Hanger-type bridging tool and bridging method

Abstract

The application belongs to the technical field of drilling tools, and discloses a hanging and clamping type temporary plugging tool and a temporary plugging method. The hanging and clamping type temporary plugging tool comprises a sealing sleeve, a pressure-bearing pipe, a sealing ring, a pushing sleeve, a sliding sleeve, a connecting rod assembly and a fixing sleeve. The top outer side of the sealing sleeve is connected with a pushing cylinder, and the inner side is connected with a center joint. The top inner side of the pressure-bearing pipe is provided with a pressure-bearing thread and is threadedly connected with the center joint. The top outer side of the pressure-bearing pipe is connected with the inner wall of the sealing sleeve through a first connecting ring. The sealing ring is arranged on the bottom outer side of the sealing sleeve. The pushing sleeve is arranged on the outer side of the pressure-bearing pipe. The top end of the pushing sleeve abuts against the bottom end of the sealing ring. The sliding sleeve is arranged on the pressure-bearing pipe and is connected with the pressure-bearing pipe through a second connecting ring. The connecting rod assembly is arranged between the pushing sleeve and the sliding sleeve and can abut against the inner wall of the casing string after being rotated and expanded outward. The fixing sleeve is threadedly connected with the bottom end of the pressure-bearing pipe and elastically abuts against the bottom end of the sliding sleeve. The application solves the problem of setting failure and is beneficial to the smooth implementation of the fracturing process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of drilling tools, in particular to a hanging and clamping type temporary plugging tool and a temporary plugging method. BACKGROUND

[0002] In order to improve the initial production and ultimate recovery of oil and gas, separate layer injection and production and multi-stage staged fracturing have become one of the effective means for efficient development of unconventional oil and gas resources. Temporary plugging tools realize the staged sealing of wellbores by setting and sealing, and are important equipment for realizing multi-stage staged fracturing.

[0003] At present, the setting process of the temporary plugging tool mainly uses the structure mode of embedding high-strength buttons on the outer circle of the slip assembly. Under the action of the axial force of the downhole setting tool, the buttons are bitten into the inner wall of the casing during the outward expansion of the slip, so as to realize the anchoring of the temporary plugging tool. However, due to the deformation of the casing or the insufficient biting depth of the buttons, the phenomenon of slippage and movement of the temporary plugging tool after setting may easily occur during the construction process, resulting in setting failure and fracturing failure. At the same time, the high-strength buttons cannot be dissolved in the downhole, and the particles are small, resulting in a high proportion of residual materials, which causes difficulties in subsequent flowback and fishing; when the high-strength buttons are bitten into the inner wall of the casing to a certain depth under the action of pressure, the local damage to the inner wall of the casing will occur, the strength will decrease, and the risk of casing deformation will increase. In addition, the current temporary plugging tools generally use multi-petal slips to push sealing rings to realize sealing, but the multi-petal slips may be affected by the resistance of the well wall and other factors, resulting in premature setting or disintegration during the downhole process, which delays the subsequent construction and affects the economic benefits of single well. SUMMARY

[0004] The purpose of the present application is to provide a hanging and clamping type temporary plugging tool and a temporary plugging method to solve the problem of easy setting failure of the existing temporary plugging tool.

[0005] To achieve this purpose, the following technical solutions are adopted in the present application:

[0006] A hanging and clamping type temporary plugging tool for internal plugging of a casing string, the casing string comprising an upper casing, a coupling and a lower casing, the coupling being provided with internal threads at both ends to threadedly connect the upper casing and the lower casing respectively, and a convex space being formed between the end portions of the upper casing and the lower casing and the inner wall of the coupling; the hanging and clamping type temporary plugging tool comprising:

[0007] a sealing sleeve, the top end of the sealing sleeve being connected with a push cylinder on the outside and being connected with a center joint on the inside;

[0008] A pressure-bearing pipe, an inner side of a top end of the pressure-bearing pipe is provided with a pressure-bearing thread to be connected with the central joint thread, an outer side of the top end of the pressure-bearing pipe is connected with an inner wall of the sealing sleeve through a first connecting ring, when the sealing sleeve is moved relative to the central joint by the pushing cylinder, the sealing sleeve can drive the first connecting ring to slide on the pressure-bearing pipe from the top end to the bottom end in one direction;

[0009] A sealing ring, the sealing ring is sleeved on an outer side of a bottom end of the sealing sleeve;

[0010] A pushing sleeve, the pushing sleeve is sleeved on an outer side of the pressure-bearing pipe, a top end of the pushing sleeve abuts against a bottom end of the sealing ring, when the sealing sleeve slides along the pressure-bearing pipe, the sealing ring can be gradually deformed to abut against an inner wall of the casing string under the interaction of the pushing sleeve and the sealing sleeve;

[0011] A sliding sleeve, the sliding sleeve is sleeved on the pressure-bearing pipe and connected with the pressure-bearing pipe through a second connecting ring, the sliding sleeve can drive the second connecting ring to slide on the pressure-bearing pipe from the bottom end to the top end in one direction;

[0012] A connecting rod assembly, the connecting rod assembly is arranged between the pushing sleeve and the sliding sleeve, when the pushing sleeve and the sliding sleeve have a relatively close sliding movement on the pressure-bearing pipe, the connecting rod assembly can be expanded in diameter and abut against the inner wall of the casing string to be anchored or hung up;

[0013] A fixing sleeve, the fixing sleeve is threadedly connected to a bottom end of the pressure-bearing pipe and elastically abuts against a bottom end of the sliding sleeve.

[0014] As preferred, the hanging-up type temporary plugging tool further comprises a supporting ring, the supporting ring is sleeved on an outer side of a bottom end of the sealing sleeve and abuts against a bottom end of the sealing ring, the supporting ring is formed by a plurality of Z-shaped arc segments overlapping with each other, and the supporting ring can be radially expanded to support the sealing ring after being pressed.

[0015] As preferred, an outer side of the sealing sleeve is sequentially provided with a first outer circular surface, a second outer circular surface, a first outer conical surface and a second outer conical surface from a top end to a bottom end, an outer diameter of the first outer circular surface is smaller than an outer diameter of the second outer surface, a stepped surface is formed between the first outer circular surface and the second outer circular surface, the pushing cylinder is connected to the first outer circular surface and abuts against the stepped surface; a taper of the first outer conical surface is larger than a taper of the second outer conical surface, the sealing ring and the supporting ring are both sleeved on the second outer conical surface, the second outer conical surface makes the supporting ring radially expand when the supporting ring and the sealing sleeve slide relative to each other; a top end of an inner side of the sealing sleeve is provided with a first inner conical surface, the first inner conical surface is in contact with the central joint.

[0016] Preferably, the inner wall and the outer wall of the first connecting ring are respectively provided with a first sawtooth inner thread and a first sawtooth outer thread, the inner wall and the outer wall of the second connecting ring are respectively provided with a second sawtooth inner thread and a second sawtooth outer thread, the bottom end inner wall of the sealing sleeve is provided with a third sawtooth inner thread, the inner wall of the sliding sleeve is provided with a fourth sawtooth inner thread, the pressure-bearing pipe is provided with a third sawtooth outer thread and a fourth sawtooth outer thread, and the first sawtooth inner thread and the first sawtooth outer thread are connected with the third sawtooth outer thread and the third sawtooth inner thread, respectively, and the second sawtooth inner thread and the second sawtooth outer thread are connected with the fourth sawtooth outer thread and the fourth sawtooth inner thread, respectively.

[0017] Preferably, the first connecting ring and the second connecting ring are both C-shaped rings with openings, the pitch of the first sawtooth outer thread is greater than the pitch of the first sawtooth inner thread, and the pitch of the second sawtooth outer thread is greater than the pitch of the second sawtooth inner thread.

[0018] Preferably, the inner top end of the pushing sleeve is provided with a second inner taper surface, the second inner taper surface has the same taper as the second outer taper surface of the sealing sleeve, and the second outer taper surface is slidably connected to the second inner taper surface and abuts against the end of the second inner taper surface.

[0019] Preferably, the connecting rod assembly includes a first connecting rod and a second connecting rod, one end of the first connecting rod is rotatably connected to the pushing sleeve, the other end of the first connecting rod is rotatably connected to the second connecting rod, one end of the second connecting rod away from the first connecting rod is rotatably connected to the sliding sleeve, and a pin is arranged between the first connecting rod and the pushing sleeve and between the second connecting rod and the sliding sleeve to initially position.

[0020] Preferably, the bottom end face of the sliding sleeve is circumferentially provided with a plurality of mounting holes, and each mounting hole is provided with an elastic member, and the two ends of the elastic member are respectively abutted against the hole bottom of the mounting hole and the fixing sleeve.

[0021] Preferably, the top end of the fixing sleeve is provided with an enlarged hole, the sliding sleeve is inserted into the enlarged hole, and the axial depth of the enlarged hole is greater than the elastic sliding distance of the sliding sleeve.

[0022] Preferably, the sealing sleeve, the first connecting ring, the pressure-bearing pipe, the supporting ring, the pushing sleeve, the sliding sleeve, the connecting rod assembly, and the fixing sleeve are all made of a soluble metal material, and the sealing ring is made of a soluble rubber material, and the soluble metal material and the soluble rubber material can be dissolved in the well to release the hanging and setting, and restore the drift diameter of the casing string.

[0023] A hanging card type temporary plugging method, the hanging card type temporary plugging tool is applied, and the hanging card type temporary plugging method comprises the following steps:

[0024] The hanging card type temporary plugging tool is lowered into the casing string and located in the upper casing above the convex space through the push cylinder and the center joint;

[0025] The center joint is kept stationary, the push cylinder is continuously pushed to move downward, the sealing sleeve drives the first connecting ring to slide downward along the pressure-bearing pipe under the action of the push cylinder, and the sealing ring is gradually deformed to abut against the inner wall of the upper casing under the interaction of the push sleeve and the sealing sleeve;

[0026] The push cylinder is continuously pushed to move downward, the connecting rod assembly between the push sleeve and the sliding sleeve is once expanded in diameter outward and abuts against the inner wall of the upper casing, the pressure-bearing pipe is separated from the center joint, and the push cylinder is separated from the sealing sleeve;

[0027] The pressure ball is put, and the hanging card type temporary plugging tool realizes casing string sealing after the pressure ball contacts the sealing sleeve;

[0028] When the upper end pressure of the hanging card type temporary plugging tool is greater than the lower end pressure, the hanging card type temporary plugging tool slides downward until the connecting rod assembly is separated from the upper casing, the connecting rod assembly is twice expanded in diameter outward under the elastic abutting action of the fixed sleeve and the sliding sleeve to abut against the inner wall of the coupling, and the hanging card type temporary plugging tool stops sliding downward when the hanging card type temporary plugging tool slides to the end of the lower casing, and the hanging card type temporary plugging tool realizes hanging card sliding stop.

[0029] As preferred, the hanging card type temporary plugging method further comprises the steps that the hanging card type temporary plugging tool is dissolved under the specific temperature and salinity conditions in the well to release the hanging card and setting.

[0030] The beneficial effects of the present application are as follows:

[0031] The hanging card type temporary plugging tool provided by the present application is provided with the sealing ring outside the bottom end of the sealing sleeve, the sealing ring can abut against and seal the inner wall of the casing string when the push cylinder pushes the sealing sleeve to move downward relative to the center joint, the connecting rod assembly is arranged between the push sleeve and the sliding sleeve to expand in diameter, the push sleeve and the sliding sleeve are both one-way sliding, so that the connecting rod assembly can abut against the inner wall of the casing string to anchor after being rotated, the connecting rod assembly can further rotate and abut against the inner wall of the coupling of the casing string to hang and position and realize sliding stop when the hanging card type temporary plugging tool slides downward under stress, the sliding and channeling phenomenon after setting is avoided, the setting failure problem is effectively solved, and the smooth implementation of the fracturing process is facilitated.

[0032] The hanging card type temporary plugging tool provided by the application has a special anchor structure without a slip button, the anchor structure of the connecting rod assembly can withstand a construction pressure difference greater than or equal to 70 MPa, the effective plugging time at the well bottom is greater than or equal to 24 hours, and the applicable temperature range is 30-150 DEG C. In addition, the hanging card type temporary plugging tool as a whole has no high-strength button, can be completely dissolved after construction, has no insoluble substances or has greatly reduced insoluble structural parts, the proportion of residues after dissolution is extremely low, and the dissolution performance of the hanging card type temporary plugging tool is effectively improved. The inner side of the top end of the pressure-bearing pipe is provided with a pressure-bearing thread connected with the center joint thread, the pressure-bearing thread is only released from the connection under a specified pressure, and therefore the hanging card type temporary plugging tool is safe and reliable during the lowering and working process and will not be blocked, disintegrated or prematurely set, can effectively guarantee the smooth construction of staged fracturing, effectively promotes the iteration and upgrading of conventional temporary plugging tools, forms a new hanging and positioning type temporary plugging tool structure technology system, is suitable for large-scale fracturing operations of shale oil under different temperature, salinity and other working conditions, and plays a certain guiding role for the further development of staged fracturing technology.

[0033] The hanging card type temporary plugging method provided by the application realizes the abutment and hanging of the connecting rod assembly and the inner wall of the convex space in the hanging card type temporary plugging tool at the top end of the lower casing through one-time rotation and two-time rotation and diameter expansion of the connecting rod assembly, utilizes the convex space structure of the casing string and the one-way sliding setting of the push sleeve and the sliding sleeve, and realizes the slip stopping of the connecting rod assembly under the elastic abutment of the sliding sleeve and the fixed sleeve, thereby avoiding the continuous sliding and movement after setting and effectively solving the setting failure problem, and facilitating the smooth implementation of the fracturing process. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a structural schematic view of the hanging card type temporary plugging tool provided by the embodiment of the application lowered into the casing string;

[0035] Figure 2 is a state schematic view of the hanging card type temporary plugging tool provided by the embodiment of the application set in the casing string;

[0036] Figure 3 is a state schematic view of the hanging card type temporary plugging tool provided by the embodiment of the application set after hanging in the casing string;

[0037] Figure 4 is a front view of the initial state of the support ring in the hanging card type temporary plugging tool provided by the embodiment of the application;

[0038] Figure 5 is a side view of the initial state of the support ring in the hanging card type temporary plugging tool provided by the embodiment of the application; Figure 4

[0039] Figure 6 is a front view of the state of the support ring in the hanging card type temporary plugging tool provided by the embodiment of the application after radial expansion.​

[0040] Figure 7 is Figure 6 Figure 6 is a side view of the support ring after radial expansion.

[0041] In the drawings:

[0042] 1, push cylinder; 2, center joint; 3, sealing sleeve; 4, first connecting ring; 5, pressure bearing pipe; 6, sealing ring; 7, support ring; 71, Z-shaped arc segment; 8, push sleeve; 9, first cylindrical pin; 10, first pin; 11, first connecting rod; 12, second cylindrical pin; 13, second connecting rod; 14, second pin; 15, third cylindrical pin; 16, sliding sleeve; 17, second connecting ring; 18, elastic member; 19, third pin; 20, fixed sleeve; 21, upper sleeve pipe; 22, coupling; 23, lower sleeve pipe; 24, pressure ball. DETAILED DESCRIPTION

[0043] The application will be further described below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are intended to be merely illustrative of the application and not in limitation thereof. It should also be understood that, for the purpose of clarity, only those structures of the application that are relevant to the present application have been shown in the drawings.

[0044] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0046] In the description of the present embodiments, the terms "upper", "lower", "right", "left", and the like, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used to distinguish in the description, and have no special meaning.

[0047] A hanging card type temporary plugging tool, such as Figures 1-7 , is used for internal plugging of a casing string, the casing string comprising an upper casing 21, a coupling 22, and a lower casing 23, the coupling 22 being provided with internal threads at both ends to threadedly connect the upper casing 21 and the lower casing 23, respectively, and the end portions of the upper casing 21 and the lower casing 23 forming a convex space with the inner wall of the coupling 22; the hanging card type temporary plugging tool can be set in the upper casing 21 and hung and set in position at the top end of the lower casing 23 at the convex space after sliding down.

[0048] As Figures 1-3The hanging card type temporary plugging tool comprises a sealing sleeve 3, a pressure bearing pipe 5, a sealing ring 6, a pushing sleeve 8, a sliding sleeve 16, a connecting rod assembly and a fixing sleeve 20, the top outer side of the sealing sleeve 3 is connected with the pushing barrel 1, and the inner side is connected with the center joint 2, the pushing barrel 1 and the center joint 2 are used for driving and controlling the hanging card type temporary plugging tool to be sent into a specified position in the casing string and to be set and sealed, the top inner side of the pressure bearing pipe 5 is provided with a pressure bearing thread and is threadedly connected with the center joint 2, the top outer side of the pressure bearing pipe 5 is connected with the inner wall of the sealing sleeve 3 through the first connecting ring 4, when the pushing barrel 1 pushes the sealing sleeve 3 to move relative to the center joint 2, the sealing sleeve 3 can drive the first connecting ring 4 to slide on the pressure bearing pipe 5 in one direction from the top end to the bottom end, the sealing ring 6 is sleeved on the outer side of the bottom end of the sealing sleeve 3, the sealing ring 6 is used for abutting against the inner wall of the upper casing 21 to realize the plugging of the upper casing 21 when being set and sealed, in the embodiment of the application, the sealing ring 6 can be deformed under the pushing action of the pushing barrel 1 to abut against the inner wall of the upper casing 21, the sealing ring 6 is made of soluble rubber material and can be completely dissolved under certain temperature conditions, the pushing sleeve 8 is sleeved on the outer side of the pressure bearing pipe 5, the top end of the pushing sleeve 8 abuts against the bottom end of the sealing ring 6, when the sealing sleeve 3 slides along the pressure bearing pipe 5, the sealing ring 6 can be gradually deformed to abut against the inner wall of the casing string under the interaction of the pushing sleeve 8 and the sealing sleeve 3, thereby realizing the sealing between the hanging card type temporary plugging tool and the casing string, the sliding sleeve 16 is sleeved on the pressure bearing pipe 5 and is connected with the pressure bearing pipe 5 through the second connecting ring 17, the sliding sleeve 16 can drive the second connecting ring 17 to slide on the pressure bearing pipe 5 in one direction from the bottom end to the top end, the connecting rod assembly is arranged between the pushing sleeve 8 and the sliding sleeve 16, when the pushing sleeve 8 and the sliding sleeve 16 have relative close sliding movement on the pressure bearing pipe 5, the connecting rod assembly can be expanded in diameter and abut against the inner wall of the upper casing 21 or the inner wall of the coupling 22 outwardly to realize anchoring or hanging card sliding stop, the fixing sleeve 20 is threadedly connected with the bottom end of the pressure bearing pipe 5 and elastically abuts against the bottom end of the sliding sleeve 16.

[0049] The hanging card type temporary plugging tool provided by the application can realize the deformation of the sealing ring 6 under the interaction of the pushing sleeve 8 and the sealing sleeve 3 and the sealing of the inner wall of the upper casing 21 when the pushing barrel 1 pushes the sealing sleeve 3 to move downward, thereby ensuring the sealing performance of the sealing ring 6, the connecting rod assembly is arranged between the pushing sleeve 8 and the sliding sleeve 16 to be expanded in diameter, the connecting rod assembly can abut against the inner wall of the upper casing 21 after being rotated to anchor, when the hanging card type temporary plugging tool slides downward on the inner wall of the upper casing 21, the connecting rod assembly can continue to be expanded in diameter and abut against the inner wall of the coupling 22 when sliding to the convex space, and finally stops at the end of the lower casing 23 to realize the sliding stop positioning, the hanging card type temporary plugging tool provided by the embodiment of the application can effectively avoid the sliding and movement of the hanging card type temporary plugging tool after being set and sealed, solve the problem of setting and sealing failure, and facilitate the smooth implementation of the fracturing process.

[0050] As preferred, the hanging card type temporary plugging tool further comprises a supporting ring 7 sleeved outside the bottom end of the sealing sleeve 3 and abutting against the bottom end of the sealing ring 6, the supporting ring 7 is formed by a plurality of Z-shaped arc segments 71 overlapping with each other, and the supporting ring 7 can be radially expanded to support the sealing ring 6 after being pressed.

[0051] As shown in Figures 4-7 the supporting ring 7 comprises a plurality of Z-shaped arc segments 71, the plurality of Z-shaped arc segments 71 are sequentially overlapped at the head and tail to form the supporting ring 7, the supporting ring 7 is sleeved on the sealing sleeve 3, when the inner hole of the supporting ring 7 increases in diameter under the action of the sealing sleeve 3, the plurality of Z-shaped arc segments 71 move outward and expand, and during the moving outward and expanding, the plurality of Z-shaped arc segments 71 always remain at least partially overlapped without separation, and no gap is generated, so that the supporting ring 7 can always provide reliable support for the bottom end of the sealing ring 6 during the deformation and sealing of the sealing ring 6, so as to improve the sealing stability and reliability of the sealing ring 6. If a gap is generated between the Z-shaped arc segments 71 after moving outward and expanding, the sealing ring 6 will deform through the gap when subjected to the top end pressure, and then the pressure will be suddenly reduced, resulting in a loss of sealing.

[0052] As preferred, the outer side of the sealing sleeve 3 is sequentially provided with a first outer cylindrical surface, a second outer cylindrical surface, a first outer conical surface and a second outer conical surface from the top end to the bottom end, the outer diameter of the first outer cylindrical surface is smaller than the outer diameter of the second outer surface, a stepped surface is formed between the first outer cylindrical surface and the second outer cylindrical surface, the push cylinder 1 is connected to the first outer cylindrical surface and abuts against the stepped surface, thereby facilitating the push cylinder 1 to be driven downward at the stepped surface; the taper of the first outer conical surface is greater than the taper of the second outer conical surface, the sealing ring 6 and the supporting ring 7 are both sleeved on the second outer conical surface, when the push cylinder 1 pushes the sealing sleeve 3 downward, the supporting ring 7 and the sealing sleeve 3 slide relative to each other, the sealing ring 6 and the sealing sleeve 3 slide relative to each other, that is, the supporting ring 7 and the sealing ring 6 can both slide along the second outer conical surface towards the first outer conical surface, during the sliding, the sealing ring 6 is deformed by extrusion to seal, the inner hole of the supporting ring 7 expands in diameter to radially expand to synchronously support the bottom end of the sealing ring 6; the top end of the inner side of the sealing sleeve 3 is provided with a first inner conical surface, the first inner conical surface is in contact with the center joint 2 for installation, positioning and guiding.

[0053] As shown in Figure 1, the first inner conical surface is matched and installed with the third outer conical surface on the center joint 2, after the hanging and clamping type temporary plugging tool is lowered into the sealing position in the casing string, the pressure bearing thread can be sheared under the pushing force of the pushing barrel 1, so that the center joint 2 and the pressure bearing pipe 5 are disconnected, at this time, the first inner conical surface is used to bear the pressure ball 24 for sealing, so that the pressure ball 24 can be stably sealed in the sealing sleeve 3 to block the inner hole of the pressure bearing pipe 5. Further, the bottom end of the center joint 2 is also provided with a fourth outer conical surface, which is used to be matched and installed with the second inner conical surface at the top end of the pressure bearing pipe 5, so as to facilitate the connection positioning and guiding between the pressure bearing pipe 5 and the center joint 2. It should be noted that the top end outer wall of the pressure bearing pipe 5 is provided with a pressure bearing thread, and the outer wall of the bottom end of the center joint 2 is provided with an external thread, and the pressure bearing pipe 5 and the center joint 2 are threadedly connected to be initially connected and fixed.

[0054] As preferred, the inner wall and the outer wall of the first connecting ring 4 are respectively provided with a first sawtooth-shaped inner thread and a first sawtooth-shaped outer thread, the inner wall and the outer wall of the second connecting ring 17 are respectively provided with a second sawtooth-shaped inner thread and a second sawtooth-shaped outer thread, the bottom end inner wall of the sealing sleeve 3 is provided with a third sawtooth-shaped inner thread, the inner wall of the sliding sleeve 16 is provided with a fourth sawtooth-shaped inner thread, and the pressure bearing pipe 5 is provided with a third sawtooth-shaped outer thread and a fourth sawtooth-shaped outer thread. The first sawtooth-shaped inner thread and the first sawtooth-shaped outer thread are matched and connected with the third sawtooth-shaped outer thread and the third sawtooth-shaped inner thread respectively, so that the sealing sleeve 3 can slide in one direction along the pressure bearing pipe 5 from the top end to the bottom end. The second sawtooth-shaped inner thread and the second sawtooth-shaped outer thread are matched and connected with the fourth sawtooth-shaped outer thread and the fourth sawtooth-shaped inner thread respectively, so that the sliding sleeve 16 can slide in one direction along the pressure bearing pipe 5 from the bottom end to the top end.

[0055] As shown in Figure 1 , the functions of the first connecting ring 4 and the second connecting ring 17 are to prevent the reverse movement of the pushing sleeve 8 and the sliding sleeve 16 after the first connecting ring 4 and the second connecting ring 17 slide on the pressure bearing pipe 5, according to the reverse prevention function of the sawtooth-shaped thread, so as to ensure that the connecting rod assembly cannot reverse rotation after the diameter is expanded, and to ensure that the connecting rod assembly can reliably abut against the inner wall of the upper casing 21 and the inner wall of the coupling 22.

[0056] As preferred, the first connecting ring 4 and the second connecting ring 17 are both C-shaped rings with openings, the pitch of the first sawtooth-shaped outer thread is greater than the pitch of the first sawtooth-shaped inner thread, and the pitch of the second sawtooth-shaped outer thread is greater than the pitch of the second sawtooth-shaped inner thread.

[0057] It can be understood that the C-shaped ring with the opening is beneficial to be opened after being stressed. When the sealing sleeve 3 moves along the pressure-bearing pipe 5 under the action of the push cylinder 1, the sealing sleeve 3 drives the first connecting ring 4 to move on the pressure-bearing pipe 5. Due to the arrangement of the C-shaped ring, the diameter of the C-shaped ring can change continuously during the movement. At the same time, the pitch of the first sawtooth-shaped external thread is greater than the pitch of the first sawtooth-shaped internal thread, which is beneficial to the movement driving and the movement after the movement without reverse movement, and the self-locking performance is good. Similarly, the second connecting ring 17 has a force towards the push sleeve 8 under the action of the elastic member 18. The pitch of the second sawtooth-shaped external thread is greater than the pitch of the second sawtooth-shaped internal thread, so that the sliding sleeve 16 can smoothly move towards the direction of the push sleeve 8 and will not move reversely after the movement, thereby realizing self-locking.

[0058] As preferred, the top end of the push sleeve 8 is internally provided with a second inner taper surface, the second inner taper surface is consistent with the taper of the second outer taper surface of the sealing sleeve 3, and the second outer taper surface can be slidably connected along the second inner taper surface and abut against the end of the second inner taper surface.

[0059] As shown in Figure 1 and Figure 2 , the top end of the push sleeve 8 forms a tapered hole with the second inner taper surface. In the initial state, the sealing ring 6 and the supporting ring 7 are both sleeved on the bottom end edge of the second outer taper surface and abut against the top end of the push sleeve 8. After being subjected to the setting force of the push cylinder 1, the sealing sleeve 3 moves downward and gradually inserts into the tapered hole of the push sleeve 8. At this time, the relative movement between the push sleeve 8 and the sealing sleeve 3 causes the sealing ring 6 to be deformed and gradually abut against the inner wall of the upper sleeve 21, until the bottom end of the sealing sleeve 3 abuts against the bottom end step surface of the tapered hole, as shown in Figure 2 If the sealing sleeve 3 is continuously pushed, the push sleeve 8 will move synchronously under the action of the sealing sleeve 3 and cause the connecting rod assembly to rotate until the connecting rod assembly abuts against the inner wall of the upper sleeve 21, and the push sleeve 8 no longer moves downward. Under the action of the push sleeve 8, the sealing ring 6 moves and deforms to the first outer taper surface of the sealing sleeve 3, and has the maximum deformation sealing performance.

[0060] As preferred, the connecting rod assembly includes a first connecting rod 11 and a second connecting rod 13. One end of the first connecting rod 11 is rotationally connected with the push sleeve 8, the other end is rotationally connected with the second connecting rod 13, and the end of the second connecting rod 13 away from the first connecting rod 11 is rotationally connected with the sliding sleeve 16. Pins (including the first pin 10 and the second pin 14) are arranged between the first connecting rod 11 and the push sleeve 8, between the first connecting rod 11 and the second connecting rod 13, and between the second connecting rod 13 and the sliding sleeve 16, respectively, to initially position.

[0061] As shown in Figure 1As shown, the first connecting rod 11 is rotationally connected with the push sleeve 8 through the first cylindrical pin 9, and the relative position between the two in the initial state is locked through the first pin 10; the first connecting rod 11 and the second connecting rod 13 are rotationally connected through the second cylindrical pin 12; the second connecting rod 13 and the sliding sleeve 16 are rotationally connected through the third cylindrical pin 15, and the relative position between the two in the initial state is locked through the second pin 14. The shearing force of the first pin 10 and the second pin 14 can ensure that the first connecting rod 11 and the second connecting rod 13 cannot rotate within a certain range of influence, and the hanging and clamping type temporary plugging tool will not be prematurely set during the process of being lowered into the well. When the pushing force of the push cylinder 1 is greater than the shearing force of the first pin 10 and the second pin 14, the first pin 10 and the second pin 14 are sheared, and then the first connecting rod 11 and the second connecting rod 13 rotate relative to each other.

[0062] In some embodiments, the bottom end of the push sleeve 8 is circumferentially provided with a plurality of first installation grooves, and the first connecting rod 11 is rotationally connected in the first installation groove; the top end of the sliding sleeve 16 is circumferentially provided with a plurality of second installation grooves, and the second connecting rod 13 is rotationally connected in the second installation groove. The outer circumferential surface of the slot of the first installation groove and the second installation groove is a beveled structure to facilitate the rotation of the first connecting rod 11 and the second connecting rod 13. The first pin 10 and the second pin 14 threadedly connect the first connecting rod 11 and the second connecting rod 13 in the first installation groove and the second installation groove. Preferably, the connecting rod assembly is provided with 4-8 groups, preferably eight groups, and the eight groups of connecting rod assemblies are uniformly distributed along the axis of the pressure-bearing pipe 5 to provide a circumferentially uniform force.

[0063] As a preferred, the bottom end face of the sliding sleeve 16 is circumferentially provided with a plurality of installation holes, and each installation hole is provided with an elastic member 18, and the two ends of the elastic member 18 are respectively abutted to the hole bottom of the installation hole and the top end face of the fixing sleeve 20.

[0064] As shown, Figure 1 In this embodiment, the installation hole is a cylindrical hole, which is uniformly arranged around the axis of the sliding sleeve 16. The outer wall of the sliding sleeve 16 corresponding to the installation hole is provided with a stepped outer cylindrical surface. The elastic member 18 is preferably a cylindrical helical compression spring. Generally, 4-12 elastic members 18 are provided. In this embodiment, eight elastic members 18 are provided. The two ends of the elastic member 18 are respectively abutted to the hole bottom of the installation hole and the fixing sleeve 20, so as to realize the elastic abutment between the fixing sleeve 20 and the sliding sleeve 16.

[0065] As a preferred, the top end of the fixing sleeve 20 is provided with an expansion hole, and the sliding sleeve 16 is inserted into the expansion hole. The axial depth of the expansion hole is greater than the elastic sliding distance of the sliding sleeve 16.

[0066] As shown, Figure 1The bottom end of the sliding sleeve 16 is inserted into the counterbore of the fixing sleeve 20 and abuts against the step surface of the counterbore to limit the movement, and the sliding sleeve 16 is always located in the counterbore during the movement, that is, the axial depth of the counterbore is greater than the rebound length of the elastic member 18, when the hanging and clamping type temporary plugging tool is slid downward into the convex space, the elastic member 18 drives the sliding sleeve 16 to slide after elastic elongation and makes the second connecting rod 13 rotate and expand in diameter for the second time, at this time, the bottom end of the sliding sleeve 16 is always located in the counterbore, and it can be understood that the counterbore plays a role of sliding limiting and guiding the sliding sleeve 16. In order to improve the connecting strength of the fixing sleeve 20, the third pin 19 is provided between the fixing sleeve 20 and the pressure bearing pipe 5 to prevent the fixing sleeve 20 from loosening. The outer peripheral wall of the bottom end of the fixing sleeve 20 is provided with a guide inclined surface, which is beneficial to the guiding effect of the hanging and clamping type temporary plugging tool when the hanging and clamping type temporary plugging tool is lowered into the casing string. The center hole of the fixing sleeve 20 is provided with a step surface, and the pressure bearing pipe 5 can be limited by abutting against the step surface after being threadedly connected with the fixing sleeve 20, so as to avoid damage caused by excessive connection.

[0067] The hanging and clamping type temporary plugging tool provided by the embodiment of the present application realizes the segmented closure or plugging of the wellbore by setting and sealing, and is used to realize multi-stage segmented fracturing.

[0068] The push cylinder 1 and the center joint 2 are matched tools for setting and sealing of the hanging and clamping type temporary plugging tool, are made of alloy steel and can be repeatedly used. The elastic member 18 is usually made of spring steel or the like to ensure a certain elasticity and rigidity. The sealing ring 6 is made of soluble rubber material, and the sealing sleeve 3, the first connecting ring 4, the pressure bearing pipe 5, the supporting ring 7 (including the Z-shaped arc segment 71), the push sleeve 8, the connecting rod assembly (including the first cylindrical pin 9, the first pin 10, the first connecting rod 11, the second cylindrical pin 12, the second connecting rod 13, the second pin 14 and the third cylindrical pin 15), the sliding sleeve 16, the second connecting ring 17, the third pin 19, the fixing sleeve 20 and the pressure ball 24 are all made of soluble metal material, such as soluble aluminum alloy and soluble magnesium alloy, so that the hanging and clamping type temporary plugging tool can be dissolved in the liquid with a certain temperature and salinity at the well bottom after the casing temporary plugging and the segmented fracturing construction (usually only 8-24 hours of effective plugging and working time of the temporary plugging tool is needed) is completed, and the setting and sealing and plugging are released.

[0069] The embodiment of the present application also provides a hanging and clamping type temporary plugging method, which is used for anchoring the hanging and clamping type temporary plugging tool in the casing string and achieving the sliding positioning after setting and sealing by clamping at the collar 22 after sliding down, to avoid setting and sealing failure.

[0070] In combination Figures 1-3 The hanging and clamping type temporary plugging method provided by the embodiment of the present application includes the following steps:

[0071] S1, the hanging card type temporary plugging tool is lowered into the casing string by the push cylinder 1 and the center joint 2 and located in the upper casing 21 above the convex space; specifically, the hanging card type temporary plugging tool is assembled, the push cylinder 1 is matched with the first outer circular surface of the sealing sleeve 3 and in contact with the stepped surface between the first outer circular surface and the second outer circular surface, the third outer tapered surface and the fourth outer tapered surface of the center joint 2 are matched with the first inner tapered surface and the second inner tapered surface of the front end of the pressure-bearing pipe 5 of the sealing sleeve 3 and the pressure-bearing pipe 5 respectively, and the center joint 2 is in place with the pressure-bearing threaded connection of the pressure-bearing pipe 5. The hanging card type temporary plugging tool is lowered into the casing string by the push cylinder 1 and the center joint 2 and located above the coupling 22 near the planned fracturing position.

[0072] S2, after reaching the specified position, the center joint 2 is kept stationary and the push cylinder 1 is continuously pushed downward, under the action of the pushing force of the downhole tool, the sealing sleeve 3 drives the first connecting ring 4 to slide downward along the pressure-bearing pipe 5, at this time the first pin 10 and the second pin 14 between the connecting rod assembly and the push sleeve 8 and the sliding sleeve 16 are in a locked state, i.e. not cut off; the sealing ring 6 is gradually deformed to abut against the inner wall of the upper casing 21 under the interaction of the push sleeve 8 and the sealing sleeve 3, the support ring 7 moves and expands on the second outer tapered surface of the sealing sleeve 3, and the second outer tapered surface of the sealing sleeve 3 is gradually inserted into the tapered hole of the push sleeve 8.

[0073] S3, the push cylinder 1 is continuously pushed downward, when the pushing force reaches a certain value, the first pin 10 and the second pin 14 are cut off, the connecting rod assembly between the push sleeve 8 and the sliding sleeve 16 is rotated and expanded in diameter outwardly once and abuts against the inner wall of the upper casing 21 and cannot continue to rotate, the sealing ring 6 moves to stop ascending between the first outer tapered surface and the second outer tapered surface and fills the annular gap between the sealing sleeve 3 and the upper casing 21 to achieve sealing, at this time the elastic member 18 is still in a compressed state; when the push cylinder 1 continues to push, the pressure-bearing threaded connection is cut off, the pressure-bearing pipe 5 is separated from the center joint 2, the push cylinder 1 is separated from the sealing sleeve 3, i.e. the downhole tool is separated from the hanging card type temporary plugging tool.

[0074] S4, the pressure ball 24 is dropped, after the pressure ball 24 contacts the sealing sleeve 3, the hanging card type temporary plugging tool achieves casing string sealing;

[0075] In the fracturing process, when the pressure at the upper end of the whole hanging card type temporary plugging tool is greater than the pressure at the lower end, the hanging card type temporary plugging tool slides downward due to no positioning, until the sliding link assembly is separated from the upper sleeve 21, the sliding link assembly is secondarily rotated and expanded in diameter to abut against the inner wall of the coupling 22 under the elastic abutting action of the fixed sleeve 20 and the sliding sleeve 16, and the hanging card type temporary plugging tool stops sliding downward when sliding to the end of the lower sleeve 23, so as to realize setting and positioning. It can be understood that when the top end of the sliding link assembly is separated from the bottom end of the upper sleeve 21 and enters the convex space, the sliding link assembly has an upward force under the elastic force of the elastic member 18 after the limitation force disappears, and the sliding sleeve 16 and the second connecting ring 17 push the second link 13 upward to rotate, when the first link 11 and the second link 13 are linked and rotated to abut against the inner wall of the convex space (i.e. the inner wall of the coupling 22), the second link 13 has a reverse rotating trend after being contacted by the top end of the lower sleeve 23, and since the sliding sleeve 16, the second connecting ring 17 and the pressure-bearing pipe 5 are connected by the zigzag thread, the position of the sliding sleeve 16 is locked and cannot slide reversely, so the sliding link assembly cannot rotate reversely, and the hanging card type temporary plugging tool does not slide downward any more, so as to achieve the effect of hanging card setting and positioning.

[0076] The hanging card type temporary plugging method provided by the application realizes that the hanging card type temporary plugging tool is finally clamped to the inner wall of the convex space through the first and second rotating and expanding of the sliding link assembly, the sliding link assembly is prevented from sliding under the elastic abutting action of the sliding sleeve 16 and the fixed sleeve 20 by using the convex space structure of the sleeve string, the phenomenon of setting and positioning and then sliding and moving is avoided, the problem of setting and positioning failure is effectively solved, and the fracturing process is smoothly implemented.

[0077] The hanging card type temporary plugging method, the hanging card type temporary plugging tool sequentially passes through the processes of lowering, loading deformation, releasing, ball throwing and hanging card, and then effectively sets and positions and temporarily plugs the sleeve string, after the fracturing construction, the hanging card type temporary plugging tool can be dissolved in the liquid at a certain temperature and salinity at the well bottom to release the setting and plugging, that is, the hanging card type temporary plugging method further includes the step of dissolving and releasing after the hanging card setting and positioning of the hanging card type temporary plugging tool, and realizes the closed loop of the life cycle of the hanging card type temporary plugging tool.

[0078] Obviously, the above embodiments of the application are only examples for clearly illustrating the application, and are not intended to limit the implementation modes of the application. Those skilled in the art can make various obvious changes, re-adjustments and replacements without departing from the protection scope of the application. It is unnecessary and impossible to enumerate all the implementation modes. Any modification, equivalent replacement and improvement made within the spirit and principle of the application shall be included in the protection scope of the claims of the application.

Claims

1. A hanger-type temporary plugging tool for internal plugging of a casing string; characterized in that, The hanging card type temporary plugging tool comprises: a sealing sleeve (3) connected with a push cylinder (1) at the top end and a center joint (2) at the inner side; a pressure-bearing pipe (5) provided with a pressure-bearing thread at the top end and connected with the center joint (2) through the thread, and connected with the inner wall of the sealing sleeve (3) through a first connecting ring (4) at the top end; when the push cylinder (1) pushes the sealing sleeve (3) to move relative to the center joint (2), the sealing sleeve (3) can drive the first connecting ring (4) to slide on the pressure-bearing pipe (5) from the top end to the bottom end in one direction; a sealing ring (6) sleeved on the bottom end of the sealing sleeve (3); a push sleeve (8) sleeved on the outer side of the pressure-bearing pipe (5), and abutting against the bottom end of the sealing ring (6); when the sealing sleeve (3) slides along the pressure-bearing pipe (5), the sealing ring (6) can be gradually deformed to abut against the inner wall of the casing string under the interaction of the push sleeve (8) and the sealing sleeve (3); a sliding sleeve (16) sleeved on the pressure-bearing pipe (5) and connected with the pressure-bearing pipe (5) through a second connecting ring (17), and capable of driving the second connecting ring (17) to slide on the pressure-bearing pipe (5) from the bottom end to the top end in one direction; a connecting rod assembly arranged between the push sleeve (8) and the sliding sleeve (16), and capable of rotating outward to expand the diameter and abut against the inner wall of the casing string to anchor or hang when the push sleeve (8) and the sliding sleeve (16) have a relatively close sliding movement on the pressure-bearing pipe (5); a fixing sleeve (20) threadedly connected to the bottom end of the pressure-bearing pipe (5) and elastically abutting against the bottom end of the sliding sleeve (16); a supporting ring (7) sleeved on the bottom end of the sealing sleeve (3) and abutting against the bottom end of the sealing ring (6), and formed by a plurality of Z-shaped arc segments (71) overlapping with each other, and capable of expanding radially to support the sealing ring (6) under pressure.

2. The hanger-type bridging tool of claim 1, wherein, The outer side of the sealing sleeve (3) is sequentially provided with a first outer circular face, a second outer circular face, a first outer tapered face and a second outer tapered face from the top end to the bottom end, the outer diameter of the first outer circular face is smaller than that of the second outer circular face, a stepped face is formed between the first outer circular face and the second outer circular face, the push cylinder (1) is connected to the first outer circular face and abuts against the stepped face, the taper of the first outer tapered face is larger than that of the second outer tapered face, the sealing ring (6) and the supporting ring (7) are both sleeved on the second outer tapered face, the second outer tapered face causes the supporting ring (7) to expand radially when the supporting ring (7) slides relative to the sealing sleeve (3), and the top end of the inner side of the sealing sleeve (3) is provided with a first inner tapered face, and the first inner tapered face is in contact with the center joint (2).

3. The hanger-type bridging tool of claim 1, wherein, The inner wall and the outer wall of the first connecting ring (4) are respectively provided with a first sawtooth inner thread and a first sawtooth outer thread, the inner wall and the outer wall of the second connecting ring (17) are respectively provided with a second sawtooth inner thread and a second sawtooth outer thread, the bottom end inner wall of the sealing sleeve (3) is provided with a third sawtooth inner thread, the inner wall of the sliding sleeve (16) is provided with a fourth sawtooth inner thread, the pressure-bearing pipe (5) is provided with a third sawtooth outer thread and a fourth sawtooth outer thread, the first sawtooth inner thread and the first sawtooth outer thread are respectively matched with the third sawtooth outer thread and the third sawtooth inner thread, so that the sealing sleeve (3) can slide in one direction along the pressure-bearing pipe (5) from the top end to the bottom end, and the second sawtooth inner thread and the second sawtooth outer thread are respectively matched with the fourth sawtooth outer thread and the fourth sawtooth inner thread, so that the sliding sleeve (16) can slide in one direction along the pressure-bearing pipe (5) from the bottom end to the top end.

4. The hanging caliper bridge plug of claim 3, wherein, The first connecting ring (4) and the second connecting ring (17) are both C-shaped rings with openings, the pitch of the first sawtooth outer thread is greater than the pitch of the first sawtooth inner thread, and the pitch of the second sawtooth outer thread is greater than the pitch of the second sawtooth inner thread.

5. The hanger-type bridging tool of claim 1, wherein, The top end of the push sleeve (8) is internally provided with a second inner taper surface, the second inner taper surface is consistent in taper with a second outer taper surface of the sealing sleeve (3), and the second outer taper surface can be slidably connected to the second inner taper surface and abut against an end of the second inner taper surface.

6. The hanger-type bridging tool of claim 1, wherein, The connecting rod assembly includes a first connecting rod (11) and a second connecting rod (13), one end of the first connecting rod (11) is rotationally connected to the push sleeve (8), the other end is rotationally connected to the second connecting rod (13), one end of the second connecting rod (13) away from the first connecting rod (11) is rotationally connected to the sliding sleeve (16), and a pin is arranged between the first connecting rod (11) and the push sleeve (8) and between the second connecting rod (13) and the sliding sleeve (16) to initially position.

7. The hanger-type bridging tool of claim 1, wherein, A plurality of mounting holes are circumferentially arranged on the bottom end face of the sliding sleeve (16), and an elastic member (18) is arranged in each mounting hole, and two ends of the elastic member (18) are respectively abutted against the hole bottom of the mounting hole and the fixing sleeve (20).

8. The hanger-type bridging tool of claim 1, wherein, The top end of the fixing sleeve (20) is provided with an enlarged hole, the sliding sleeve (16) is inserted into the enlarged hole, and the axial depth of the enlarged hole is greater than the elastic sliding distance of the sliding sleeve (16).

9. The hanger-type bridging tool of claim 1, wherein, The sealing sleeve (3), the first connecting ring (4), the pressure-bearing pipe (5), the support ring (7), the push sleeve (8), the sliding sleeve (16), the connecting rod assembly, and the fixing sleeve (20) are all made of a soluble metal material, the sealing ring (6) is made of a soluble rubber material, and the hanging and clamping type temporary plugging tool can be dissolved underground to release the setting.

10. A method of hanging-off by means of a temporary bridge plug, characterized in that, The hanging and clamping type temporary plugging method comprises the following steps: The hanging type temporary plugging tool is lowered into the casing string through the pushing cylinder (1) and the center joint (2) and located in the upper casing (21) above the convex space; The center joint (2) is kept stationary, and the pushing cylinder (1) is continuously pushed to move downward, the sealing sleeve (3) drives the first connecting ring (4) to slide downward along the pressure-bearing pipe (5) under the action of the pushing cylinder (1), and the sealing ring (6) is gradually deformed to abut against the inner wall of the upper casing (21) under the interaction of the pushing sleeve (8) and the sealing sleeve (3); The pushing cylinder (1) is continuously pushed to move downward, the connecting rod assembly between the pushing sleeve (8) and the sliding sleeve (16) is once expanded in diameter outward and abuts against the inner wall of the upper casing (21), the pressure-bearing pipe (5) is separated from the center joint (2), and the pushing cylinder (1) is separated from the sealing sleeve (3); The pressure ball (24) is put, and after the pressure ball (24) contacts the sealing sleeve (3), the hanging type temporary plugging tool realizes the sealing of the casing string; When the upper end pressure of the hanging type temporary plugging tool is greater than the lower end pressure, the hanging type temporary plugging tool slides downward until the connecting rod assembly is separated from the upper casing (21), the connecting rod assembly is twice expanded in diameter outward under the elastic abutting action of the fixed sleeve (20) and the sliding sleeve (16) to abut against the inner wall of the coupling (22), and the hanging type temporary plugging tool stops sliding downward when sliding to the end of the lower casing (23), realizing hanging and sliding stop.

11. The method of claim 10, wherein, The steps of releasing the hanging and setting of the hanging type temporary plugging tool also include: after the fracturing construction is completed, the hanging type temporary plugging tool is automatically dissolved under the specific temperature and salinity conditions in the well to release the hanging and setting, and restore the drift diameter of the casing string.

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