Casing inner wall cleaning tool

Abstract

The present application belongs to the technical field of oil and gas drilling and completion engineering, and discloses a casing inner wall cleaning tool, which comprises a tool main body, a central pipe, a starting assembly, a receiving assembly, a transposition assembly and a scraping assembly. The tool main body is sleeved outside the central pipe, the receiving assembly is arranged above the central pipe, the receiving assembly and the central pipe can move downward synchronously in the tool main body under the action of the starting assembly, the transposition assembly is slidably arranged on the central pipe, the central pipe has at least a first locking position and a second locking position, the scraping assembly is arranged on the tool main body and elastically abuts against the central pipe, and the scraping assembly has at least a scraping state and a drilling and grinding state. In the scraping state, the transposition assembly is located at the first locking position, and the scraping assembly protrudes outside the tool main body. In the drilling and grinding state, the transposition assembly is located at the second locking position, and the scraping assembly is embedded in the central pipe. The present application realizes the implementation of the through, scraping and washing operation by only once drilling.

Description

Technical Field

[0001] This invention relates to the field of oil and gas drilling and completion engineering technology, and in particular to a casing inner wall cleaning tool. Background Technology

[0002] Currently, during the drilling, completion, and production operations of oil and gas wells, the casing inevitably suffers from contamination, corrosion, or other damage due to various factors during cementing, completion, or prolonged production use. The continuous accumulation of impurities such as cement blocks, oil deposits, salt deposits, hard wax, burrs, and rust inside the casing wall causes a gradual reduction in the casing's inner diameter, negatively impacting subsequent well workover and other downhole operations. Existing technology often employs casing scrapers to scrape the inner wall of the casing to remove impurities, restore the casing's diameter, and facilitate the smooth implementation of tool tripping and other operations. When the annular space between the downhole tool and the casing inner wall is relatively small in oil and gas wells, thorough scraping of the casing wall is even more necessary before construction can proceed. Casing scraping effectively improves the success rate of tool tripping and operations and is an indispensable procedure in oil and water well operations. For example, a conventional spring-loaded casing scraper uses an elastically expanding and compressing scraper block to scrape and clean the inner wall of the casing. When encountering stubborn burrs or scale, it is necessary to remove the casing string and lower a grinding string with a grinding shoe for rotary grinding. Then, the casing scraper string is lowered again for further scraping. In existing technologies, the grinding shoe and casing scraper are often lowered simultaneously to save one trip of string removal. However, the rotary grinding process can damage the casing scraper and even cause drill jamming. Therefore, how to achieve the cleaning, scraping, and rinsing of the casing inner wall in a single drilling operation is a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0003] The purpose of this invention is to provide a casing inner wall cleaning tool that can achieve the cleaning, scraping and washing of the casing inner wall in a single drilling operation.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A tool for cleaning the inner wall of a casing, including:

[0006] The tool body and the central tube, with the tool body fitted onto the outside of the central tube;

[0007] The tool body includes an initiating component and a receiving component, the receiving component being positioned above the central tube, and both the receiving component and the central tube being able to move downwards synchronously within the tool body under the action of the initiating component.

[0008] The tool includes a shifting component and a scraping component. The shifting component is slidably disposed on the central tube, and the central tube has at least a first locking position and a second locking position. The scraping component is disposed on the tool body and elastically presses against the central tube. The scraping component has at least a scraping state and a drilling state. In the scraping state, the shifting component is located in the first locking position and the scraping component protrudes from the outside of the tool body. In the drilling state, the shifting component is located in the second locking position and the scraping component is embedded in the central tube.

[0009] Optionally, the transposition assembly includes a transposition slip ring, a transposition slip pin, a retaining ring, and a return spring. The transposition slip pin is disposed on the transposition slip ring and slidably disposed on the transposition channel of the central tube. The transposition slip ring, the retaining ring, and the return spring are sequentially sleeved on the outside of the central tube. When the central tube moves downward, it can compress the return spring, and the central tube can move upward under the action of the return spring.

[0010] Optionally, the transposition channel is provided with equal-length slots, short slots and long slots that are interconnected in pairs, the first locking position is located in the short slot and the second locking position is located in the long slot.

[0011] When the central tube moves downward, the shifting pin can slide from the short groove to the equal-length groove, and when the central tube moves upward under the action of the return spring, the shifting pin can slide from the equal-length groove to the long groove, so as to switch between the scraping state and the drilling state.

[0012] Optionally, the scraping assembly includes a scraping block, a support spring, a mounting plate, and a positioning member 94. One end of the support spring is embedded in the scraping block, and the other end is connected to the mounting plate. The positioning member passes through the scraping block and the mounting plate in sequence.

[0013] Optionally, a first mounting groove is provided on the outer side of the central tube. In the drilling state, the mounting plate can be embedded in the first mounting groove, and at this time, the distance between the outer side of the scraper block and the axis of the central tube is less than or equal to the outer diameter of the tool body.

[0014] Optionally, the scraping assembly further includes an elastic sheet and a first fixing member. A second mounting groove is provided on the outer side of the central tube. The first fixing member can fix one end of the elastic sheet in the second mounting groove, and the other end of the elastic sheet 95 elastically presses against the scraping block.

[0015] Optionally, the scraping assembly further includes a pressure block, a stop block, and a second fixing member. The pressure block is fixed to the tool body by the second fixing member. The elastic sheet and the first fixing member are located between the limiting end of the pressure block and the second mounting groove. The stop block is also fixed to the tool body by the second fixing member, and the pressure block is located between the scraping block and the stop block.

[0016] Alternatively, the actuation assembly includes a steel ball and a basket, the steel ball being able to enter through an opening at the top of the tool body and sequentially pass through the receiving assembly and the central tube until it is confined to the bottom of the basket.

[0017] Optionally, the receiving assembly includes a limiting ring, a ball seat, and a central tube connector. The limiting ring is used to limit the ball seat within the tool body. One end of the central tube connector is connected to the ball seat, and the other end is connected to the central tube. The actuation assembly contains a steel ball that can sit on the ball seat and push the ball seat, the central tube connector, and the central tube to move downward synchronously with it.

[0018] Optionally, the tool body includes an upper connector, a shifting cylinder, a scraping cylinder, and a lower connector connected in sequence. The receiving component is disposed inside the upper connector, the shifting component is disposed inside the shifting cylinder, and a plurality of scraping components are spirally disposed on the scraping cylinder.

[0019] The beneficial effects of this invention are:

[0020] In this invention, the starting component drives the receiving component and the central tube to move synchronously downward within the tool body. The shifting component, slidably mounted on the central tube, can switch between a first locking position and a second locking position, thereby changing the operating state of the scraping component. Specifically, when the shifting component is in the first locking position, the scraping component is in a scraping state, protruding from the outside of the tool body, allowing for scraping and cleaning of the tube wall inside the casing. When the shifting component is in the second locking position, the scraping component is embedded in the central tube and is in a grinding state. At this point, the entire tool can perform rotary grinding on the inner wall of the casing to treat stubborn burrs, scale, etc. Thus, scraping, unblocking, and cleaning operations can be performed with only one drilling operation, significantly reducing the number of drilling operations compared to existing scraping equipment and greatly shortening the construction cycle for unblocking, scraping, and cleaning, effectively reducing operating costs. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the sleeve inner wall cleaning tool according to an embodiment of the present invention;

[0022] Figure 2 This is a partially enlarged view of the receiving component in the casing inner wall cleaning tool described in an embodiment of the present invention;

[0023] Figure 3 This is a partially enlarged view of the repositioning component in the casing inner wall cleaning tool described in an embodiment of the present invention;

[0024] Figure 4 This is a partially enlarged view of the activation component in the casing inner wall cleaning tool described in an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the casing inner wall cleaning tool in its initial state according to an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the casing inner wall cleaning tool in a scraping state according to an embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of the ball seat in the casing inner wall cleaning tool according to an embodiment of the present invention;

[0028] Figure 8 This is a side view of the ball seat in the casing inner wall cleaning tool according to an embodiment of the present invention;

[0029] Figure 9 This is a schematic diagram of the repositioning channel on the central tube of the casing inner wall cleaning tool described in an embodiment of the present invention;

[0030] Figure 10 This is a cross-sectional schematic diagram of the scraping block in the casing inner wall cleaning tool according to an embodiment of the present invention;

[0031] Figure 11 This is a schematic diagram of the scraping block in the casing inner wall cleaning tool according to an embodiment of the present invention;

[0032] Figure 12 This is a left view of the scraping block in the casing inner wall cleaning tool described in an embodiment of the present invention;

[0033] Figure 13 This is a right view of the scraping block in the casing inner wall cleaning tool described in an embodiment of the present invention.

[0034] In the picture:

[0035] 10 - Upper connector; 20 - Transposition cylinder; 30 - Scraper cylinder; 40 - Lower connector;

[0036] 50 - Starting component; 60 - Receiving component; 70 - Center tube; 80 - Transposition component; 90 - Scraping component;

[0037] 101-Anti-rotation pin; 102-First anti-detachment pin; 103-First limiting step; 201-Second anti-detachment pin; 301-Third anti-detachment pin;

[0038] 51-Steel ball; 52-Basket; 53-Snap ring; 521-Limiting protrusion; 522-Inner cavity;

[0039] 61-Limiting ring; 62-Ball seat; 63-Upper connector of central tube; 601-First scraper ring; 602-First seal;

[0040] 621 - Abutting end; 622 - Trumpet mouth; 6221 - Gap;

[0041] 701-Felt ring; 702-First mounting groove; 703-Second mounting groove; 71-Equal length groove; 72-Short groove; 73-Long groove;

[0042] 81-Shifting slip ring; 82-Shifting pin; 83-Retaining ring; 84-Reset spring; 801-Limit pin;

[0043] 91-Scraper block; 92-Support spring; 93-Mounting plate; 94-Positioning component; 95-Elastic sheet; 96-First fixing component; 97-Pressure block; 98-Stop block; 99-Second fixing component; 901-Second seal; 902-Second mud scraper ring; 911-Connecting part; 912-Grinding part; 913-Accommodation groove. Detailed Implementation

[0044] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0045] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] Currently, during the drilling, completion, and production operations of oil and gas wells, the casing inevitably suffers from contamination, corrosion, or other damage due to various factors during cementing, completion, or prolonged production use. The continuous accumulation of impurities such as cement blocks, oil deposits, salt deposits, hard wax, burrs, and rust inside the casing wall causes a gradual reduction in the casing's inner diameter, negatively impacting subsequent well workover and other downhole operations. Existing technology often employs casing scrapers to scrape the inner wall of the casing to remove impurities, restore the casing's diameter, and facilitate the smooth implementation of tool tripping and other operations. When the annular space between the downhole tool and the casing inner wall is relatively small in oil and gas wells, thorough scraping of the casing wall is even more necessary before construction can proceed. Casing scraping effectively improves the success rate of tool tripping and operations and is an indispensable procedure in oil and water well operations. For example, a conventional spring-loaded casing scraper uses an elastically expanding and compressing scraper block to scrape and clean the inner wall of the casing. When encountering stubborn burrs or scale, it is necessary to remove the casing string and lower a grinding string with a grinding shoe for rotary grinding. Then, the casing scraper string is lowered again for further scraping. In existing technologies, the grinding shoe and casing scraper are often lowered simultaneously to save one trip of string removal. However, the rotary grinding process can damage the casing scraper and even cause drill jamming. Therefore, how to achieve the cleaning, scraping, and rinsing of the casing inner wall in a single drilling operation is a problem that needs to be solved by those skilled in the art.

[0048] The technical solution of this embodiment will be further described below with reference to the accompanying drawings and specific implementation methods.

[0049] like Figures 1-13As shown, this embodiment provides a casing inner wall cleaning tool including a tool body, a central tube 70, an actuating component 50, a receiving component 60, a shifting component 80, and a scraping component 90. The tool body is sleeved on the outside of the central tube 70, and the receiving component 60 is disposed above the central tube 70. The receiving component 60 and the central tube 70 can move downward synchronously inside the tool body under the action of the actuating component 50. The shifting component 80 is slidably disposed on the central tube 70, and the central tube 70 has at least a first locking position and a second locking position. The scraping component 90 is disposed on the tool body and elastically presses against the central tube 70. The scraping component 90 has at least a scraping state and a drilling state. In the scraping state, the shifting component 80 is located in the first locking position, and the scraping component 90 protrudes from the outside of the tool body. In the drilling state, the shifting component 80 is located in the second locking position, and the scraping component 90 is embedded in the central tube 70.

[0050] Specifically, in this embodiment, the starting component 50 drives the receiving component 60 and the central tube 70 to move synchronously downward within the tool body. The shifting component 80, slidably mounted on the central tube 70, can switch between a first locking position and a second locking position, thereby changing the operating state of the scraping component 90. Specifically, when the shifting component 80 is in the first locking position, the scraping component 90 is in a scraping state, protruding from the outside of the tool body, allowing for scraping and cleaning of the tube wall within the casing. When the shifting component 80 is in the second locking position, the scraping component 90 is embedded in the central tube 70, in a grinding state. At this time, the entire tool can perform rotary grinding on the inner wall of the casing to treat stubborn burrs, scale, etc. Thus, scraping, unblocking, and cleaning operations can be achieved with only one drilling operation. Compared to existing technologies, this significantly reduces the number of drilling operations for scraping equipment and greatly shortens the construction cycle for unblocking, scraping, and cleaning, effectively reducing operating costs.

[0051] The specific structure of the cleaning tool for the inner wall of the casing in this embodiment is described below.

[0052] like Figure 1As shown, the cannula inner wall cleaning tool in this embodiment includes a tool body, a starting component 50, a receiving component 60, a central tube 70, a shifting component 80, and a scraping component 90. Specifically, the tool body in this embodiment includes an upper connector 10, a shifting cylinder 20, a scraping cylinder 30, and a lower connector 40, which are connected sequentially to form the overall structure of the cannula inner wall cleaning tool. Further, the tool body is sleeved on the outside of the central tube 70, and the central tube 70 is movably disposed inside the tool body. Optionally, the receiving component 60 is disposed above the central tube 70 and located inside the upper connector 10. In this embodiment, the receiving component 60 and the central tube 70 can move downward synchronously inside the tool body under the action of the starting component 50 to perform subsequent shifting operations. Optionally, in this embodiment, the shifting component 80 is disposed inside the shifting cylinder 20 and slidably disposed on the central tube 70. The central tube 70 is provided with at least a first locking position and a second locking position, and the shifting component 80 can slide and switch between the first locking position and the second locking position to achieve different operating effects. Specifically, several scraping components 90 are spirally arranged on the scraping cylinder 30 of the tool body and can elastically press against the central tube 70. Exemplarily, in this embodiment, the scraping components 90 have at least a scraping state and a drilling state. In the scraping state, the switching component 80 is in a first locked position, at which time the scraping components 90 protrude from the outside of the tool body and can scrape and clean the inner wall of the casing. In the drilling state, the switching component 80 is in a second locked position, at which time the scraping components 90 are embedded in the central tube 70 for storage, allowing the entire device to perform drilling operations without interference from the scraping components 90. Thus, under the action of the starting component 50, the central tube 70 can be driven to move, thereby realizing the sliding switching of the switching component 80 on the central tube 70, achieving the switching between the scraping state and the drilling state of the scraping components 90, adapting to different construction needs, and forming a drilling tool assembly integrating grinding, drill pipe, cleaning, drill pipe, well gauge, and drill pipe cleaning and drilling.

[0053] Combination Figures 1-4As shown, specifically, in this embodiment, the upper connector 10 is further provided with an anti-rotation pin 101, a first anti-detachment pin 102, and a first limiting step 103; the shifting cylinder 20 is provided with a second anti-detachment pin 201 and a second limiting step; and the scraping cylinder 30 is provided with a third anti-detachment pin 301. Optionally, the upper connector 10, shifting cylinder 20, scraping cylinder 30, and lower connector 40 are sequentially connected by threads to form the tool body, ensuring the four components are integrated, enabling them to move synchronously without relative rotation. Furthermore, the upper connector 10 and shifting cylinder 20 are connected by the first anti-detachment pin 102, the shifting cylinder 20 and scraping cylinder 30 are connected by the second anti-detachment pin 201, and the scraping cylinder 30 and lower connector 40 are connected by the third anti-detachment pin 301, thereby further ensuring that the connected components are less prone to loosening and guaranteeing the overall stability of the tool body connection. For example, the first anti-detachment pin 102 connection is also provided with a balance hole to connect the inside of the tool body with the outside, thereby balancing the fluid pressure inside and outside the tool body and avoiding the influence of pressure during use.

[0054] like Figure 2 and Figure 3 As shown, in this embodiment, a first limiting step 103 is also provided to limit the position of the receiving component 60 within the upper connector 10, so that the upward movement of the central tube 70 is restricted and it will not detach from the upper connector 10. Furthermore, an anti-rotation groove is provided on the outer side of the central tube 70, and an anti-rotation pin 101 is provided on the cylinder wall of the upper connector 10 and can be inserted into the anti-rotation groove to ensure that the upper connector 10 and the central tube 70 cannot rotate relative to each other. This allows the shifting component 80, sleeved outside the central tube 70, to rotate relative to the central tube 70 within the shifting cylinder 20 and slide, achieving the shifting effect. Similarly, a second limiting step is provided in the shifting cylinder 20 to limit the position of the shifting component 80, so that the upward movement of the shifting component 80 is restricted and it will not detach from the shifting cylinder 20.

[0055] Combination Figure 1 and Figure 4As shown, in this embodiment, the starting component 50 includes a steel ball 51, a ball basket 52, and a retaining ring 53. The ball basket 52 is provided with a limiting protrusion 521 and an inner cavity 522. Optionally, in this embodiment, the steel ball 51 can enter through an opening at the top of the tool body, that is, at the top of the upper connector 10, and sequentially pass through the receiving component 60 and the central tube 70 until it is limited to the bottom of the ball basket 52. Through multiple projections of the steel ball 51, the relative position between the central tube 70 and the shifting component 80 can be changed multiple times, thereby achieving a shifting effect and realizing the transformation of the scraping component 90 into different states. Exemplarily, the ball basket 52 and the retaining ring 53 are both located in the lower connector 40. The lower connector 40 is provided with a third limiting step, which can limit the top of the ball basket 52. The retaining ring 53 is located at the bottom of the ball basket 52 and limited in the lower connector 40. Thus, the bottom of the ball basket 52 is limited by the retaining ring 53, and the position of the ball basket 52 is locked. Furthermore, in this embodiment, the basket 52 is designed with a hollow structure and is made of high-quality spring steel to ensure that the basket 52 has good deformation capacity, so as to provide a cushioning effect for the falling steel ball 51.

[0056] For example, the basket 52 is provided with limiting protrusions 521 at both the top and bottom. When the steel ball 51 moves downward to the top limiting protrusion 521, due to its instantaneous axial force and gravity, the steel ball 51 can pass through the top limiting protrusion 521 and enter the inner cavity 522 under the combined action of the basket 52 and the bottom limiting protrusion 521, thus trapping the steel ball 51 and preventing it from falling further downward. For example, the inner diameter of the top limiting protrusion 521 is larger than the inner diameter of the bottom limiting protrusion 521, making it easier for the steel ball 51 to pass through the top but more difficult to pass through the bottom, thus trapping the steel ball 51.

[0057] like Figure 2 and Figure 7 , Figure 8 As shown, optionally, the receiving component 60 includes a limiting ring 61, a ball seat 62, a central tube upper connector 63, a first scraper ring 601, and a first seal 602. The ball seat 62 is provided with an abutment end 621 and a flared end 622, and the flared end 622 is also provided with a gap 6221. Specifically, the limiting ring 61 is provided at the top to limit the ball seat 62 in the tool body. One end of the central tube connector 63 is connected to the ball seat 62, and the other end is connected to the central tube 70, thereby achieving a stable connection between the receiving component 60 and the central tube 70. Optionally, in this embodiment, the receiving component 60 and the central tube 70 constitute a central tube system. The central tube system (except for the limiting ring 61) can move downward and upward in the tool body. For example, the steel ball 51 can be seated on the ball seat 62, and under its force, it can push the ball seat 62, the central tube upper connector 63, and the central tube 70 to move downward synchronously, thereby achieving the effect of subsequent repositioning operations.

[0058] Specifically, in this embodiment, the limiting ring 61 is connected to the upper connector 10 by a thread, thus fixing the position of the limiting ring 61. When the central tube system moves, the limiting ring 61 will not move synchronously with it. Furthermore, the limiting ring 61 restricts the contact end 621 of the ball seat 62, preventing the ball seat 62 from moving upwards, thereby ensuring that the upward movement of the central tube system is limited. Combined with... Figure 1 and Figure 8 As shown, exemplarily, in this embodiment, the ball seat 62 is manufactured using high-quality spring steel, and its flared opening 622 is configured as a split structure, allowing its inner diameter to change under tremendous impact force. Specifically, after the steel ball 51 is inserted from the wellhead, the steel ball 51 enters the tool body under the action of gravity, and the steel ball 51 first enters the flared opening 622 of the ball seat 62 at the top of the upper connector 10. Under the action of the high-pressure liquid injected at the wellhead, the steel ball 51 can push the central tube system, excluding the limiting ring 61, to move downwards synchronously with it inside the tool body. Under continuous pressure at the wellhead, the steel ball 51 gradually moves toward the central tube 70 in the flared opening 622. Due to the gap 6221 of the flared opening 622, the steel ball 51 continuously exerts an outward force on the inner wall of the flared opening 622, causing its inner diameter to gradually increase. This expands the space around the steel ball 51, allowing it to enter the upper connector 63 of the central tube and the central tube 70 sequentially through the ball seat 62, until it finally falls into the basket 52 to complete a ball-throwing operation.

[0059] Optionally, a ball seat 62 is installed above the connector 63 on the central tube and screwed to the central tube 70 below. A first scraper ring 601 and a first seal 602 are sleeved on the outside of the screwed connection to form a piston structure. Exemplarily, in this embodiment, two first scraper rings 601 and two first seals 602 are provided, with the two first seals 602 located between the two first scraper rings 601. Optionally, the first scraper ring 601 is made of polytetrafluoroethylene to block mud. The first scraper ring 601 is located on the upper and lower sides of the first seal 602, effectively reducing damage to the seal ring caused by surrounding mud during movement. Different materials can also be selected in this embodiment, which will not be elaborated here.

[0060] Combination Figure 1 , Figure 3 and Figure 9As shown, a felt ring 701 is provided on the outer side of the central tube 70, and a shifting channel is provided on the central tube 70, which has several equal-length grooves 71, short grooves 72, and long grooves 73. Further, the shifting assembly 80 includes a shifting slip ring 81, a shifting pin 82, a retaining ring 83, and a return spring 84, and a limiting pin 801 is also provided on the shifting assembly 80. Optionally, the shifting pin 82 is disposed on the shifting slip ring 81 and slidably disposed on the shifting channel of the central tube 70, while the shifting slip ring 81, retaining ring 83, and return spring 84 are sequentially sleeved on the outer side of the central tube 70. Optionally, when the central tube 70 is subjected to a force and moves downward inside the tool body, the return spring 84 can be compressed, and when the central tube 70 loses its force, the central tube 70 can move upward under the action of the return spring 84. Furthermore, during the up-and-down movement of the central tube 70, the shifting pin 82 can switch between different positions on the shifting channel, thereby realizing the switching between different operating states of the scraping assembly 90.

[0061] Specifically, in this embodiment, the felt ring 701 is sleeved on the outside of the central tube 70 and located between the repositioning component 80 and the first anti-detachment pin 102, serving the same function as the first mud scraper ring 601, both used for cleaning. Figure 9 As shown, further, the transposition channel extends to the left with an equal-length groove 71, and extends to the right with a short groove 72 and a long groove 73 respectively. Multiple sets of short grooves 72 and long grooves 73 are spaced apart and arranged axially, and an equal-length groove 71 is provided between each adjacent short groove 72 and long groove 73. The equal-length grooves 71, short grooves 72, and long grooves 73 are interconnected, and the channels connecting any two of them are inclined to facilitate the subsequent sliding transposition of the transposition pin 82 among them. For example, the equal-length grooves 71 are all of the same length, the short grooves 72 are longer than the equal-length grooves 71, and the short grooves 72 are shorter than the long grooves 73, to facilitate locking the position of the transposition pin 82. Specifically, the first locking position is set in the short groove 72, and the second locking position is set in the long groove 73. When the central tube 70 moves downward, the shifting pin 82 can rotate to the left and slide from the short groove 72 to the equal-length groove 71. When the central tube 70 moves upward under the action of the return spring 84, the shifting pin 82 can rotate to the right and gradually slide from the equal-length groove 71 to the long groove 73, thereby switching the scraping assembly 90 from the scraping state to the drilling state. Conversely, when the shifting pin 82 slides from the long groove 73 to the equal-length groove 71 and then to the short groove 72, the scraping assembly 90 can return from the drilling state to the scraping state, thereby realizing the switching between the scraping state and the drilling state.

[0062] Combination Figure 3As shown, the shifting slip ring 81 is limited below the second limiting step of the shifting cylinder 20 and is limited on the limiting pin 801, thereby ensuring that the shifting slip ring 81 will not move axially. Optionally, the limiting pin 801 passes through the shifting cylinder 20 to its interior to ensure that the shifting slip ring 81 can abut against the top of the limiting pin 801. Further, the shifting slip ring 81 is provided with a mounting hole, one end of the shifting slip pin 82 is installed in the mounting hole, and the other end is inserted into the shifting channel. The retaining ring 83 is located between the return spring 84 and the limiting pin 801, and the return spring 84 is located between the retaining ring 83 and the second anti-disengagement pin 201. Thus, the retaining ring 83 can limit the top of the return spring 84, and the return spring 84 can achieve the return effect through its elastic action.

[0063] Specifically, in this embodiment, initially, the displacement pin 82 of the casing inner wall cleaning tool is located in the first locked position of the short groove 72. At this time, the scraping assembly 90 is in the scraping state, which can ensure that the tool can scrape and clean the inner wall of the casing. After the steel ball 51 is dropped, the tool body remains stationary. The steel ball 51 pushes the ball seat 62, the upper connector 63 of the central tube, and the central tube 70 to move downward relative to the displacement slip ring 81 and squeeze the return spring 84. The displacement pin 82 on the displacement slip ring 81 slides from the short groove 72 to the equal-length groove 71 above it in the displacement channel. The steel ball 51 passes through the ball seat 62 and falls rapidly inside the upper connector 63 of the central tube and the central tube 70. After the ball basket 52 is in place, the ball seat 62, the upper connector 63 of the central tube, and the central tube 70 lose downward pressure, and thus lose the downward squeezing force on the return spring 84. The return spring 84 returns to its original position under its elastic action, and conversely provides an upward force on the ball seat 62, the upper connector 63 of the central tube, and the central tube 70. The central tube 70 moves upward relative to the shifting slip ring 81. At this time, the shifting slip pin 82 gradually slides downward in the shifting channel from the equal length groove 71 until it slides to the second locking position in the long groove 73, realizing that the central tube 70 moves upward by one end and completes the shifting, realizing the effect of the scraping assembly 90 switching from the scraping state to the drilling state.

[0064] Combination Figures 1-6 , Figures 10-13 As shown, in this embodiment, the outer side of the central tube 70 is also provided with a first mounting groove 702 and a second mounting groove 703 for mounting the limiting scraping assembly 90. Optionally, the scraping assembly 90 includes a scraping block 91, a support spring 92, a mounting plate 93, a positioning member 94, an elastic sheet 95, a first fixing member 96, a pressure block 97, a stop block 98, and a second fixing member 99. The scraping assembly 90 is also provided with a second seal 901 and a second scraping ring 902, and the scraping block 91 is provided with a connecting part 911, a grinding part 912, and a receiving groove 913.

[0065] like Figure 5 and Figure 6As shown, optionally, the outer side of the central tube 70 is provided with a plurality of first mounting grooves 702, and the upper and lower sides of the first mounting grooves 702 are provided with large-angle chamfers, while the bottom of the mounting plate 93 is provided with a large-angle chamfer. The two are sized to match, so that the mounting plate 93 can be embedded in the first mounting grooves 702 in the drilling state. Further, after the mounting plate 93 is embedded in the first mounting grooves 702, the distance between the outer side of the scraper block 91 and the axis of the central tube 70 is less than or equal to the outer diameter D1 of the tool body, thereby ensuring that the entire scraping assembly 90 does not protrude from the outside of the tool body, so as to avoid interference and damage to the scraping assembly 90 during drilling operations. Specifically, Figure 5 In the drilling and grinding state, Figure 6 In the scraping state, the scraping component 90 protrudes from the outside of the tool body, meaning that the outermost outer diameter D2 is greater than the outer diameter D1 of the tool body.

[0066] Combination Figures 10-13 As shown, specifically, the scraping block 91 is provided with a connecting portion 911 for connecting the elastic sheet 95, and the inner side of the scraping block 91 is provided with a plurality of receiving grooves 913 for accommodating the support springs 92. Exemplarily, in this embodiment, five receiving grooves 913 are provided, and correspondingly, five support springs 92 are also provided, and the support springs 92 are always in a compressed state to apply a radially outward force to the scraping block 91. Further, the grinding portion 912 is configured as an arc shape, and the grinding portion 912 is provided with a plurality of spiral scraping grooves for scraping and cleaning the inner wall of the sleeve. Figure 5 and Figure 6 As shown, in this embodiment, one end of the support spring 92 is embedded in the receiving groove 913 of the scraper block 91, and the other end is connected to the side of the mounting plate 93 away from the first mounting groove 702. The positioning member 94 is sequentially inserted through the scraper block 91 and the mounting plate 93 to connect the two, thereby ensuring the stable setting of the scraper block 91, the support spring 92 and the mounting plate 93.

[0067] Furthermore, a second mounting groove 703 is provided on the outer side of the central tube 70, and the second mounting groove 703 is connected to the first mounting groove 702. Specifically, the first fixing member 96 can fix one end of the elastic piece 95 in the second mounting groove 703, while the other end of the elastic piece 95 elastically presses against the connecting part 911 of the scraper block 91. In this way, the elastic piece 95 applies radially inward pressure to the scraper block 91, resisting the radially outward thrust applied to the scraper block 91 by the support spring 92, thereby pressing the scraper block 91 tightly against the first mounting groove 702 or the outer side of the central tube 70. For example, both ends of the scraper block 91 are provided with connecting parts 911, and each connecting part 911 is pressed by the elastic piece 95 and fixed by the first fixing member 96, thereby ensuring that the scraper block 91 is tightly pressed against the central tube 70 and stably placed.

[0068] Furthermore, both the pressure block 97 and the stop block 98 are fixed to the scraping cylinder 30 of the tool body by the second fixing member 99. The longitudinal cross-section of the pressure block 97 is a trapezoidal cross-section that is narrower at the top and wider at the bottom. In this embodiment, the narrower end is set as the limiting end of the pressure block 97. The elastic sheet 95, the first fixing member 96, and the connecting part 911 are located between the limiting end and the second mounting groove 703. This can effectively prevent the elastic sheet 95 from detaching from the scraping block 91 and limit the position of the scraping block 91 to prevent it from falling off. Furthermore, the pressure block 97 is located between the scraping block 91 and the stop block 98. This allows the stop block 98 to limit the position of the pressure block 97 and the limiting end of the pressure block 97 to limit the position of the scraping block 91, preventing the scraping block 91 from detaching from the tool body and ensuring the stable placement of the entire scraping assembly 90 on the scraping cylinder 30. For example, the pressure block 97 and the stop block 98 can be disposed at the bottom of the scraper block 91, or they can be disposed both above and below the scraper block 91. There is no limitation here; they can be disposed as needed. Optionally, a second seal 901 and a second mud scraper ring 902 are also sleeved on the outside of the central tube 70, and both are located below the third anti-detachment pin 301 and sandwiched between the central tube 70 and the lower connector 40. Accordingly, the second mud scraper ring 902 is made of polytetrafluoroethylene to block mud, and the second mud scraper ring 902 is located below the second seal 901, which can effectively reduce damage to the sealing ring caused by surrounding mud, etc.

[0069] Furthermore, in conjunction with the setting of the transposition component 80, when the central tube 70 is initially in place, the mounting plate 93 abuts against the outside of the central tube 70, and the scraper block 91 protrudes from the scraper cylinder 30, so that it is in a scraping state and can perform cleaning operations; after the ball is thrown, the central tube 70 moves upward a certain distance, and the mounting plate 93 is embedded in the first mounting groove 702, so that the scraper block 91 is housed in the tool body and is in a drilling state, so that drilling operations can be performed without causing interference or damage.

[0070] In summary, when the casing inner wall cleaning tool is lowered into the well, the scraper block 91 protrudes from the tool body and is in a scraping state. Then, when the tool encounters resistance below and requires drilling, a steel ball 51 is dropped from the wellhead and pressurized, causing the steel ball 51 to fall into the ball basket 52 sequentially through the limiting ring 61, ball seat 62, central tube upper connector 63, and central tube 70. During this process, the downward thrust generated by the pressure pushes the central tube 70 downward relative to the tool body, causing the transposition pin 82 to move from the short groove 72 into the equal-length groove 71. Subsequently, after the steel ball 51 enters the basket 52, the circulation passage downhole is opened, and the surface pressure drops. Pressurization then stops, causing the return spring 84 to move upwards under its elastic force. The return spring 84 then slides into the long groove 73 in the shifting slide rail via the shifting pin 82. This aligns the first mounting groove 702 on the central tube 70 with the mounting plate 93, allowing the scraper block 91 to press the mounting plate 93 into the first mounting groove 702 under the pressure of the elastic plate 95. This ensures that the maximum outer diameter of the scraper block 91 is less than or equal to the outer diameter of the tool body, enabling drilling operations. When scraping and cleaning are required, the ball-throwing and pressurization operations are repeated, causing the central tube 70 to reposition itself. This allows the mounting plate 93 to exit the first mounting groove 702 under the movement of the central tube 70, returning to its original position (scraping state), thus achieving the scraping and cleaning operation of the casing inner wall.

[0071] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A tool for cleaning the inner wall of a casing, characterized in that, include: The tool body and the central tube (70) are fitted onto the outside of the central tube (70); A starting component (50) and a receiving component (60) are provided, wherein the receiving component (60) is disposed above the central tube (70), and the receiving component (60) and the central tube (70) are able to move downward synchronously inside the tool body under the action of the starting component (50); The tool body has a shifting component (80) and a scraping component (90). The shifting component (80) is slidably disposed on the central tube (70), and the central tube (70) has at least a first locking position and a second locking position. The scraping component (90) is disposed on the tool body and elastically presses against the central tube (70). The scraping component (90) has at least a scraping state and a drilling state. In the scraping state, the shifting component (80) is located in the first locking position, and the scraping component (90) protrudes from the outside of the tool body. In the drilling state, the shifting component (80) is located in the second locking position, and the scraping component (90) is embedded in the central tube (70). The transposition assembly (80) includes a transposition slip ring (81), a transposition slip pin (82), a retaining ring (83), and a return spring (84). The transposition slip pin (82) is disposed on the transposition slip ring (81) and slidably disposed on the transposition channel of the central tube (70). The transposition slip ring (81), the retaining ring (83), and the return spring (84) are sequentially sleeved on the outside of the central tube (70). When the central tube (70) moves downward, it can compress the return spring (84), and the central tube (70) can move upward under the action of the return spring (84). The transposition channel is provided with two interconnected equal-length slots (71), short slots (72) and long slots (73), the first locking position is set in the short slot (72) and the second locking position is set in the long slot (73); When the central tube (70) moves downward, the shifting pin (82) can slide from the short groove (72) to the equal-length groove (71), and when the central tube (70) moves upward under the action of the return spring (84), the shifting pin (82) can slide from the equal-length groove (71) to the long groove (73) to switch between the scraping state and the drilling state.

2. The casing inner wall cleaning tool according to claim 1, characterized in that, The scraping assembly (90) includes a scraping block (91), a support spring (92), a mounting plate (93), and a positioning element (94). One end of the support spring (92) is embedded in the scraping block (91), and the other end is connected to the mounting plate (93). The positioning element (94) passes through the scraping block (91) and the mounting plate (93) in sequence.

3. The casing inner wall cleaning tool according to claim 2, characterized in that, The outer side of the central tube (70) is provided with a first mounting groove (702). In the drilling state, the mounting plate (93) can be embedded in the first mounting groove (702), and at this time, the distance between the outer side of the scraper block (91) and the axis of the central tube (70) is less than or equal to the outer diameter of the tool body.

4. The casing inner wall cleaning tool according to claim 2, characterized in that, The scraping assembly (90) further includes an elastic sheet (95) and a first fixing member (96). A second mounting groove (703) is provided on the outside of the central tube (70). The first fixing member (96) can fix one end of the elastic sheet (95) in the second mounting groove (703), and the other end of the elastic sheet (95) elastically presses against the scraping block (91).

5. The casing inner wall cleaning tool according to claim 4, characterized in that, The scraping assembly (90) further includes a pressure block (97), a stop block (98), and a second fixing member (99). The pressure block (97) is fixed to the tool body by the second fixing member (99). The elastic sheet (95) and the first fixing member (96) are located between the limiting end of the pressure block (97) and the second mounting groove (703). The stop block (98) is also fixed to the tool body by the second fixing member (99), and the pressure block (97) is located between the scraping block (91) and the stop block (98).

6. The casing inner wall cleaning tool according to claim 1, characterized in that, The starting component (50) includes a steel ball (51) and a ball basket (52). The steel ball (51) can enter through the opening at the top of the tool body and pass through the receiving component (60) and the central tube (70) in sequence until it is limited to the bottom of the ball basket (52).

7. The casing inner wall cleaning tool according to claim 1, characterized in that, The receiving component (60) includes a limiting ring (61), a ball seat (62), and a central tube connector (63). The limiting ring (61) is used to limit the ball seat (62) in the tool body. One end of the central tube connector (63) is connected to the ball seat (62), and the other end is connected to the central tube (70). The starting component (50) is provided with a steel ball (51). The steel ball (51) can sit on the ball seat (62) and push the ball seat (62), the central tube connector (63), and the central tube (70) to move downward synchronously with it.

8. The casing inner wall cleaning tool according to claim 1, characterized in that, The tool body includes an upper connector (10), a shifting cylinder (20), a scraping cylinder (30), and a lower connector (40) connected in sequence. The receiving component (60) is disposed inside the upper connector (10), the shifting component (80) is disposed inside the shifting cylinder (20), and a plurality of scraping components (90) are spirally disposed on the scraping cylinder (30).

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