channel is re-established between the wellbore and the reservoir, the productivity of the oil and gas well is restored, the single-well recovery rate is increased, and finally the stable production and production increase of the old oilfield are realized.

[0003] However, some commonly used hanging tools at present are limited by size and cannot effectively seal the annulus. After the cementing pressure bump ends, due to the high density of the cementing fluid, there is a situation where formation fluid spits back after the cementing displacement in some formations, resulting in difficulty in ensuring the cementing quality. Summary of the Invention

[0004] The purpose of the present invention is to provide a retrievable sealing suspension device and a cementing method, which can solve the problem of poor cementing quality caused by poor formation pressure bearing capacity or fluid spitting back.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] The retrievable sealing suspension device includes:

[0007] An upper joint, which is used to connect with a drill pipe;

[0008] An outer casing, which is used to retrieve and connect with a casing;

[0009] A central pipe, which is connected with the upper joint, the central pipe is arranged in the outer casing, and the central pipe is used to lower a pressure-holding ball and a drill pipe rubber plug;

[0010] A release sub, one end of the release sub is arranged on the upper joint, and the other end of the release sub is detachably connected with the upper joint;

[0011] A slip assembly, which is arranged on the outer casing, and the slip assembly can radially abut against the inner wall of the upper casing under the action of the hydraulic pressure in the central pipe;

[0012] An expansion sealing assembly, which includes an actuating structure and a rubber barrel. An expansion sealing through hole is formed in the outer casing, the actuating structure is arranged on the outer casing corresponding to the expansion sealing through hole, and the rubber barrel is arranged around the outer casing and axially abuts against the actuating structure;

[0013] When the central tube is lifted, the actuating structure can communicate with the displacement water in the outer casing through the expansion sealing through-hole, and the actuating structure can move axially along the outer casing under the action of the hydraulic pressure of the displacement water in the outer casing, so that the rubber cylinder is compressed and deformed and elastically abuts against the inner wall of the upper casing.

[0014] Preferably, the slip assembly includes slip pieces, a first piston and a cone ring. The first piston is axially movably arranged on the outer casing, and the slip pieces are arranged on the first piston; The cone ring is arranged around the outer casing in a ring shape, the cone ring has a guiding inclined surface, and the slip pieces can axially abut against the guiding inclined surface.

[0015] Preferably, the slip assembly further includes a first hydraulic cylinder. The first hydraulic cylinder is arranged around the outer casing in a ring shape, and there is a first annular groove between the first hydraulic cylinder and the outer casing. The first piston is arranged in the first annular groove;

[0016] A first hydraulic hole is opened on the central tube, a second hydraulic hole corresponding to the first hydraulic hole is opened on the outer casing, and the second hydraulic hole communicates with the bottom of the first annular groove.

[0017] Preferably, the expansion sealing assembly further includes a first sealing ring. The first sealing ring is arranged on the central tube between the expansion sealing through-hole and the first hydraulic hole, and the first sealing ring abuts against the inner wall of the outer casing.

[0018] Preferably, the actuating structure includes a second piston and a retaining ring. The retaining ring is fixed on the outer wall of the outer casing. One end of the rubber cylinder in the axial direction abuts against the retaining ring, and the second piston is axially movably arranged on the outer casing;

[0019] Axially along the outer casing, the rubber cylinder is arranged between the retaining ring and the second piston. The second piston can apply an axial force to the rubber cylinder, so that the rubber cylinder deforms and elastically abuts against the inner wall of the upper casing in the circumferential direction.

[0020] Preferably, the actuating structure further includes a second hydraulic cylinder. The second hydraulic cylinder is arranged around the outer casing in a ring shape, and there is a second annular groove between the second hydraulic cylinder and the outer casing. The second piston is arranged in the second annular groove, and the expansion sealing through-hole communicates with the bottom of the second annular groove.

[0021] Preferably, the expansion sealing assembly further includes a second sealing ring. The second sealing ring is arranged on the central tube between the expansion sealing through-hole and the pressure-holding ball, and the second sealing ring abuts against the inner wall of the outer casing.

[0022] Preferably, the expansion sealing assembly further includes a backstop ring disposed on the second piston;

[0023] Axially along the outer sleeve, the backstop ring is located between the second piston and the rubber barrel. Anti-backlash teeth extending toward the rubber barrel are provided on the outer wall of the outer sleeve, and anti-backlash grooves matching the anti-backlash teeth are provided on the inner wall of the backstop ring. The anti-backlash teeth can abut against the anti-backlash grooves in a direction away from the rubber barrel.

[0024] Preferably, the release sub is threadedly connected to the upper adapter.

[0025] A cementing method using the retrievable hanging sealing device described above includes the following steps:

[0026] S1. Lower the upper adapter into the upper casing in the well using the drill pipe and reach the designated depth;

[0027] S2. Lower the pressure buildup ball so that the pressure buildup ball falls through the central pipe into the ball seat, and turn on the water pump to build up pressure;

[0028] S3. When the hydraulic pressure in the central pipe rises to the preset pressure value of the slip assembly, the slip assembly abuts against the inner wall of the upper casing radially to achieve setting and hanging;

[0029] S4. Disconnect the release sub from the upper adapter;

[0030] S5. Inject cement into the central pipe, press in the drill pipe plug and inject water for displacement;

[0031] S6. When the hydraulic pressure in the central pipe rises to the preset pressure value of the actuating structure, drive the central pipe to lift a preset distance through the upper adapter, so that the displacement water flows to the actuating structure through the expansion sealing through-hole, and the actuating structure axially squeezes the rubber barrel under the action of the hydraulic pressure in the outer sleeve;

[0032] S7. After the rubber barrel abuts tightly against the inner wall of the outer sleeve to complete the packoff seal, lift the drill pipe and remove the upper adapter and the central pipe from the well.

[0033] The beneficial effects of the present invention are as follows:

[0034] The retrievable sealing and hanging device provided by the present invention has an upper connecting pipe connected to a central pipe. The outer sleeve pipe is detachably connected to the upper connecting pipe through a releasing sub. The slip assembly and the expansion sealing assembly are both arranged on the outer sleeve pipe. The upper connecting pipe is connected to the upper drill pipe. Therefore, the whole device is connected into an integral structure through the upper connecting pipe, which is convenient for the whole device to be lowered into the upper casing in the well. Since the central pipe is used to lower the pressure holding ball, and the pressure holding ball falls onto the ball seat through the central pipe, the central pipe can perform pressure holding inside the pipe. Since the outer sleeve pipe can radially abut against the inner wall of the upper casing under the action of the hydraulic pressure in the central pipe, the slip assembly can anchor the whole device in the upper casing, thus completing the setting operation of the retrievable sealing and hanging device. The outer sleeve pipe is provided with an expansion sealing through hole, and the actuating structure is correspondingly arranged on the outer sleeve pipe opposite to the expansion sealing through hole. Since lifting the central pipe can make the displacement water in the outer sleeve pipe communicate with the actuating structure through the expansion sealing through hole, the actuating structure can axially move under the action of the hydraulic pressure and extrude the rubber cylinder, so that the rubber cylinder can be elastically abutted against the inner wall of the upper casing after being compressed and deformed, thereby separating the annulus between the outer sleeve pipe and the upper casing and sealing the lower annulus, effectively solving the problem of poor cementing quality caused by poor formation pressure bearing capacity or fluid backflow. Since the releasing sub is detachably connected to the upper connecting pipe, the releasing of the upper connecting pipe is completed in advance before cement injection, which is convenient for subsequent cement injection displacement pressure bumping, sealing of the expansion sealing assembly, and cleaning of the top by lifting the central pipe, thus completing the cementing operation.

[0035] When using this cementing method, by using the expansion sealing assembly to seal the annulus after cement injection, the use of the expansion sealing assembly can avoid serious leakage in the annulus, effectively improve the cementing quality, thereby improving the pressure bearing capacity of the cement slurry in the annulus, avoiding the remedial measure of squeezing cement, meeting the requirements of fracturing construction, and thus avoiding the occurrence of fracturing accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a half-sectional view of the upper connecting pipe and the releasing sub part provided by the specific embodiment of the present invention;

[0037] Figure 2 It is a half-sectional view of the slip assembly part provided by the specific embodiment of the present invention;

[0038] Figure 3 It is a half-sectional view of the expansion sealing assembly part provided by the specific embodiment of the present invention.

[0039] In the figure:

[0040] 1 - upper connecting pipe;

[0041] 2 - outer sleeve pipe; 21 - expansion sealing through hole; 22 - second hydraulic hole;

[0042] 3 - central pipe; 31 - first hydraulic hole;

[0043] 4 - Retrievable Subsection

[0044] 5 - Slip Assembly; 51 - Slip Piece; 52 - First Piston; 53 - Cone Ring; 54 - First Cylinder

[0045] 6 - Expansion Seal Assembly; 61 - Actuating Structure; 611 - Second Piston; 612 - Retaining Ring; 613 - Second Cylinder; 62 - Rubber Cylinder; 63 - First Seal Ring; 64 - Second Seal Ring; 65 - Anti - reverse Ring Detailed Embodiment

[0046] The present invention will be further described in detail below with reference to the accompanying 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.

[0047] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. 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 circumstances.

[0048] 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 of 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 between them. Moreover, the first feature being "above", "over", and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is lower than that of the second feature.

[0049] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", "left", 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 component referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood 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 meaning.

[0050] As Figures 1 to 3As shown in the figure, the present invention provides a retrievable sealing suspension device. The retrievable sealing suspension device includes an upper joint 1, an outer sleeve 2, a central tube 3, a releasing sub 4, a slip assembly 5, and an expansion sealing assembly 6. The upper joint 1 is used to connect with a drill pipe; the outer sleeve 2 is used for retrieving and connecting with a casing; the central tube 3 is connected to the upper joint 1, the central tube 3 passes through the outer sleeve 2, and the central tube 3 is used for lowering a pressure holding ball and a drill pipe rubber plug; one end of the releasing sub 4 is arranged on the upper joint 1, and the other end of the releasing sub 4 is detachably connected to the upper joint 1; the slip assembly 5 is arranged on the outer sleeve 2, and the slip assembly 5 can radially abut against the inner wall of the upper layer casing under the action of the hydraulic pressure in the central tube 3; the expansion sealing assembly 6 includes an actuating structure 61 and a rubber barrel 62. An expansion sealing through hole 21 is formed on the outer sleeve 2, the actuating structure 61 is arranged on the outer sleeve 2 corresponding to the expansion sealing through hole 21, and the rubber barrel 62 is annularly arranged on the outer sleeve 2 and axially abuts against the actuating structure 61. In this embodiment, the first direction is the direction vertically downward along the central tube 3. Figure 1 , Figure 2 and Figure 3 are connected end to end in sequence along the first direction to form a complete retrievable sealing suspension device. The expansion sealing assembly 6 is located below the slip assembly 5 along the first direction; the upper joint 1 is connected to the central tube 3, the outer sleeve 2 is detachably connected to the upper joint 1 through the releasing sub 4, both the slip assembly 5 and the expansion sealing assembly 6 are arranged on the outer sleeve 2, and the upper joint 1 is connected to the upper drill pipe. Therefore, the whole device is connected into an integral structure through the upper joint 1, which is convenient for the whole device to be lowered into the upper layer casing in the well; since the central tube 3 is used for lowering the pressure holding ball, and the pressure holding ball falls onto the ball seat through the central tube 3, the central tube 3 can perform internal pressure holding; since the outer sleeve 2 can radially abut against the inner wall of the upper layer casing under the action of the hydraulic pressure in the central tube 3, the slip assembly 5 can anchor the whole device in the upper layer casing, thereby completing the setting operation of the retrievable sealing suspension device.

[0051] Lifting the central pipe 3 enables the actuating structure 61 to communicate with the displacement water in the outer casing 2 through the expansion sealing through-hole 21. The actuating structure 61 can move axially along the outer casing 2 under the action of the hydraulic pressure of the displacement water in the outer casing 2, so that the rubber cylinder 62 is compressed and deformed and elastically abuts against the inner wall of the upper casing. In this embodiment, the outer casing 2 is provided with an expansion sealing through-hole 21, and the actuating structure 61 is arranged on the outer casing 2 corresponding to the expansion sealing through-hole 21. Since lifting the central pipe 3 enables the displacement water in the outer casing 2 to communicate with the actuating structure 61 through the expansion sealing through-hole 21, the actuating structure 61 can move axially under the action of the hydraulic pressure and extrude the rubber cylinder 62, so that the rubber cylinder 62 is compressed and deformed and can elastically abut against the inner wall of the upper casing, thereby separating the annulus between the outer casing 2 and the upper casing and sealing the lower annulus, effectively solving the problem of poor cementing quality caused by poor formation pressure bearing or fluid backflow, and preventing cement settlement caused by the upward escape of bottom gas; it can be understood that after injecting cement into the well, the expansion sealing assembly 6 is used to seal the annulus to ensure that the cement can completely enter the annulus, thereby ensuring the cementing quality; since the releasing sub 4 is detachably connected to the upper joint, the upper joint 1 can be detached from the releasing sub 4 after cementing is completed, so that the upper joint 1 and the central pipe 3 can be lifted out of the well by using a drill pipe for the next cementing operation. Specifically, the outer diameter of the central pipe 3 is smaller than the inner diameter of the outer casing 2, the central pipe 3 is inserted through the outer casing 2, and the central pipe 3 is used for lowering a pressure-holding ball. The pressure-holding ball falls onto the lower ball seat through the central pipe 3, so as to achieve pressure holding inside the central pipe 3; the actuating structure 61 is arranged on the outer casing 2 corresponding to the position of the expansion sealing through-hole 21. Since the expansion sealing through-hole 21 is blocked by the internal central pipe 3, the displacement water in the central pipe 3 cannot flow in, preventing the expansion sealing assembly 6 from sealing the annulus before the cement completely enters the annulus between the outer casing 2 and the upper casing, and ensuring that the cement can be completely injected into the annulus; it can be understood that the outer casing 2 has a re-connectable function, can hang a large-diameter small casing and re-connect the casing to meet the requirements of repeated fracturing.

[0052] Further, as Figure 2As shown, the slip assembly 5 includes slip tiles 51, a first piston 52, and a cone ring 53. The first piston 52 is axially movably disposed on the outer casing 2, and the slip tiles 51 are disposed on the first piston 52. The cone ring 53 is disposed around the outer casing 2. The cone ring 53 has a guiding inclined surface, and the slip tiles 51 can be axially abutted against the guiding inclined surface. In this embodiment, the cone ring 53 has a guiding inclined surface, and the distance between the guiding inclined surface and the axis of the central tube 3 gradually increases in the first direction, thus forming a cone mechanism. The hydraulic pressure in the central tube 3 acts on the first piston 52, and the first piston 52 pushes the slip tiles 51 to move axially. During the movement, the slip tiles 51 are abutted against the guiding inclined surface, so that the slip tiles 51 are supported by the cone ring 53 and open to abut against the inner wall of the upper casing, thereby firmly fixing the outer casing 2 on the upper casing to achieve hanging.

[0053] Specifically, as Figure 2 shown, the slip assembly 5 further includes a first hydraulic cylinder 54. The first hydraulic cylinder 54 is disposed around the outer casing 2. There is a first annular groove between the first hydraulic cylinder 54 and the outer casing 2. The first piston 52 is disposed in the first annular groove. A first hydraulic hole 31 is formed in the central tube 3, and a second hydraulic hole 22 corresponding to the first hydraulic hole 31 is formed in the outer casing 2. The second hydraulic hole 22 communicates with the bottom of the first annular groove. In this embodiment, the first hydraulic cylinder 54 is of an annular structure. The first hydraulic cylinder 54 is sleeved on the outer wall of the outer casing 2. A first annular groove is formed between the bottom surface and the side wall of the first hydraulic cylinder 54 and the outer casing 2. The first piston 52 is slidably disposed in the first annular groove, and there is a gap between the bottom of the first piston 52 and the bottom surface of the first hydraulic cylinder 54. The second hydraulic hole 22 communicates with this gap. When pressure is built up in the central tube 3, the water in the central tube 3 will sequentially pass through the first hydraulic hole 31 and the second hydraulic hole 22 and enter the first annular groove. The hydraulic pressure in the first annular groove increases. The first piston 52 will shear the pin between the first piston 52 and the first hydraulic cylinder 54 under the action of the hydraulic pressure, and the first piston 52 will move axially, thereby pushing the slip tiles 51 to abut against the inner wall of the upper casing.

[0054] Specifically, as Figure 2 and Figure 3As shown, the expansion sealing assembly 6 further includes a first sealing ring 63. The first sealing ring 63 is disposed on the central tube 3 between the expansion through hole 21 and the first hydraulic hole 31. The first sealing ring 63 abuts against the inner wall of the outer casing 2. In this embodiment, the outer diameter of the central tube 3 is smaller than the inner diameter of the outer casing 2, and there is an annular cavity between the central tube 3 and the outer casing 2. The first sealing ring 63 is a commonly used rubber sealing ring in the art. A plurality of first sealing rings 63 are arranged along the axial direction of the outer casing 2 to form multiple seals between the central tube 3 and the outer casing 2 to ensure the sealing effect. Along the axial direction of the outer casing 2, the expansion sealing assembly 6 is disposed below the slip assembly 5, that is, the depth at which the expansion sealing assembly 6 is disposed is deeper than that of the slip assembly 5. When pressure is built up in the central tube 3, water will flow into the annular cavity between the central tube 3 and the outer casing 2 through the first hydraulic hole 31. Since the first sealing ring 63 is disposed between the expansion through hole 21 and the first hydraulic hole 31, the first sealing ring 63 will block this part of the water to prevent the water from flowing into the expansion through hole 21 through the annular cavity and squeezing the rubber cylinder 62 in advance to isolate the annulus, ensuring that the cement can completely enter the annulus to improve the cementing quality.

[0055] Further, as Figure 3 shown, the actuating structure 61 includes a second piston 611 and a retaining ring 612. The retaining ring 612 is fixed to the outer wall of the outer casing 2. One end of the rubber cylinder 62 in the axial direction abuts against the retaining ring 612. The second piston 611 is axially movably disposed on the outer casing 2. Along the axial direction of the outer casing 2, the rubber cylinder 62 is disposed between the retaining ring 612 and the second piston 611. The second piston 611 can apply an axial force to the rubber cylinder 62 to cause the rubber cylinder 62 to deform and elastically abut against the inner wall of the upper casing in the circumferential direction. In this embodiment, the retaining ring 612 is fixed to the outer casing 2 and protrudes from the outer wall of the outer casing 2. One end of the rubber cylinder 62 in the axial direction abuts against the retaining ring 612. The second piston 611 has the same structure as the first piston 52, and both are tubular structures sleeved on the outer casing 2. The second piston 611 can axially move under the action of an external force, thereby squeezing the rubber cylinder 62, causing the rubber cylinder 62 to be deformed under pressure and expand radially to abut against the inner wall of the outer upper casing, thereby separating and sealing the annulus between the outer casing 2 and the upper casing to form a sealing structure.

[0056] Specifically, as Figure 3As shown, the actuating structure 61 further includes a second hydraulic cylinder 613. The second hydraulic cylinder 613 is disposed around the outer casing 2. There is a second annular groove between the second hydraulic cylinder 613 and the outer casing 2. The second piston 611 is disposed in the second annular groove, and the expansion sealing through hole 21 communicates with the bottom of the second annular groove. In this embodiment, the second hydraulic cylinder 613 has the same structure as the first hydraulic cylinder 54. A second annular groove is formed between the bottom surface and the side wall of the second hydraulic cylinder 613 and the outer casing 2. The second piston 611 is slidably disposed in the second annular groove and there is a gap between the bottom of the second piston 611 and the bottom surface of the second hydraulic cylinder 613. The expansion sealing through hole 21 communicates with this gap. When using a drill pipe plug to displace after injecting cement, the construction personnel lift the central pipe 3 to make the expansion sealing through hole 21 communicate with the displacement water entering the outer casing 2. The displacement water enters the second hydraulic cylinder 613 through the expansion sealing through hole 21. Under the action of the hydraulic pressure of the displacement water, the second piston 611 will shear the pin between the second piston 611 and the second hydraulic cylinder 613, and then the second piston 611 axially moves to extrude the rubber cylinder 62.

[0057] Specifically, as Figure 3 shown, the expansion sealing assembly 6 further includes a second sealing ring 64. The second sealing ring 64 is disposed on the central pipe 3 between the expansion sealing through hole 21 and the pressure holding ball. The second sealing ring 64 abuts against the inner wall of the outer casing 2. In this embodiment, the second sealing ring 64 is a commonly used rubber sealing ring in the art. A plurality of second sealing rings 64 are axially disposed along the outer casing 2, so as to form multiple seals between the central pipe 3 and the outer casing 2 to ensure the sealing effect. Along the placement direction of the retrievable sealing and hanging device in the well, the second sealing ring 64 is disposed below the expansion sealing through hole 21 to prevent the displacement water from entering the expansion sealing through hole 21 through the annular cavity between the outer casing 2 and the central pipe 3 to drive the rubber cylinder 62 to seal before the cement completely enters the annulus. At the same time, when the construction personnel lift the central pipe 3 to make the displacement water flow into the expansion sealing through hole 21, at this time the central pipe 3 has not been completely removed from the well. The second sealing ring 64 can play a role in holding the pressure on the displacement water entering the annular cavity between the central pipe 3 and the outer casing 2, so that the hydraulic pressure in the second annular groove can quickly rise to the required pressure to drive the second piston 611 to move.

[0058] Further, as Figure 3As shown, the expansion sealing assembly 6 further includes a backstop ring 65. The backstop ring 65 is arranged on the second piston 611. Along the axial direction of the outer sleeve 2, the backstop ring 65 is located between the second piston 611 and the rubber cylinder 62. On the outer wall of the outer sleeve 2, there are backstop teeth extending towards the rubber cylinder 62. On the inner wall of the backstop ring 65, there is a backstop groove matching the backstop teeth, and the backstop teeth can abut against the backstop groove along the direction away from the rubber cylinder 62. In this embodiment, the backstop ring 65 is arranged at the end of the second piston 611. On the outer wall of the outer sleeve 2, there are backstop teeth, and on the inner wall of the backstop ring 65, there is a backstop groove matching the backstop teeth. When the second piston 611 moves in the first direction, the backstop ring 65 can be pushed to squeeze the rubber cylinder 62. After the rubber cylinder 62 is squeezed in place, since the backstop teeth are stuck in the backstop groove, the backstop ring 65 cannot retreat, thus always squeezing the rubber cylinder 62 to prevent the second piston 611 from accidentally retreating and causing the sealing of the annulus by the rubber cylinder 62 to fail.

[0059] Further, the releasing sub 4 is threadedly connected to the upper connecting pipe 1. In this embodiment, the releasing sub 4 is threadedly connected to the upper connecting pipe 1. When performing the releasing operation, the upper connecting pipe 1 can be rotated by the drill pipe to be separated from the releasing sub 4.

[0060] This embodiment also provides a cementing method using the above-mentioned hanging and sealing structure, including the following steps:

[0061] S1. Use the drill pipe to lower the upper connecting pipe 1 into the upper casing in the well and reach the designated depth. In this embodiment, the construction personnel connect the upper connecting pipe 1 to the drill pipe and use the drill pipe to lower the upper connecting pipe 1 into the upper casing in the well to the designated depth.

[0062] S2. Lower the pressure - holding ball so that the pressure - holding ball falls through the central pipe 3 into the ball seat, and start the water pump for pressure - holding. In this embodiment, the construction personnel put the pressure - holding ball into the central pipe 3, the pressure - holding ball falls through the central pipe 3 onto the lower ball seat, and then start the pump for pressure - holding operation.

[0063] S3. When the hydraulic pressure in the central pipe 3 rises to the preset pressure value of the slip assembly 5, the slip assembly 5 abuts against the inner wall of the upper casing along the radial direction to achieve hanging. In this embodiment, after starting the pump for pressure - holding, as the hydraulic pressure in the central pipe 3 rises to the preset pressure of the first piston 52, the first piston 52 will move axially and drive the slip pieces 51 to open. The slip pieces 51 abut against the inner wall of the upper casing along the radial direction, thereby firmly fixing the outer sleeve 2 on the upper casing to achieve hanging.

[0064] S4. Disconnect the releasing sub 4 from the upper connecting pipe 1. In this embodiment, the construction personnel drive the upper connecting pipe 1 to rotate through the drill tool so that the upper connecting pipe 1 is disconnected from the releasing sub 4 to achieve releasing. At this time, the upper connecting pipe 1 and the central pipe 3 are still in the well and are not taken out.

[0065] S5. Inject cement into the central pipe 3, press in the drill pipe plug and inject water for displacement. In this embodiment, the construction personnel use tools to inject cement into the central pipe 3 to start cementing, and press in the drill pipe plug for displacement, so that the cement enters the annulus between the outer casing 2 and the upper casing.

[0066] S6. When the liquid pressure in the central pipe 3 rises to the preset pressure value of the actuating structure 61, drive the central pipe 3 to lift a preset distance through the upper connection pipe 1, so that the displacement water flows to the actuating structure 61 through the expansion sealing through hole 21. Under the action of the liquid pressure in the outer casing 2, the actuating structure 61 axially extrudes the rubber cylinder 62. In this embodiment, the construction personnel drive the central pipe 3 to lift a preset distance through the upper connection pipe 1, so that the expansion sealing through hole 21 is communicated with the displacement water entering the outer casing 2, and the displacement water flows into the second hydraulic cylinder 613 through the expansion sealing through hole 21, thereby driving the second piston 611 to move under the action of the liquid pressure to extrude the rubber cylinder 62 to deform, so as to realize the isolation of the annulus.

[0067] S7. When the rubber cylinder 62 abuts against the inner wall of the outer casing 2 to complete the isolation seal, lift the drill pipe and take out the upper connection pipe 1 and the central pipe 3 from the well. In this embodiment, when the rubber cylinder 62 completes the isolation of the annulus, the construction personnel lift the drill pipe and take out the upper connection pipe 1 and the central pipe 3 from the well, thus completing the cementing operation.

[0068] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting 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. A reconnectable sealing suspension device, characterized in that: include: An upper pipe (1), the upper pipe (1) being used for connecting to a drill pipe; An outer casing (2), wherein the outer casing (2) is used for connecting back the casing; A central tube (3), the central tube (3) being connected to the upper tube (1), the central tube (3) being inserted into the outer tube (2), and the central tube (3) being used for lowering a pressure-holding ball and a drill pipe rubber plug; A release short section (4), one end of which is arranged on the upper connecting pipe (1), and the other end of which is detachably connected to the upper connecting pipe (1); A slip assembly (5), wherein the slip assembly (5) is arranged on the outer casing (2), and the slip assembly (5) can be radially pressed against the inner wall of the upper casing under the action of the liquid pressure in the central pipe (3); An expansion sealing assembly (6), the expansion sealing assembly (6) comprising an execution structure (61) and a rubber sleeve (62), the outer sleeve (2) being provided with an expansion sealing through hole (21), the execution structure (61) being arranged on the outer sleeve (2) corresponding to the expansion sealing through hole (21), the rubber sleeve (62) being arranged in an annular manner on the outer sleeve (2) and abutting against the execution structure (61) along the axial direction; Lifting the central tube (3) upward enables the execution structure (61) to communicate with the displacement water in the outer sleeve (2) through the expansion seal through hole (21); the execution structure (61) can move axially along the outer sleeve (2) under the action of the liquid pressure of the displacement water in the outer sleeve (2), so that the rubber sleeve (62) is compressed and deformed and elastically pressed against the inner wall of the upper sleeve.

2. The reconnectable sealing suspension device according to claim 1, characterized in that: The cava assembly (5) comprises a cava piece (51), a first piston (52) and a conical ring (53); the first piston (52) is axially movably arranged on the outer sleeve (2); the cava piece (51) is arranged on the first piston (52); the conical ring (53) is arranged on the outer sleeve (2); the conical ring (53) has a guiding inclined surface, and the cava piece (51) can be axially abutted against the guiding inclined surface.

3. The reconnectable sealing suspension device according to claim 2, characterized in that: The slip assembly (5) further comprises a first liquid cylinder (54), the first liquid cylinder (54) being arranged on the outer sleeve (2), a first annular groove being provided between the first liquid cylinder (54) and the outer sleeve (2), and the first piston (52) being arranged in the first annular groove; The central tube (3) is provided with a first hydraulic hole (31), the outer sleeve (2) is provided with a second hydraulic hole (22) corresponding to the first hydraulic hole (31), and the second hydraulic hole (22) is communicated with the bottom of the first annular groove.

4. The reconnectable sealing suspension device according to claim 3, characterized in that: The expansion seal assembly (6) further comprises a first sealing ring (63), wherein the first sealing ring (63) is arranged on the central tube (3) between the expansion seal through hole (21) and the first hydraulic hole (31), and the first sealing ring (63) abuts against the inner wall of the outer sleeve (2).

5. The reconnectable sealing suspension device according to claim 1, characterized in that: The execution structure (61) comprises a second piston (611) and a retaining ring (612), wherein the retaining ring (612) is fixed on the outer wall of the outer sleeve (2), one end of the rubber sleeve (62) along the axial direction abuts against the retaining ring (612), and the second piston (611) is movably arranged on the outer sleeve (2) along the axial direction; Along the axial direction of the outer sleeve (2), the rubber sleeve (62) is arranged between the retaining ring (612) and the second piston (611), and the second piston (611) can apply an axial force to the rubber sleeve (62) so that the rubber sleeve (62) is deformed and elastically pressed against the inner wall of the upper sleeve along the circumferential direction.

6. The reconnectable sealing suspension device according to claim 5, characterized in that: The execution structure (61) also includes a second liquid cylinder (613), which is arranged on the outer sleeve (2) in an annular manner. A second annular groove is provided between the second liquid cylinder (613) and the outer sleeve (2). The second piston (611) is arranged in the second annular groove. The expansion sealing through hole (21) is connected to the bottom of the second annular groove.

7. The reconnectable sealing suspension device according to claim 6, characterized in that: The expansion seal assembly (6) further comprises a second sealing ring (64), wherein the second sealing ring (64) is arranged on the central tube (3) between the expansion seal through hole (21) and the pressure holding ball, and the second sealing ring (64) abuts against the inner wall of the outer sleeve (2).

8. The reconnectable sealing suspension device according to claim 6, characterized in that: The expansion seal assembly (6) further comprises a stop ring (65), wherein the stop ring (65) is arranged on the second piston (611); Along the axial direction of the outer sleeve (2), the stop ring (65) is located between the second piston (611) and the rubber cylinder (62); the outer wall of the outer sleeve (2) is provided with a stop tooth extending toward the rubber cylinder (62); the inner wall of the stop ring (65) is provided with a stop groove matching the stop tooth; the stop tooth can abut against the stop groove in a direction away from the rubber cylinder (62).

9. The reconnectable sealing suspension device according to claim 1, characterized in that: The drop-out short section (4) is threadedly connected to the upper pipe (1).

10. A cementing method, characterized in that: Using the reconnectable sealing suspension device according to any one of claims 1 to 9 comprises the following steps: S1, using the drill pipe to lower the upper pipe (1) into the upper casing in the well and reach a specified depth; S2, lowering the pressure-holding ball so that it passes through the central tube (3) and falls into the ball seat, and starting the water pump to hold the pressure; S3, when the liquid pressure in the central pipe (3) increases to a preset pressure value of the slip assembly (5), the slip assembly (5) abuts against the inner wall of the upper casing in the radial direction to achieve hanging; S4, disconnecting the drop-out short section (4) from the upper connecting section (1); S5, injecting cement into the central pipe (3), pressing in the drill pipe plug and injecting water for displacement; S6. When the liquid pressure in the central tube (3) increases to a preset pressure value of the execution structure (61), the central tube (3) is lifted up by a preset distance through the upper tube (1), so that the displacement water flows through the expansion seal through hole (21) to the execution structure (61), and the execution structure (61) squeezes the rubber sleeve (62) in the axial direction under the action of the liquid pressure in the outer sleeve (2); S7. When the rubber tube (62) is pressed against the inner wall of the outer casing (2) to complete the isolation seal, the drill pipe is lifted up, and the upper pipe (1) and the center pipe (3) are taken out of the well.

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