Downhole tubular column composite descaling and scale recovery integrated operation robot

Abstract

The invention relates to the technical field of petroleum and natural gas underground intelligent operation equipment, and discloses an underground tubular column composite descaling and scale recovery integrated operation robot. Comprising a central cable, a supporting mechanism, a chemical agent rotary spraying mechanism, a rotary variable-diameter scraping mechanism, a decoupling mechanism, a variable-diameter scale collecting device, an agent supply system, a control system and a cable winding and unwinding system. The supporting mechanism realizes reliable anchoring and blockage removal of the robot in the well; the chemical agent rotary spraying mechanism realizes 360-degree uniform chemical treatment on the pipe wall, and effectively softens and dissolves hard scale; the rotary reducing scraping mechanism realizes mechanical scraping of scale layers with different pipe diameters and different thicknesses; the variable-diameter scale collection device can actively adapt to the pipe diameter, and the scale recovery stability is guaranteed. According to the device and the method, combined, self-adaptive and visual cleaning and scale recovery integrated operation on a complex scale layer is realized, and the safety, the high efficiency and the reliability of petroleum and natural gas downhole tubular column descaling operation are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of intelligent downhole operation equipment technology for oil and gas wells, specifically to an integrated robot for downhole tubing descaling and scale recovery. Background Technology

[0002] In the mid-to-late stages of oil and gas field development, scaling is a common problem on the inner walls of production tubing, including inorganic salt scale, organic scale, and a mixture of both. The deposition of these scales significantly reduces the tubing's internal diameter, increases fluid flow resistance, leading to decreased oil and gas production, a surge in energy consumption, and in severe cases, complete blockage of the tubing, triggering downhole safety accidents and causing substantial economic losses. Therefore, regular and effective descaling and deblocking of production tubing is a critical maintenance operation for maintaining normal oil and gas well production and extending well life.

[0003] Currently, descaling of downhole tubing mainly relies on two categories of technologies: chemical cleaning and physical cleaning. Chemical cleaning dissolves scale by circulating or immersing the tubing in a specific solvent. While it doesn't require removing the tubing, its effectiveness against thick, hard scale is limited, the reaction cycle is long, the overall cost is high, and there is a risk of chemical contamination of the production formation. More importantly, it cannot be effectively coordinated with mechanical cleaning in the same operation, making it difficult to achieve efficient combined cleaning. Physical cleaning mainly relies on tools such as scrapers and cleaning balls to physically scrape the tubing wall under the impetus of fluid pressure differential or the traction of coiled tubing. Although these methods are effective against hard scale, they have the following inherent limitations:

[0004] 1. Traditional tools lack active anchoring support and unblocking capabilities, relying on passive drive. They are prone to jamming in vertical wells and highly deviated wells, resulting in low operational accuracy and efficiency.

[0005] 2. The operation process is discontinuous and inefficient. After a single pass, the tubing string often needs to be pulled out or the ball repeatedly dropped, making it impossible to continuously clean long sections of the well in one trip.

[0006] 3. Existing technologies generally do not have the function of collecting scale and debris in real time during scraping. The scale and debris scraped off fall directly to the bottom of the well or move with the fluid, which can easily re-accumulate in the low-lying areas of the tubing string, valves or tool strings, causing more serious secondary blockages, or enter the surface treatment system with the produced fluid, aggravating equipment wear.

[0007] In addition to solving the problems of existing descaling devices, the following functions and requirements also need to be realized and met for the special environment and working conditions downhole.

[0008] 1. To address the issues of traditional tools relying on passive drive and being prone to jamming in variable-diameter sections of complex wellbores, a support system with reliable anchoring and support functions needs to be designed to ensure that the robot can be stably and controllably supported and operated in both vertical and steeply inclined sections of long and deep wells.

[0009] 2. To address the limited effectiveness of single chemical or mechanical cleaning methods, an integrated module for descaling tools needs to be designed. This module should be able to combine mechanical scraping and chemical spraying as a composite descaling mode in a single operation, depending on the type of scale, to achieve efficient and adaptive cleaning.

[0010] Following comprehensive market research and technical evaluation, no existing downhole descaling equipment can fully and efficiently meet all the aforementioned functional requirements. Therefore, there is an urgent need to invent a novel integrated robot suitable for descaling and scale recovery of production well tubing in oil and gas wells. Summary of the Invention

[0011] To address the aforementioned technical problems, an integrated robot for downhole tubing descaling and scale recovery has been invented. This robot comprises a central cable, a support mechanism, a chemical rotary spraying mechanism, a rotary variable-diameter scraping mechanism, a decoupling mechanism, a variable-diameter scale collection device, a chemical supply system, a control system, and a cable retraction system. The support mechanism ensures reliable anchoring, stable support, and unblocking of the robot within the downhole tubing. The chemical rotary spraying mechanism provides 360° uniform spraying to the tubing wall, effectively softening and dissolving hard scale, providing pretreatment for mechanical removal. The rotary variable-diameter scraping mechanism adaptively adjusts according to the tubing diameter and scale thickness to mechanically scrape the scale. The decoupling mechanism isolates the rotational movement of the scraping mechanism, ensuring the stability of the subsequent collection device. The variable-diameter scale collection device actively adapts to different tubing diameters, filtering and collecting scraped scale in real time to prevent secondary blockage. Through the coordinated operation of these mechanisms, this invention achieves a combined descaling mode of chemical treatment and mechanical scraping, simultaneously recovering scale. This robot is adaptive, visualized, and capable of continuous operation. It can complete the cleaning of long well sections in a single run, significantly improving the efficiency, safety, and reliability of descaling operations in oil and gas wells. It effectively solves the technical problems of discontinuous operation, easy clogging, and inability to recover scale debris in traditional methods.

[0012] The technical solution adopted by this invention to solve its technical problem is as follows: an integrated robot for downhole tubing descaling and scale recovery, characterized in that it includes a central cable, a support mechanism, a chemical agent rotary spraying mechanism, a rotary variable diameter scraping mechanism, a decoupling mechanism, a variable diameter scale collection device, a chemical supply system, a control system, and a cable winding and unwinding system.

[0013] The central cable is connected to the support mechanism, the chemical agent rotary spraying mechanism, and the rotary diameter-changing scraping mechanism. The support mechanism is connected to the central cable at the top and the chemical agent rotary spraying mechanism at the bottom. The chemical agent rotary spraying mechanism is connected to the rotary diameter-changing scraping mechanism at the bottom. The rotary diameter-changing scraping mechanism is connected to the decoupling mechanism at the bottom. The decoupling mechanism is connected to the variable diameter scale collection device at the bottom. The variable diameter scale collection device is connected to the decoupling mechanism at the top. The chemical agent supply system is connected to the control system at the top and the chemical agent rotary spraying mechanism at the bottom. The cable winding and unwinding system is connected to the control system at the top and the central cable at the bottom.

[0014] The integrated robot for descaling and scale recovery of the downhole tubing is characterized in that: the upper end of the central cable is connected to the cable winding and unwinding system, and the lower end is connected in sequence along the axial direction to the support mechanism, the chemical agent rotary spraying mechanism, and the rotary diameter-changing scraping mechanism, which are used to provide power and transmit signals;

[0015] The support mechanism includes a track wheel assembly, a support rod, a spring push rod, a slider, a movable push rod, a connecting flange, a support mechanism body, and a camera module. The track wheel assembly is connected to the support mechanism body via the support rod. The spring push rod is mounted on the slider and connected to the track wheel assembly. The slider is mounted on the support mechanism body. The movable push rod is mounted on the support mechanism body and connected to the slider. The upper end of the connecting flange is mounted on the support mechanism body, and the lower end is connected to the chemical agent rotary spraying mechanism. The camera module is mounted on the track wheel assembly.

[0016] The chemical agent rotary spraying mechanism includes an inner stator flange, a sleeve connecting ring, a hollow shaft motor inner stator, a sliding ring, a hollow shaft motor outer rotor, an agent nozzle, a nozzle connection, and an agent tube interface. The upper end of the inner stator flange is connected to a support mechanism, and the lower end is connected to the hollow shaft motor inner stator. The outer end of the sleeve connecting ring is connected to the hollow shaft motor inner stator, and the inner end is connected to a rotary diameter-changing scraping mechanism. The sliding ring is installed in the hollow shaft motor outer rotor and contacts the hollow shaft motor inner stator. The lower end of the hollow shaft motor outer rotor is connected to the rotary diameter-changing scraping mechanism. The upper end of the nozzle connection is connected to the hollow shaft motor outer rotor. The agent nozzle is installed on the nozzle connection, and the agent tube interface is installed on the hollow shaft motor outer rotor.

[0017] The rotary variable diameter scraping mechanism includes a central sleeve, a mounting flange seat, an electric strut, an upper scraping plate, a lower scraping plate, a needle roller bearing, and a thrust ball bearing I. The upper end of the central sleeve is connected to the chemical agent rotary spraying mechanism, and the lower end is equipped with a needle roller bearing and a thrust ball bearing I. The inside of the mounting flange seat is in contact with the needle roller bearing. The electric strut is mounted on the mounting flange seat, and its other end is connected to the lower scraping plate. The upper scraping plate is mounted on the lower scraping plate by bolts.

[0018] The decoupling mechanism includes a partition plate, a thrust ball bearing II, a decoupling rod, a thrust ball bearing III, and a decoupling housing; the upper end of the partition plate is connected to the rotary variable diameter scraping mechanism, and the lower end is connected to the decoupling housing; the upper end of the decoupling rod is equipped with a thrust ball bearing II, and the lower end is equipped with a thrust ball bearing III; the lower end of the decoupling rod is connected to a variable diameter scale collection device through thread I.

[0019] The variable diameter scale collection device includes a central tube, a movable base, a support plate, an expansion plate, a tension spring, a fixed base, a collection connecting rod, a scale collection bucket, a flexible collection cloth, a sliding groove plate, and a sliding bolt. The central tube is internally connected to the collection connecting rod via threads, and the movable base and the fixed base are installed at its outer end. The expansion plate is connected to the movable base and the fixed base at both ends via support plates, and the expansion plate has an arc working surface I for conforming to the inner wall of the tube column. The sliding groove plate is installed on the upper and lower end faces of the expansion plate via sliding bolts, and the sliding groove plate has an arc working surface II for conforming to the inner wall of the tube column. The tension spring is connected to the movable base and the fixed base at both ends, respectively. The upper end of the flexible collection cloth is connected to the sliding groove plate, and the other end is connected to the scale collection bucket. The lower end of the scale collection bucket is connected to the collection connecting rod via threads.

[0020] The chemical supply system is installed on the ground and supplies chemical agents according to work requirements; the control system is installed on the ground, receives image information collected by the camera module, and adjusts the working status of the cable winding and laying system and the chemical supply system according to work requirements. The cable winding and laying system is installed on the ground and can receive and transmit the power and signals transmitted by the control system, and adjust the cable status.

[0021] The aforementioned integrated robot for descaling and scale recovery of downhole tubing is characterized in that: the inner stator of the hollow shaft motor is provided with a threaded hole and a groove I; the inner stator flange is installed on the threaded hole by screws; and the sliding ring is installed in the groove I.

[0022] The integrated robot for descaling and debris recovery of downhole tubing is characterized in that: the mounting flange seat is provided with a through hole I, a groove II, a step I, and a through hole II; the outer rotor of the hollow shaft motor is connected to the through hole I by bolts; the electric strut is installed in the groove II; the needle roller bearing is installed in the step I; and the central sleeve is connected to the sleeve connecting ring through the through hole II.

[0023] The aforementioned integrated robot for descaling and debris recovery of downhole tubing is characterized in that: the decoupling rod is provided with a mating cylindrical surface I, a step II, a mating cylindrical surface II, an inclined surface, and a thread I; the thrust ball bearing II is installed on the mating cylindrical surface I; the thrust ball bearing III is installed on the mating cylindrical surface II; the step II is located between the thrust ball bearing II and the thrust ball bearing III; and the collection connecting rod is connected to the decoupling rod through the thread I.

[0024] The aforementioned integrated robot for descaling and scale recovery of downhole tubing is characterized in that: the enlarged plate is provided with a through hole III, an arc working surface I, and a through hole IV; the sliding bolt is installed on the through hole III; and the support plate is installed on the through hole IV by bolts.

[0025] The integrated robot for descaling and scale recovery of downhole tubing is characterized in that: the sliding plate is provided with a sliding groove and an arc working surface II, and the sliding bolt connects the sliding plate to the expansion plate through the sliding groove.

[0026] The aforementioned integrated robot for combined descaling and scale recovery of downhole tubing is characterized by the following steps in its continuous descaling operation:

[0027] S1. Preparation and running downhole: Connect the downhole tubing composite descaling and scale recovery integrated operation robot to the cable retraction system via the central cable, check the operation of the control system for any abnormalities, connect the chemical supply system to the hollow shaft motor outer rotor via the chemical pipe interface, and then lower it to the starting position of the target descaling section inside the production tubing.

[0028] S2. Initial Positioning: The support mechanism is activated to anchor the tracked wheel assembly to the inner wall of the tubing. The camera module is used to observe the initial scaling condition of the tubing wall and fine-tune the robot's position. The camera module is also used to observe whether the variable diameter scale collection device is properly attached to the tubing wall. When the integrated downhole tubing descaling and scale recovery robot experiences blockage during the lowering and operation process, the tracked wheel assembly provides continuous thrust to overcome hard scale blockages or unexpected obstacles.

[0029] S3. Continuous compound descaling operation: Repeat the following steps, continuously advancing along the tubing from top to bottom:

[0030] S31. Chemical pretreatment: Start the chemical agent rotary spraying mechanism to perform rotary spraying on the pipe wall section to be treated at the rotary diameter scraping mechanism.

[0031] S32. Mechanical cleaning: Activate the rotary diameter-changing scraping mechanism to mechanically scrape the pipe wall section that has undergone chemical pretreatment in step S31.

[0032] S33, Scale and debris recovery: Under the action of the tension spring, the variable diameter scale and debris collection device fits against the inner wall of the tube column. The scale and debris generated by the scraping in step S32 flows with the agent and is stored in the scale and debris collection bucket after passing through the flexible collection cloth.

[0033] S34, Retraction and repositioning: Control the movement of the track wheel assembly on the support mechanism to retract the support mechanism and lower the tool to the next working section through the cable retraction system;

[0034] S4. Recycling complete:

[0035] S41. Tool recovery: After completing the descaling operation of all target well sections, the robot is lifted to the wellhead through the cable retraction system.

[0036] S42. Cleaning and maintenance: Disassemble and clean the debris collection bucket of the variable diameter debris collection device, and perform overall maintenance on the robot.

[0037] Beneficial effects of the invention

[0038] 1. This invention employs a support mechanism to achieve adaptive support and anchoring operations, eliminating tool jamming in the well, and is equipped with a camera module to enable visualized operations downhole. A single downhole run can complete a one-trip, continuous descaling operation on the target well section, improving pipeline cleaning efficiency and significantly reducing operating costs and oil and gas production losses.

[0039] 2. This invention uses a hollow shaft motor to integrate the rotary spraying of chemical agents with mechanical scraping, achieving 360° full coverage of the pipe wall with chemical agents and 360° rotary scraping in tandem, improving descaling efficiency and coverage, reducing the risk of damage to the pipe wall, and extending the service life of the tubing.

[0040] 3. This invention employs an expanding plate, a sliding plate, and a tension spring to form an active, variable-diameter scale collection device. This achieves effective collection and storage of scale, eliminating the risk of scale falling to the bottom of the well or clogging the tubing string, and avoiding secondary blockages and surface process contamination caused by traditional methods. Attached Figure Description

[0041] Figure 1 This is a schematic diagram illustrating the operation of the present invention;

[0042] Figure 2 This is a three-dimensional perspective view of the integrated robot for descaling and scale recovery of downhole tubing according to the present invention.

[0043] Figure 3 This is a three-dimensional perspective view of the support mechanism of the present invention;

[0044] Figure 4 This is a cross-sectional view of the chemical agent rotary spraying mechanism of the present invention;

[0045] Figure 5 This is a cross-sectional view of the rotary variable diameter scraping mechanism of the present invention;

[0046] Figure 6 This is a cross-sectional view of the decoupling mechanism of the present invention;

[0047] Figure 7 This is a diagram of the variable diameter debris collection device of the present invention;

[0048] Figure 8 This is a diagram of the inner stator of the hollow shaft motor of the present invention;

[0049] Figure 9 This is a diagram showing the installation of the flange seat for this invention;

[0050] Figure 10 This is a schematic diagram of the decoupling rod structure of the present invention;

[0051] Figure 11 This is a three-dimensional perspective view of the diameter-expanding plate of the present invention;

[0052] Figure 12 This is a three-dimensional perspective view of the slide plate of the present invention;

[0053] Figure 13 This is a diagram showing the downhole operation of the integrated robot for composite descaling and scale recovery of the downhole tubing string according to the present invention.

[0054] Figure 14 This is a flowchart illustrating the workflow of the present invention.

[0055] In the diagram, 1. Central cable; 2. Support mechanism; 3. Rotary chemical spraying mechanism; 4. Rotary variable diameter scraping mechanism; 5. Decoupling mechanism; 6. Variable diameter scale collection device; 201. Track wheel assembly; 202. Support rod; 203. Spring push rod; 204. Slider; 205. Moving push rod; 206. Connecting flange; 207. Main body of support mechanism; 208. Camera module; 301. Inner stator flange; 302. Sleeve connecting ring; 303. Hollow shaft motor inner stator; 304. Sliding ring; 305. Hollow shaft motor outer rotor; 306. Chemical nozzle; 307. Nozzle connection; 308. Chemical tube interface; 401. Center sleeve; 402. Mounting flange seat; 403. Electric strut; 404. Upper scraper plate; 405. Lower scraper plate; 406. Needle roller bearing; 407. Thrust ball bearing I; 501. Partition plate; 502. Thrust ball bearing II; 503. Decoupling rod; 504, Thrust ball bearing III; 505, Decoupling housing; 601, Central tube; 602, Movable base; 603, Support plate; 604, Expanding plate; 605, Tension spring; 606, Fixed base; 607, Collection connecting rod; 608, Debris collection bucket; 609, Flexible collection cloth; 610, Sliding plate; 611, Sliding bolt; 7, Chemical supply system; 8, Control system; 9, Cable winding system; 303 1. Threaded hole; 3032. Groove I; 4021. Through hole I; 4022. Groove II; 4023. Step I; 4024. Through hole II; 5031. Mating cylindrical surface I; 5032. Step II; 5033. Mating cylindrical surface II; 5034. Inclined surface; 5035. Thread I; 6041. Through hole III; 6042. Arc working surface I; 6043. Through hole IV; 6101. Sliding groove; 6102. Arc working surface II. Detailed Implementation

[0056] The present invention will be further described below with reference to the accompanying drawings. The scope of protection of the present invention is not limited to the following description:

[0057] like Figures 1-14 As shown, this embodiment is an integrated robot for descaling and scale recovery of downhole tubing, characterized by comprising: a central cable 1, a support mechanism 2, a chemical agent rotary spraying mechanism 3, a rotary variable diameter scraping mechanism 4, a decoupling mechanism 5, a variable diameter scale collection device 6, a chemical supply system 7, a control system 8, and a cable retraction system 9.

[0058] The central cable 1 is connected to the support mechanism 2, the chemical agent rotary spraying mechanism 3, and the rotary diameter-changing scraping mechanism 4 respectively. The support mechanism 2 is connected to the central cable 1 at the top and the chemical agent rotary spraying mechanism 3 at the bottom. The chemical agent rotary spraying mechanism 3 is connected to the rotary diameter-changing scraping mechanism 4 at the bottom. The rotary diameter-changing scraping mechanism 4 is connected to the decoupling mechanism 5 at the bottom. The decoupling mechanism 5 is connected to the variable diameter scale collection device 6 at the bottom. The variable diameter scale collection device 6 is connected to the decoupling mechanism 5 at the top. The chemical supply system 7 is connected to the control system 8 at the top and the chemical agent rotary spraying mechanism 3 at the bottom. The cable winding and unwinding system 9 is connected to the control system 8 at the top and the central cable 1 at the bottom.

[0059] In this embodiment, the support mechanism 2 includes a track wheel assembly 201, a support rod 202, a spring push rod 203, a slider 204, a movable push rod 205, a connecting flange 206, a support mechanism body 207, and a camera module 208. The track wheel assembly 201 is connected to the support mechanism body 207 via the support rod 202. The spring push rod 203 is mounted on the slider 204 and connected to the track wheel assembly 201. The slider 204 is mounted on the support mechanism body 207. The movable push rod 205 is mounted on the support mechanism body 207 and connected to the slider 204. The upper end of the connecting flange 206 is mounted on the support mechanism body 207, and the lower end is connected to the chemical agent rotary spraying mechanism 3. The camera module 208 is mounted on the track wheel assembly 201.

[0060] In this embodiment, the chemical agent rotary spraying mechanism 3 includes an inner stator flange 301, a sleeve connecting ring 302, a hollow shaft motor inner stator 303, a sliding ring 304, a hollow shaft motor outer rotor 305, an agent nozzle 306, a nozzle connection 307, and an agent pipe interface 308. The upper end of the inner stator flange 301 is connected to the support mechanism 2, and the lower end is connected to the hollow shaft motor inner stator 303. The outer end of the sleeve connecting ring 302 is connected to the hollow shaft motor inner stator 303. The inner end of the sliding ring 304 is connected to the rotary variable diameter scraping mechanism 4. The sliding ring 304 is installed in the outer rotor 305 of the hollow shaft motor and contacts the inner stator 303 of the hollow shaft motor. The lower end of the outer rotor 305 of the hollow shaft motor is connected to the rotary variable diameter scraping mechanism 4. The upper end of the nozzle connection 307 is connected to the outer rotor 305 of the hollow shaft motor. The medicine nozzle 306 is installed on the nozzle connection 307. The medicine tube interface 308 is installed on the outer rotor 305 of the hollow shaft motor.

[0061] In this embodiment, the rotary variable diameter scraping mechanism 4 includes a central sleeve 401, a mounting flange seat 402, an electric support rod 403, an upper scraping plate 404, a lower scraping plate 405, a needle roller bearing 406, and a thrust ball bearing I 407. The upper end of the central sleeve 401 is connected to the chemical agent rotary spraying mechanism 3, and the lower end is equipped with the needle roller bearing 406 and the thrust ball bearing I 407. The interior of the mounting flange seat 402 is in contact with the needle roller bearing 406. The electric support rod 403 is mounted on the mounting flange seat 402, and its other end is connected to the lower scraping plate 405. The upper scraping plate 404 is mounted on the lower scraping plate 405 by bolts.

[0062] In this embodiment, the decoupling mechanism 5 includes a partition plate 501, a thrust ball bearing II 502, a decoupling rod 503, a thrust ball bearing III 504, and a decoupling housing 505. The upper end of the partition plate 501 is connected to the rotary variable diameter scraping mechanism 4, and the lower end is connected to the decoupling housing 505. The upper end of the decoupling rod 503 is equipped with the thrust ball bearing II 502, and the lower end is equipped with the thrust ball bearing III 504. The lower end of the decoupling rod 503 is connected to the variable diameter scale collection device 6 through thread I 5035.

[0063] In this embodiment, the variable diameter debris collection device 6 includes a central tube 601, a movable base 602, a support plate 603, an expanding plate 604, a tension spring 605, a fixed base 606, a collection connecting rod 607, a debris collection bucket 608, a flexible collection cloth 609, a sliding groove plate 610, and a sliding bolt 611. The central tube 601 is internally connected to the collection connecting rod 607 via threads, and the movable base 602 and the fixed base 606 are installed at its outer end. The two ends of the expanding plate 604 are respectively connected to the movable base 602 and the fixed base 606 via the support plate 603. The expansion plate 604 is connected to the inner wall of the tube column. The sliding plate 610 is installed on the upper and lower end faces of the expansion plate 604 by the sliding bolt 611. The sliding plate 610 has an arc working surface II 6102 for fitting the inner wall of the tube column. The two ends of the tension spring 605 are respectively connected to the movable base 602 and the fixed base 606. The upper end of the flexible collection cloth 609 is connected to the sliding plate 610, and the other end is connected to the scale collection bucket 608. The lower end of the scale collection bucket 608 is connected to the collection connecting rod 607 by threads.

[0064] In this embodiment, the agent supply system 7 is installed on the ground and supplies chemical agents according to work requirements; the control system 8 is installed on the ground, receives image information collected by the camera module 208, and adjusts the working status of the cable winding system 9 and the agent supply system 7 according to work requirements. The cable winding system 9 is installed on the ground and can receive and transmit the power and signals transmitted by the control system 8, and adjust the cable status.

[0065] In this embodiment, the hollow shaft motor inner stator 303 is provided with a threaded hole 3031 and a groove I 3032. The inner stator flange 301 is installed on the threaded hole 3031 by screws, and the sliding ring 304 is installed in the groove I 3032.

[0066] In this embodiment, the mounting flange seat 402 is provided with a through hole I 4021, a groove II 4022, a step I 4023, and a through hole II 4024. The hollow shaft motor outer rotor 305 is connected to the through hole I 4021 by bolts. The electric support rod 403 is installed in the groove II 4022. The needle roller bearing 406 is installed in the step I 4023. The central sleeve 401 is connected to the sleeve connecting ring 302 through the through hole II 4024.

[0067] In this embodiment, the decoupling rod 503 is provided with a mating cylindrical surface I 5031, a step II 5032, a mating cylindrical surface II 5033, an inclined surface 5034, and a thread I 5035. The thrust ball bearing II 502 is installed on the mating cylindrical surface I 5031, and the thrust ball bearing III 504 is installed on the mating cylindrical surface II 5033. The step II 5032 is located between the thrust ball bearing II 502 and the thrust ball bearing III 504. The collecting connecting rod 607 is connected to the decoupling rod 503 through the thread I 5035.

[0068] In this embodiment, the expanded diameter plate 604 is provided with a through hole Ⅲ 6041, an arc working surface Ⅰ 6042, and a through hole Ⅳ 6043. The sliding bolt 611 is installed on the through hole Ⅲ 6041, and the support plate 603 is installed on the through hole Ⅳ 6043 by bolts.

[0069] In this embodiment, the slide plate 610 is provided with a slide groove 6101 and an arc working surface II 6102, and the sliding bolt 611 connects the slide plate 610 to the expansion plate 604 through the slide groove 6101.

[0070] In this embodiment, the integrated robot for combined descaling and scale recovery of downhole tubing includes the following steps for continuous descaling operation:

[0071] S1. Preparation and running downhole: Connect the integrated robot for descaling and scale recovery of the downhole tubing to the cable retraction system 9 via the central cable 1. Check the operation of the control system 8 to ensure that its operation is normal. Connect the chemical supply system 7 to the outer rotor 305 of the hollow shaft motor via the chemical pipe interface 308. Then, lower it to the starting position of the target descaling section inside the production tubing.

[0072] S2. Initial Positioning: The support mechanism 2 is activated to anchor the track wheel assembly 201 to the inner wall of the tubing. The camera module 208 is used to observe the initial scaling condition of the tubing wall and fine-tune the robot position. The camera module 208 is also used to observe whether the variable diameter scale collection device 6 is in contact with the tubing wall abnormally. When the integrated robot for descaling and scale recovery of the downhole tubing experiences blockage during the lowering and operation process, the track wheel assembly 201 provides continuous thrust to overcome hard scale blockage or unexpected obstacles.

[0073] S3. Continuous compound descaling operation: Repeat the following steps, continuously advancing along the tubing from top to bottom:

[0074] S31. Chemical pretreatment: Start the chemical agent rotary spraying mechanism 3 to perform rotary spraying on the pipe wall section to be treated at the rotary diameter scraping mechanism 4.

[0075] S32. Mechanical cleaning: Start the rotary variable diameter scraping mechanism 4 to mechanically scrape the pipe wall section that has undergone chemical pretreatment in step S31.

[0076] S33. Scale and debris recovery: Under the action of the tension spring 605, the variable diameter scale and debris collection device 6 adheres to the inner wall of the tube column. The scale and debris generated by the scraping in step S32 flows with the agent and is stored in the scale and debris collection bucket 608 after passing through the flexible collection cloth 609.

[0077] S34, Retraction and repositioning: Control the movement of the track wheel assembly 201 on the support mechanism 2 to retract the support mechanism 2, and lower the tool to the next working section through the cable retraction system 9;

[0078] S4. Recycling complete:

[0079] S41. Tool recovery: After completing the descaling operation of all target well sections, the robot is lifted to the wellhead through the cable retraction system 9;

[0080] S42. Cleaning and maintenance: Disassemble and clean the debris collection bucket 608 of the variable diameter debris collection device 6, and perform overall maintenance on the robot.

[0081] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0082] In the description of this invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0083] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0084] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0085] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A robot for integrated descaling and scale recovery of downhole tubing, characterized in that: The center cable (1), the supporting mechanism (2), the chemical agent rotating spraying mechanism (3), the rotating variable-diameter scraping mechanism (4), the decoupling mechanism (5), the variable-diameter scale collection device (6), the chemical agent supply system (7), the control system (8) and the cable winding and unwinding system (9) are included. The center cable (1) is connected with the supporting mechanism (2), the chemical agent rotating spraying mechanism (3) and the rotating variable-diameter scraping mechanism (4) respectively.

2. The downhole string composite scale removal and scale debris recovery integrated robot of claim 1, wherein: The center cable (1) is connected with the cable winding and unwinding system (9) at the upper end and connected with the supporting mechanism (2), the chemical agent rotating spraying mechanism (3) and the rotating variable-diameter scraping mechanism (4) at the lower end in sequence along the axial direction, for providing power and transmitting signals. The supporting mechanism (2) comprises a track wheel group (201), a supporting rod (202), a spring push rod (203), a sliding block (204), a moving push rod (205), a connecting flange (206), a supporting mechanism body (207) and a camera module (208). The track wheel group (201) is connected to the supporting mechanism body (207) through the supporting rod (202). The spring push rod (203) is installed on the sliding block (204) and connected with the track wheel group (201). The sliding block (204) is installed on the supporting mechanism body (207). The moving push rod (205) is installed on the supporting mechanism body (207) and connected with the sliding block (204). The upper end of the connecting flange (206) is installed on the supporting mechanism body (207) and the lower end is connected with the chemical agent rotating spraying mechanism (3). The camera module (208) is installed on the track wheel group (201). The chemical agent rotating spraying mechanism (3) comprises an inner stator flange (301), a sleeve connecting ring (302), a hollow shaft motor inner stator (303), a sliding ring (304), a hollow shaft motor outer rotor (305), an agent nozzle (306), a nozzle connecting (307), an agent pipe interface (308); the upper end of the inner stator flange (301) is connected with the supporting mechanism (2), and the lower end is connected with the hollow shaft motor inner stator (303); the outer end of the sleeve connecting ring (302) is connected with the hollow shaft motor inner stator (303), and the inner end is connected with the rotating variable-diameter scraping mechanism (4); the sliding ring (304) is installed in the hollow shaft motor outer rotor (305) and is in contact with the hollow shaft motor inner stator (303); the lower end of the hollow shaft motor outer rotor (305) is connected with the rotating variable-diameter scraping mechanism (4); the upper end of the nozzle connecting (307) is connected with the hollow shaft motor outer rotor (305); the agent nozzle (306) is installed on the nozzle connecting (307); and the agent pipe interface (308) is installed on the hollow shaft motor outer rotor (305); The rotating variable-diameter scraping mechanism (4) comprises a center sleeve (401), a mounting flange seat (402), an electric supporting rod (403), a scraping upper plate (404), a scraping lower plate (405), a needle bearing (406), and a thrust ball bearing I (407); the upper end of the center sleeve (401) is connected with the chemical agent rotating spraying mechanism (3), and the lower end is provided with the needle bearing (406) and the thrust ball bearing I (407); the inside of the mounting flange seat (402) is in contact with the needle bearing (406); the electric supporting rod (403) is installed on the mounting flange seat (402) and is connected with the scraping lower plate (405) at the other end; and the scraping upper plate (404) is installed on the scraping lower plate (405) through bolts; The decoupling mechanism (5) comprises a partition plate (501), a thrust ball bearing II (502), a decoupling rod (503), a thrust ball bearing III (504), and a decoupling shell (505); the upper end of the partition plate (501) is connected with the rotating variable-diameter scraping mechanism (4), and the lower end is connected with the decoupling shell (505); the upper end of the decoupling rod (503) is provided with the thrust ball bearing II (502), and the lower end is provided with the thrust ball bearing III (504); and the lower end of the decoupling rod (503) is connected with the variable-diameter scale collection device (6) through threads I (5035). The variable-diameter dirt collecting device (6) comprises a center pipe (601), a movable base (602), a support sheet (603), a diameter-expanding sheet (604), a tension spring (605), a fixed base (606), a collecting connecting rod (607), a dirt collecting barrel (608), a flexible collecting cloth (609), a sliding chute sheet (610), and a sliding bolt (611); the center pipe (601) is connected with the collecting connecting rod (607) through threads inside, and the outer end is provided with the movable base (602) and the fixed base (606); the diameter-expanding sheet (604) is connected with the movable base (602) and the fixed base (606) through the support sheet (603) at both ends, and has a circular arc working surface I (6042) for abutting against the inner wall of the pipe column; the sliding chute sheet (610) is installed on the upper and lower end faces of the diameter-expanding sheet (604) through the sliding bolt (611), and has a circular arc working surface II (6102) for abutting against the inner wall of the pipe column; the tension spring (605) is connected with the movable base (602) and the fixed base (606) at both ends; the upper end of the flexible collecting cloth (609) is connected with the sliding chute sheet (610), and the other end is connected with the dirt collecting barrel (608); and the lower end of the dirt collecting barrel (608) is connected with the collecting connecting rod (607) through threads. The medicament supply system (7) is installed on the ground and supplies chemical medicaments according to work requirements; the control system (8) is installed on the ground, receives image information collected by the camera module (208), and adjusts the operation state of the cable winding and unwinding system (9) and the medicament supply system (7) according to work requirements; and the cable winding and unwinding system (9) is installed on the ground, can receive and transmit power and signals transmitted by the control system (8), and adjusts the state of the cable.

3. The downhole string composite scale removal and scale debris recovery integrated robot of claim 2, wherein: The hollow shaft motor inner stator (303) is provided with a threaded hole (3031) and a groove I (3032); the inner stator flange (301) is installed on the threaded hole (3031) through screws; and the sliding ring (304) is installed in the groove I (3032).

4. The downhole string composite scale removal and scale debris recovery integrated robot of claim 2, wherein: The mounting flange seat (402) is provided with a through hole I (4021), a groove II (4022), a step I (4023), and a through hole II (4024); the hollow shaft motor outer rotor (305) is connected with the through hole I (4021) through bolts; the electric supporting rod (403) is installed in the groove II (4022); the needle roller bearing (406) is installed on the step I (4023); and the center sleeve (401) is connected with the sleeve connecting ring (302) through the through hole II (4024).

5. The downhole string composite scale removal and scale debris recovery integrated robot of claim 2, wherein: The decoupling rod (503) is provided with a matching cylindrical surface I (5031), a step II (5032), a matching cylindrical surface II (5033), an inclined surface (5034) and a thread I (5035), the thrust ball bearing II (502) is installed on the matching cylindrical surface I (5031), the thrust ball bearing III (504) is installed on the matching cylindrical surface II (5033), the step II (5032) is located between the thrust ball bearing II (502) and the thrust ball bearing III (504), and the collecting connecting rod (607) is connected with the decoupling rod (503) through the thread I (5035).

6. The downhole string composite scale removal and scale debris recovery integrated robot of claim 2, wherein: The expanding sheet (604) is provided with a through hole III (6041), a circular arc working surface I (6042) and a through hole IV (6043), the sliding bolt (611) is installed on the through hole III (6041), and the supporting sheet (603) is installed on the through hole IV (6043) through a bolt.

7. The downhole string composite scale removal and scale debris recovery integrated robot of claim 2, wherein: The sliding groove sheet (610) is provided with a sliding groove (6101) and a circular arc working surface II (6102), and the sliding bolt (611) connects the sliding groove sheet (610) to the expanding sheet (604) through the sliding groove (6101).

8. The downhole string composite scale removal and scale debris recovery integrated robot of claim 1, wherein: The composite descaling continuous operation comprises the following steps: S1, preparation and downhole: the downhole pipe string composite descaling and scale scrap recovery integrated operation robot is connected with the cable winding and unwinding system (9) through the central cable (1), the action of the control system (8) is checked, whether the action is abnormal, the medicament supply system (7) is connected to the hollow shaft motor outer rotor (305) through the medicament pipe interface (308), and then is lowered into the target descaling section starting position in the production pipe string; S2, initial positioning: the caterpillar wheel group (201) is anchored to the inner wall of the pipe string through the action of the supporting mechanism (2), the initial scaling condition of the pipe wall is observed through the camera module (208), the position of the robot is fine adjusted, whether the variable diameter scale scrap collecting device (6) is abnormally attached to the pipe wall is observed through the camera module (208), when the downhole pipe string composite descaling and scale scrap recovery integrated operation robot appears to be stuck during the lowering process and the operation process, the continuous thrust is provided through the action of the caterpillar wheel group (201), and the hard scale blockage or accidental obstacle can be overcome; S3, composite descaling continuous operation: the following steps are repeatedly executed, and the pipe string is continuously pushed from top to bottom: S31, chemical pretreatment: the chemical medicament rotating spraying mechanism (3) is started, and the pipe wall section to be treated at the rotating variable diameter scraping mechanism (4) is sprayed in rotation; S32, mechanical cleaning: the rotating variable diameter scraping mechanism (4) is started, and the pipe wall section subjected to the chemical pretreatment in step S31 is mechanically scraped; S33, scale scrap recovery: the variable diameter scale scrap collecting device (6) is attached to the inner wall of the pipe string under the action of the tension spring (605), the scale scrap generated in step S32 is stored in the scale scrap collecting barrel (608) after flowing through the flexible collecting cloth (609) along with the medicament. S34, contraction transposition: control the track wheel group (201) on the support mechanism (2) to act, realize the contraction of the support mechanism (2), and lower the tool to the next operation section through the cable winding and unwinding system (9); S4, complete recovery: S41, tool recovery: after completing the descaling operation of all target well sections, the robot is lifted to the wellhead through the cable winding and unwinding system (9); S42, cleaning and maintenance: disassemble and clean the scale collection barrel (608) of the variable-diameter scale collection device (6), and maintain the whole robot.

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