A recyclable well casing rust removal device

Abstract

This invention discloses a recyclable well casing rust removal device, comprising a timely sealing mechanism, a hydraulic rotary rust removal mechanism, and a pneumatic booster mechanism connected in sequence. The timely sealing mechanism allows the cup-shaped packer to automatically retract after rust removal operations cease. The hydraulic rotary rust removal mechanism achieves ideal rust removal results through fluid impact rust removal and fine-toothed brush rotation. The pneumatic booster mechanism propels the device upwards with pneumatic force, enabling pressure testing and recycling. This device is suitable for rust removal operations on various sizes of tubing, casing, drill pipe, drill collars, and angular drill pipe. It not only removes rust from the inner wall of the casing but also prevents downhole accidents such as casing blockage caused by rust slag falling off. By integrating the pressure testing function into the device, it further improves the utilization rate of working hours, effectively reduces labor intensity and operational risks, and ensures safe construction at the work site.

Description

Technical Field

[0001] This invention relates to the field of downhole operations technology for oil and gas wells, and in particular to a recyclable in-well tubing rust removal device. Background Technology

[0002] In the process of oil and gas development, a large number of specialized pipes are required at the work site. These specialized pipes include tubing, casing, drill pipe, drill collars, and angular drill pipe. The working conditions of these oil-specific pipes are very complex and the working environment is very harsh, making them highly susceptible to corrosion of the inner wall of the tubing string. The most common situation is the appearance of corrosion products—rust—on the inner wall of the tubing string. The main reasons include: 1) During tripping operations, repeated friction of the tubing string causes the anti-rust layer on the surface of the pipe to peel off. The pipe without the protective layer reacts with the air to produce rust; 2) The well fluid contains salt, hydrogen sulfide, carbon dioxide, and organic acids, as well as bacteria and other microorganisms mixed in during the injection of engineering fluids such as fracturing fluid and drilling fluid into the well. It also contains a large amount of oxygen. The tubing string in the well undergoes electrochemical and oxidative reactions with these substances, producing rust; and 3) During high-temperature and high-pressure well operations, the difference in the coefficient of thermal expansion between the anti-rust layer and the tubing string generates stress that causes the anti-rust layer to peel off, allowing it to react chemically with the well fluids and gases, producing rust. Meanwhile, under the influence of external forces such as vibration, rust falls into the well, causing downhole accidents such as tubing blockage.

[0003] Based on the above problems, in order to ensure construction quality and safety and improve work time utilization, it is necessary to promptly perform rust removal and rust recovery operations on the well casing at the work site. However, currently, the main method used on-site is to scrape the rust off the inner wall of the casing with blades. This method is incomplete, cannot effectively recover the scraped rust, is time-consuming and labor-intensive, inconvenient to operate, and the rust removal effect is unsatisfactory. Therefore, the operation of rust removal and rust recovery on the well casing at the work site has become a bottleneck affecting a series of problems such as work time utilization, labor intensity, and construction quality and safety. Therefore, there is an urgent need for a multi-functional rust removal device with reliable structure and stable performance to ensure safe, high-quality, and efficient construction at the work site. Summary of the Invention

[0004] The purpose of this invention is to provide a recyclable well tubing inner wall rust removal device that enables recyclable tubing inner wall rust removal operations and prevents downhole accidents such as tubing blockage caused by rust residue falling off.

[0005] Therefore, the technical solution of the present invention is as follows:

[0006] A recyclable well casing rust removal device includes a timely sealing mechanism, a hydraulic rotary rust removal mechanism, and a pneumatic booster mechanism connected in sequence; wherein,

[0007] The timely packer mechanism includes, from top to bottom, a bowl-shaped packer, a claw-type support frame, an outer cylinder, and an upper support shaft, all fitted around the outside of the central tube. The bowl-shaped packer is fixed to the top outer wall of the central tube. The claw-type support frame is in a contracted state, tightly fitted to the outside of the bowl-shaped packer, with its bottom end movably positioned on the outer wall of the central tube, and can expand as the bowl-shaped packer opens. The top of the upper support shaft is initially inserted and temporarily secured with a pin between the lower inner wall of the outer cylinder and the outer wall of the central tube, forming an annular space at the bottom. The annular boss on the inner wall of the top of the support shaft presses against the annular boss on the outer wall of the bottom of the central tube, so that the upper support shaft, outer cylinder and central tube enclose a sealed hydraulic chamber filled with high-pressure hydraulic oil. When the pin is sheared, the upper support shaft moves upward in the annular space and encloses the central tube to form an annular sealed chamber. Two axial flow holes connected to the sealed hydraulic chamber are symmetrically opened on the annular boss at the top of the upper support shaft, and each axial flow hole is temporarily blocked by a built-in crushing disc.

[0008] The hydraulic rotary rust removal mechanism includes multiple conical nozzles, multiple cavitation nozzles, several fine-toothed brushes, a fine-toothed brush booster mechanism, and a lower support shaft mounted on a rotating cylinder. The top of the rotating cylinder is rotatably mounted on the outside of the lower support shaft via a first rotating bearing, and the two are connected by a retaining spring to form a movable limit connection. The bottom of the rotating cylinder is rotatably mounted on the outside of the upper support shaft via a second rotating bearing, and the two are connected by a retaining spring to form a movable limit connection. On the side wall of the rotating cylinder, from top to bottom, are sequentially provided a first conical nozzle mounting hole group, a first cavitation nozzle mounting hole group, a brush body mounting hole group, a second cavitation nozzle mounting hole group, and a second conical nozzle mounting hole group. Each conical nozzle mounting hole group and each cavitation nozzle... Each nozzle mounting hole assembly consists of multiple mounting holes evenly distributed along the circumference, with each mounting hole extending from the outer wall of the rotating cylinder along the same oblique direction to the inner wall of the rotating cylinder. Multiple conical nozzles are divided into two parts and fixed in corresponding conical nozzle mounting holes. Multiple cavitation nozzles are also divided into two parts and fixed in corresponding cavitation nozzle mounting holes. The brush body mounting hole assembly consists of several vertical strip-shaped brush body mounting holes evenly distributed along the circumference. Several closely spaced brushes are assembled in corresponding brush body mounting holes. A closely spaced brush booster mechanism is located between the closely spaced brushes and can push the closely spaced brushes out of the brush body mounting holes to the outside of the rotating cylinder under hydraulic pressure.

[0009] Furthermore, the claw-type support frame consists of two symmetrically arranged active claws and multiple driven claws evenly distributed between the two active claws. The active claw is a claw body composed of an upper trapezoidal plate, a lower trapezoidal plate, a rectangular shoulder, a connecting plate, and a claw head. Both the upper and lower trapezoidal plates are inverted and parallel to each other, staggered vertically. The rectangular shoulder connects the upper and lower trapezoidal plates, forming a double-step shape. The connecting plate is vertically fixed to the back of the rectangular shoulder, and its bottom end has an annular connecting portion protruding to the outside of the rectangular shoulder. The axis of the annular connecting portion is perpendicular to the rectangular shoulder. The claw head is fixed to the annular connecting portion of the connecting plate with its angled towards the front of the trapezoidal plate. The driven claw is composed of an upper trapezoidal plate, a lower trapezoidal plate, a rectangular shoulder, and a connecting plate. The claw body is composed of plates, and its upper trapezoidal plate, lower trapezoidal plate, rectangular shoulder, and connecting plate, as well as their connection relationship, are the same as those of the active claw. All claw bodies are arranged circumferentially in such a way that the upper trapezoidal plate of one claw body is pressed against the lower trapezoidal plate of the adjacent claw body, forming an inverted conical cylindrical body that is initially contracted and tightly attached to the conical outer wall of the bowl-shaped packer. Correspondingly, several slots are evenly distributed along the circumferential direction on the top end face of the outer cylinder, with the same number of slots as the number of claw bodies. Two claw head insertion slots are symmetrically opened on the outer wall of the central tube. The bottom ends of the connecting plates of several claw bodies are embedded in the slots, and each claw body is movably connected in twelve slots by fitting its annular connecting part onto the movable shaft provided on the wall of each slot. The claw heads of the two active claws are respectively inserted into the two claw head insertion slots.

[0010] Furthermore, the upper outer diameter of the upper support shaft is larger than its lower outer diameter, forming a second annular step at the connection between its upper and lower outer walls, and the top of the rotating cylinder abuts against the lower end face of the second annular step; the upper inner diameter of the upper support shaft is larger than its lower inner diameter, forming a third annular step at the connection between its upper and lower inner walls, and the width of the third annular step is the same as the width of the lower end face of the annular boss on the outer wall of the bottom of the central tube.

[0011] Furthermore, the conical-straight nozzle is a tube body with a conical cavity and a straight cavity inside, and the straight cavity is connected and communicates with the small-diameter end of the conical cavity; each conical-straight nozzle is set in the conical-straight nozzle mounting hole with its straight cavity close to the outside of the rotating cylinder and its conical cavity close to the inside of the rotating cylinder.

[0012] Furthermore, the cavitation nozzle is a tube body with a conical cavity, a first-stage straight cavity, a second-stage straight cavity, and a third-stage straight cavity connected in sequence. The first-stage straight cavity is connected to the small-diameter end of the conical cavity, and the inner diameters of the first-stage, second-stage, and third-stage straight cavities increase progressively. Each cavitation nozzle is installed in the conical-straight nozzle mounting hole with its third-stage straight cavity near the inside of the rotating cylinder and its conical cavity near the outside of the rotating cylinder.

[0013] Furthermore, each fine-tooth brush consists of a comb frame, comb teeth, and a baffle. The comb frame is a U-shaped frame formed by sequentially connecting a first comb tooth mounting plate, a spring mounting plate, and a second comb tooth mounting plate. The spring mounting plate is a plate with a flat inner surface and a sloping outer surface. The comb frame is positioned within the brush body mounting hole with its spring mounting plate partially located inside the rotating cylinder and its sloping outer surface facing upwards. The baffle is positioned between the two comb tooth mounting plates of the comb frame, and its upper and lower ends are fixed to the outside of the rotating cylinder by screws. On the wall; the fine-tooth brush booster mechanism consists of several sets of compression springs and an inverted conical slider with a straight hole inside; the several sets of compression springs are respectively arranged in the comb frame of the twelve fine-tooth brushes; each set of compression springs consists of three helical springs, which are arranged at intervals from top to bottom in the comb frame, and one end of each helical spring is fixed to the baffle plate and the other end is fixed to the inner side plate of the compression spring mounting plate; the inverted conical slider with a straight hole inside is arranged in the conical inner cavity surrounded by all the fine-tooth brushes, and its outer conical surface matches the inner conical surface of the conical inner cavity.

[0014] Furthermore, the pneumatic booster mechanism consists of a multifunctional pressure testing body and a pressure testing seat; among which,

[0015] The multifunctional pressure test body consists of a booster shell, two upper check valves, and one lower check valve. The booster shell is inserted into a blind hole axially formed from the bottom surface of the lower support shaft, and is fixed to the lower support shaft by multiple pins arranged circumferentially, with a gap between its top and the bottom of the blind hole. The booster shell has a cavity for holding a gas generating agent, and two Z-shaped flow channels extending from its outer wall to the cavity and one straight flow channel extending from its bottom surface to the cavity are symmetrically formed on the booster shell. The two upper check valves are respectively located in the Z-shaped flow channels and near the port of the cavity, so that fluid can only flow into the cavity from the Z-shaped flow channels. The lower check valve is located in the straight flow channel and near the port of the cavity, so that fluid or gas can only flow out of the cavity to the outside.

[0016] The pressure test seat is pre-fixed on the bottom end face of the tube column. It is a cylinder with an axial through hole in its center, and the top surface is a groove that adapts to the convex spherical surface of the bottom end of the booster shell, so that the bottom end of the booster shell can be sealed in the groove, and the second flow channel on it is connected to the axial through hole of the pressure test seat.

[0017] Furthermore, a sealing ring is provided on the outer wall of the central tube to form a seal between the upper outer wall of the central tube and the upper inner wall of the outer cylinder; a sealing ring is provided on the outer wall of the upper support shaft to form a seal between the top outer wall of the upper support shaft and the lower inner wall of the outer cylinder; a sealing ring is provided on the lower outer wall of the central tube to form a seal between the lower outer wall of the central tube and the inner wall of the annular boss of the upper support shaft; a sealing ring is provided on the upper outer wall of the lower support shaft, between the retaining ring and the second rotating bearing, so that a seal is formed between the rotating cylinder and the lower support shaft.

[0018] Furthermore, the recyclable well casing rust removal device also includes an auxiliary retrieval mechanism, which consists of a buoyancy ball and a connecting pipe; the buoyancy ball is a carbon fiber sphere; the top end of the connecting pipe is fixed to the bottom of the buoyancy ball, and the bottom end is connected to the top inner wall of the central pipe.

[0019] Furthermore, the recyclable well casing inner wall rust removal device also includes a rust storage tool, which is a cylindrical body with an opening at the top and a closed bottom, and has flow holes evenly distributed on the side wall and bottom surface of the body; the rust storage tool is fixed in the center on the bottom surface of the pressure test seat, and its inner cavity is connected to the axial through hole of the pressure test seat.

[0020] Compared with existing technologies, this recyclable in-well tubing rust removal device is suitable for rust removal operations on tubing, casing, drill pipe, drill collars, and angular drill pipe of various sizes. Its timely packer mechanism allows the cup-shaped packer to automatically retract after the rust removal operation stops. Its hydraulic rotary rust removal mechanism can achieve ideal rust removal results through fluid impact rust removal and fine-toothed brush rotary rust removal. Its pneumatic booster mechanism can propel the device upward with pneumatic power to achieve pressure testing and recycling. Its auxiliary retrieval mechanism can realize the recycling and reuse of tools at different well depths.

[0021] In summary, this recyclable well tubing inner wall rust removal device not only achieves the purpose of recyclable tubing inner wall rust removal, but also prevents downhole accidents such as tubing blockage caused by rust slag falling off. At the same time, it integrates pressure testing function into the device, further improving the utilization rate of working hours, effectively reducing labor intensity and operational risks, and ensuring safe, high-quality, and efficient construction at the work site. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of the recyclable well casing inner wall rust removal device of the present invention;

[0023] Figure 2 This is a schematic diagram of the liquid and gas flow in the working state of the recyclable well casing inner wall rust removal device of the present invention;

[0024] Figure 3 A cross-sectional view of the recyclable well casing inner wall rust removal device of the present invention with an auxiliary retrieval mechanism installed on top;

[0025] Figure 4 A cross-sectional view of the bottom of the recyclable well casing inner wall rust removal device of the present invention, with a rust storage tool installed thereon;

[0026] Figure 5 This is a schematic diagram of the assembly structure of the bowl-shaped packer, claw-type support frame, and central tube of the recyclable well casing rust removal device of the present invention.

[0027] Figure 6 This is a schematic diagram of the outer cylinder of the recyclable well casing inner wall rust removal device of the present invention;

[0028] Figure 7 This is a schematic diagram of the structure of the central tube of the recyclable well casing inner wall rust removal device of the present invention;

[0029] Figure 8(a) is a side view of the assembled structure of the bowl-shaped packer and claw-type support frame of the recyclable well casing rust removal device of the present invention.

[0030] Figure 8(b) is a vertical view of the assembly structure of the bowl-shaped packer and claw-type support frame of the recyclable well casing rust removal device of the present invention.

[0031] Figure 8(c) is a top view of the assembled structure of the bowl-shaped packer and claw-type support frame of the recyclable well casing rust removal device of the present invention.

[0032] Figure 8(d) is a top view of the claw-type support frame of the recyclable well casing inner wall rust removal device of the present invention;

[0033] Figure 9(a) is a schematic diagram of the cooperation relationship between adjacent active claws and driven claws in the open state of the claw-type support frame of the recyclable well casing rust removal device of the present invention.

[0034] Figure 9(b) is a schematic diagram of the active claw of the claw-type support frame of the recyclable well casing inner wall rust removal device of the present invention.

[0035] Figure 9(c) is a side view of the active claw of the claw-type support frame of the recyclable well casing inner wall rust removal device of the present invention.

[0036] Figure 10(a) is a schematic diagram of the cooperation relationship between adjacent active claws and driven claws in the contracted state of the claw-type support frame of the recyclable well casing rust removal device of the present invention.

[0037] Figure 10(b) is a schematic diagram of the driven claw of the claw-type support frame of the recyclable well casing inner wall rust removal device of the present invention.

[0038] Figure 10(c) is a side view of the driven claw of the claw-type support frame of the recyclable well casing inner wall rust removal device of the present invention.

[0039] Figure 11 This is a cross-sectional view of the hydraulic rotating cylinder at point AA of the recyclable well casing rust removal device of the present invention.

[0040] Figure 12 This is a cross-sectional view of the hydraulic rotating cylinder at point BB of the recyclable well casing rust removal device of the present invention.

[0041] Figure 13 This is a schematic diagram of the hydraulic rotating cylinder of the recyclable well casing rust removal device of the present invention;

[0042] Figure 14 is a schematic diagram of the fine-toothed brush structure of the recyclable well casing inner wall rust removal device of the present invention;

[0043] Figure 15 This is a schematic diagram of the assembly of the hydraulic rotating cylinder and the fine-toothed brush of the recyclable well casing inner wall rust removal device of the present invention.

[0044] Figure 16 This is a cross-sectional view of the auxiliary retrieval mechanism of the recyclable well casing inner wall rust removal device of the present invention;

[0045] Figure 17 This is a cross-sectional view of the pneumatic booster mechanism of the recyclable well casing inner wall rust removal device of the present invention.

[0046] Figure 18 for Figure 17 A magnified view of part C in the middle. Detailed Implementation

[0047] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention.

[0048] like Figure 1 As shown, the recyclable well casing rust removal device includes a timely sealing mechanism 1, a hydraulic rotary rust removal mechanism 2, and a pneumatic booster mechanism 3; wherein,

[0049] See Figure 2 and Figure 3 The timely sealing mechanism 1 includes an outer cylinder 1-1, a central tube 1-2, a bowl-shaped packer 1-3, a claw-type support frame 1-4, and an upper support shaft 1-6; specifically,

[0050] The outer cylinder 1-1 is a cylindrical body with an upper inner diameter smaller than a lower inner diameter, so that a first annular step is formed at the connection between the upper inner wall and the lower inner wall;

[0051] The central tube 1-2 is a cylindrical body with an annular protrusion on the outer wall at the bottom end. Its outer diameter is adapted to the upper inner diameter of the outer tube 1-1, and its length is greater than the length of the outer tube 1-1. The central tube 1-2 is inserted into the outer tube 1-1, with its top end protruding to the outside of the outer tube 1-1, and an annular space is formed between its lower outer wall and the lower inner wall of the outer tube 1-1.

[0052] See Figure 2 and Figure 5The bowl-shaped packer 1-3 consists of an inverted conical packer cylinder and a cylindrical connecting cylinder extending from the bottom of the packer cylinder. It is made of rubber material and has good elasticity, which allows it to quickly recover its deformation under large deformation. The connecting cylinder of the bowl-shaped packer 1-3 is fitted on the outside of the top of the central tube 1-2 and is bonded to the outer wall of the top of the central tube 1-2. The claw-type support frame 1-4 is fitted on the outside of the bowl-shaped packer 1-3 and is tightly attached to the outer wall of the packer cylinder of the bowl-shaped packer 1-3, so that the opened bowl-shaped packer 1-3 can be supported by the claw-type support frame 1-4, so as not to deform excessively and lose the sealing effect.

[0053] Referring to Figures 8(a), 8(b), 8(c), and 8(d), the claw-type support frame 1-4 consists of two active claws 1-4-1 and ten driven claws 1-4-2. The ten driven claws 1-4-2 are evenly distributed between the two active claws, so that the twelve claw bodies are arranged circumferentially and form an inverted conical cylindrical body that is tightly attached to the outer wall of the packer cylinder of the bowl-shaped packer 1-3; wherein,

[0054] Referring to Figures 9(b) and 9(c), the active claw 1-4-1 is a claw body composed of an upper trapezoidal plate, a lower trapezoidal plate, a rectangular shoulder, a connecting plate, and a claw head. The upper and lower trapezoidal plates are both inverted and parallel to each other, with the upper and lower plates staggered. The rectangular shoulder connects the upper and lower trapezoidal plates, making the connected upper trapezoidal plate, rectangular shoulder, and lower trapezoidal plate form a double-step shape. The rectangular shoulder is preferably perpendicular to the upper and lower trapezoidal plates. The connecting plate is fixed to the back of the rectangular shoulder, and its bottom end has an annular connecting part that protrudes to the outside of the rectangular shoulder, and the axial direction of the annular connecting part is perpendicular to the rectangular shoulder. The claw head is fixed to the annular connecting part of the connecting plate with its angled towards the front of the trapezoidal plate.

[0055] Referring to Figures 10(b) and 10(c), the driven claw 1-4-2 is a claw body composed of an upper trapezoidal plate, a lower trapezoidal plate, a rectangular shoulder, and a connecting plate. Both the upper and lower trapezoidal plates are inverted, parallel to each other, and staggered vertically. The rectangular shoulder connects the upper and lower trapezoidal plates, creating a double-step shape between them. Preferably, the rectangular shoulder is perpendicular to both the upper and lower trapezoidal plates. The connecting plate is fixed to the back of the rectangular shoulder, and its bottom end has an annular connecting plate protruding to the outside of the rectangular shoulder. The annular connecting part is perpendicular to the rectangular shoulder. Specifically, taking the adjacent active claw 1-4-1 and driven claw 1-4-2 as an example, in the clockwise direction, the upper trapezoidal plate of the driven claw 1-4-2 on the left presses against the lower trapezoidal plate of the active claw 1-4-1 on the right, so that the two are in a contracted state in their natural state, as shown in Figure 10(a); when the two are subjected to the opening force of the bowl-shaped packer 1-3, they will separate from each other until the upper trapezoidal plate and the lower trapezoidal plate that were originally pressed against each other are misaligned, as shown in Figure 9(a).

[0056] When adjacent claws are assembled, in a clockwise direction, the upper trapezoidal plate of the left claw is pressed onto the lower trapezoidal plate of the right claw, so that the claw support frame 1-4 formed by the sequential engagement of the twelve claws is in a contracted state in the initial state; correspondingly, twelve slots 1-1-1 are evenly distributed along the circumferential direction on the top end face of the outer cylinder 1-1, and two claw head insertion slots 1-2-1 are symmetrically opened on the outer wall of the central tube 1-2; the bottom ends of the connecting plates of the twelve claws are embedded in the slots 1-1-1, and each claw is movably connected in the twelve slots 1-1-1 by fitting its annular connecting part onto the movable shaft provided on the groove wall of each slot 1-1-1; at the same time, the claw heads of the two active claws 1-4-1 are inserted into the two claw head insertion slots 1-2-1.

[0057] The upper support shaft 1-6 is a cylindrical body with an annular boss on its inner top wall. The upper outer diameter of the upper support shaft 1-6 is larger than its lower outer diameter, forming a second annular step at the connection between the upper and lower outer walls of the upper support shaft 1-6. The upper inner diameter of the upper support shaft 1-6 is larger than its lower inner diameter, forming a third annular step at the connection between the upper and lower inner walls of the upper support shaft 1-6. The inner diameter of the annular boss at the top of the upper support shaft 1-6 is matched with the outer diameter of the central tube 1-2. The upper outer diameter of the upper support shaft 1-6 is adapted to the lower inner diameter of the outer cylinder 1-1 and the outer diameter of the annular boss at the bottom of the central tube 1-2, so that the top end of the upper support shaft 1-6 is inserted into the annular space formed by the central tube 1-2 and the outer cylinder 1-1, and together with the outer cylinder 1-1 and the central tube 1-2, forms a sealed hydraulic chamber 1-5; the upper support shaft 1-6 and the outer cylinder 1-1 are connected and fixed together by multiple pins evenly distributed along the circumference, and the top annular boss... The platform is fitted onto the annular protrusion at the bottom of the central tube 1-2; the width of the third annular step is the same as the width of the lower end face of the annular protrusion on the outer wall of the bottom of the central tube 1-2, so that the pressure generated by the pumping fluid on the lower end face of the annular protrusion at the bottom of the central tube 1-2 is equal to the pressure generated by the pumping fluid on the upper end face of the third annular step, thereby ensuring that the central tube 1-2 will not descend on its own due to the pressure difference between the upper and lower end faces of the pumping fluid, that is, ensuring that the outer cylinder 1-1, the central tube 1-2 and the upper support shaft 1-6 remain relatively stationary during the downward movement of the device; the distance from the bottom of the outer cylinder 1-1 to the third annular step is less than the distance from the bottom of the central tube 1-2 to the third annular step, so that when the outer cylinder 1-1 and the central tube 1-2 descend synchronously to the position of the third annular step, the length of the top of the central tube 1-2 exposed to the outside of the outer cylinder 1-1 is reduced relative to the exposed length in the initial state, so as to use the positional change between the two to further push the claw support frame 1-4 to contract;

[0058] Two axial flow holes are symmetrically opened on the annular boss at the top of the upper support shaft 1-6, which are connected to the sealed hydraulic chamber 1-5. Each axial flow hole is temporarily blocked by a built-in crushing disc. High-pressure hydraulic oil is injected into the sealed hydraulic chamber 1-5. When squeezed, the pressure rises, crushing the crushing disc and flowing into the annular sealed chamber 1-7 formed by the central tube 1-2 and the upper support shaft 1-6. Specifically, the pressure provided by the high-pressure hydraulic oil should be equal to or slightly lower than the pressure of the pumping fluid.

[0059] To ensure the sealing of the hydraulic chamber 1-5, a sealing ring is provided on the outer wall of the central tube 1-2 to form a seal between the upper outer wall of the central tube 1-2 and the upper inner wall of the outer cylinder 1-1; a sealing ring is provided on the outer wall of the upper support shaft 1-6 to form a seal between the top outer wall of the upper support shaft 1-6 and the lower inner wall of the outer cylinder 1-1; a sealing ring is provided on the lower outer wall of the central tube 1-2 to form a seal between the lower outer wall of the central tube 1-2 and the inner wall of the annular boss of the upper support shaft 1-6.

[0060] See Figure 2 and Figure 3The working principle of this timely packer mechanism in practical application is as follows: When the pump truck is started, it pumps fluid at a certain pressure into the tubing. Under the pressure of the fluid, the cup-shaped packer 1-3 opens and adheres tightly to the inner wall of the tubing. The fluid can only flow into the device through the central tube 1-2. Hydraulic pressure acts on the open end face of the cup-shaped packer 1-3, thereby pushing the outer cylinder 1-1, the central tube 1-2, and the upper support shaft 1-6 downward synchronously, thus causing the entire device to descend. When the device descends to its position (i.e., touches the test pressure seat 3-10), under the action of inertial force, the outer cylinder 1-1 and the central tube 1-2 continue to move downward, shearing the pin between the outer cylinder 1-1 and the upper support shaft 1-6. The upper support shaft 1-6 moves upward relative to the upper support shaft 1-5 in the sealed hydraulic chamber. The high-pressure hydraulic oil in the sealed hydraulic chamber 1-5 is squeezed and the pressure rises, thereby breaking the rupture disc and flowing towards the area enclosed by the central tube 1-2 and the upper support shaft 1-6. The sealed chamber 1-7 is formed. At the same time, since the lower end face of the annular step at the bottom of the central tube 1-2 is not subjected to the pressure generated by the pumping fluid after the pump stops, and the high-pressure hydraulic oil acts on the upper surface of the annular boss at the bottom of the central tube 1-2, the central tube 1-2 moves further down relative to the outer cylinder 1-1. At the same time, it pulls down the active claw 1-4-1 of the claw-type support frame 1-4, causing the two active claws 1-4-1 to rotate actively toward the center line of the central tube 1-2. The other driven claws 1-4-2 rotate synchronously toward the center line of the central tube 1-2 under the drive of the two active claws 1-4-1. That is, all the claws rotate toward the center of the central tube 1-2 and are in a contracting state. During the contraction of the claw-type support frame 1-4, the bowl-shaped packer 1-3 contracts synchronously toward the center, so that it leaves the inner wall of the tube column. A certain gap is formed between the outer edge and the inner wall of the tube column, the packer is released, and the entire device is easy to float and recover.

[0061] See Figure 2 The hydraulic rotary rust removal mechanism 2 includes eight conical nozzles 2-2, eight cavitation nozzles 2-3, twelve sets of compression springs 2-4, twelve fine-tooth brushes 2-5, an inverted conical slider 2-6 with a straight hole inside, two retaining springs 2-7, and a lower support shaft 2-8 mounted on a rotating cylinder 2-1; wherein,

[0062] The rotating cylinder 2-1 is a cylindrical body with an inner diameter larger than the lower outer diameter of the upper support shaft 1-6. The rotating cylinder 2-1 is fitted onto the lower outer side of the upper support shaft 1-6, with its top end abutting against the lower end face of the second annular step on the upper support shaft 1-6. Simultaneously, the rotating cylinder 2-1 is rotatably connected to the upper support shaft 1-6 via a first rotating bearing located on its inner wall at the top end. An annular groove is formed on each of the contacting surfaces of the rotating cylinder 2-1 and the upper support shaft 1-6, with a retaining spring 2-7 embedded within each groove to form a limiting connection, preventing misalignment between the rotating cylinder 2-1 and the upper support shaft 1-6 during relative rotation. Preferably, a sealing ring is provided on the lower outer wall of the upper support shaft 1-6, between the retaining spring 2-7 and the first rotating bearing, to create a seal between the rotating cylinder 2-1 and the upper support shaft 1-6.

[0063] See Figure 13 On the upper sidewall of the rotating cylinder 2-1, a row of conical straight nozzle mounting holes and a row of cavitation nozzle mounting holes are formed from top to bottom. The conical straight nozzle mounting hole group consists of four conical straight nozzle mounting holes 2-6-1 evenly distributed along the circumference, and each conical straight nozzle mounting hole 2-6-1 is a mounting hole formed through the sidewall of the rotating cylinder 2-1 with the same oblique opening method. The cavitation nozzle mounting hole group consists of four cavitation nozzle mounting holes 2-6-2 evenly distributed along the circumference, and each cavitation nozzle mounting hole 2-6-2 is a mounting hole formed through the sidewall of the rotating cylinder 2-1 with the same oblique opening method. In this sample, a row of conical nozzle mounting holes and a row of cavitation nozzle mounting holes are formed from bottom to top on the lower inner wall of the rotating cylinder 2-1. The conical nozzle mounting hole group consists of four conical nozzle mounting holes 2-6-1 evenly distributed along the circumference, and each conical nozzle mounting hole 2-6-1 is a mounting hole formed through the side wall of the rotating cylinder 2-1 in the same oblique opening manner. The cavitation nozzle mounting hole group consists of four cavitation nozzle mounting holes 2-6-2 evenly distributed along the circumference, and each conical nozzle mounting hole 2-6-2 is a mounting hole formed through the side wall of the rotating cylinder 2-1 in the same oblique opening manner.

[0064] See Figure 11Four conical nozzles 2-2 are fixed in four conical nozzle mounting holes 2-6-1 respectively. Specifically, the conical nozzle 2-2 is a nozzle made of hard alloy, with a tube body having a conical cavity and a straight cavity inside. The straight cavity is connected and communicates with the small-diameter end of the conical cavity. Each conical nozzle 2-2 is set in the conical nozzle mounting hole with its straight cavity near the outside of the rotating cylinder 2-1 and its conical cavity near the inside of the rotating cylinder 2-1. In actual application, when fluid flows into the hydraulic rotating cylinder 2-1, the fluid is sprayed onto the inner wall of the tube column through the conical nozzle 2-2, generating a reaction force on the hydraulic rotating cylinder 2-1, thereby providing hydraulic power. Under the support of the rotating bearing, the hydraulic rotating cylinder 2-1 begins to rotate. At the same time, the sprayed conical fluid has the effect of flushing and preliminary rust removal on the inner wall of the tube column.

[0065] See Figure 12 Four cavitation nozzles 2-3 are respectively fixed in four cavitation nozzle mounting holes 2-6-2; specifically, the cavitation nozzle 2-3 is a nozzle made of hard alloy, and its interior has a tube body with a conical cavity, a first-stage straight cavity, a second-stage straight cavity, and a third-stage straight cavity connected in sequence. The first-stage straight cavity is connected to the small-diameter end of the conical cavity, and the inner diameter of the first-stage straight cavity, the second-stage straight cavity, and the third-stage straight cavity increases progressively; each cavitation nozzle 2-3 has its third-stage straight cavity close to the inner side of the rotating cylinder 2-1, and the conical... The tube cavity is positioned close to the outside of the rotating cylinder 2-1 within the mounting hole of the conical nozzle. In practical applications, when fluid flows into the hydraulic rotating cylinder 2-1, the fluid is simultaneously ejected through the cavitation nozzle 2-3. During the ejection process, due to the internal flow channel structure of the cavitation nozzle 2-3, the fluid pressure is lower than the saturated vapor pressure, resulting in cavitation bubbles being generated inside the fluid. When the cavitation bubbles reach the vicinity of the inner wall of the tube column, they burst, generating a strong impact on the inner wall of the tube column, thereby achieving the effect of impact rust removal.

[0066] A brush mounting hole group is provided on the middle side wall of the rotating cylinder 2-1. The brush mounting hole group consists of twelve brush mounting holes evenly distributed along the circumference. Each brush mounting hole is a vertical elongated through hole that is opened along the axis of the rotating cylinder 2-1 and penetrates the side wall of the rotating cylinder 2-1.

[0067] See Figure 3As shown in Figure 14, twelve closely spaced brushes 2-5 are respectively assembled in twelve brush body mounting holes. Each closely spaced brush 2-5 consists of a comb frame 2-5-1, comb teeth 2-5-2, and a baffle 2-5-3. The comb frame 2-5-1 is a U-shaped frame formed by connecting a first comb tooth mounting plate, a spring mounting plate, and a second comb tooth mounting plate in sequence. The spring mounting plate is a plate with a flat inner side and a sloping outer side. The comb frame 2-5-1 is set in the brush body mounting hole with its spring mounting plate partially located in the inner cavity of the rotating cylinder 2-1 and its sloping outer side facing upward. The baffle 2-5-3 is set between the two comb tooth mounting plates of the comb frame 2-5-1 and its upper and lower ends are fixed to the outer wall of the rotating cylinder 2-1 by screws. The comb teeth 2-5-2 are composed of several short steel wires fixed in a dense manner on the outer end faces of the two comb tooth mounting plates, and the gaps between adjacent steel wires are extremely small.

[0068] Twelve sets of compression springs 2-4 are respectively installed in the comb tooth frame 2-5-1 of the twelve closely spaced brushes 2-5. Specifically, each set of compression springs 2-4 consists of three helical springs, which are spaced apart from top to bottom in the comb tooth frame 2-5-1. One end of each helical spring is fixed to the baffle 2-5-3 and the other end is fixed to the inner side plate of the compression spring mounting plate. The helical springs have a certain pressure resistance, and the spacing between adjacent spring coils on the helical springs is equal so that they can contract and deform synchronously when subjected to external pressure, and store energy.

[0069] An inverted conical slider 2-6 with a straight hole is positioned within a conical cavity formed by all the closely spaced brushes 2-5, and its outer conical surface mates with the inner conical surface of the conical cavity, allowing it to slide up and down along the inner conical surface of the conical cavity. Simultaneously, due to the different pressures on the upper and lower surfaces of the inverted conical slider 2-6 with the straight hole, with the pressure on the upper surface being greater than that on the lower surface, a pressure difference is generated between the upper and lower surfaces, with the overall force directed downwards. In practical applications, during the initial pumping of fluid, the inverted conical slider 2-6 with the straight hole, under the downward pressure difference, slides along the conical cavity formed by all the closely spaced brushes 2-5. As the inner cavity descends, the compression spring 2-4 is compressed by the compression spring mounting plate, causing the fine-toothed brush 2-5 to extend outward from the rotating cylinder 2-1. Its comb teeth 2-5-2 are tightly attached to the inner wall of the tubing. The greater the pressure of the pumped fluid, the tighter the fine-toothed brush 2-5 is attached to the inner wall of the tubing, and the better the rust removal effect. Furthermore, when the rotating cylinder 2-1 rotates, the fine-toothed brush 2-5 rotates synchronously with the rotating cylinder 2-1, and the comb teeth 2-5-2 act on the inner wall of the tubing to remove rust. When the pumping stops, the liquid pressure in the tubing decreases, and the fine-toothed brush 2-5 automatically retracts under the action of the compression spring 2-4. The inverted conical slider 2-6 with a straight hole inside slides upward and returns to its initial position.

[0070] The lower support shaft 2-8 is a cylindrical body with a blind hole at the bottom. Its upper outer diameter is adapted to the inner diameter of the rotating cylinder 2-1, and its lower outer diameter is adapted to the outer diameter of the rotating cylinder, so that a fourth annular step is formed at the connection between the upper and lower outer walls. The top end of the lower support shaft 2-8 is inserted into the inner side of the bottom end of the rotating cylinder 2-1, and it is rotatably connected to the lower support shaft 2-8 through a second rotating bearing provided on the inner wall of the bottom end of the rotating cylinder 2-1. At the same time, an annular groove is provided on the wall surface of the rotating cylinder 2-1 and the lower support shaft 2-8 that are in contact. Another retaining ring 2-7 is built into the annular groove of the two to form a limiting connection, so that the rotating cylinder 2-1 and the lower support shaft 2-8 will not be misaligned during relative rotation. Preferably, a sealing ring is provided on the upper outer wall of the lower support shaft 2-8, between the retaining ring 2-7 and the second rotating bearing, so that the rotating cylinder 2-1 and the lower support shaft 2-8 are sealed.

[0071] See Figure 17 and Figure 18 The pneumatic booster mechanism 3 consists of a multi-functional test body and a test seat 3-10; wherein, the multi-functional test body consists of a booster shell 3-1, two upper single-flow valves 3-6, and one lower single-flow valve 3-9;

[0072] The booster shell 3-1 is a cylinder with an internal cylindrical cavity 3-7 for holding the gas generating agent 3-8. Two first flow channels 3-2 are symmetrically formed on the side wall of the booster shell 3-1, extending from the outer wall of the booster shell 3-1 to the cylindrical cavity 3-7. Both first flow channels 3-2 are Z-shaped channels. Each first flow channel 3-2 consists of a first transverse flow channel formed on the outer wall of the booster shell 3-1, a vertical flow channel extending vertically upwards from the end of the first transverse flow channel, and a second transverse flow channel extending from the end of the vertical flow channel. Two upper single-flow valves 3-6 are respectively located within the two first flow channels 3-2 and near the ports of the cylindrical cavity 3-7, ensuring that fluid can only flow into the cylindrical cavity 3-7 through the two first flow channels 3-2, and cannot flow from the cylindrical cavity 3-7 into the two first flow channels 3-2. An axially upward-facing opening is formed at the center of the bottom surface of the booster shell 3-1. A second flow channel extends into the cylindrical cavity 3-7; a lower check valve 3-9 is located within the second flow channel and near the port of the cylindrical cavity 3-7, allowing liquid or gas within the cylindrical cavity 3-7 to flow out through the second flow channel to the outside of the booster housing 3-1, while liquid outside the booster housing 3-1 cannot flow into the cylindrical cavity 3-7 through the second flow channel; the upper check valve 3-6 and the lower check valve 3-9 have the same structure, both consisting of a check ball and a spring; correspondingly, an annular groove is machined on the inner wall of the flow channel where the check valve is installed, locally increasing the inner diameter of the flow channel at that location; the check ball and spring are located within the annular groove, with the check ball positioned on the side closest to the flowing liquid, allowing the liquid to open the connecting channel by squeezing the check ball and spring; the spring force within each check valve can be adjusted as needed to control the speed at which fluid enters the cylindrical cavity 3-7 and the timing of its exit from the cylindrical cavity 3-7;

[0073] The top outer wall of the booster housing 3-1 is recessed and forms a fifth annular step. Multiple blind holes 3-3 are formed circumferentially on the outer wall of the booster housing 3-1 below the fifth annular step. Correspondingly, a sixth annular step is provided on the wall of the blind hole of the lower support shaft 2-8, so that when the upper part of the booster housing 3-1 is fully inserted into the blind hole of the lower support shaft 2-8, the upper end face of the fifth annular step fits against the lower end face of the sixth annular step on the wall of the blind hole. Multiple pin holes 3-4 are formed circumferentially on the side wall of the lower support shaft 2-8 below the sixth annular step, so that in the initial state, the top of the booster housing 3-1 is partially closed with the bottom of the blind hole of the lower support shaft 2-8. The booster housing 3-1 is inserted into the blind hole in a spaced manner, and is fixed to the lower support shaft 2-8 by pins that are respectively set in the pin hole 3-4 and the blind hole 3-3. Two liquid transmission holes 3-5 are symmetrically opened on the side wall of the lower support shaft 2-8, which is located above the first transverse flow channel and below the pin hole 3-4. The opening position of the two liquid transmission holes 3-5 on the side wall of the lower support shaft 2-8 is adapted to the opening position of the first transverse flow channel, and the axial spacing between them is consistent with the spacing between the booster housing 3-1 and the bottom of the blind hole of the lower support shaft 2-8. The bottom end of the booster housing 3-1 is machined into a convex spherical surface that matches the test pressure seat 3-10.

[0074] The pressure test seat 3-10 is pre-fixed on the bottom end face of the tube column to be derusted. It is a cylindrical disc with an axial through hole in the center, and the top surface is machined with a groove that matches the convex spherical surface of the bottom end of the booster shell 3-1, so that the bottom end of the booster shell 3-1 can be sealed in the groove.

[0075] In practical application, the specific working process of the pneumatic booster mechanism 3 is as follows: When the device descends to the position of the test pressure seat 3-10, the multifunctional test pressure body is blocked and sealed on the test pressure seat 3-10, while the components connected above it continue to move downward under inertia, causing the pin between the multifunctional test pressure body and the lower support shaft 2-8 to shear off, and the booster housing 3-1 is fully inserted into the blind hole of the lower support shaft 2-8. At this time, the two liquid transmission holes 3-5 are connected to the two first flow channels 3-2, allowing the liquid outside the device to flow into the cylindrical cavity 3-7 through the liquid transmission holes 3-5 and the first flow channels 3-2; when the liquid reaches the required volume, the gas generating agent 3- 8. The gas reacts rapidly with the liquid to generate high-pressure gas, which pushes open the single-flow ball of the lower single-flow valve 3-9 and squeezes the spring to open the downward channel. The gas in the cylindrical cavity 3-7 is ejected downward, thus providing a reverse force for the entire tool to move upward, propelling the tool upward, away from the test pressure seat 3-10, and up to the wellhead for recycling. The speed at which the fluid enters the chamber can be adjusted by regulating the spring force of the upper single-flow valve, so that the time required to inject the target amount of liquid inside is consistent with the test pressure time of the synchronous tubing string. The gas generating agent 3-8 is aluminum-magnesium alloy powder or nitride powder, which can react chemically with a certain volume of water to generate gas.

[0076] As a preferred embodiment, the device further includes an auxiliary retrieval mechanism 4, which is connected to the top of the central tube 1-2; see also Figure 16 The auxiliary salvage mechanism 4 consists of a buoyancy ball 4-1 and a connecting pipe 4-2. The buoyancy ball 4-1 is used to provide additional buoyancy for the device to float, and is specifically made of carbon fiber. The top end of the connecting pipe 4-2 is fixed to the bottom of the buoyancy ball 4-1, and the bottom end is fixed to the inner wall of the top end of the central pipe 1-2 by a threaded connection.

[0077] As a preferred embodiment, the device further includes a rust chip storage tool 5, which is a cylindrical body with an opening at the top and a closed bottom. Flow holes are evenly distributed on the side walls and bottom surface of the body, with the diameter of the holes allowing fluid to pass through but preventing rust chips from passing through. The rust chip storage tool 5 is centrally fixed to the bottom surface of the pressure testing seat 3-10, and its inner cavity is connected to the axial through-hole of the pressure testing seat 3-10. In practical applications, all rust chips generated during rust removal fall into the rust chip storage tool 5 through the axial through-hole of the pressure testing seat 3-10 for storage and recovery. The rust chip storage tool 5 can also be an existing pipe tool with the same structure and function, such as a blind-plug screen or a retrieval basket.

[0078] The specific working process of using this recyclable well casing rust removal device to remove rust from the casing is as follows:

[0079] After the tubing string is installed in the well, a recyclable rust removal device for the inner wall of the tubing string is inserted into the wellhead, and a water hose is connected to the pump truck at the wellhead. The pump truck is started, and fluid at a certain pressure is pumped into the tubing string. Under the pressure of this fluid, the cup-shaped packer 1-3 is in an open state and tightly adheres to the inner wall of the tubing string. At this time, the fluid can only flow into the interior of the tool through the central pipe 1-2. The fluid pressure on the cup-shaped packer 1-3 is the main driving force for the downward movement of the tool. At the same time, it is not excessively deformed and loses its sealing effect under the support of the claw-type support frame 1-4.

[0080] During the downward movement of the device, fluid enters the rotating cylinder 2-1 from the central tube 1-2 and is ejected through the conical nozzle 2-2 and the cavitation nozzle 2-3 installed on the side wall of the rotating cylinder 2-1, respectively. The fluid ejected by the conical nozzle 2-2 exerts a reverse force on the rotating cylinder, thereby driving the rotating cylinder 2-1 to rotate. The fluid ejected by the conical nozzle 2-2 also plays an auxiliary role in rust removal by scouring the inner wall of the tube column. Due to the special internal flow channel structure of the cavitation nozzle 2-3, the fluid ejected from the cavitation nozzle 2-3 has a pressure lower than the saturated vapor pressure, which generates cavitation bubbles inside the fluid. When the cavitation bubbles reach the vicinity of the inner wall of the tube column, they burst, generating a strong impact on the inner wall of the tube column, thereby playing a role in rust removal by impact. At the same time, hydraulic pressure acts on the inverted conical slider 2-6 with straight holes inside, which pushes the fine-toothed brush 2-5 outward so that the brush teeth press against the inner wall of the tube column during the downward movement, and the brushing motion with the rotation cleans and removes rust from the inner wall of the tube column.

[0081] When the device descends to the test pressure seat 3-10 pre-fixed at the bottom of the tubing, the rust removal operation on the inner wall of the tubing is completed, and the pumping of fluid into the tubing stops. At this time, due to inertial force, the outer cylinder 1-1 and the central tube 1-2 continue to move downward, thereby shearing the pin between the outer cylinder 1-1 and the upper support shaft 1-6. This causes the upper support shaft 1-6 to move upward within the annular cavity formed between the outer cylinder 1-1 and the central tube 1-2. The high-pressure hydraulic oil in the upper annular sealed chamber 1-5 is squeezed and its pressure rises, breaking the rupture disc and flowing towards the central tube 1-2 and... Inside the annular chamber 1-7 formed by the upper support shaft 1-6; simultaneously, since the bottom surface of the central tube 1-2 is not subjected to the pressure generated by the pumping fluid after the pump stops, the central tube 1-2 moves downward under the action of hydraulic oil, causing the two active claws in the claw support frame 1-4 to rotate toward the centerline of the central tube 1-2, while its driven claw 1-4-2 rotates synchronously under the action of the active claw 1-4-1, causing the claw support frame 1-4 to form a contraction posture; the bowl-shaped packer 1-3 contracts toward the center with the claw support frame 1-4 and leaves the inner wall of the tube column;

[0082] Simultaneously, the pins between the outer cylinder and the upper support shaft 1-6 are sheared, and the pins between the booster shell 3-1 and the lower support shaft 2-8 are also sheared, connecting the first flow channel to the outside of the device. At this time, the pump is started on the ground to pressurize the entire well string to test its sealing performance. If the pressure inside the string does not drop within a certain period of time, the pressure test is considered successful. During the pressure test, the speed at which the external fluid enters the internal chamber of the test body through the first flow channel is controllably regulated by the spring of the upper check valve 3-6. Therefore, after the pressure test, the volume of fluid entering the internal chamber of the test body is just enough to react with the gas generator. The gas generator reacts with the fluid to produce a large amount of gas, which opens the lower check valve 3-9 in the second flow channel, causing the gas-liquid mixture to be sprayed downwards, providing an upward force to the entire device and causing it to move upwards toward the wellhead and away from the test seat 3-10. At this time, the ground displays automatic pressure relief, indicating that the pressure test is successful, and the pump is stopped. Driven by the generated gas, the entire device moves upward, gradually reaching the wellhead for recycling.

[0083] As an optional auxiliary retrieval mechanism installed in the device, it is generally used in well derusting devices with shallow well depths. If the well is deep and the device cannot be moved to the wellhead by relying solely on gas thrust and the buoyancy of the buoyancy ball, the device will not be equipped with an auxiliary retrieval mechanism. Instead, after the derusting operation is completed, the retrieval tool will be directly lowered to the central pipe 1-2 and connected to the central pipe 1-2 to retrieve the device from the bottom of the well.

[0084] As for the rust and iron filings generated during the rust removal process, for tubing, drill pipes and other tubing, storage tools such as blind plug screens and scoop baskets can be installed at the bottom of the tubing for storage. When the tubing is pulled up, it can be pulled up to the ground together with the tubing.

Claims

1. A recyclable well casing inner wall rust removal device, characterized in that, It includes a timely sealing mechanism (1), a hydraulic rotary rust removal mechanism (2), and a pneumatic booster mechanism (3) connected in sequence; among which, The timely sealing mechanism (1) includes a bowl-shaped packer (1-3), a claw-type support frame (1-4), an outer cylinder (1-1), and an upper support shaft (1-6) sequentially fitted from top to bottom on the outside of the central tube (1-2). The bowl-shaped packer (1-3) is fixed to the top outer wall of the central tube (1-2). The claw-type support frame (1-4) is in a contracted state, tightly fitted to the outside of the bowl-shaped packer (1-3), and its bottom end is movably set on the outer wall of the central tube (1-2), and can be in an expanded state as the bowl-shaped packer (1-3) opens. The top end of the upper support shaft (1-6) is initially inserted and temporarily fixed with a pin between the lower inner wall of the outer cylinder (1-1) and the outer wall of the central tube (1-2), forming a... At the bottom of the annular space, the annular boss on the inner wall of the top of the upper support shaft (1-6) is press-fitted onto the annular boss on the outer wall of the bottom of the central tube (1-2), so that the upper support shaft (1-6), the outer cylinder (1-1), and the central tube (1-2) enclose a sealed hydraulic chamber (1-5) filled with high-pressure hydraulic oil. When the pin is sheared, the upper support shaft (1-6) moves upward in the annular space and encloses the central tube (1-2) to form an annular sealed chamber (1-7). Two axial flow holes connected to the sealed hydraulic chamber (1-5) are symmetrically opened on the annular boss at the top of the upper support shaft (1-6), and each axial flow hole is temporarily blocked by a built-in crushing disc. The hydraulic rotary rust removal mechanism (2) includes multiple conical nozzles (2-2), multiple cavitation nozzles (2-3), several fine-toothed brushes (2-5), a fine-toothed brush booster mechanism, and a lower support shaft (2-8) mounted on a rotating cylinder (2-1). The top end of the rotating cylinder (2-1) is rotatably mounted on the outside of the lower support shaft (2-9) via a first rotating bearing, and the two are connected by a retaining ring (2-7) to form a movable limiting connection. The bottom end of the rotating cylinder (2-1) is rotatably mounted on the outside of the upper support shaft (1-6) via a second rotating bearing, and the two are connected by a retaining ring (2-7) to form a movable limiting connection. On the side wall of the rotating cylinder (2-1), from top to bottom, there are sequentially arranged a first conical nozzle mounting hole group, a first cavitation nozzle mounting hole group, a brush body mounting hole group, a second cavitation nozzle mounting hole group, and a second conical nozzle mounting hole group; each conical nozzle... The straight nozzle mounting hole group and each cavitation nozzle mounting hole group are composed of multiple mounting holes evenly distributed along the circumference, and each mounting hole is formed by extending from the outer wall of the rotating cylinder (2-1) along the same oblique direction to the inner wall of the rotating cylinder (2-1); multiple conical straight nozzles (2-2) are divided into two parts and fixed in each conical straight nozzle mounting hole respectively; multiple cavitation nozzles (2-3) are divided into two parts and fixed in each cavitation nozzle mounting hole respectively; the brush body mounting hole group is composed of several vertical strip brush body mounting holes evenly distributed along the circumference; several closely spaced brushes (2-5) are respectively assembled in each brush body mounting hole respectively; the closely spaced brush booster mechanism is set between several closely spaced brushes (2-5) and can push the closely spaced brushes (2-5) out of the brush body mounting hole to the outside of the rotating cylinder (2-1) under hydraulic action.

2. The recyclable well casing inner wall rust removal device according to claim 1, characterized in that, The claw-type support frame (1-4) consists of two symmetrically arranged active claws (1-4-1) and multiple driven claws (1-4-2) evenly distributed between the two active claws (1-4-1). The active claw (1-4-1) is a claw body composed of an upper trapezoidal plate, a lower trapezoidal plate, a rectangular shoulder, a connecting plate, and a claw head. Both the upper and lower trapezoidal plates are inverted and parallel to each other, with the upper and lower plates intersecting. The rectangular shoulder connects the upper and lower trapezoidal plates. Between them, the upper trapezoidal plate, the rectangular shoulder, and the lower trapezoidal plate form a double-step shape. The connecting plate is vertically fixed to the back of the rectangular shoulder, and its bottom end has an annular connecting part that protrudes to the outside of the rectangular shoulder. The axis of the annular connecting part is perpendicular to the rectangular shoulder. The claw head is fixed to the annular connecting part of the connecting plate in a manner that it is inclined towards the front of the trapezoidal plate. The driven claw (1-4-2) is a claw body composed of the upper trapezoidal plate, the lower trapezoidal plate, the rectangular shoulder, and the connecting plate, and its upper trapezoidal plate and lower trapezoidal plate The rectangular shoulder and connecting plate and their connection relationship are the same as those of the active claw (1-4-1); all the claw bodies are arranged circumferentially in such a way that the upper trapezoidal plate of one claw body is pressed against the lower trapezoidal plate of the adjacent claw body, forming an inverted conical cylindrical body that is initially contracted and tightly attached to the conical outer wall of the bowl-shaped packer (1-3); correspondingly, a number of slots (1-1-1) are evenly distributed along the circumferential direction on the top end face of the outer cylinder (1-1), which is the same number as the number of claw bodies. Two claw head insertion slots (1-2-1) are symmetrically opened on the outer wall of the central tube (1-2); the bottom ends of the connecting plates of several claw bodies are embedded in the slots (1-1-1), and each claw body is movably connected in the twelve slots (1-1-1) by fitting its annular connecting part onto the movable shaft set on the slot wall of each slot (1-1-1). The claw heads of the two active claws (1-4-1) are respectively inserted into the two claw head insertion slots (1-2-1).

3. The recyclable well casing inner wall rust removal device according to claim 1, characterized in that, The upper outer diameter of the upper support shaft (1-6) is larger than its lower outer diameter, so that a second annular step is formed at the connection between the upper outer wall and the lower outer wall. The top of the rotating cylinder (2-1) abuts against the lower end face of the second annular step. The upper inner diameter of the upper support shaft (1-6) is larger than its lower inner diameter, so that a third annular step is formed at the connection between the upper inner wall and the lower inner wall. The width of the third annular step is the same as the width of the lower end face of the annular boss on the bottom outer wall of the central tube (1-2).

4. The recyclable well casing inner wall rust removal device according to claim 1, characterized in that, The conical-straight nozzle (2-2) is a tube body with a conical cavity and a straight cavity inside. The straight cavity is connected and communicates with the small-diameter end of the conical cavity. Each conical-straight nozzle (2-2) is set in the conical-straight nozzle mounting hole with its straight cavity close to the outside of the rotating cylinder (2-1) and its conical cavity close to the inside of the rotating cylinder (2-1).

5. The recyclable well casing inner wall rust removal device according to claim 1, characterized in that, The cavitation nozzle (2-3) is a tube body with a conical cavity, a first-stage straight cavity, a second-stage straight cavity and a third-stage straight cavity connected in sequence. The first-stage straight cavity is connected to the small-diameter end of the conical cavity, and the inner diameter of the first-stage straight cavity, the second-stage straight cavity and the third-stage straight cavity increases step by step. Each cavitation nozzle (2-3) is set in the conical-straight nozzle mounting hole with its third-stage straight cavity close to the inner side of the rotating cylinder (2-1) and its conical cavity close to the outer side of the rotating cylinder (2-1).

6. The recyclable well casing inner wall rust removal device according to claim 1, characterized in that, Each fine-tooth brush (2-5) consists of a comb frame (2-5-1), comb teeth (2-5-2), and a baffle (2-5-3). The comb frame (2-5-1) is a U-shaped frame formed by connecting a first comb tooth mounting plate, a spring mounting plate, and a second comb tooth mounting plate in sequence. The spring mounting plate is a plate with a flat inner surface and a sloping outer surface. The comb frame (2-5-1) is positioned in the brush body mounting hole with its spring mounting plate partially located inside the rotating cylinder (2-1) and its sloping outer surface facing upwards. The baffle (2-5-3) is positioned between the two comb tooth mounting plates of the comb frame (2-5-1), and its upper and lower ends are fixed to the rotating cylinder (2-1) by screws. On the outer wall; the fine-tooth brush booster mechanism consists of several sets of compression springs (2-4) and an inverted conical slider (2-6) with a straight hole inside; the several sets of compression springs (2-4) are respectively set in the comb frame (2-5-1) of the twelve fine-tooth brushes (2-5); each set of compression springs (2-4) consists of three helical springs, which are arranged at intervals from top to bottom in the comb frame (2-5-1), and one end of each helical spring is fixed on the baffle (2-5-3) and the other end is fixed on the inner side plate of the compression spring mounting plate; the inverted conical slider (2-6) with a straight hole inside is set in the conical inner cavity surrounded by all the fine-tooth brushes (2-5), and its outer conical surface matches the inner conical surface of the conical inner cavity.

7. The recyclable well casing inner wall rust removal device according to claim 1, characterized in that, The pneumatic booster mechanism (3) consists of a multifunctional pressure test body and a pressure test seat (3-10); among which, The multifunctional pressure test body consists of a booster housing (3-1), two upper check valves (3-6), and one lower check valve (3-9). The booster housing (3-1) is inserted into a blind hole axially opened from the bottom surface of the lower support shaft (2-9), and is fixed to the lower support shaft (2-9) by multiple pins arranged circumferentially, with a gap between its top and the bottom of the blind hole. The booster housing (3-1) has a cavity (3-7) for holding a gas generating agent (3-8), and two symmetrically arranged valves are provided on the booster housing (3-1). A Z-shaped flow channel (3-2) extends from its outer wall into the cavity (3-7) and a straight flow channel extends axially from its bottom surface into the cavity (3-7); two upper check valves (3-6) are respectively located in the Z-shaped flow channel (3-2) and near the port of the cavity (3-7), so that fluid can only flow into the cavity (3-7) from the Z-shaped flow channel (3-2); a lower check valve (3-9) is located in the straight flow channel and near the port of the cavity (3-7), so that fluid or gas can only flow out of the cavity (3-7) to the outside; The pressure test seat (3-10) is pre-fixed on the bottom end face of the tube column. It is a cylinder with an axial through hole in its center and a groove on its top surface that is adapted to the convex spherical surface at the bottom of the booster shell (3-1), so that the bottom of the booster shell (3-1) can be sealed in the groove, and the second flow channel on it is connected to the axial through hole of the pressure test seat (3-10).

8. The recyclable well casing inner wall rust removal device according to claim 1, characterized in that, A sealing ring is provided on the outer wall of the central tube (1-2) to form a seal between the upper outer wall of the central tube (1-2) and the upper inner wall of the outer cylinder (1-1); a sealing ring is provided on the outer wall of the upper support shaft (1-6) to form a seal between the upper outer wall of the top end of the upper support shaft (1-6) and the lower inner wall of the outer cylinder (1-1); a sealing ring is provided on the lower outer wall of the central tube (1-2) to form a seal between the lower outer wall of the central tube (1-2) and the inner wall of the annular boss of the upper support shaft (1-6); a sealing ring is provided on the upper outer wall of the lower support shaft (2-8) and between the retaining ring (2-7) and the second rotating bearing, so that a seal is formed between the rotating cylinder (2-1) and the lower support shaft (2-8).

9. The recyclable well casing inner wall rust removal device according to claim 1, characterized in that, It also includes an auxiliary salvage mechanism (4), which consists of a buoyancy ball (4-1) and a connecting pipe (4-2); the buoyancy ball (4-1) is a carbon fiber sphere; the top end of the connecting pipe (4-2) is fixed to the bottom of the buoyancy ball (4-1), and the bottom end is connected to the inner wall of the top end of the central pipe (1-2).

10. The recyclable well casing inner wall rust removal device according to claim 1, characterized in that, It also includes a rust storage tool (5), which is a cylindrical body with an opening at the top and a closed bottom, and has flow holes evenly distributed on the side wall and bottom surface of the body; the rust storage tool (5) is fixed in the center on the bottom surface of the pressure test seat (3-10), and its inner cavity is connected to the axial through hole of the pressure test seat (3-10).

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