Combined sleeve self-adapting reducing scraper

Abstract

The application discloses a combined casing self-adaptive variable-diameter scraper, which comprises an outer pipe, at least one group of scraper assemblies, an inner sliding sleeve, an elastic assembly and a diameter measuring assembly. Each group of scraper assemblies comprises a plurality of scraper blocks. The inner sliding sleeve is arranged axially movably in the inner part of the outer pipe. The elastic assembly comprises a plurality of elastic sheets. The diameter measuring assembly comprises a plurality of diameter measuring connecting rods. The upper end of the diameter measuring connecting rod is arranged axially movably by the side wall of the outer pipe into the outer pipe. The diameter measuring connecting rod is axially moved upward at the upper end under the action of the shrinkage of the well wall and the extrusion of the well wall, and pushes each elastic sheet to pop out and separate from the inner sliding sleeve, so that the inner sliding sleeve is moved downward and drives each scraper block to shrink radially inward. The combined casing self-adaptive variable-diameter scraper can automatically adjust the scraping diameter range in the well, and the combined casing cleaning operation can be completed by one pipe column. The problems that the existing combined casing wellbore cleaning needs to be repeatedly tripped are solved, and the scraping force of the scraper assembly in different diameter casings can be ensured to be basically consistent.

Description

Technical Field

[0001] This invention relates to the field of oilfield well completion operation technology, and in particular to a combined casing adaptive variable diameter scraper. Background Technology

[0002] As oil and gas exploration and development gradually moves towards deeper formations, the proportion of deep wells, ultra-deep wells, and long horizontal wells in some major production areas is rapidly increasing. Long well construction cycles have become a bottleneck for the rapid production of deep natural gas. After drilling or perforation operations, specialized casing scrapers are required for wellbore cleaning to remove cement and burrs left on the casing inner wall. Failure to remove these will affect the subsequent tooling, scratch the packer rubber, and affect the setting effect. However, as well depth increases, the wellbore structure becomes more complex. More and more typical wellbore structures use casing combinations such as 7″+5″ and 7 3 / 4″+5 1 / 2″ from top to bottom. This requires running two different scrapers corresponding to the casing size, scraping and cleaning the casing in each run, and repeatedly pulling in and out the tubing to change tools, resulting in long well completion cycles.

[0003] The paper "Structural Design and Testing of Variable Diameter Scraper" introduces a combined casing scraper with a split leaf spring structure, but it suffers from significant differences in scraping force across wellbore diameters. Patent application number 202110049934.4, entitled "A Controllable Variable Diameter Scraper," proposes a scraper that uses a dedicated hydraulic line to control the opening and closing of the scraper blade; however, installing the hydraulic line independently presents significant construction difficulties and high operating costs. Patents application number 201910247041.3, entitled "A Variable Diameter Scraper," and application number 202010126785.2, entitled "A Variable Diameter Casing Scraper," respectively propose scrapers that, after ball insertion, use hydraulic pressure to gradually open the scraper blade to adapt to larger diameter casing, first scraping the lower, smaller diameter casing and then adjusting to scrape the upper, larger diameter casing.

[0004] Research has shown that most variable diameter scrapers proposed for cleaning combined sleeves with a larger diameter at the top and a smaller diameter at the bottom have problems such as requiring dedicated hydraulic lines or ball-throwing pressure, resulting in complex construction operations, poor adaptability, and large differences in scraping force, making it difficult to guarantee the scraping effect. Therefore, there is an urgent need for a more reliable and convenient combined sleeve variable diameter scraper. Summary of the Invention

[0005] The purpose of this invention is to provide a combined casing adaptive variable diameter scraper that can automatically adjust the scraping diameter range downhole, and complete the combined casing cleaning operation in one trip of the tubing string. This solves the problem that existing combined casing wellbore cleaning requires repeated tripping in and out of the drill string, and can ensure that the scraping force of the scraper assembly is basically consistent in casings of different diameters.

[0006] The objective of this invention is achieved by providing a combined sleeve adaptive variable diameter scraper, comprising:

[0007] outer tube;

[0008] At least one set of scraper assemblies, each set of scraper assemblies including multiple scraper blocks circumferentially spaced on the upper outer side of the outer tube and capable of radial retraction;

[0009] The inner sliding sleeve is axially movable inside the outer tube, and its upper end can extend out from the side wall of the outer tube and connect with the scraper assembly.

[0010] The elastic component includes a plurality of elastic plates circumferentially spaced inside the outer tube. The lower end of each elastic plate can abut against and be limited on the inner wall of the outer tube, and the upper end can be locked onto the lower end of the inner sleeve to axially limit the inner sleeve.

[0011] The diameter measuring assembly includes multiple diameter measuring rods circumferentially spaced on the lower outer side of the outer tube. The upper end of the diameter measuring rod can extend axially into the outer tube from the side wall. Under the pressure of the well wall shrinking, the upper end of the diameter measuring rod can move upward axially and push each elastic plate out of the inner sliding sleeve, so that the inner sliding sleeve moves downward and drives each scraper block to retract radially inward.

[0012] In a preferred embodiment of the present invention, each measuring rod includes a lower measuring rod, an upper measuring rod, and an axial sliding rod that are sequentially hinged from bottom to top. The lower end of the lower measuring rod is hinged to the outer tube, the angle between the lower measuring rod and the upper measuring rod is an obtuse angle, and the upper end of the axial sliding rod can extend into the outer tube.

[0013] In a preferred embodiment of the present invention, a roller is further provided at the hinge position of the lower measuring rod and the upper measuring rod.

[0014] In a preferred embodiment of the present invention, a plurality of lower insertion holes are provided circumferentially on the side wall of the outer tube, the upper end of the axial sliding rod can pass through the lower insertion holes, and a sealing ring is provided between the axial sliding rod and the lower insertion holes.

[0015] In a preferred embodiment of the present invention, a plurality of lower mounting grooves are provided circumferentially at intervals on the lower outer side wall of the outer tube, and each measuring rod is installed in the corresponding lower mounting groove; the lower end of the lower measuring rod is hinged to the bottom groove wall of the lower mounting groove, and the top groove wall of each lower mounting groove is provided with a lower insertion hole communicating with the inside of the outer tube, and the upper end of the axial sliding rod can pass through the lower insertion hole.

[0016] In a preferred embodiment of the present invention, a limiting groove is formed on the inner wall of the outer tube, and a retaining groove is formed on the lower outer wall of the inner sliding sleeve. The lower end of the elastic piece can abut against the bottom groove wall of the limiting groove, and the upper end of the elastic piece can be engaged in the retaining groove.

[0017] In a preferred embodiment of the present invention, an upper protruding ring is provided inwardly on the inner wall of the middle part of the outer tube, and a lower protruding ring is provided outwardly on the outer wall of the inner sleeve. The lower protruding ring is located below the upper protruding ring. A compression spring is provided on the outer sleeve of the inner sleeve, and the upper and lower ends of the compression spring can respectively abut against the upper protruding ring and the lower protruding ring.

[0018] In a preferred embodiment of the present invention, each scraper assembly further includes a drive link and at least two parallel driven rods located above the drive link. The drive link includes an upper drive rod and a lower drive rod that are hinged together vertically. The lower end of the lower drive rod is connected to the inner sliding sleeve, and the upper end of the upper drive rod is hinged to the lower inner wall of the scraper block. The axial direction of the lower drive rod is parallel to the axial direction of the outer tube, and the axial direction of the upper drive rod is inclined upward from the inside of the outer tube to the outside. The lower end of the driven rod is hinged to the upper inner wall of the scraper block, and the upper end of the driven rod is hinged to the outer tube. The axial direction of the driven rod is inclined downward from the inside of the outer tube to the outside.

[0019] In a preferred embodiment of the present invention, the upper outer wall of the inner sliding sleeve is formed with a plurality of installation limiting spaces, and the lower drive rod can be limited and installed in the corresponding installation limiting spaces; an adjusting spring is sleeved on the lower outer side of the lower drive rod, and a stop portion is formed on the outer wall of the lower drive rod, and the upper and lower ends of the adjusting spring can respectively abut against the stop portion and the bottom limiting portion of the installation limiting space.

[0020] In a preferred embodiment of the present invention, the inner sliding sleeve includes a sliding sleeve body and a plurality of mounting plates extending upward from the upper end of the sliding sleeve body and arranged circumferentially at intervals. Each mounting plate is provided with an upper limit portion and a lower limit portion spaced vertically along the axial direction. The area enclosed by the upper limit portion, the mounting plate and the lower limit portion constitutes an installation limiting space, and the lower limit portion constitutes a bottom limiting portion. The lower limit portion is located inside the outer tube, and the upper end of the mounting plate extends out from the side wall of the outer tube.

[0021] In a preferred embodiment of the present invention, a plurality of upper mounting slots are respectively provided on the upper outer wall of the outer tube corresponding to the positions of a plurality of scraper blocks. The upper end of each driven rod is hinged to the upper groove wall of the upper mounting slot. The bottom groove wall of each upper mounting slot is provided with an upper insertion hole communicating with the interior of the outer tube. The mounting plate and the lower drive rod can both move through the upper insertion hole.

[0022] In a preferred embodiment of the present invention, there are two sets of scraper assemblies arranged vertically at intervals, and the scraper blocks of the two sets of scraper assemblies are staggered in the circumferential direction of the outer tube.

[0023] In a preferred embodiment of the present invention, the lower limit portion of each mounting plate corresponding to the lowest layer scraper assembly can abut against the upper convex ring after the inner sleeve moves downward.

[0024] In a preferred embodiment of the present invention, a slide rail extending axially along the outer tube is provided on the mounting plate, and a track groove extending axially along the outer tube and passing through the upper and lower parts is provided on the lower drive rod, and the slide rail can be slidably inserted into the track groove.

[0025] In a preferred embodiment of the present invention, the upper limit portion on each mounting plate is detachably provided at the top of the mounting plate.

[0026] As described above, the scraper of the present invention, through the cooperation of the caliper assembly, the elastic assembly, and the inner sliding sleeve, allows the scraper to be lowered from a large-diameter casing into a small-diameter casing. The pressure exerted by the well wall on the caliper assembly causes the caliper assembly to push the elastic plates open and the inner sliding sleeve to move downwards, thereby automatically causing the scraper blocks to radially contract, thus reducing the overall outer diameter of the scraper. It is an adaptive variable-diameter scraper suitable for combined casings with a larger diameter at the top and a smaller diameter at the bottom. By sensing the wellbore diameter in real time through the caliper assembly, the scraper automatically adjusts its scraping diameter range downhole, eliminating the need for dedicated hydraulic lines or ball-dropping pressurization operations. This simplifies operation, enhances adaptability, and allows for the completion of combined casing cleaning with a single tubing run. This solves the problem of repeated tripping for cleaning existing combined casing wellbore cleaning, saving tripping time and reducing the wellbore preparation cycle for completion operations. Furthermore, by using the downward movement of the inner sliding sleeve to actively reduce the radial diameter of each scraper block, the scraping force of the scraper assembly remains essentially consistent within casings of different diameters, resulting in better scraping performance. Attached Figure Description

[0027] The accompanying drawings are intended only to illustrate and explain the present invention and do not limit the scope of the invention.

[0028] in:

[0029] Figure 1 : A schematic diagram of the structure of the combined sleeve adaptive variable diameter scraper provided by the present invention.

[0030] Figure 2 : A perspective view of the inner sliding sleeve when a set of scraper assemblies is provided for the present invention.

[0031] Figure 3 : A perspective view of the inner sliding sleeve when the present invention is provided with two sets of scraper assemblies.

[0032] Figure 4 : This is a schematic diagram showing the cooperation between the mounting plate and the upper limit part provided by the present invention.

[0033] Figure 5 : A schematic diagram of the drive linkage provided by the present invention.

[0034] Explanation of icon numbers:

[0035] 1. Outer tube; 11. Lower mounting groove; 12. Limiting groove; 13. Upper convex ring; 14. Upper mounting groove;

[0036] 2. Scraper assembly; 21. Scraper block; 22. Drive linkage; 221. Upper drive rod; 222. Lower drive rod; 2221. Stop; 223. Adjusting spring; 224. Track groove; 23. Driven rod;

[0037] 3. Inner sliding sleeve; 31. Slot; 32. Lower convex ring; 33. Compression spring; 34. Installation limiting space; 35. Sliding sleeve body; 351. Limiting ring; 36. Mounting plate; 361. Slide rail; 37. Upper limit part; 38. Lower limit part;

[0038] 4. Elastic sheet;

[0039] 5. Diameter measuring assembly; 51. Diameter measuring connecting rod; 511. Lower diameter measuring rod; 512. Upper diameter measuring rod; 513. Axial sliding rod; 52. Roller; 53. Sealing ring. Detailed Implementation

[0040] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0041] like Figures 1 to 5 As shown, this embodiment provides a combined sleeve adaptive variable diameter scraper, including:

[0042] Outer tube 1;

[0043] At least one set of scraper assemblies 2, each set of scraper assemblies 2 including a plurality of scraper blocks 21 circumferentially spaced on the upper outer side of the outer tube 1 and capable of radial retraction;

[0044] The inner sliding sleeve 3 is axially movable inside the outer tube 1, and its upper end can extend out from the side wall of the outer tube 1 and connect with the scraper assembly 2.

[0045] The elastic component includes a plurality of elastic pieces 4 circumferentially spaced inside the outer tube 1. The lower end of each elastic piece 4 can abut against and be limited on the inner wall of the outer tube 1, and the upper end can be locked onto the lower end of the inner sliding sleeve 3 to axially limit the inner sliding sleeve 3.

[0046] The diameter measuring assembly 5 includes multiple diameter measuring connecting rods 51 circumferentially spaced on the lower outer side of the outer tube 1. The upper end of the diameter measuring connecting rod 51 can extend into the outer tube 1 through the side wall of the outer tube 1 and move axially. Under the action of the well wall shrinking and being squeezed by the well wall, the upper end of the diameter measuring connecting rod 51 can move upward axially and push each elastic plate 4 to pop out and disengage from the inner sliding sleeve 3, so that the inner sliding sleeve 3 moves downward and drives each scraper block 21 to retract radially inward.

[0047] The scraper can be used to scrape the inner wall of the combined sleeve, which includes a large-diameter sleeve and a small-diameter sleeve connected vertically. The outer tube 1 is set vertically when in use. The scraper assembly 2, the inner sliding sleeve 3 and the diameter measuring assembly 5 are distributed along the axial direction of the outer tube 1 at the upper, middle and lower parts of the outer tube 1, respectively.

[0048] In the initial state, due to the presence of the elastic plates 4 in the elastic assembly, the inner sliding sleeve 3 cannot move downwards inside the outer tube 1. At this time, the position of the inner sliding sleeve 3 remains stationary, and the size of each scraper block 21 in the scraper assembly 2 can match the inner diameter of the large-diameter casing. After the scraper is lowered into the large-diameter casing, the lower part of the caliper measuring assembly 5 can contact the inner wall of the casing to sense changes in the well diameter. Each scraper block 21 of the scraper assembly 2 can perform scraping operations on the inner wall of the large-diameter casing. When the scraper is further lowered into the small-diameter casing, the lower part of the caliper measuring assembly 5, under the pressure of the well wall, will cause the upper ends of each caliper measuring rod 51 to move upwards, pushing each elastic plate 4 to spring open. When all the elastic plates 4 have springed open, the inner sliding sleeve 3 can move downwards, causing each scraper block 21 to contract radially inwards, reducing the overall outer diameter of the scraper and matching it with the inner diameter of the small-diameter casing, thereby performing scraping operations on the inner wall of the small-diameter casing.

[0049] Therefore, in this embodiment, the scraper, through the cooperation of the caliper measuring component 5, the elastic component, and the inner sliding sleeve 3, allows the scraper to be lowered from the large-diameter casing into the small-diameter casing. The pressure of the well wall on the caliper measuring component 5 causes the caliper measuring component 5 to push the elastic plates 4 open and the inner sliding sleeve 3 to move downwards, thereby causing each scraper block 21 to automatically retract radially, thus reducing the overall outer diameter of the scraper. This is an adaptive variable-diameter scraper suitable for combined casings with a larger diameter at the top and a smaller diameter at the bottom. By sensing the wellbore diameter in real time through the caliper measuring component 5, the scraper automatically adjusts the scraping diameter range downhole, eliminating the need for dedicated hydraulic lines or ball-dropping pressurization operations. This simplifies the operation, enhances adaptability, and allows for the completion of combined casing cleaning operations in a single tubing run. This solves the problem of repeated tripping for cleaning existing combined casing wellbore, saving tripping time and reducing the wellbore preparation cycle for well completion operations. In addition, by using the downward movement of the inner sliding sleeve 3 to drive each scraper block 21 to actively reduce its radial diameter, the scraping force of the scraper assembly 2 in sleeves of different diameters can be kept basically the same, resulting in a better scraping effect.

[0050] In order to facilitate the caliper assembly 5 to sense changes in well wall size and move upward when the well wall size decreases, each caliper connecting rod 51 includes a lower caliper rod 511, an upper caliper rod 512 and an axial sliding rod 513 that are hinged from bottom to top. The lower end of the lower caliper rod 511 is hinged to the outer tube 1, and the angle between the lower caliper rod 511 and the upper caliper rod 512 is an obtuse angle. The upper end of the axial sliding rod 513 can extend into the outer tube 1.

[0051] In its natural state, the lower measuring rod 511 and the upper measuring rod 512 maintain an obtuse angle relationship, and their hinged joint can closely adhere to the inner wall of the casing. Generally, a roller 52 is also provided at the hinged joint of the lower measuring rod 511 and the upper measuring rod 512. The axis of the roller 52 is perpendicular to the plane containing the axes of the two rods, and it rolls in contact with the well wall, which can reduce the friction between the roller and the well wall. During the scraper's entry process, the roller 52 contacts the well wall and keeps close to the casing wall in real time to sense the well diameter. When the scraper enters the small-diameter casing, the well diameter decreases, and the well wall will squeeze the roller 52 inward. The roller 52 pushes the lower measuring rod 511 and the upper measuring rod 512 inward, increasing the included angle between the two rods. This causes the upper end of the upper measuring rod 512 to move upward, which in turn pushes the axial sliding rod 513 upward.

[0052] It is understood that multiple lower insertion holes are circumferentially opened on the side wall of the outer tube 1, and the upper end of the axial sliding rod 513 can pass through the lower insertion holes. In order to prevent impurities in the well from entering the scraper and affecting the movement of the diameter measuring assembly 5, a sealing ring 53 is provided between the axial sliding rod 513 and the lower insertion holes to achieve internal and external sealing.

[0053] To facilitate processing and installation, the lower outer side wall of the outer tube 1 is provided with a plurality of lower mounting grooves 11 spaced apart circumferentially. Each measuring rod 51 is installed in the corresponding lower mounting groove 11. The lower end of the lower measuring rod 511 is hinged to the bottom groove wall of the lower mounting groove 11. The top groove wall of each lower mounting groove 11 is provided with a lower insertion hole that communicates with the interior of the outer tube 1. The upper end of the axial sliding rod 513 can pass through the lower insertion hole to extend into the outer tube 1.

[0054] The number of the lower mounting slot 11, the lower insertion hole, and the diameter measuring rod 51 are the same, depending on the specific needs. For example, in this embodiment, there are four diameter measuring rods 51, which are evenly distributed around the outer tube 1 and form a 90-degree angle with each other.

[0055] The aforementioned elastic piece 4 can be, for example, a spring sheet, which is a long strip with a certain curvature. A limiting groove 12 can be formed on the inner wall of the outer tube 1, and a retaining groove 31 can be formed on the lower outer wall of the inner sliding sleeve 3. The lower end of the elastic piece 4 can abut against the bottom wall of the limiting groove 12, and the upper end of the elastic piece 4 can be engaged in the retaining groove 31. The limiting groove 12 on the outer tube 1 and the retaining groove 31 on the inner sliding sleeve 3 can both be in the form of annular grooves, or they can both include multiple grooves arranged circumferentially, depending on the specific needs.

[0056] In the initial state, the lower end of the elastic piece 4 is fixed to the outer tube 1, and the upper end is inclined inward and just fits into the groove 31 of the inner sliding sleeve 3 to prevent the inner sliding sleeve 3 from sliding downward. When the axial sliding rod 513 moves upward and contacts the inwardly inclined surface of the elastic piece 4, it pushes the elastic piece 4 outward and the upper end of the elastic piece 4 disengages from the groove 31 of the inner sliding sleeve 3.

[0057] Furthermore, an upper protruding ring 13 is provided inwardly on the inner wall of the middle part of the outer tube 1, and a lower protruding ring 32 is provided outwardly on the outer wall of the inner sliding sleeve 3. The lower protruding ring 32 is located below the upper protruding ring 13. The aforementioned limiting groove 12 is located below the upper protruding ring 13, and the locking groove 31 is located below the lower protruding ring 32. A compression spring 33 is provided on the outer sleeve of the inner sliding sleeve 3. The upper and lower ends of the compression spring 33 can respectively abut against the upper protruding ring 13 and the lower protruding ring 32.

[0058] In its initial state (i.e., when the upper end of the elastic plate 4 is engaged with the inner sleeve 3), the compression spring 33 is in a compressed and energy-storing state. The lower part of the inner sleeve 3 is supported by the elastic plate 4 from the slot 31, and the upper part is supported by the upper protruding ring 13 of the outer tube 1, thus remaining in a fixed state. When the upper ends of the elastic plates 4 distributed around the perimeter are disengaged from the slots 31 of the inner sleeve 3, the lower part of the inner sleeve 3 loses its constraint, and the compression spring 33 will push the inner sleeve 3 downward.

[0059] To facilitate the radial inward retraction of each scraper block 21 when the inner sliding sleeve 3 moves downward, each scraper assembly 2 also includes a drive link 22 and at least two parallel driven rods 23 located above the drive link 22. The drive link 22 includes an upper drive rod 221 and a lower drive rod 222 that are hinged together. The lower end of the lower drive rod 222 is connected to the inner sliding sleeve 3, and the upper end of the upper drive rod 221 is hinged to the lower inner wall of the scraper block 21. The axial direction of the lower drive rod 222 is parallel to the axial direction of the outer tube 1, and the axial direction of the upper drive rod 221 is inclined upward from the inside of the outer tube 1 to the outside. The lower end of the driven rod 23 is hinged to the upper inner wall of the scraper block 21, and the upper end of the driven rod 23 is hinged to the outer tube 1. The axial direction of the driven rod 23 is inclined downward from the inside of the outer tube 1 to the outside.

[0060] The upper outer wall of the inner sliding sleeve 3 has multiple installation limiting spaces 34, and the lower drive rod 222 can be limited and installed in the corresponding installation limiting space 34; an adjusting spring 223 is sleeved on the lower outer side of the lower drive rod 222, and a stop part 2221 is formed on the outer wall of the lower drive rod 222. The upper and lower ends of the adjusting spring 223 can respectively abut against the stop part 2221 and the bottom limiting part of the installation limiting space 34.

[0061] During normal scraping operations, the overall outer diameter of the scraper should be slightly larger than the inner diameter of the casing to be scraped. This allows the lower drive rod 222 to slide along the installation limit space 34 when each scraper block 21 is squeezed by the well wall during scraping operations. The spring 223 is used to reduce shock, and at the same time, the spring is initially in a compressed state to provide scraping force for the scraper block 21 to contact the inner wall of the casing.

[0062] The adjusting spring 223 is always in a compressed state. A certain gap is maintained between the lower end of the lower drive rod 222 and the bottom limiting part of the installation limiting space 34. During use, the lower drive rod 222 can move slightly up and down, ensuring that each scraper block 21 can fit tightly against the well wall during scraping, thus guaranteeing the scraping effect. Furthermore, since the radial contraction of each scraper block 21 is achieved by the downward movement of the inner sliding sleeve 3, it does not generate a particularly large compressive force on the adjusting spring 223. This ensures that the force provided by the adjusting spring 223 to the scraper block 21 is basically the same, guaranteeing that the scraping force of the scraper assembly 2 is basically consistent within sleeves of different diameters. Each drive linkage 22 consists of two rod sections connected by a hinge, with an obtuse angle between them. The lower drive rod 222 is installed horizontally within the installation limiting space 34 and can slide up and down along the elongated installation limiting space 34. The upper drive rod 221 is connected to the lower part of the scraper block 21 by a hinge and is in an inclined state. An adjusting spring 223 is installed at the lower part of the mounting limit space 34, and the end of the lower drive rod 222 is inserted into the spring.

[0063] At least two driven rods 23 are connected to the upper part of the scraper block 21. Each driven rod 23 is of equal size and length and is parallel to each other. The driven rods 23 are connected to the scraper block 21 by hinges and are in an inclined state with the inclination direction opposite to that of the upper drive rod 221. The other end of the driven rod 23 is fixed to the outer tube 1 by hinges.

[0064] Generally, each scraper assembly 2 can be equipped with two driven rods 23. When the inner sliding sleeve 3 moves downward, it drives the drive connecting rod 22 to move downward. The drive connecting rod 22 applies a downward pulling force to the scraper block 21. Since the scraper block 21 is connected to two parallel driven rods by hinges, the scraper block 21 moves downward and inward in a state that is parallel to the outer tube 1, thereby reducing the overall outer diameter of the scraper, so that it can enter the smaller diameter sleeve to carry out scraping operations.

[0065] Reference Figure 2 and Figure 3 The inner sliding sleeve 3 includes a sliding sleeve body 35 and a plurality of mounting plates 36 extending upward from the upper end of the sliding sleeve body 35 and arranged circumferentially at intervals. Each mounting plate 36 is provided with an upper limit portion 37 and a lower limit portion 38 spaced vertically along the axial direction. The area enclosed by the upper limit portion 37, the mounting plate 36 and the lower limit portion 38 constitutes the aforementioned mounting limiting space 34. The lower limit portion 38 constitutes a bottom limiting portion. The lower limit portion 38 is located inside the outer tube 1, and the upper end of the mounting plate 36 extends out from the side wall of the outer tube 1.

[0066] The inner sliding sleeve 3 is limited by the upper convex ring 13 during its downward movement, which restricts the downward movement distance. This ensures that after the scraper block 21 is driven to retract inward, the overall outer diameter of the scraper block 21 is just slightly larger than the inner diameter of the lower small diameter sleeve, and the outer diameter formed by the roller 52 is not larger than the maximum outer diameter of the scraper block 21 in its open state.

[0067] To facilitate processing and installation, multiple upper mounting slots 14 are provided on the upper outer wall of the outer tube 1 at the positions of multiple scraper blocks 21. The upper end of each driven rod 23 is hinged to the upper groove wall of the upper mounting slot 14. The bottom groove wall of each upper mounting slot 14 is provided with an upper insertion hole that connects to the inside of the outer tube 1. The mounting plate 36 and the lower drive rod 222 can both move through the upper insertion hole.

[0068] It is understood that the number of upper mounting slots 14 is the same as the number of scraper blocks 21. When there are at least two sets of scraper assemblies 2, each set of scraper assemblies 2 should be arranged at intervals along the axial direction of the outer tube 1, that is, each set of scraper assemblies 2 is distributed in multiple layers along the axial direction of the outer tube 1. The scraper blocks 21 of two adjacent sets of scraper assemblies 2 should be staggered along the circumference of the outer tube 1. The gap between the scraper blocks 21 in the same layer can serve as a fluid channel. The scraper blocks 21 in adjacent layers are staggered along the circumference so that the scraping range of the scraper blocks 21 can cover the circumference of the sleeve during the scraping operation, ensuring more thorough scraping. A set of mounting slot assemblies should be provided on the outer wall of the outer tube 1 for each set of scraper assemblies 2. Each set of mounting slot assemblies includes multiple upper mounting slots 14 arranged at intervals along the circumference of the outer tube 1.

[0069] The specific number of scraper components 2 and scraper blocks 21 in each group of scraper components 2 can be determined as needed. In this embodiment, it is preferred that there are two groups of scraper components 2 arranged vertically and alternately, and the scraper blocks 21 of each group of scraper components 2 are staggered in the circumferential direction of the outer tube 1. Each group of scraper components 2 may include four scraper blocks 21, which facilitates processing and ensures that the scraping range covers the circumference of the sleeve.

[0070] In addition, the lower limit portion 38 of each mounting plate 36 corresponding to the lowest layer scraper assembly 2 can abut against the upper convex ring 13 after the inner sliding sleeve 3 moves downward.

[0071] The number of installation limiting spaces 34 is the same as the number of scraper blocks 21. When one set of scraper assembly 2 is set, each installation limiting space 34 on the inner sliding sleeve 3 is set in one layer, such as Figure 2 As shown; when scraper assembly 2 is set with at least two sets, refer to Figure 3The mounting and limiting spaces 34 of the inner sliding sleeve 3 are also arranged in layers. The inner sliding sleeve 3 is provided with multiple sets of limiting zones arranged axially at intervals. Each set of limiting zones includes multiple mounting and limiting spaces 34 arranged circumferentially at intervals. In each layer of limiting zones, the lower limiting part 38 of each mounting plate 36 is located on the same circumference, and the upper limiting part 37 is located on the same circumference and at the top of the mounting plate 36. In the bottom limiting zone, the lower limiting part 38 is located above the upper convex ring 13, and the inner sliding sleeve 3 can move downward until the lower limiting part 38 abuts against the upper convex ring 13.

[0072] For the bottom limiting zone group, a limiting ring 351 is generally provided outwardly at the top of the sliding sleeve body 35. The bottom of the mounting plate 36 is connected to the limiting ring 351, and the portion of the limiting ring 351 corresponding to each mounting plate 36 constitutes the corresponding lower limiting part 38. For the limiting zone groups of the remaining layers, a lower limiting block is provided at a certain distance from the top of the mounting plate 36, and this lower limiting block constitutes the lower limiting part 38. In each limiting zone group, the upper limiting part 37 is provided at the top of the mounting plate 36, which can be an upper limiting block provided at the top of the mounting plate 36. When the number of scraper assemblies 2 is two groups, such as Figure 3 As shown, the mounting plates 36 in the inner sliding sleeve 3 are also divided into two groups. The length of the mounting plates 36 in one group is greater than the length of the mounting plates 36 in the other group, and the mounting plates 36 in these two groups are staggered along the circumferential direction.

[0073] After the measuring rod 51 initially opens outward, the outer diameter formed by it and the roller 52 should not be greater than the maximum outer diameter of the scraper block 21 in its open state. During the downward movement of the inner sliding sleeve 3, it will be limited by the upper convex ring 13, restricting the downward movement distance. This ensures that after the scraper block 21 retracts inward, the overall outer diameter of the scraper block 21 is just slightly larger than the inner diameter of the lower small-diameter sleeve, and the outer diameter formed by each roller 52 is not greater than the maximum outer diameter of the scraper block 21 in its open state.

[0074] Furthermore, refer to Figure 4 and Figure 5 A slide rail 361 extending axially along the outer tube 1 is provided on the mounting plate 36. A track groove 224 extending axially along the outer tube 1 and passing through it vertically is provided on the lower drive rod 222. The slide rail 361 can be slidably inserted into the track groove 224. The slide rail 361 is located within the installation limiting space 34, and the track groove 224 is located on the side of the lower drive rod 222 facing the mounting plate 36. The cooperation between the slide rail 361 and the track groove 224 can guide the movement of the lower drive rod 222, ensuring smooth operation. The upper limit part 37 on each mounting plate 36 is detachably provided on the top of the mounting plate 36. For example, the upper limit part 37 can be connected to the mounting plate 36 by screws to facilitate disassembly and installation of the lower drive rod 222.

[0075] Furthermore, the aforementioned scraper can be used to scrape combined sleeves with a larger diameter at the top and a smaller diameter at the bottom. The adaptive diameter-changing working method of this scraper includes the following steps:

[0076] S1. The scraper is lowered into the large-diameter casing. The roller 52 contacts the inner wall of the casing to sense the well diameter in real time. The scraper block 21 is pressed against the casing well wall under the action of the adjusting spring 223. As the scraper is lowered, the scraper block 21 continuously scrapes the casing wall.

[0077] S2. After the large-diameter casing is scraped, the scraper continues to be lowered. The measuring rod 51 enters the small-diameter casing. The roller 52 is squeezed by the well wall, pushing the lower measuring rod 511 and the upper measuring rod 512 inward, and causing the axial sliding rod 513 to move upward.

[0078] S3. After the axial sliding rod 513 moves upward and contacts the inwardly inclined surface of the elastic plate 4, it pushes the elastic plate 4 outward and the upper end of the elastic plate 4 disengages from the groove 31 of the inner sliding sleeve 3.

[0079] S4. When the upper ends of the elastic plates 4 distributed around the perimeter are disengaged from the slots 31 of the inner sliding sleeve 3, the lower part of the inner sliding sleeve 3 loses its constraint, and the compression spring 33 pushes the inner sliding sleeve 3 to move downward.

[0080] S5. During the downward movement of the inner sliding sleeve 3, the drive linkage 22 moves downward. The drive linkage 22 applies downward and inward pulling force to the scraper block 21. Since the scraper block 21 is connected by two parallel driven linkages through a hinge, the scraper block 21 moves downward and inward in a state parallel to the outer tube 1, thereby reducing the overall outer diameter of the scraper. It can then continue to be lowered into the scraper to enter the small diameter sleeve for scraping operations.

[0081] In summary, the scraper in this embodiment is designed with a diameter measuring component 5 to sense the well diameter in real time. When the tool scrapes the upper large-diameter casing and enters the lower small-diameter casing, the diameter measuring connecting rod 51 contracts under the constraint of the well wall, triggering the inner sliding sleeve 3 to move downward. The inner sliding sleeve 3 drives the drive connecting rod 22 to move downward, causing the scraper block 21 to contract inward, thereby reducing the scraper's scraping diameter to the range of the lower casing diameter. Continuing to descend, it can perform scraping and cleaning operations on the lower small-diameter casing. The multiple diameter measuring connecting rods 51 distributed around the tubing string can only trigger the scraper block 21 to contract after they are all fully compressed (even after all the elastic plates 4 have popped open), which can avoid accidental contact with well wall deposits or sand bridges. Using this scraper to scrape the combined casing with a larger diameter at the top and a smaller diameter at the bottom, there is no need to pull out the drill string to change tools, or to perform additional ball dropping or pressure testing. The scraper adapts to the casing diameter, enabling the scraping of the combined casing in one trip.

[0082] The above are merely illustrative embodiments of the present invention and are not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A combined sleeve adaptive variable diameter scraper, characterized in that, include: outer tube; At least one set of scraper assemblies, each set of scraper assemblies including a plurality of scraper blocks circumferentially spaced on the upper outer side of the outer tube and capable of radial retraction; The inner sliding sleeve is axially movable inside the outer tube, and its upper end can extend out from the side wall of the outer tube and connect to the scraper assembly. The elastic component includes a plurality of elastic pieces circumferentially spaced inside the outer tube. The lower end of each elastic piece can abut against and be limited on the inner wall of the outer tube, and the upper end can be engaged with the lower end of the inner sleeve to axially limit the inner sleeve. The diameter measuring assembly includes a plurality of diameter measuring connecting rods circumferentially spaced on the lower outer side of the outer tube. The upper ends of the diameter measuring connecting rods can extend axially into the outer tube from the side wall. Under the action of the well wall shrinking and being squeezed by the well wall, the upper ends of the diameter measuring connecting rods can move upward axially and push each of the elastic plates to pop out and disengage from the inner sliding sleeve, so that the inner sliding sleeve moves downward and drives each of the scraper blocks to retract radially inward.

2. The combined sleeve adaptive diameter scraper as described in claim 1, characterized in that, Each of the measuring rods includes a lower measuring rod, an upper measuring rod, and an axial sliding rod that are hinged sequentially from bottom to top. The lower end of the lower measuring rod is hinged to the outer tube, and the angle between the lower measuring rod and the upper measuring rod is an obtuse angle. The upper end of the axial sliding rod can extend into the outer tube.

3. The combined sleeve adaptive diameter scraper as described in claim 2, characterized in that, A roller is also provided at the hinge position of the lower measuring rod and the upper measuring rod.

4. The combined sleeve adaptive diameter scraper as described in claim 2, characterized in that, Multiple insertion holes are provided circumferentially on the side wall of the outer tube, through which the upper end of the axial sliding rod can pass, and a sealing ring is provided between the axial sliding rod and the insertion holes.

5. The combined sleeve adaptive diameter scraper as described in claim 4, characterized in that, The lower outer wall of the outer tube is provided with a plurality of lower mounting slots spaced apart circumferentially, and each measuring rod is installed in the corresponding lower mounting slot; the lower end of the lower measuring rod is hinged to the bottom wall of the lower mounting slot, and the top wall of each lower mounting slot is provided with a lower insertion hole communicating with the interior of the outer tube, and the upper end of the axial sliding rod can pass through the lower insertion hole.

6. The combined sleeve adaptive diameter scraper as described in claim 1, characterized in that, A limiting groove is formed on the inner wall of the outer tube, and a retaining groove is formed on the lower outer wall of the inner sliding sleeve. The lower end of the elastic piece can abut against the bottom groove wall of the limiting groove, and the upper end of the elastic piece can be engaged in the retaining groove.

7. The combined sleeve adaptive diameter scraper as described in claim 1, characterized in that, An upper protruding ring is provided on the inner wall of the middle part of the outer tube, and a lower protruding ring is provided on the outer wall of the inner sleeve. The lower protruding ring is located below the upper protruding ring. A compression spring is provided on the outer sleeve of the inner sleeve, and the upper and lower ends of the compression spring can respectively abut against the upper protruding ring and the lower protruding ring.

8. The combined sleeve adaptive diameter scraper as described in claim 7, characterized in that, Each scraper assembly further includes a drive linkage and at least two parallel driven rods located above the drive linkage. The drive linkage includes an upper drive rod and a lower drive rod that are hinged together vertically. The lower end of the lower drive rod is connected to the inner sliding sleeve, and the upper end of the upper drive rod is hinged to the lower inner wall of the scraper block. The axial direction of the lower drive rod is parallel to the axial direction of the outer tube, and the axial direction of the upper drive rod is inclined upward from the inside of the outer tube to the outside. The lower end of the driven rod is hinged to the upper inner wall of the scraper block, and the upper end of the driven rod is hinged to the outer tube. The axial direction of the driven rod is inclined downward from the inside of the outer tube to the outside.

9. The combined sleeve adaptive diameter scraper as described in claim 8, characterized in that, The upper outer wall of the inner sliding sleeve has multiple installation limiting spaces, and the lower drive rod can be limited and installed in the corresponding installation limiting space; an adjusting spring is sleeved on the lower outer side of the lower drive rod, and a stop part is formed on the outer wall of the lower drive rod, and the upper and lower ends of the adjusting spring can respectively abut against the stop part and the bottom limiting part of the installation limiting space.

10. The combined sleeve adaptive diameter scraper as described in claim 9, characterized in that, The inner sliding sleeve includes a sliding sleeve body and a plurality of mounting plates extending upward from the upper end of the sliding sleeve body and arranged circumferentially at intervals. Each mounting plate is provided with an upper limit portion and a lower limit portion spaced vertically along the axial direction. The area enclosed by the upper limit portion, the mounting plate and the lower limit portion constitutes the installation limiting space, and the lower limit portion constitutes the bottom limiting portion. The lower limit portion is located inside the outer tube, and the upper end of the mounting plate extends out from the side wall of the outer tube.

11. The combined sleeve adaptive diameter scraper as described in claim 10, characterized in that, Multiple upper mounting slots are respectively opened on the upper outer wall of the outer tube at the positions of multiple scraper blocks. The upper end of each driven rod is hinged to the upper groove wall of the upper mounting slot. The bottom groove wall of each upper mounting slot is provided with an upper insertion hole that communicates with the inside of the outer tube. The mounting plate and the lower drive rod can both move through the upper insertion hole.

12. The combined sleeve adaptive diameter scraper as described in claim 10, characterized in that, The number of scraper assemblies is two sets, arranged vertically at intervals, and the scraper blocks of each of the two sets of scraper assemblies are staggered in the circumferential direction of the outer tube.

13. The combined sleeve adaptive diameter scraper as described in claim 12, characterized in that, The lower limit portion of each mounting plate corresponding to the lowest layer of the scraper assembly can abut against the upper convex ring after the inner sleeve moves downward.

14. The combined sleeve adaptive diameter scraper as described in claim 10, characterized in that, The mounting plate has a slide rail extending axially along the outer tube, and the lower drive rod has a track groove extending axially along the outer tube and passing through it vertically. The slide rail can be slidably inserted into the track groove.

15. The combined sleeve adaptive diameter scraper as described in claim 14, characterized in that, The upper limit portion on each of the mounting plates is detachably provided at the top of the mounting plate.

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