Inflatable pipe tool string for horizontal well bore reconstruction and application, well bore reconstruction method

Abstract

The application discloses an expansion pipe tool pipe column for horizontal well bore reconstruction and application and a well bore reconstruction method. The expansion pipe tool pipe column comprises an expansion pipe, an expansion cone, an expansion connecting rod and a delivery pipe column which are sequentially connected in the pipe body of the expansion pipe, at least one pipe outer sealing element which is located outside the pipe body of the expansion pipe, wherein the pipe outer sealing element comprises a first annular structure, a second annular structure and a mesh structure which is located between the first annular structure and the second annular structure, the outer diameter of the first annular structure is larger than the outer diameter of the second annular structure, the outer diameter of the mesh structure is smaller than the outer diameter of the second annular structure, and the pipe outer sealing element is in interference fit with a casing in the well bore after the expansion pipe is expanded, so that the expansion pipe is anchored in the well bore. The tool pipe column can improve the pressure bearing capacity in the repeated fracturing process of the horizontal well reconstruction, meet the repeated fracturing requirement, reduce the pressure of the connecting joint, avoid the tripping and damage of the connecting joint.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of horizontal well fracturing, in particular to an expanded pipe tool string for reconstructing a horizontal well bore and application and a well bore reconstruction method. BACKGROUND

[0002] With the wide application of multi-stage fracturing technology in low-grade oil and gas reservoirs, the number of horizontal wells continues to grow rapidly. A large number of fracturing reconstruction of horizontal wells effectively supports the exploration and development of unconventional resources. Due to the limitations of early reconstruction concepts and technologies, the initial fracturing of horizontal wells has large fracture spacing, low construction discharge, small fracturing scale, incomplete reconstruction, large production decline rate after fracturing, about 60% decline in the first year, fast energy depletion, and less than 10% of the primary recovery rate, which requires repeated fracturing.

[0003] The current horizontal well repeated fracturing technology research and test has widely carried out dynamic temporary plugging and double-sealing single-clamping process technology to realize repeated fracturing of well bore reconstruction. There are currently three directions of well bore reconstruction technology, namely expanded pipe patching, small casing well bore and chemical plugging reconstruction technology, which are still in the exploratory stage. Among them, the expanded pipe patching reconstructs the well bore to restore the integrity of the well bore, has the advantages of high mechanical plugging strength, small drift loss, etc., and can meet the demand of repeated fracturing of the original well of the subsequent bridge shooting. Compared with drilling a new well, this scheme has the advantages of low operation cost, high production efficiency and less well interference. SUMMARY

[0004] The present application found that when the expanded pipe patching reconstructs the well bore, there is a serious corrosion or even damage to the inner wall of the well bore for repeated fracturing of the old well. The expanded pipe is expanded after the wear of the outer seal of the expanded pipe during the running process, and the anchoring pressure effect in the casing is poor, which cannot meet the demand of subsequent repeated fracturing. In addition, during the repeated fracturing process, the reconstructed well section is subjected to high pressure and large displacement fracturing for a long time, which causes the connecting joint to bear a large pressure and be easily tripped and damaged.

[0005] In view of the above problems, the present application is proposed to provide an expanded pipe tool string for reconstructing a horizontal well bore and application and a well bore reconstruction method to overcome the above problems or at least partially solve the above problems.

[0006] The embodiment of the present application provides an expanded pipe tool string for reconstructing a horizontal well bore, which comprises: an expanded pipe; an expanded cone, an expanded connecting rod and a delivery string connected in sequence in the pipe body of the expanded pipe; and at least one outer seal located outside the pipe body of the expanded pipe.

[0007] The outer pipe seal comprises a first annular structure, a second annular structure and a mesh structure between the two, the outer diameter of the first annular structure is larger than the outer diameter of the second annular structure; the outer diameter of the mesh structure is smaller than the outer diameter of the second annular structure;

[0008] After the expansion of the expansion pipe is completed, the outer pipe seal is in interference fit with the casing in the wellbore, so that the expansion pipe is anchored in the wellbore.

[0009] In some optional embodiments, the mesh of the mesh structure is quadrilateral, and the inclination angle of the warp and weft in the mesh structure is 30°-60°;

[0010] Or the mesh of the mesh structure is hexagonal;

[0011] Or the mesh of the mesh structure comprises tangent circular mesh and mesh formed by the intersection of tangent circles.

[0012] In some optional embodiments, the difference between the outer diameter of the first annular structure and the outer diameter of the second annular structure is determined according to the friction loss generated by the length of the wellbore.

[0013] In some optional embodiments, the expansion pipe comprises a plurality of expansion pipe segments, the bottom end of the lowest expansion pipe segment is provided with a bottom plug, and the top end of the uppermost expansion pipe segment is provided with a sealing cap.

[0014] In some optional embodiments, the expansion pipe segments are connected through connecting threaded joints; the connecting threaded joint comprises:

[0015] Two connecting pipe heads of two adjacent expansion pipe segments; one of the connecting pipe heads of the expansion pipe segment is provided with an internal thread; the other connecting pipe head of the expansion pipe segment is provided with an internal thread;

[0016] An elastic fixed sleeve between the external thread and the internal thread;

[0017] A metal sheath arranged outside the two connecting pipe heads.

[0018] In some optional embodiments, the outer diameter of the metal sheath is not greater than the outer diameter of the second annular structure.

[0019] In some optional embodiments, the elastic fixed sleeve is a rubber fixed sleeve, which is formed by winding and filling a flexible rubber material with a diameter of not greater than 2 mm between the internal thread and the external thread of the connecting threaded joint of the expansion pipe.

[0020] In some optional embodiments, the delivery pipe string comprises a plurality of oil pipes and a flexible universal joint;

[0021] One end of the oil pipe is connected with the expansion connecting rod;

[0022] The flexible universal joint is arranged between two adjacent oil pipes.

[0023] In some alternative embodiments, the flexible universal joint comprises a first joint head, a second joint head and a joint head connecting member.

[0024] The first joint head is provided with a boss, and the boss is provided with a boss shaft hole.

[0025] The second joint head is provided with a matching groove, and the groove wall of the groove is provided with a groove shaft hole.

[0026] The joint head connecting member penetrates the boss shaft hole and the groove shaft hole, so that the first joint head and the second joint head can rotate relative to each other within a preset angle range.

[0027] After the first joint head and the second joint head are installed through the joint head connecting member, a gap is formed between the boss side outer side and the groove inner side.

[0028] In some alternative embodiments, the above-mentioned expandable pipe tool pipe string further comprises:

[0029] At least one casing inner centralizer arranged on the oil pipe in the delivery pipe string to center the position of the oil pipe in the casing; and / or

[0030] At least one expandable pipe inner centralizer arranged on the oil pipe in the delivery pipe string to center the position of the oil pipe in the expandable pipe.

[0031] In some alternative embodiments, the centralizer comprises:

[0032] A centralizer body and a plurality of spiral protrusions arranged outside the centralizer body.

[0033] The centralizer body has a middle through hole to be nested on the oil pipe; the spiral protrusions are circumferentially and uniformly arranged, and the spiral angle of the spiral protrusions is 15°-45°.

[0034] The embodiment of the present application provides application of the above-mentioned expandable pipe tool pipe string for horizontal well bore reconstruction in a horizontal well bore reconstruction and repeated fracturing process.

[0035] The embodiment of the present application provides a horizontal well bore reconstruction method, which is realized by using the above-mentioned expandable pipe tool pipe string for horizontal well bore reconstruction, and the method comprises:

[0036] Lowering the expandable pipe tool pipe string for horizontal well bore reconstruction into a horizontal well bore;

[0037] The expansion cone is extracted from the expansion pipe, the expansion pipe is expanded during the extraction, and the external pipe seal outside the expansion pipe is in contact with the wellbore to anchor the expansion pipe in the wellbore.

[0038] The beneficial effects of the above technical solutions provided by the embodiments of the present application at least include:

[0039] The external pipe seal of the expansion pipe tool pipe string provided by the embodiments of the present application solves the problem of weak pressure bearing capacity caused by the wear of the external pipe seal in the repeated fracturing process of the horizontal well reconstruction. The external pipe seal adopts a first annular structure, a second annular structure, and a mesh structure located between the two annular structures. The outer diameter of the first annular structure is larger than that of the second annular structure to solve the problem of friction loss during running. After running into the wellbore, the outer diameters of the first annular structure and the second annular structure are basically the same. After the expansion pipe is expanded, the first annular structure and the second annular structure can be well anchored in the wellbore to suspend the expansion pipe, thereby improving the pressure bearing capacity of the expansion pipe tool pipe string in the repeated fracturing process, meeting the repeated fracturing requirement, reducing the pressure on the connection joint, and avoiding its tripping and damage.

[0040] The connection thread joint of different pipe sections of the expansion pipe of the above expansion pipe tool pipe string guarantees its sealing performance during fracturing deformation through the elastic solid sleeve between the inner and outer threads. The metal sheath protects the connection thread joint to further avoid tripping and damage of the thread joint during expansion, improve the pressure bearing capacity of the thread joint, and guarantee its sealing effect.

[0041] The above expansion pipe tool pipe string adopts a head-type universal joint connection for the running pipe string, and a centralizer is used to centralize the running pipe string, so as to guarantee that the running pipe string can be located in the center of the wellbore and improve the stress condition of the running pipe string in the complex wellbore space, adapt to the bending radius of the wellbore, and enable the running pipe string to smoothly enter and exit the wellbore without being stuck due to excessive friction between the wellbore and the wellbore caused by the bending of the wellbore.

[0042] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

[0043] The technical solutions of the present application will be further described in detail below with reference to the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0044] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate embodiments of the present application, and are used to explain the present application, and do not constitute a limitation on the present application. In the drawings:

[0045] Figure 1 Structure diagram of the pipe string of the expansion pipe tool for reconstructing the wellbore of the horizontal well in the embodiment of the present application;

[0046] Figure 2 Structure diagram of the external pipe seal in the embodiment of the present application;

[0047] Figure 3 Structure diagram of the connection thread joint in the embodiment of the present application;

[0048] Figure 4 Structure diagram of the flexible universal joint in the embodiment of the present application;

[0049] Figure 5 Front view of the centralizer in the embodiment of the present application;

[0050] Figure 6 Left view of the centralizer in the embodiment of the present application. Figure 5

[0051] Explanation of reference signs:

[0052] 1 - bottom plug, 2 - expansion cone, 3 - expansion connecting rod, 4 - external pipe seal, 5 - internal centralizer of the expansion pipe, 6 - expansion pipe, 7 - connection thread joint, 8 - oil pipe, 9 - internal centralizer of the casing, 10 - flexible universal joint, 11 - delivery pipe string, 12 - casing, 13 - sealing cover;

[0053] 41 - first annular structure, 42 - second annular structure, 43 - mesh structure between the two;

[0054] 71 - internal thread, 72 - external thread, 73 - elastic fixed sleeve, 74 - metal sheath;

[0055] 101 - first joint head, 102 - second joint head, 103 - joint head connecting piece. DETAILED DESCRIPTION

[0056] Exemplary embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be accurately conveyed to those skilled in the art.

[0057] ​In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, 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 limiting the application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0058] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; 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 communication inside 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.

[0059] The existing expansion pipe generally uses high-strength expansion pipe material, and on this basis, for repeated fracturing of old wells, there are serious corrosion and even damage to the inner wall of the wellbore, the adaptability of the outer sealing element seriously affects the suspension force of the expansion pipe tool in the casing and the pressure bearing effect during subsequent repeated fracturing, and higher requirements are put forward for the structure of the outer sealing element. The present application is committed to researching and solving this technical problem, and through long-term research, it is found that the outer sealing element of the expansion pipe produces friction between the wellbore during running, resulting in wear, and the anchoring force between the outer sealing element of the expansion pipe and the casing becomes weaker after the expansion of the expansion pipe, resulting in insufficient suspension force and poor pressure bearing effect; the poor pressure bearing capacity leads to higher requirements for the pressure bearing of the connecting threaded joint during multiple fracturing.

[0060] In order to solve the above problems, the present application provides a kind of expansion pipe tool string for horizontal wellbore reconstruction, its structure refers to Figure 1 As shown in the figure, it includes: expansion pipe 6;Expansion cone 2, expansion connecting rod 3 and delivery pipe string 11 connected in turn in the pipe body of expansion pipe 6;At least one outer sealing element 4 located outside the pipe body of expansion pipe 6;

[0061] The structure of the outer sealing element 4 refers to Figure 2 As shown in the figure, it includes first annular structure 41, second annular structure 42 and mesh structure 43 between them, the outer diameter of first annular structure 41 is greater than the outer diameter of second annular structure 42;The outer diameter of mesh structure 43 is smaller than the outer diameter of second annular structure 42;

[0062] After the expansion of the expansion pipe 6, the pipe external seal 4 is in interference fit with the casing 12 in the wellbore, so that the expansion pipe 6 is anchored in the wellbore.

[0063] The expansion pipe tool pipe string solves the problem of weak pressure bearing capacity caused by the wear of the pipe external seal in the repeated fracturing process of the horizontal well reconstruction by the specially designed pipe external seal. The pipe external seal adopts a first annular structure, a second annular structure and a mesh structure between the two, wherein the outer diameter of the first annular structure is larger than that of the second annular structure, so as to solve the problem of friction loss in the running process, so that the outer diameters of the first annular structure and the second annular structure after the running wear are basically the same, and the expansion pipe can be well anchored in the wellbore after the expansion of the expansion pipe, thereby playing a role of suspending the expansion pipe, thereby improving the pressure bearing capacity of the expansion pipe tool pipe string in the repeated fracturing process, meeting the repeated fracturing requirement, reducing the pressure of the connecting joint, and avoiding the tripping and damage of the connecting joint.

[0064] Optionally, the mesh holes of the mesh structure 42 can be designed in different shapes according to the needs. Preferably, the mesh holes of the mesh structure 42 are quadrilaterals, and the inclination angles of the warp and weft in the mesh structure are 30°-60°; or the mesh holes of the mesh structure 42 are hexagons; or the mesh holes of the mesh structure 42 include tangent circular mesh holes and mesh holes formed by the intersection of tangent circles.

[0065] The warp and weft in the mesh structure and the mesh holes formed by the warp and weft ensure the sealing between the expansion pipe and the wellbore. Since the mesh structure is adopted, the warp and weft are in contact with the wellbore to achieve sealing after the expansion of the expansion pipe. Even if the wellbore has a through hole corresponding to the position of the mesh hole, the sealing can also be achieved by the warp and weft around the mesh hole. Therefore, this structure can not only adapt to the deformation in the expansion process, but also ensure the sealing effect.

[0066] Optionally, the difference between the outer diameter of the first annular structure 41 and the outer diameter of the second annular structure 42 is determined according to the friction loss caused by the length of the running wellbore. Since the expansion pipe tool pipe string will generate friction with the casing in the wellbore during the running process, which will cause the wear of the pipe external seal. In order to ensure the anchoring effect after the expansion, the friction condition during the running of the tool pipe string is studied, and the pipe external seal is designed in the form of two annular structures, wherein the outer diameter of one end of the annular structure is larger, which provides a friction allowance for the friction in the running process, so that the annular structure after the friction loss can still be well anchored with the wellbore, and the pressure bearing capacity of the expansion pipe after the expansion is sufficient.

[0067] Optionally, the expansion cone 2 and the expansion cone connecting rod 3 are connected and positioned by a wedge-shaped block, the expansion cone connecting rod 3 is provided with an annular groove or an arc-shaped groove, the expansion cone 2 is provided with a corresponding annular conical groove or an arc-shaped conical groove, and a conical connecting block is arranged in the groove; taking the annular groove as an example, the conical connecting block is placed in the annular groove, when the expansion cone connecting rod 3 is inserted into the through hole of the expansion cone 2, under the action of the wedge surface, the wedge-shaped connecting block retreats into the annular groove, after the expansion cone connecting rod 3 is moved to the position, the wedge-shaped connecting block pops out into the annular conical groove, and the expansion cone 2 and the expansion cone connecting rod 3 are clamped together.

[0068] The pipe string of the expansion pipe tool in the embodiment of the application adopts a special pipe external sealing element structure, two special pipe external sealing elements with different shapes, i.e., an annular structure at both ends of the expansion pipe and a mesh structure in the middle, are used to implement suspension and pipe external sealing of the expansion pipe. The annular structure adopts a variable interference amount and variable hardness design to reduce wear and tear during running in, and after the compensation, the sealing element is compressed due to the designed interference amount, and is mainly used to provide suspension force. The mesh structure sealing element adopts a 30-60° inclined mesh design, has better self-adaptability, and is mainly used to separate the pipe external space between the expansion pipe and the casing, reduce the external pressure acting area, and prevent crushing.

[0069] During the reconstruction of the horizontal well bore and the repeated fracturing process, the reconstructed well section needs to withstand high pressure and large displacement fracturing construction for multiple times and for a long time, and high requirements are put forward for the pressure bearing of the connecting threaded joint. Based on this, the connecting threaded joint is designed and improved by the inventors.

[0070] Since the connecting threaded joint is prone to deformation and unclamping during the expansion process, the sealing performance of the threaded connection part is poor, in order to ensure the sealing effect, a sealing filling material is added between the internal thread and the external thread, in order to protect the thread and reduce the deformation of the threaded part during the expansion process, a metal sealing structure is added outside the threaded joint to protect the threaded part and avoid damage to the threaded screw.

[0071] Optionally, the expansion pipe 6 includes a plurality of expansion pipe segments, the bottom end of the bottommost expansion pipe segment is provided with a bottom plug 1, and the top end of the uppermost expansion pipe segment is provided with a sealing cover 13. The bottom plug 1 is a fishable or drillable bottom plug.

[0072] Optionally, the expansion pipe segments are connected through the connecting threaded joint 7; the structure of the connecting threaded joint 7 is shown in the drawing and includes two connecting pipe heads of two adjacent expansion pipe segments; the connecting pipe head of one of the expansion pipe segments is provided with an internal thread 71; the connecting pipe head of the other expansion pipe segment is provided with an internal thread 72; an elastic fixed sleeve 73 is arranged between the external thread and the internal thread; and a metal sheath 74 is arranged outside the two connecting pipe heads. The internal thread and the external thread can be conical threads or ordinary cylindrical threads. Figure 3 The internal thread and the external thread can be conical threads or ordinary cylindrical threads.

[0073] Optionally, the elastic sleeve 73 is a rubber sleeve, which is a flexible rubber material with a diameter of not more than 2 mm, wound and filled between the internal thread 71 and the external thread 72 of the connecting threaded joint 7 of the expansion pipe 6. It can also be wound and filled between the metal sheath 74 and the expansion pipe.

[0074] Optionally, the outer diameter of the metal sheath 74 is not greater than the outer diameter of the second annular structure 42, and preferably, the outer diameter of the metal sheath 74 is equal to the outer diameter of the second annular structure 42.

[0075] The above expansion pipe tool pipe string, the connecting threaded joints of different pipe sections of the expansion pipe, the expansion threaded joint adopts a "metal + rubber" composite structure protective sleeve to protect the connecting thread from tripping during expansion. The rubber protective sleeve is clamped between the expansion pipe and the casing after being supplemented, filled and sealed, and a second seal is provided outside the joint in addition to the original thread seal. The connecting threaded joint ensures its sealing performance during fracturing deformation through the elastic sleeve between the internal and external threads, and the connecting threaded joint is protected by the metal sheath, further avoiding tripping and damage of the threaded joint during expansion, improving the pressure-bearing capacity of the threaded joint, and ensuring its sealing effect.

[0076] During the reconstruction of the horizontal wellbore, the expansion pipe tool pipe string is applied in the horizontal well. Due to the spatial complexity of the well trajectory, the pipe string is subjected to complex bending stress during running and operation, which affects the reliability of the tool pipe string and puts high requirements on the centralization and centering of the whole pipe string. Based on this, the present inventors improve the structure of the tool attention tubing string.

[0077] During the running and supplemental operation of the expansion pipe tool pipe string in the horizontal well, the pipe string is not easy to centralize in the horizontal section and the build-up section, and is subjected to complex stress. The centralizer and the flexible connecting rod are added at the specified position to ensure that the operation pipe string is as centralized as possible inside the expansion pipe and the casing, and the frictional resistance between the pipe string and the horizontal section and the expansion pipe and the casing is greatly reduced. The flexible connecting rod is designed and processed based on the principle of the ball tooth universal joint, has good flexibility and axial tensile performance, and is added at the build-up section position of the operation pipe string, which, in combination with the use of the centralizer, can relieve unnecessary contact between the build-up section pipe string and the well wall, and greatly reduce the frictional resistance between the pipe string and the build-up section and the casing.

[0078] Optionally, in the above expansion pipe tool pipe string, the pipe string includes multiple sections of oil pipes 8 and flexible universal joints 10; one end of the oil pipe 8 is connected with the expansion connecting rod 3; and the flexible universal joint 10 is arranged between adjacent two sections of oil pipes 8. The oil pipe 8 can be an external upset oil pipe.

[0079] Optionally, the structure of the flexible universal joint 10 is shown in Figure 4As shown, it comprises a first joint head 101, a second joint head 102 and a joint connecting piece 103; the first joint head 101 is provided with a boss, and the boss is provided with a boss shaft hole; the second joint head 102 is provided with a matching groove, and the groove wall is provided with a groove shaft hole; the joint connecting piece 103 penetrates the boss shaft hole and the groove shaft hole, so that the first joint head 101 and the second joint head 102 can rotate relative to each other within a preset angle range; after the first joint head 101 and the second joint head 102 are installed through the joint connecting piece 103, there is a gap between the boss side outer side and the groove inner side.

[0080] In some optional embodiments, the above-mentioned expandable pipe tool pipe string further comprises:

[0081] At least one casing centralizer 9 is arranged on the tubing 8 in the delivery pipe string to center the position of the tubing 8 in the casing 13. The casing centralizer 9 can be arranged as needed, and one is arranged at a certain distance on the tubing 8. The casing centralizer 9 has a ring structure and is nested on the tubing 8, and the outer side is arc-shaped to contact the inner side of the casing 12 to realize the function of centralizing the delivery pipe string.

[0082] In some optional embodiments, the above-mentioned expandable pipe tool pipe string further comprises:

[0083] At least one expandable pipe centralizer 5 is arranged on the tubing 8 in the delivery pipe string to center the position of the tubing 8 in the expandable pipe 6. The expandable pipe centralizer 5 can be arranged as needed, and one is arranged at a certain distance on the tubing 8. The expandable pipe centralizer 5 has a ring structure and is nested on the tubing 8, and the outer side is arc-shaped to contact the inner side of the expandable pipe 6 to realize the function of centralizing the delivery pipe string.

[0084] The structure of the casing centralizer 9 and the expandable pipe centralizer 5 is similar. The inner diameter and outer diameter of the casing centralizer can be designed according to the outer diameter of the tubing and the inner diameter of the casing. The inner diameter and outer diameter of the expandable pipe centralizer can be designed according to the outer diameter of the tubing and the inner diameter of the expandable pipe before expansion. The structure of the centralizer is shown in Figure 5 and Figure 6 As shown, wherein, Figure 5 is a front view, Figure 6 is a left view. The centralizer comprises a centralizer body 51 and a spiral protrusion 52 arranged outside the centralizer body 51; the spiral protrusions 52 are arranged uniformly in a circle, and the number of the spiral protrusions 52 can be designed as needed, for example, 3, 4 or 6, etc. The centralizer body has a through hole in the middle, so that the centralizer can be nested on the tubing 8. Optionally, the outer side of the spiral protrusion is an arc surface with a certain arc, which can reduce the friction with the casing 13 or the expandable pipe 6 during the expansion of the expandable pipe. Optionally, the spiral angle of the spiral protrusion is 15°-45°, and preferably 30°.

[0085] The expansion pipe tool pipe string, the delivery pipe string is connected by using a head type universal joint, and the delivery pipe string is righted by a centralizer, so that the delivery pipe string can be located in the center of the wellbore, and the stress condition of the delivery pipe string in the complex wellbore space is improved, the bending radius of the wellbore is adapted, and the delivery pipe string can smoothly enter and exit the wellbore, and the delivery pipe string will not be stuck due to excessive friction between the delivery pipe string and the wellbore caused by the bending of the wellbore.

[0086] Based on the same inventive concept, the application further provides an application of the expansion pipe tool pipe string for horizontal wellbore reconstruction in a repeated fracturing process of the horizontal wellbore reconstruction.

[0087] Based on the same inventive concept, the application further provides a horizontal wellbore reconstruction method, which is implemented by using the expansion pipe tool pipe string for horizontal wellbore reconstruction, and the method comprises the following steps of:

[0088] lowering the expansion pipe tool pipe string for horizontal wellbore reconstruction into a horizontal wellbore;

[0089] moving the expansion connecting rod and the expansion cone by the delivery pipe string, so that the expansion pipe is expanded in the process of extracting the expansion cone from the expansion pipe, and the external pipe sealing element outside the expansion pipe is in contact with the wellbore to anchor the expansion pipe in the wellbore.

[0090] The expansion pipe tool pipe string and the horizontal wellbore reconstruction method provided by the application can efficiently, safely and completely implement the horizontal wellbore reconstruction, form the horizontal well expansion pipe subsidy wellbore reconstruction technology, and meet the bridge shooting combined operation repeated fracturing construction. The technical problems in the fracturing process are solved by the design of the special thread connection joint, the special external pipe sealing element, the operation pipe string centralizer and the flexible connecting rod. The method forms the horizontal well expansion pipe subsidy wellbore reconstruction technology, and in actual application, the reconstructed well section can bear an internal pressure of 70 MPa, meets the bridge shooting combined operation process, meets the 10 m 3 / min displacement fracturing construction, and the single reconstruction length is not less than 100 m.

[0091] The φ108*7 specification expansion pipe tool pipe string is suitable for 5.5in casing continuous subsidy wellbore reconstruction of a horizontal well section, the reconstructed well section has a 105mm internal diameter, can bear a pressure of 70 MPa, meets the lowering into a horizontal section within 1500, the single continuous subsidy length can be more than 100 m, has been verified by field tests, meets the subsequent bridge shooting combined operation repeated fracturing needs, and can reliably bear a pressure.

[0092] It should be understood that the specific order or hierarchy of steps in the processes disclosed is an example. Based upon design preferences, it should be understood that the specific order or hierarchy of steps in the processes could be rearranged, or other steps added without departing from the scope of the disclosure. The accompanying method claims present elements of the various steps in a sample order, and as such claims should not necessarily be construed as depended on the particular order or hierarchy of the steps presented.

[0093] In the detailed description above, various features are grouped together in single embodiments for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting a necessity that the claimed subject matter requires more features than the claims do. Rather, inventive embodiments can lie in less than all features of a single disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate preferred embodiment. By way of general introduction, the following detailed description discloses various embodiments of the present application. The skilled person will recognize that the various embodiments can be further combined and arranged in various ways. Accordingly, the embodiments described herein are intended to embrace all such alterations, modifications and variations which fall within the scope of the appended claims. Additionally, where the disclosure or claims recite "a," "an," "the" or similar referents, this is to be interpreted to mean "one or more." Further, any use of the term "or" in the description or claims is to be interpreted as "non-exclusive or." In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the various embodiments. However, various embodiments can be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail since not to unnecessarily obscure aspects of the embodiments.

[0094] The above description includes one or more examples of the embodiments. Of course, not all possible combinations of components or methods described above will be described to not obscure the embodiments. However, one of ordinary skill in the art will recognize that further combinations and permutations of various embodiments are possible. Accordingly, the embodiments described herein are intended to embrace all such alterations, modifications and variations which fall within the scope of the appended claims. Additionally, where the disclosure or claims recite "a," "an," "the" or similar referents, this is to be interpreted to mean "one or more." Further, any use of the term "or" in the description or claims is to be interpreted as "non-exclusive or."

Claims

1. An expandable tubular tool string for horizontal wellbore reconstruction, characterized in that: include: expansion tube; An expansion cone, an expansion connecting rod and a delivery string are located in the expansion pipe body and are connected in sequence; at least one external seal located outside the expansion tube; The outer pipe seal comprises a first annular structure, a second annular structure and a mesh structure located therebetween. The outer diameter of the first annular structure is larger than the outer diameter of the second annular structure, so that the outer diameters of the first annular structure and the second annular structure are substantially the same after being worn in the wellbore. The outer diameter of the mesh structure is smaller than the outer diameter of the second annular structure. After the expansion tube is expanded, the outer seal of the tube is interference-fitted with the casing in the wellbore, so that the expansion tube is anchored in the wellbore; after the expansion tube is expanded, the warp and weft of the mesh structure are in contact with the wellbore to achieve sealing; The meshes of the mesh structure are quadrilaterals, and the inclination angles of the warps and latitudes in the mesh structure are 30° to 60°; or the meshes of the mesh structure are hexagonal; or the meshes of the mesh structure include tangent circular meshes and meshes formed by the intersection of tangent circles; The difference between the outer diameter of the first annular structure and the outer diameter of the second annular structure is determined according to the friction loss generated by the length of the lowering into the wellbore.

2. The expandable tubular tool string according to claim 1, wherein: The expansion pipe comprises a plurality of expansion pipe sections, the bottom end of the lowest expansion pipe section is provided with a bottom plug, and the top end of the highest expansion pipe section is provided with a sealing cover.

3. The expandable tubular tool string according to claim 2, wherein: The expansion pipe sections are connected by connecting threaded joints; the connecting threaded joints include: Two connecting pipe heads of two adjacent expansion pipe sections; one connecting pipe head of the expansion pipe section is provided with an internal thread; the other connecting pipe head of the expansion pipe section is provided with an internal thread; an elastic sleeve located between the external thread and the internal thread; A metal sheath is arranged outside the two connecting pipe heads.

4. The expandable tubular tool string according to claim 3, wherein: The outer diameter of the metal sheath is no greater than the outer diameter of the second annular structure.

5. The expandable tubular tool string according to claim 4, wherein: The elastic sleeve is a rubber sleeve, which is formed by winding and filling between the internal thread and the external thread of the connecting thread joint of the expansion pipe with a flexible rubber material no thicker than 2 mm.

6. The expandable tubular tool string according to claim 1, wherein: The delivery string includes multiple sections of oil pipe and a flexible universal joint; One end of the oil pipe is connected to the expansion connecting rod; The flexible universal joint is arranged between two adjacent sections of oil pipe.

7. The expandable tubular tool string according to claim 6, wherein: The flexible universal joint comprises: a first joint head, a second joint head and a joint head connecting piece; The first joint is provided with a boss, and the boss is provided with a boss shaft hole; The second joint is provided with a matching groove, and the groove wall of the groove is provided with a groove shaft hole; The joint connecting piece passes through the boss shaft hole and the groove shaft hole, so that the first joint and the second joint can rotate relative to each other within a preset angle range; After the first joint and the second joint are installed through the joint connector, a gap is formed between the outer side surface of the boss and the inner side surface of the groove.

8. The expandable tubular tool string according to any one of claims 1 to 7, characterized in that: Also includes: at least one in-casing centralizer disposed on the tubing in the delivery string to center the tubing within the casing; and / or At least one expandable tubing centralizer is provided on the tubing in the delivery string to center the tubing in the expandable tubing.

9. The expandable tubular tool string according to claim 6, wherein: The centralizer comprises: A centralizer body and a plurality of spiral protrusions disposed outside the centralizer body; The centralizer body has a middle through hole for being nested on the oil pipe; the spiral protrusions are evenly distributed around the circumference, and the spiral angle of the spiral protrusions is 15°-45°.

10. Use of the expandable tubular tool string for horizontal wellbore reconstruction according to any one of claims 1 to 9 in a horizontal wellbore reconstruction refracturing process.

11. A horizontal wellbore reconstruction method, characterized in that: The method is implemented using an expandable tubular tool string for horizontal wellbore reconstruction according to any one of claims 1 to 9, and comprises: Lowering the expansion tubing tool string for horizontal wellbore reconstruction into the horizontal wellbore; The expansion connecting rod and the expansion cone are driven to move by the delivery string, so that the expansion tube is expanded during the process of the expansion cone being withdrawn from the expansion tube, and the outer tube seal outside the expansion tube contacts the wellbore to anchor the expansion tube in the wellbore.

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