A sliding-rail type variable-diameter through-well device and a through-well method

Abstract

The application relates to the technical field of oil workover operation, and particularly discloses a sliding rail type variable-diameter running-in device and a running-in method. The sliding rail type variable-diameter running-in device comprises an upper joint, a driving member, a center body, a split claw, an expansion rib and a locking member, the upper joint is sleeved outside one end of the center body, the locking member is sleeved outside the other end of the center body, one end of the upper joint is used for connecting a downhole tool, the other end of the upper joint is radially spaced apart from the center body and is provided with the axially movable driving member between the center body, the split claw is sleeved outside the center body and is connected with the driving member, the driving member can drive the split claw to move axially, the expansion rib is sleeved outside the center body and is located between the split claw and the locking member, the expansion rib can move radially relative to the center body along with the axial movement of the split claw to change the outer diameter of the sliding rail type variable-diameter running-in device. The running-in device and the method for switching the outer diameter are simple and convenient, and the running-in operation of the multiple sizes of casings can be completed by lifting one operation pipe column.

Description

Technical Field

[0001] This invention relates to the field of oil well workover technology, and in particular to a sliding rail type variable diameter well cleaning device and well cleaning method. Background Technology

[0002] In well workover operations in various oilfields, it is common to encounter situations where the depth of casing reduction points needs to be determined. The general practice is to use a wellbore cleaning operation, which involves running a wellbore gauge. When the gauge encounters a casing reduction point, it encounters resistance. By measuring the length of the run-in tubing, the depth of the casing reduction point can be determined. However, conventional wellbore gauges cannot continue downhill after encountering resistance; they can only measure the uppermost casing reduction point, and cannot measure possible second or third reduction points. Furthermore, as oil and water wells gradually transition to deeper formations, a single well often uses two sizes of production casing, such as a 7-inch casing and a 5-inch casing well configuration. This makes it impossible for a single set of conventional wellbore gauges to complete the wellbore cleaning task for both casing sizes. Conventional wellbore cleaning methods often require running multiple tubing strings and using wellbore gauges with different outer diameters to complete such complex wellbore cleaning operations. This results in long construction cycles, low efficiency, and high costs for well cleaning operations. Therefore, a well cleaning device with an adjustable outer diameter and corresponding process methods are needed to improve efficiency and reduce operating costs.

[0003] CN 109469453 B discloses a sand flushing and well cleaning method using a sand flushing and well cleaning device. The device includes a central tube, a pressure-driven assembly, a truncated cone, and a variable-diameter sleeve. A cylinder sleeve is coaxially fitted around the central tube, forming a receiving space between the cylinder sleeve and the central tube. The pressure-driven assembly includes a piston disposed within the receiving space, with one end of the piston connected to the large-diameter end of the truncated cone. The central tube has a fluid inlet communicating with the receiving space. The pressure-driven assembly also includes a sliding sleeve and a ball-throwing device disposed within the central tube. The sliding sleeve is disposed within the central tube and can block the fluid inlet. The ball-throwing device engages with the sliding sleeve, allowing the sliding sleeve to slide axially along the central tube to expose the fluid inlet. Pressurizing the ball into the central tube causes the pressure-driven assembly to drive the truncated cone into the variable-diameter sleeve, increasing the diameter of the variable-diameter sleeve. This prior art discloses that by pressing the piston, the connected truncated cone penetrates the gap between the variable-diameter sleeve and the central tube, increasing the diameter of the variable-diameter sleeve and thus increasing the outer diameter of the tool. However, the structure of this existing technology makes it difficult to controllably restore the diameter of the variable sleeve when it continues to descend.

[0004] Based on this, there is room for improvement in the control of the outer diameter of the well-drainage device. Summary of the Invention

[0005] One of the technical problems to be solved by this invention is the long construction cycle, low efficiency and high cost of well cleaning operations involving multiple trips of casing string running in a single well with two different sizes of production casing and well cleaning gauges with different outer diameter specifications.

[0006] To solve the above-mentioned technical problems, embodiments of the present invention provide a sliding rail type variable diameter wellbore access device, comprising: Central body; An upper connector is fitted on the outer side of one end of the central body. One end of the upper connector is used to connect to the downhole tool, and the other end is radially spaced from the central body. An axially movable drive component is provided between the other end of the upper connector and the central body. A locking element fitted onto the outer side of the other end of the central body; A split claw is sleeved on the outside of the central body and connected to the driving component. The driving component can drive the split claw to move axially. An expansion rib is fitted on the outside of the central body and located between the split claw and the locking member. The expansion rib can move radially relative to the central body as the split claw moves axially to change the outer diameter of the slide rail type variable diameter well-connection device.

[0007] In some embodiments, a connector is further included, which is sleeved outside the central body and has its two ends connected to the drive member and the splitting claw, respectively. The connector is used to transmit the force of the drive member to the splitting claw.

[0008] In some embodiments, the central body includes a first threaded portion, a first smooth portion, a second smooth portion, a main body portion, and a second threaded portion connected in sequence. The first threaded portion is used to connect to the upper connector, and the second threaded portion is used to connect to the locking member. The diameter of the second smooth portion is larger than the diameter of the first smooth portion to form a limiting portion of the split claw between the two.

[0009] In some embodiments, a closed chamber is defined between the other end of the upper connector, the drive member, and the central body, and pressure changes in the closed chamber can cause axial movement of the drive member.

[0010] In some embodiments, a first through hole is provided at the center of one end of the central body connected to the upper connector. The first through hole is in fluid communication with the closed chamber through a through hole provided on the side wall of the central body, and pressure changes in the closed chamber can be caused through the first through hole and the through hole.

[0011] In some embodiments, the upper connector has a first connecting portion, a second connecting portion, and a third connecting portion connected in sequence. The first connecting portion is connected to the downhole tool, the second connecting portion is connected to the center body, and the inner diameter of the third connecting portion is larger than the inner diameter of the second connecting portion. The second connecting portion, the third connecting portion, the drive member, and the center body define a closed chamber.

[0012] In some embodiments, the main body includes a central portion, a plurality of transition portions and a plurality of edge portions, each of the plurality of transition portions being connected to the central portion, and the plurality of edge portions corresponding one-to-one with the plurality of transition portions, with each edge portion being connected to the corresponding transition portion.

[0013] In some embodiments, a plurality of transition portions are arranged circumferentially around the axis of the central portion, and a plurality of side portions are arranged circumferentially around the axis of the central portion.

[0014] In some embodiments, a receiving space is formed between two adjacent side portions, the corresponding transition portions of the two adjacent side portions, and the central portion, and the receiving space is used to receive the expansion ribs.

[0015] In some embodiments, the side of the edge portion away from the transition portion is a second arc surface, and each side of the second arc surface of the edge portion is provided with a first boss, which is used to restrict the radial movement of the expansion rib relative to the central body.

[0016] In some embodiments, a plurality of expansion ribs are included, each expansion rib matching a receiving space of the central body.

[0017] In some embodiments, the inner surface shape of the expansion rib matches the bottom surface shape of the receiving space, and a second protrusion is provided on each side of the inner surface of the expansion rib. The second protrusion cooperates with the first protrusion of the central body. The first and second protrusions restrict the expansion rib on the central body and limit the maximum distance of radial movement of the expansion rib relative to the central body.

[0018] In some embodiments, the split claw includes a base and a plurality of split claws, the base being disc-shaped, and the plurality of split claws being arranged circumferentially around the axis of the base on the front side of the base.

[0019] In some embodiments, the base has a circular base opening at its center, the base is fitted onto the first smooth portion of the central body, and a plurality of claws are fitted onto the second smooth portion of the central body. The axial movement of the base is restricted by a limiting portion between the second smooth portion and the first smooth portion.

[0020] In some embodiments, the plurality of flaps are all at a first distance from the center of the base opening. The first distance is greater than the radius of the base opening. The diameter of the base opening is greater than the diameter of the first smooth portion of the central body and less than the diameter of the second smooth portion. The first distance is greater than the radius of the second smooth portion of the central body.

[0021] In some embodiments, each flap is matched with a receiving space of the central body, and the flap can be moved into the matched receiving space.

[0022] In some embodiments, the two ends of the expansion rib have a first inclined surface and a second inclined surface, respectively; the end of the split claw opposite to the expansion rib is provided with a third inclined surface, which matches the first inclined surface of the expansion rib; the end of the locking member opposite to the expansion rib is provided with a fourth inclined surface, which matches the second inclined surface of the expansion rib; when the split claw moves toward the expansion rib and contacts the expansion rib, the first inclined surface of the expansion rib moves radially away from the central body along the third inclined surface, and the second inclined surface of the expansion rib moves radially away from the central body along the fourth inclined surface, thereby allowing the expansion rib to move radially relative to the central body as the split claw moves axially.

[0023] In some embodiments, there are three transition portions, three edge portions, three receiving spaces, three expansion ribs, and three flap claws.

[0024] Another aspect of the present invention provides a well-clearing method, implemented using the aforementioned sliding rail type variable diameter well-clearing device, comprising the following steps: Step 1: Connect the sliding rail type variable diameter wellbore device to the lowest end of the downhole tool and lower it into the well; Step 2: The sliding rail type variable diameter well-through device descends with the downhole tool until it encounters an obstruction, and the obstruction location is recorded. Step 3: The drive mechanism of the sliding rail type variable diameter well-through device reduces the outer diameter of the sliding rail type variable diameter well-through device, lowers and lowers the well tool, and the sliding rail type variable diameter well-through device passes through the obstruction position. Step 4: After passing the obstruction point, the drive component of the sliding rail type variable diameter well access device increases the outer diameter of the sliding rail type variable diameter well access device and lowers the well tool. Step 5: Repeat steps 2 and 3 until the well is cleared; Step 6: After well cleaning is completed, lift up the downhole tool, and the sliding rail variable diameter well cleaning device will be lifted out of the wellhead along with the downhole tool. In some embodiments, if the sliding rail type variable diameter well access device cannot pass through the obstruction position in step 3, the process proceeds directly to step 6.

[0025] Through the above technical solutions, the sliding rail type variable diameter well cleaning device and well cleaning method provided by the present invention can be equipped with a variety of standard well cleaning sizes; the outer diameter of the device can be switched; the method of switching the outer diameter is simple and convenient, and well cleaning operations for various sizes of casing can be completed by pulling out one working string. Moreover, the process method has fast construction speed, low labor intensity and simple operation method. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the sliding rail type variable diameter well-through device of the present invention in an expanded state; Figure 2 yes Figure 1 An enlarged schematic diagram of a portion of the sliding rail type variable diameter well access device shown in the dashed box; Figure 3 yes Figure 1 Cross-sectional view along line AA; Figure 4 This is a perspective view of the central body of the sliding rail type variable diameter well-connecting device of the present invention; Figure 5 This is a schematic diagram of the sliding rail type variable diameter well-through device of the present invention in the retracted state; Figure 6 yes Figure 5 Cross-sectional view along line BB; Figure 7 This is a schematic diagram of the specific implementation process of the sliding rail type variable diameter well-through device of the present invention encountering the first 7-inch casing diameter reduction point. Figure 8 This is a schematic diagram of the specific implementation process of the sliding rail type variable diameter well-through device of the present invention encountering the second 7-inch casing diameter reduction point. Figure 9 This is a schematic diagram illustrating the specific implementation process of the sliding rail type variable diameter well-connection device of the present invention, encountering a point where the diameter of a five-inch casing is reduced. Detailed Implementation

[0028] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0029] These embodiments are provided to make the invention thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0030] It should be noted that, in the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0031] Furthermore, the terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible range of error. "Parallel" is not strictly parallel, but within the permissible range of error. Terms such as "including" or "comprising" mean that the element preceding the word encompasses the element listed after the word, and do not exclude the possibility of encompassing other elements as well.

[0032] It should also be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device.

[0033] All terms used in this invention have the same meaning as understood by one of ordinary skill in the art to which this invention pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0034] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0035] like Figure 1 , Figure 2 and Figure 5As shown, the sliding rail type variable diameter well-drilling device 36 provided by the present invention includes: an upper connector 1, a driving component 2, a central body 3, a split claw 5, an expansion rib 6, and a locking component 7. The upper connector 1 is sleeved on the outer side of one end of the central body 3, and the locking component 7 is sleeved on the outer side of the other end of the central body 3. One end of the upper connector 1 is used to connect to the downhole tool, and the other end of the upper connector 1 is radially spaced from the central body 3 and an axially movable driving component 2 is provided between the upper connector 1 and the central body 3. The split claw 5 is sleeved on the outer side of the central body 3 and connected to the driving component 2. The driving component 2 can drive the split claw 5 to move axially. The expansion rib 6 is sleeved on the outer side of the central body 3 and located between the split claw 5 and the locking component 7. The expansion rib 6 can move radially relative to the central body 3 as the split claw 5 moves axially to change the outer diameter of the sliding rail type variable diameter well-drilling device 36.

[0036] The sliding rail type variable diameter well-through device 36 of the present invention also includes a connector 4, which is sleeved on the outside of the central body 3 and its two ends are respectively connected to the driving member 2 and the split claw 5. The connector 4 is used to transmit the force of the driving member 2 to the split claw 5.

[0037] Compared with the prior art, the sliding rail type variable diameter well cleaning device 36 of the present invention, through the structural design of the split claw 5, the expansion rib 6 and the central body 3, can change the outer diameter of the sliding rail type variable diameter well cleaning device 36. It can complete the well cleaning operation for casing of various sizes by running up and down the working tubing in one trip, thereby solving the technical problems of long construction cycle, low efficiency and high cost of well cleaning operation when running up and down the two sizes of production casing in one well and using well cleaning gauges with different outer diameter specifications.

[0038] In some embodiments, a closed chamber 25 is defined between the other end of the upper connector 1, the drive member 2, and the central body 3, and pressure changes in the closed chamber 25 can cause the drive member 2 to move axially.

[0039] In some embodiments, a first through hole is provided at the center of one end of the central body 3 connected to the upper connector 1. The first through hole is in fluid communication with the closed chamber 25 through a through hole 14 provided on the side wall of the central body 3, and pressure changes in the closed chamber 25 can be caused through the first through hole and the through hole 14.

[0040] In some embodiments, such as Figure 1 and Figure 4As shown, the central body 3 includes a first threaded portion 8, a first smooth portion 9, a second smooth portion 10, a main body portion 11, and a second threaded portion 12, which are coaxially arranged and connected in sequence. The first threaded portion 8 is used to connect to the upper connector 1, and the second threaded portion 12 is used to connect to the locking member 7. The diameter of the second smooth portion 10 is larger than the diameter of the first smooth portion 9 to form a limiting portion for the split claw 5 between them. The limiting portion refers to the step formed at the connection between the first smooth portion 9 and the second smooth portion 10, which prevents further movement of the split claw 5. The first threaded portion 8, the first smooth portion 9, the second smooth portion 10, and the second threaded portion 12 are all cylindrical. For example, the central body 3 is integrally formed.

[0041] In some embodiments, the first threaded portion 8 has an external thread, and the first threaded portion 8 is located inside the upper connector 1 and threadedly connected to the upper connector 1.

[0042] In some embodiments, a first through hole is provided at the center of the first threaded portion 8, and a cavity is provided at the center of the end of the first smooth portion 9 connected to the first threaded portion 8. The cavity communicates with the first through hole of the first threaded portion 8, and the cavity of the first smooth portion 9 and the first through hole of the first threaded portion 8 form a pressure chamber 13. Figure 2 As shown.

[0043] In some embodiments, the diameter of the first through hole of the first threaded portion 8 is equal to the diameter of the cavity of the first smooth portion 9.

[0044] In some embodiments, a through hole 14 is provided on the side wall corresponding to the cavity of the first smooth portion 9, and the through hole 14 penetrates the wall of the first smooth portion 9, such as... Figure 2 As shown. The first through hole is in fluid communication with the closed chamber 25 through a through hole 14 provided on the side wall of the first smooth portion 9.

[0045] In some embodiments, such as Figure 3 and Figure 4 As shown, the main body 11 includes a central portion 15, multiple transition portions 16, and multiple side portions 17. Each of the multiple transition portions 16 is connected to the central portion 15, and the multiple side portions 17 correspond one-to-one with the multiple transition portions 16, with each side portion 17 connected to its corresponding transition portion 16. The multiple transition portions 16 are arranged circumferentially around the axis of the central portion 15, and the multiple side portions 17 are also arranged circumferentially around the axis of the central portion 15. For example, the main body 11 is integrally formed.

[0046] In some embodiments, a receiving space 19 is formed between two adjacent side portions 17, the corresponding transition portions 16 of each of the two adjacent side portions 17, and the central portion 15. The receiving space 19 is used to receive the expansion ribs 6.

[0047] In some embodiments, the central portion 15 is cylindrical, and the diameter of the central portion 15 is equal to the diameter of the second smooth portion 10.

[0048] In some embodiments, the transition portion 16 is an irregular column shape, the length of the transition portion 16 is equal to the length of the central portion 15, and the transition portion 16 has a uniform cross section in the length direction. The cross section of the transition portion 16 in the plane perpendicular to its length direction is a trapezoidal shape.

[0049] In some embodiments, the side portion 17 is an irregular column shape, the length of the side portion 17 is equal to the length of the central portion 15 and the side portion 17 has a uniform cross section in the length direction, the cross section of the side portion 17 in the plane perpendicular to its length direction is a fan-shaped shape, the side of the side portion 17 connected to the transition portion 16 is a first arc surface and the side of the side portion 17 away from the transition portion 16 is a second arc surface 18.

[0050] like Figure 3 and Figure 6 As shown, a first boss 20 is provided on each side of the second arc surface 18 of the edge portion 17. The first boss 20 is provided along the side edge of the second arc surface 18 of the edge portion 17 and protrudes outward. The first boss 20 is used to restrict the radial movement of the expansion rib 6 relative to the central body 3. The length of the first boss 20 is the same as the length of the edge portion 17.

[0051] In some embodiments, the second arc surface 18 of the plurality of edge portions 17 is located on the side surface of the imaginary first cylinder, and the diameter of the bottom circle of the first cylinder is the first diameter.

[0052] In some embodiments, the second threaded portion 12 has an external thread, and the second threaded portion 12 is located inside the locking member 7 and threadedly connected to the locking member 7.

[0053] In some embodiments, the upper connector 1 is a hollow cylindrical shape. The upper connector 1 has a first connecting portion 21, a second connecting portion 22, and a third connecting portion 23 coaxially connected in sequence. The first connecting portion 21 connects to the downhole tool. The central body 3 passes through the third connecting portion 23 and is threadedly connected to the second connecting portion 22. The inner diameter of the third connecting portion 23 is larger than the inner diameter of the second connecting portion 22. The second connecting portion 22, the third connecting portion 23, the drive member 2, and the central body 3 define a closed chamber 25. The upper connector 1 is integrally formed.

[0054] In some embodiments, the inner side of the first connecting portion 21 of the upper connector 1 is configured with a 2 7 / 8” tubing female thread structure. The 2 7 / 8” tubing female thread structure is used to connect the downhole tool, so that the sliding rail type variable diameter well-drilling device 36 can be lowered into the well through the downhole tool.

[0055] In some embodiments, the downhole tool includes a tubing string, which includes tubing 24. Tubing 24 is connected to a 27 / 8” tubing thread structure of the upper connector 1, so that the sliding rail type variable diameter well-drilling device 36 can be downhole through tubing 24.

[0056] In some embodiments, the inner side of the second connecting portion 22 of the upper connector 1 is provided with an internal thread, and the first threaded portion 8 of the central body 3 is threadedly connected to the second connecting portion 22.

[0057] In some embodiments, a hydraulic cylinder structure is formed between the inner side of the third connecting portion 23 of the upper connector 1, the bottom surface of the second connecting portion 22, and the outer side of the central body 3. The through hole 14 of the first smooth portion 9 of the central body 3 communicates with the hydraulic cylinder structure. The pressure chamber 13 communicates with the hydraulic cylinder structure through the through hole 14.

[0058] In some embodiments, the through hole 14 of the central body 3 communicates with the hydraulic cylinder structure adjacent to the second connecting portion 22 of the upper connector 1. When the drive member 2 contacts the bottom surface of the second connecting portion 22 of the upper connector 1, it will completely block the through hole 14. This design ensures that the drive member 2 will not completely block the through hole 14.

[0059] In some embodiments, the drive member 2 is disposed in the hydraulic cylinder structure and contacts the inner side of the third connecting portion 23 and the outer side of the first smooth portion 9 of the central body 3, respectively. The drive member 2 is movable within the hydraulic cylinder structure. The hydraulic cylinder structure cooperates with the drive member 2, and the top surface of the drive member 2 and the hydraulic cylinder structure form a closed chamber 25. That is, the inner side of the third connecting portion 23, the bottom surface of the second connecting portion 22, the outer side of the central body 3, and the top surface of the drive member 2 form a closed chamber 25, and the pressure inlet chamber 13 communicates with the closed chamber 25 through the through hole 14. When the size of the closed chamber 25 changes, the drive member 2 moves within the hydraulic cylinder structure. When pressure is applied into the closed chamber 25, the pressure inside the closed chamber 25 generates a thrust on the drive member 2, causing the drive member 2 to move axially away from the second connecting portion 22 and increase the size of the closed chamber 25. Conversely, when the pressure inside the sealed chamber 25 is released, a negative pressure is formed inside the sealed chamber 25, causing the drive component 2 to automatically pull back. The drive component 2 moves axially toward the second connecting part 22, thereby reducing the size of the sealed chamber 25.

[0060] In some embodiments, the driving member 2 is cylindrical and has a second through hole at its center. The diameter of the second through hole of the driving member 2 is slightly larger than the diameter of the first smooth portion 9 of the central body 3, so that the driving member 2 is fitted onto the outside of the first smooth portion 9 of the central body 3.

[0061] In some embodiments, the drive element 2 is a pressure piston.

[0062] In some embodiments, the inner side of the drive member 2 is provided with a first groove, and a first sealing ring 26 is installed in the first groove, the first sealing ring 26 sealing the drive member 2 and the center body 3.

[0063] In some embodiments, the inner side of the drive member 2 is provided with two first grooves, and a first sealing ring 26 is installed in each of the two first grooves.

[0064] In some embodiments, a second groove is provided on the outer side of the drive member 2, and a second sealing ring 27 is installed in the second groove. The second sealing ring 27 seals the drive member 2 and the third connecting portion 23 of the upper connector 1.

[0065] In some embodiments, the outer surface of the drive member 2 is provided with two second grooves, and a second sealing ring 27 is installed in each of the two second grooves.

[0066] In some embodiments, the sliding rail type variable diameter well access device 36 includes a plurality of expansion ribs 6, each expansion rib 6 matching a receiving space 19 of the central body 3.

[0067] In some embodiments, such as Figure 1 , 3 As shown, the expansion rib 6 has a long strip structure and can be accommodated in the accommodating space 19 of the central body 3. The inner surface shape of the expansion rib 6 matches the bottom surface shape of the accommodating space 19 of the central body 3. The outer surface of the expansion rib 6 is a third arc surface 28.

[0068] In some embodiments, a second protrusion 29 is provided on each side of the inner side of the expansion rib 6. The second protrusion 29 is provided along the side edge of the inner side of the expansion rib 6 and protrudes outward. The second protrusion 29 is used to restrict the radial movement of the expansion rib 6 relative to the central body 3. The length of the second protrusion 29 is less than or equal to the length of the first protrusion 20.

[0069] In some embodiments, the second boss 29 engages with the first boss 20 of the side portion 17 of the central body 3. When the expansion rib 6 moves away from the axial portion 15 of the central body 3, the second boss 29 is blocked by the first boss 20 and cannot detach from the central body 3. The first boss 20 and the second boss 29 restrict the expansion rib 6 to the central body 3 and also limit the maximum radial movement of the expansion rib 6 relative to the central body 3. When the second boss 29 contacts the first boss 20, the expansion rib 6 moves radially to the maximum distance relative to the axial portion 15 of the central body 3, and the expansion rib 6 is in an extended state. At this time, the sliding rail type variable diameter well-drilling device 36 is in an expanded state, and the third arc surface 28 of the plurality of expansion ribs 6 on the central body 3 is located on the side of the imaginary second cylinder, the bottom circle diameter of the second cylinder being the second diameter. When the expansion rib 6 is fully contained within the receiving space 19 of the central body 3, the expansion rib 6 is in a contracted state. At this time, the sliding rail type variable diameter well-drilling device 36 is in a contracted state, and the third arc surface 28 of the plurality of expansion ribs 6 on the central body 3 is located on the side of an imaginary third cylinder, the bottom circle diameter of which is the third diameter. The second diameter limits the maximum outer diameter of the sliding rail type variable diameter well-drilling device 36. The minimum outer diameter of the sliding rail type variable diameter well-drilling device 36 is limited by the larger of the first diameter and the third diameter corresponding to the second arc surface 18 of the plurality of side portions 17. In some embodiments, the first diameter is 100 mm, the second diameter is 154 mm, and the third diameter is 100 mm, that is, the outer diameter of the sliding rail type variable diameter well-drilling device 36 is in the range of 100 mm to 154 mm.

[0070] In some embodiments, such as Figure 1 and Figure 2 As shown, the expansion rib 6 has a first inclined surface 30 and a second inclined surface 31 at its two ends, respectively. The first inclined surface 30 is adjacent to the split claw 5, and the second inclined surface 31 is adjacent to the locking member 7. The end of the split claw 5 opposite to the expansion rib 6 is provided with a third inclined surface 34, which matches the first inclined surface 30 of the expansion rib 6. The end of the locking member 7 opposite to the expansion rib 6 is provided with a fourth inclined surface 35, which matches the second inclined surface 31 of the expansion rib 6. For example, the two ends of the expansion rib 6 can be designed to be identical, so that the two ends of the expansion rib 6 can be interchanged.

[0071] In some embodiments, such as Figure 1 and Figure 2 As shown, the splitting claw 5 includes a base 32 and multiple claws 33. The base 32 is disc-shaped, and the multiple claws 33 are arranged circumferentially around the axis of the base 32 on the front side of the base 32. The diameter of the base circle of the imaginary fourth cylinder formed by the multiple claws 33 is the same as the diameter of the base 32.

[0072] In some embodiments, the base 32 has a circular base opening at its center, and the plurality of petal claws 33 are each at a first distance from the center of the base opening. The first distance is greater than the radius of the base opening, the diameter of the base opening is greater than the diameter of the first smooth portion 9 of the central body 3 and less than the diameter of the second smooth portion 10, and the first distance is greater than the radius of the second smooth portion 10 of the central body 3. Therefore, the base 32 of the petal claw 5 is fitted onto the first smooth portion 9 of the central body 3, and the plurality of petal claws 33 are fitted onto the second smooth portion 10 of the central body 3. The axial movement of the base 32 relative to the central body 3 is limited by the limiting portion between the second smooth portion 10 and the first smooth portion 9 of the central body 3. Therefore, when the driving member 2 drives the petal claw 5 to move axially relative to the central body 3, the axial movement of the driving member 2 is limited by the limiting portion between the second smooth portion 10 and the first smooth portion 9 of the central body 3. That is, when the petal claw 5 moves toward the expansion rib 6, the petal claw 5 stops moving when the base 32 contacts the second smooth portion 10 of the central body 3, and the driving member 2 stops moving accordingly.

[0073] In some embodiments, the number of flaps 33 is the same as the number of expansion ribs 6.

[0074] In some embodiments, the flap 33 is manufactured by milling with a milling cutter.

[0075] In some embodiments, each flap 33 is matched with a receiving space 19 of the central body 3, and the flap 33 can be moved into the matched receiving space 19.

[0076] In some embodiments, the flap 33 is elongated, and a third inclined surface 34 is provided at the top of the flap 33. The third inclined surface 34 matches the first inclined surface 30 of the expansion rib 6. The third inclined surface 34 is designed to push the expansion rib 6 when the flap 33 is subjected to a force toward the expansion rib 6 and to act as a sliding surface for the expansion rib 6 to move upward.

[0077] In some embodiments, the third inclined surface 34 is designed to be inclined upward in the direction from the edge of the base 32 toward the center of the base opening. When the drive member 2 moves the segmented claw 5 toward the expansion rib 6 and the segmented claw 33 contacts the expansion rib 6, the first inclined surface 30 of the expansion rib 6 moves radially away from the central body 3 along the third inclined surface 34. When the expansion rib 6 is on the third inclined surface 34, if the drive member 2 moves the segmented claw 5 away from the expansion rib 6, the expansion rib 6 moves radially toward the central body 3 along the third inclined surface 34 until the expansion rib 6 is received in the receiving space 19 of the central body 3.

[0078] In some embodiments, the length of the second smooth portion 10 is set such that when the petal claw 33 of the petal claw 5 pushes the expansion rib 6 radially away from the central body 3 to contact the second boss 29 of the expansion rib 6 with the first boss 20 of the edge portion 17 of the central body 3, the base 32 of the petal claw 5 reaches the limiting portion between the first smooth portion 9 and the second smooth portion 10 of the central body 3. Therefore, the movement of the petal claw 5 is limited by the drive member 2 and the second smooth portion 10.

[0079] In some embodiments, the connector 4 is a hollow cylindrical shape. The connector 4 is sleeved on the outside of the first smooth part 9 of the central body 3. One end of the connector 4 is fixedly connected to the bottom surface of the drive member 2, and the other end of the connector 4 is fixedly connected to the back of the base 32 of the split claw 5. The connector 4 can be moved by the drive member 2, thereby moving the split claw 5.

[0080] In some embodiments, the locking member 7 has a fourth inclined surface 35 at its end adjacent to the central body 3, which matches the second inclined surface 31 of the expansion rib 6. When the driving member 2 moves the segmented claw 5 toward the expansion rib 6 and the segmented claw 33 contacts the expansion rib 6, the second inclined surface 31 of the expansion rib 6 moves radially away from the central body 3 along the fourth inclined surface 35. When the expansion rib 6 is on the fourth inclined surface 35, if the driving member 2 moves the segmented claw 5 away from the expansion rib 6, the expansion rib 6 moves radially toward the central body 3 along the fourth inclined surface 35 until the expansion rib 6 is received in the receiving space 19 of the central body 3.

[0081] In some embodiments, the locking element 7 is a locking nut.

[0082] In some embodiments, there are three of each of the transition portion 16, the edge portion 17, the receiving space 19, the expansion rib 6, and the flap claw 33.

[0083] The sliding rail type variable diameter well-drilling device 36 of the present invention forms a closed chamber 25 with its upper connector 1, driving member 2, and central body 3. The size of the closed chamber 25 is controlled by controlling the pressure in the closed chamber 25, thereby driving the driving member 2 to move. In turn, the driving member 2 drives the connecting member 4 and the split claw 5 to move. Therefore, the split claw 5 pushes the expansion rib 6 on the central body 3, causing the expansion rib 6 to move radially outward relative to the central body 3, or causing the expansion rib 6, which has been moved by the split claw 5, to move radially inward relative to the central body 3. The sliding rail type variable diameter well-drilling device 36 of this application can change to various outer diameter sizes according to needs, thereby enabling well-drilling operations in various casings.

[0084] The well-clearing method of the sliding rail type variable diameter well-clearing device 36 of the present invention includes the following steps: Step 1: Connect the sliding rail type variable diameter well-connecting device 36 to the lowest end of the downhole tool and lower it into the well; Step 2: The sliding rail type variable diameter well-connecting device 36 descends with the downhole tool until it encounters an obstruction, and the obstruction position is recorded. Step 3: The driving component 2 of the sliding rail type variable diameter well-through device 36 reduces the outer diameter of the sliding rail type variable diameter well-through device 36, lowers and lowers the well tool, and the sliding rail type variable diameter well-through device 36 passes through the obstruction position. Step 4: After passing the obstruction position, the drive component 2 of the sliding rail type variable diameter well-through device 36 increases the outer diameter of the sliding rail type variable diameter well-through device 36 and lowers the well tool. Step 5: Repeat steps 2 and 3 until the well is cleared; Step 6: After well cleaning is completed, lift up the downhole tool, and the sliding rail type variable diameter well cleaning device 36 is lifted out of the wellhead along with the downhole tool.

[0085] In some embodiments, the downhole tool is a tubing string.

[0086] In some embodiments, if the sliding guide variable diameter well access device 36 cannot pass through the obstruction position in step 3, the process proceeds directly to step 6.

[0087] In some embodiments, the sliding rail type variable diameter wellbore device 36 of this application can be used for 7-inch casing 37 and 5-inch casing 38, wherein the inner diameter of the 7-inch casing 37 is 157 mm and the inner diameter of the 5-inch casing 38 is 108 mm.

[0088] like Figures 7 to 9 As shown, the specific process of the sliding rail type variable diameter well cleaning device 36 of the present invention in well cleaning operations including a 7-inch casing 37 and a 5-inch casing 38 is as follows: First, connect the sliding rail type variable diameter well-connecting device 36 to the bottom of the tubing string and lower it into the well; Next, pressure is applied to the tubing 24 of the tubing string to maintain an internal pressure of 5 MPa. The sliding rail type reducing diameter well-through device 36 is in the expanded state. The tubing string is lowered, and the sliding rail type reducing diameter well-through device 36 descends with the tubing string inside the seven-inch casing 37 until it encounters the first seven-inch casing reduction point 39. The first obstruction position is recorded. When the sliding rail type reducing diameter well-through device 36 is in the expanded state, the maximum outer diameter of the sliding rail type reducing diameter well-through device 36 is 154 mm. Secondly, the pressure inside the tubing string is released so that the sliding rail type variable diameter well-through device 36 is in a retracted state. The tubing string is then lowered, and the sliding rail type variable diameter well-through device 36 passes through the first obstruction position. When the sliding rail type variable diameter well-through device 36 is in a retracted state, the maximum outer diameter of the sliding rail type variable diameter well-through device 36 is 100mm. Secondly, after passing the first obstruction point, pressure is applied to the tubing 24 of the tubing string to maintain the internal pressure of the tubing string at 5 MPa. The sliding rail type reducing diameter well-through device 36 is in an expanded state. The tubing string is lowered, and the sliding rail type reducing diameter well-through device 36 descends with the tubing string inside the seven-inch casing 37 until it encounters the second seven-inch casing reduction point 39. The second obstruction point is recorded. Secondly, the pressure inside the tubing string is released so that the sliding rail type variable diameter well-through device 36 is in a retracted state, the tubing string is lowered, and the sliding rail type variable diameter well-through device 36 passes through the second obstruction position. Secondly, after passing the second obstruction position, pressure is applied to the tubing 24 of the tubing string to maintain the internal pressure of the tubing string at 5 MPa. The sliding rail type variable diameter well-through device 36 is in an expanded state. The tubing string is lowered until the sliding rail type variable diameter well-through device 36 reaches the casing thread change 40, at which point the five-inch casing 38 is reached. Secondly, the pressure inside the tubing string is released so that the sliding rail type variable diameter well-through device 36 is in a retracted state, and the tubing string is lowered so that the sliding rail type variable diameter well-through device 36 enters the five-inch casing 38. Next, continue to lower the tubing string. When the sliding rail reducing diameter wellbore device 36 encounters the five-inch casing reduction point 41, record the third resistance depth. Finally, the well cleaning was completed, the tubing string was pulled up, and the sliding rail type variable diameter well cleaning device 36 was pulled out of the wellhead along with the tubing string. Before implementing the sliding rail type variable diameter wellbore device 36 of the present invention, construction preparation is required, including: preparing a sufficient number of 2 7 / 8” tubing according to the actual well depth; installing a blowout preventer assembly that matches the 2 7 / 8” tubing at the wellhead; pressurizing the sliding rail type variable diameter wellbore device 36 on the ground to test the opening and closing function of the sliding rail type variable diameter wellbore device 36 and to check whether the hydraulic cylinder structure leaks.

[0089] The sliding rail type variable diameter well-connecting device 36 of this invention is heat-resistant up to 175℃ and pressure-resistant up to 70MPa; it has a wide range of applications and can be used in oil wells, water wells, vertical wells, horizontal wells and other well types; it is applicable to the casing size range of 7-inch casing 37 and 5-inch casing 38.

[0090] In traditional well cleaning operations, the well gauge cannot be reduced in diameter and must be pulled out when obstructed, thus only the uppermost casing reduction point can be located. If the casing is abnormal, the well gauge is very likely to get stuck, preventing the tubing string from being pulled out and causing downhole accidents. The sliding rail type variable diameter well cleaning device 36 of this invention uses a tubing string to find multiple casing reduction points in one trip, especially in the 7-inch casing 37. It uses a reduceable well gauge with a maximum outer diameter between 154mm and 100mm. Even if it gets stuck, it can be reduced in diameter and pulled out, thus ensuring that it will not get stuck when working in the 7-inch casing 37. One reduceable well gauge can complete well cleaning operations for two sizes of casing, supporting 7-inch casing 37 and 5-inch casing 38. It can complete well cleaning operations for two sizes of casing in one trip. The method of use is simple and easy to operate.

[0091] The various embodiments of the present invention have now been described in detail. To avoid obscuring the concept of the invention, some details known in the art have not been described. Those skilled in the art will fully understand how to implement the technical solutions disclosed herein based on the above description.

[0092] While specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of the invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any manner.

Claims

1. A sliding rail type variable diameter well-connection device (36), characterized in that, include: Central body (3); An upper connector (1) is sleeved on the outer side of one end of the central body (3). One end of the upper connector (1) is used to connect the downhole tool, and the other end is radially spaced from the central body (3). An axially movable drive component (2) is provided between the other end of the upper connector (1) and the central body (3). A locking element (7) is fitted onto the outside of the other end of the central body (3); A split claw (5) is sleeved on the outside of the central body (3) and connected to the driving member (2). The driving member (2) can drive the split claw (5) to move axially. An expansion rib (6) is sleeved on the outside of the central body (3) and located between the split claw (5) and the locking member (7). The expansion rib (6) can move radially relative to the central body (3) as the split claw (5) moves axially to change the outer diameter of the slide rail type variable diameter well-through device (36).

2. The sliding rail type variable diameter well-connecting device (36) according to claim 1, characterized in that, It also includes a connector (4), which is sleeved outside the central body (3) and the two ends of the connector (4) are respectively connected to the drive (2) and the split claw (5). The connector (4) is used to transmit the force of the drive (2) to the split claw (5).

3. The sliding rail type variable diameter well-connecting device (36) according to claim 1, characterized in that, The central body (3) includes a first threaded portion (8), a first smooth portion (9), a second smooth portion (10), a main body portion (11), and a second threaded portion (12) connected in sequence. The first threaded portion (8) is used to connect the upper connector (1), and the second threaded portion (12) is used to connect the locking member (7). The diameter of the second smooth portion (10) is larger than the diameter of the first smooth portion (9) to form the limiting portion of the split claw (5) between the two.

4. The sliding rail type variable diameter well-connecting device (36) according to claim 1, characterized in that, A closed chamber (25) is defined between the other end of the upper connector (1), the drive member (2), and the central body (3), and pressure changes in the closed chamber (25) can cause the drive member (2) to move axially.

5. The sliding rail type variable diameter well-connecting device (36) according to claim 4, characterized in that, The center of the central body (3) connected to the upper connector (1) is provided with a first through hole. The first through hole is in fluid communication with the closed chamber (25) through a through hole (14) provided on the side wall of the central body (3). The pressure change of the closed chamber (25) can be caused by the first through hole and the through hole (14).

6. The sliding rail type variable diameter well-connecting device (36) according to claim 4, characterized in that, The upper connector (1) has a first connecting part (21), a second connecting part (22), and a third connecting part (23) connected in sequence. The first connecting part (21) is connected to the downhole tool, the second connecting part (22) is connected to the center body (3), and the inner diameter of the third connecting part (23) is larger than the inner diameter of the second connecting part (22). The second connecting part (22), the third connecting part (23), the drive member (2), and the center body (3) define the closed chamber (25).

7. The sliding rail type variable diameter well-connecting device (36) according to claim 3, characterized in that, The main body (11) includes a central part (15), a plurality of transition parts (16) and a plurality of side parts (17). Each of the plurality of transition parts (16) is connected to the central part (15). The plurality of side parts (17) and the plurality of transition parts (16) are in one-to-one correspondence and each side part (17) is connected to the corresponding transition part (16).

8. The sliding rail type variable diameter well-connecting device (36) according to claim 7, characterized in that, The plurality of transition portions (16) are arranged circumferentially around the axis of the central portion (15), and the plurality of side portions (17) are arranged circumferentially around the axis of the central portion (15).

9. The sliding rail type variable diameter well-connecting device (36) according to claim 8, characterized in that, An accommodating space (19) is formed between two adjacent side portions (17), the corresponding transition portions (16) of each of the two adjacent side portions (17), and the central portion (15), the accommodating space (19) being used to accommodate the expansion rib (6).

10. The sliding rail type variable diameter well-connecting device (36) according to claim 9, characterized in that, The side of the edge portion (17) away from the transition portion (16) is a second arc surface (18). Each side of the second arc surface (18) of the edge portion (17) is provided with a first boss (20). The first boss (20) is used to restrict the radial movement of the expansion rib (6) relative to the central body (3).

11. The sliding rail type variable diameter well-connecting device (36) according to claim 10, characterized in that, It includes a plurality of said expansion ribs (6), each of said expansion ribs (6) matching one of said receiving spaces (19) of said central body (3).

12. The sliding rail type variable diameter well-connecting device (36) according to claim 11, characterized in that, The inner surface shape of the expansion rib (6) matches the bottom surface shape of the receiving space (19). A second protrusion (29) is provided on each side of the inner surface of the expansion rib (6). The second protrusion (29) cooperates with the first protrusion (20) of the central body (3). The first protrusion (20) and the second protrusion (29) restrict the expansion rib (6) on the central body (3) and limit the maximum distance of radial movement of the expansion rib (6) relative to the central body (3).

13. The sliding rail type variable diameter well-connecting device (36) according to claim 11, characterized in that, The split claw (5) includes a base (32) and multiple claws (33). The base (32) is in the shape of a disc, and the multiple claws (33) are arranged circumferentially around the axis of the base (32) on the front side of the base (32).

14. The sliding rail type variable diameter well-connecting device (36) according to claim 13, characterized in that, The base (32) has a circular base opening at its center. The base (32) is fitted onto the first smooth part (9) of the central body (3). The plurality of claws (33) are fitted onto the second smooth part (10) of the central body (3). The axial movement of the base (32) is restricted by the limiting part between the second smooth part (10) and the first smooth part (9).

15. The sliding rail type variable diameter well-connecting device (36) according to claim 14, characterized in that, Each of the plurality of petal claws (33) has a first distance from the center of the base opening. The first distance is greater than the radius of the base opening. The diameter of the base opening is greater than the diameter of the first smooth portion (9) of the central body (3) and less than the diameter of the second smooth portion (10). The first distance is greater than the radius of the second smooth portion (10) of the central body (3).

16. The sliding rail type variable diameter well-connecting device (36) according to claim 13, characterized in that, Each of the said flaps (33) is matched with one of the said receiving spaces (19) of the central body (3), and the flaps (33) are movable into the matched receiving spaces (19).

17. The sliding rail type variable diameter well-connecting device (36) according to claim 1, characterized in that, The expansion rib (6) has a first inclined surface (30) and a second inclined surface (31) at both ends; the split claw (5) has a third inclined surface (34) at the end opposite to the expansion rib (6), and the third inclined surface (34) matches the first inclined surface (30) of the expansion rib (6); the locking member (7) has a fourth inclined surface (35) at the end opposite to the expansion rib (6), and the fourth inclined surface (35) matches the second inclined surface (31) of the expansion rib (6); when the When the split claw (5) moves toward the expansion rib (6) and the split claw (5) contacts the expansion rib (6), the first inclined surface (30) of the expansion rib (6) moves radially away from the central body (3) along the third inclined surface (34), and the second inclined surface (31) of the expansion rib (6) moves radially away from the central body (3) along the fourth inclined surface (35), thereby allowing the expansion rib (6) to move radially relative to the central body (3) as the split claw (5) moves axially.

18. The sliding rail type variable diameter well-connecting device (36) according to claim 13, characterized in that, The transition portion (16), the side portion (17), the accommodating space (19), the expansion rib (6), and the petal claw (33) are all three.

19. A well-drainage method, characterized in that, The application of the sliding rail type variable diameter well-connecting device (36) according to any one of claims 1-18 includes the following steps: Step 1: Connect the sliding rail type variable diameter well-connecting device (36) to the lowest end of the downhole tool and lower it into the well; Step 2: The sliding rail type variable diameter well-connecting device (36) descends with the downhole tool until it encounters an obstruction, and the obstruction position is recorded. Step 3: The drive component (2) of the sliding rail type variable diameter well-through device (36) reduces the outer diameter of the sliding rail type variable diameter well-through device (36), and lowers the well tool. The sliding rail type variable diameter well-through device (36) passes through the obstruction position. Step 4: After passing the obstruction position, the drive component (2) of the sliding rail type variable diameter well-through device (36) increases the outer diameter of the sliding rail type variable diameter well-through device (36) and lowers the well tool. Step 5: Repeat steps 2 and 3 until well cleaning is completed; Step 6: After well cleaning is completed, the downhole tool is lifted up, and the sliding rail type variable diameter well cleaning device (36) is lifted out of the wellhead along with the downhole tool.

20. The well cleaning method according to claim 19, characterized in that, In step 3, if the sliding rail type variable diameter well-through device (36) cannot pass through the obstruction position, then proceed directly to step 6.

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