Oil and water well casing corrosion leakage well section treatment device and method based on downhole welding

Abstract

The application discloses a kind of oil-water well casing corrosion leakage well section treatment devices based on downhole welding, including fixed installation in the ground at wellhead side winch, winch is electrically connected with control cabinet by wire, wellhead is fixedly installed with fixed pulley right above, winch is used to lift and lower steel wire rope, after being turned over fixed pulley, extend to wellhead and fixedly connected with engineering logging instrument, engineering logging instrument is bidirectional signal communication with control cabinet by wire, the fixed engineering logging instrument is below multi-arm welding system, and multi-arm welding system is bidirectional signal communication with control cabinet by wire.The application can directly weld and repair casing corrosion leakage position, realize the goal of minimum influence on original well casing and long-term treatment.The application also discloses a kind of oil-water well casing corrosion leakage well section treatment method based on downhole welding.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil and water well treatment methods, and relates to an oil and water well casing corrosion leakage well section treatment device based on downhole welding, and further relates to an oil and water well casing corrosion leakage well section treatment method based on downhole welding. BACKGROUND

[0002] The oil and water well casing corrosion leakage problem not only destroys the oilfield plane injection-production well pattern, causes longitudinal injection-production imbalance, but also directly affects the stable production and increased production of an old oilfield area, and has become a problem that needs to be solved in the later development stage. The main features of the oil and water well casing corrosion leakage problem are as follows: many leakage points and large longitudinal span. Conventional casing corrosion leakage treatment measures include whole-well small casing cementing, expansion pipe patching repair, composite patching and plugging and chemical plugging technology.

[0003] For the casing corrosion leakage problem, the adaptability of conventional treatment technology measures is poor, mainly because of the following reasons: after treatment, the wellbore diameter is seriously reduced, the effective period is short, the construction efficiency is low and the comprehensive cost is high, and the specific performance is as follows:

[0004] (1) The whole-well small casing cementing causes the inner diameter of the wellbore to be obviously reduced, seriously affecting the implementation of subsequent wellbore operations, and the narrow gap cementing easily causes poor cementing quality, resulting in a short treatment effective period;

[0005] (2) The expansion patching repair causes the wellbore to be reduced in diameter, affecting the selection of subsequent construction operations and production strings, and the long-distance expansion patching repair has high cost and process risk, and is considered to have poor adaptability from the aspects of technology and economy;

[0006] (3) When the composite patching and plugging is performed, the annulus between the original well casing and the patching and plugging pipe is small, the cementing quality is poor, and the effective period is short;

[0007] (4) The chemical plugging technology does not have the problem of casing diameter reduction, but the plugging success rate of the long-distance corrosion leakage section in the longitudinal direction is low, the effective period is short, and the comprehensive benefit is poor. SUMMARY

[0008] The purpose of the present application is to provide an oil and water well casing corrosion leakage well section treatment device based on downhole welding, which can directly weld and repair the casing corrosion leakage position, and achieve the goal of minimal impact on the original well casing and long-term treatment.

[0009] Another purpose of the present application is to provide an oil and water well casing corrosion leakage well section treatment method based on downhole welding.

[0010] The technical scheme adopted by the present application is a downhole welding oil-water well casing corrosion leakage well section treatment device, which comprises a winch fixedly installed on the ground beside the wellhead, the winch is electrically connected with a control cabinet through a wire, a fixed pulley is fixedly installed above the wellhead, the winch is used for lifting and lowering the steel wire rope, the steel wire rope is wound around the fixed pulley and then extends to the wellhead and is fixedly connected with an engineering logging instrument, the engineering logging instrument is in two-way signal communication with the control cabinet through a wire, a multi-arm welding system is fixed below the engineering logging instrument, and the multi-arm welding system is in two-way signal communication with the control cabinet through a wire.

[0011] The present application is also characterized in that,

[0012] The multi-arm welding system comprises a downhole welding system working equipment control box fixed below the engineering logging instrument, the downhole welding system working equipment control box is in two-way signal communication with the control cabinet through a wire, at least three righting telescopic structures are fixedly connected around the center of the wellhead on the top of the downhole welding system working equipment control box, a rotatable base structure is fixedly connected to the bottom of the downhole welding system working equipment control box, a welding machine arm is fixed to the bottom of the base structure, a welding gun is fixed to one side of the bottom of the welding machine arm, the welding gun is electrically connected with the downhole welding system working equipment control box through a wire, and the welding machine arm and the downhole welding system working equipment control box are electrically connected through a wire.

[0013] The righting telescopic structure comprises a righting telescopic block and an electric hydraulic cylinder, the electric hydraulic cylinder is fixedly connected around the center of the wellhead on the top of the downhole welding system working equipment control box, the righting telescopic block is fixed to the telescopic end of the telescopic piston rod of the electric hydraulic cylinder, and the electric hydraulic cylinder is electrically connected with the downhole welding system working equipment control box through a wire.

[0014] The base structure comprises a driving motor, the driving motor is fixed to the bottom of the downhole welding system working equipment control box, a rotating shaft is connected to the output end of the driving motor and away from the downhole welding system working equipment control box, a base is fixed to the rotating shaft, the base is fixedly connected with the welding machine arm, and the driving motor is electrically connected with the downhole welding system working equipment control box through a wire.

[0015] Three cameras are uniformly installed around the inner wall of the engineering logging instrument to form a ring-shaped monitoring, a fill light, an ultrasonic sensor and a temperature and humidity sensor are installed on each camera, and the camera, the fill light, the ultrasonic sensor and the temperature and humidity sensor are connected with the control cabinet through wires.

[0016] Another technical solution adopted by the present application is an oil and water well casing corrosion leakage well section treatment method based on downhole welding, which adopts the above-mentioned oil and water well casing corrosion leakage well section treatment device based on downhole welding, and specifically uses the control cabinet to control the winch to pull up and lower the lifting steel wire rope, adjusts the downhole depth of the engineering logging instrument, detects the accurate position of casing damage and the damage degree by using the engineering logging instrument, and then lowers the multi-arm welding system according to the accurate position of casing damage to weld the damaged part, and specifically implements the following steps:

[0017] Step 1, preparation before construction: install the oil and water well casing corrosion leakage well section treatment device based on downhole welding;

[0018] Step 2, use the control cabinet to control the winch to pull up and lower the lifting steel wire rope, adjust the downhole depth of the engineering logging instrument, use the engineering logging instrument to detect the accurate position of casing damage and the damage degree of the oil and water well corrosion leakage well section, and return the above detection data to the control cabinet to establish a three-dimensional model of the oilfield casing damage well;

[0019] Step 3, according to the bottom position of the damaged well section detected in step 2, use the control cabinet to control the winch to lower the steel wire rope to the bottom position of the damaged well section, and then use the control cabinet to control the electric hydraulic cylinder to extend through the downhole welding system working equipment control box, so that the extension of the centralizing extension block is against the inner wall of the well to realize the centralizing and temporary fixing of the multi-arm welding system in the well, then the control cabinet controls the driving motor to rotate through the downhole welding system working equipment control box, thereby driving the base to rotate and driving the welding machine arm to rotate, the welding gun is aimed at the casing corrosion leakage position, one position is welded, the control cabinet controls the centralizing extension block to retract, then the steel wire rope is pulled up, and each corrosion position is welded and repaired from bottom to top in turn until the treatment of the entire corrosion well section is completed;

[0020] Step 4, after completing the welding and repair of the corrosion leakage position of the entire wellbore, the engineering logging instrument is used again to detect the welded and repaired well section again, and secondary three-dimensional modeling is performed, and the welding and repair effect of the corrosion leakage well section is evaluated by comparing the detection data before and after the treatment;

[0021] Step 5, if the repair does not meet the continued use requirement, steps 3 and 4 are repeated until the repair meets the requirement, and if the repair meets the continued use requirement, the screw motor and milling cone are lowered into the well by using the workover machine power to expand the welded and repaired corrosion leakage well section, and the wellbore drift diameter is ensured.

[0022] The engineering logging instrument is used in step 2 to detect the precise position and damage degree of the casing damage of the oil-water well corrosion leakage well section, and the detection data is returned to the control cabinet and introduced into the modeling software, specifically: when the engineering logging instrument is lowered into the well, the fill light and the camera are turned on, the camera, the ultrasonic sensor and the temperature and humidity sensor all return the collected information to the control cabinet in real time, then the computer modeling is used, the three-dimensional space structure about the damage of the inner wall of the wellbore is drawn according to the image information returned by the camera and the ultrasonic information returned by the ultrasonic sensor, the three-dimensional model of the oilfield casing damage well is constructed, and the three-dimensional model also includes the temperature and humidity distribution of the oilfield casing damage well.

[0023] In step 3, when the oilfield casing damage is treated, the control cabinet controls the lifting and lowering of the steel wire rope according to the three-dimensional model of the oilfield casing damage well established for the first time, so that the multi-arm welding system is aligned with the casing corrosion leakage position, and then welding repair is sequentially performed from bottom to top.

[0024] The beneficial effects of the present application are:

[0025] (1) The present application has high detection accuracy for the corrosion leakage position of the oil-water well casing, strong pertinence for welding repair, can restore the original well casing inner diameter after milling, has low influence degree on subsequent wellbore operation, has high wellbore integrity recovery degree, and realizes the long-term management goal of the corrosion leakage of the oil-water well casing;

[0026] (2) In the welding repair process, the device used has simple overall structure, simple construction process and high operation efficiency; compared with the conventional well repair operation, the cost of the corrosion leakage management of the oil-water well casing is obviously reduced. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a structural schematic view of the oil-water well casing corrosion leakage well section treatment device based on downhole welding of the present application;

[0028] Figure 2 is a structural schematic view of the multi-arm welding system in the oil-water well casing corrosion leakage well section treatment device based on downhole welding of the present application;

[0029] Figure 3 is a circuit connection schematic view of the oil-water well casing corrosion leakage well section treatment device based on downhole welding of the present application;

[0030] Figure 4 is a flow chart of the oil-water well casing corrosion leakage well section treatment method based on downhole welding of the present application.

[0031] In the figure: 1. Control cabinet, 2. Winch, 3. Wellhead, 4. Steel wire rope, 5. Engineering logging instrument, 501. Camera, 502. Light supplement lamp, 503. Ultrasonic sensor, 504. Temperature and humidity sensor, 6. Multi-arm welding system, 601. Righting telescopic structure, 602. Downhole welding system working equipment control box, 603. Base structure, 604. Welding machine arm, 605. Welding torch, 606. Righting telescopic block, 607. Electric hydraulic cylinder, 608. Base, 609. Driving motor, 7. Fixed pulley. DETAILED DESCRIPTION

[0032] The present application will be described in detail below in conjunction with the drawings and specific embodiments.

[0033] Example 1

[0034] The present application is based on a downhole welding oil and water well casing corrosion leakage well section treatment device, which has the structure as shown in Figure 1 and Figure 3 , comprising a winch 2 fixedly installed beside the wellhead 3 on the ground, the winch 2 is electrically connected with the control cabinet 1 through the wire, a fixed pulley 7 is fixedly installed above the wellhead 3, the winch 2 is used to lift and the steel wire rope 4 below extends to the wellhead 3 after turning around the fixed pulley 7 and is fixedly connected with the engineering logging instrument 5, the engineering logging instrument 5 is in two-way signal communication with the control cabinet 1 through the wire, a multi-arm welding system 6 is fixed below the engineering logging instrument 5, and the multi-arm welding system 6 is in two-way signal communication with the control cabinet 1 through the wire.

[0035] The welding machine arm 604 and the welding torch 605 of the present application are both electrically controllable structures, which can be remotely operated by control.

[0036] As shown in Figure 2 , the multi-arm welding system 6 comprises a downhole welding system working equipment control box 602 fixed below the engineering logging instrument 5, the downhole welding system working equipment control box 602 is in two-way signal communication with the control cabinet 1 through the wire, at least three righting telescopic structures 601 are fixedly connected around the center of the wellhead on the top of the downhole welding system working equipment control box 602, a rotatable base structure 603 is fixedly connected to the bottom of the downhole welding system working equipment control box 602, a welding machine arm 604 is fixed to the bottom of the base structure 603, a welding torch 605 is fixed to one side of the bottom of the welding machine arm 604, the welding torch 605 is electrically signal linked with the downhole welding system working equipment control box 602 through the wire, and the welding machine arm 604 and the downhole welding system working equipment control box 602 are electrically signal connected through the wire.

[0037] The righting telescopic structure 601 comprises righting telescopic blocks 606 and electric hydraulic cylinders 607, at least three of the electric hydraulic cylinders 607 are fixedly connected around the well mouth center on the top of the downhole welding system working equipment control box 602, the righting telescopic blocks 606 are fixed on the telescopic ends of telescopic piston rods of the electric hydraulic cylinders 607, and the electric hydraulic cylinders are electrically signal-linked with the downhole welding system working equipment control box 602 through wires.

[0038] The base structure 603 comprises a driving motor 609, the driving motor 609 is fixed on the bottom of the downhole welding system working equipment control box 602, the output end of the driving motor 609 is connected with a rotating shaft which is fixed with a base 608, the base 608 is fixedly connected with the welding machine arm 604, the driving motor 609 is electrically signal-connected with the downhole welding system working equipment control box 602 through wires, the base 608 can realize 360° circular rotation by being driven by the driving motor and the rotating shaft, and the rotating shaft is fixedly welded with the base 608.

[0039] Three cameras 501 are uniformly arranged on the engineering logging instrument 5 around the inner wall of the well to form annular monitoring, a light supplementing lamp 502, an ultrasonic sensor 503 and a temperature and humidity sensor 504 are arranged on each camera 501, and the camera 501, the light supplementing lamp 502, the ultrasonic sensor 503 and the temperature and humidity sensor 504 are connected with the control cabinet 1 through wires.

[0040] Embodiment 2

[0041] The present application is based on the downhole welding oil-water well casing corrosion leakage well section treatment method, the downhole welding oil-water well casing corrosion leakage well section treatment device in embodiment 1 is used, the control cabinet 1 is used to control the winch 2 to pull up and drop the lifting wire rope 4, the downhole depth of the engineering logging instrument 5 is adjusted, the accurate position of casing damage and the damage degree are determined, then the multi-arm welding system 6 is lowered according to the accurate position of casing damage to weld the damaged part, and the flow is as shown in the figure, and the specific implementation steps are as follows: Figure 4

[0042] Step 1, preparation before construction: the downhole welding oil-water well casing corrosion leakage well section treatment device is installed;

[0043] Step 2, the winch 2 is controlled by the control cabinet 1 to pull up and drop the lifting wire rope 4, the downhole depth of the engineering logging instrument 5 is adjusted, the engineering logging instrument 5 is used to detect the accurate position of casing damage and the damage degree of the oil-water well corrosion leakage well section, and the above detection data is transmitted back to the control cabinet 1 to establish a three-dimensional model of the oilfield casing damage well;

[0044] ​Step 3, according to the bottom position of the damaged well section detected in step 2, the winch 2 is controlled through the control cabinet 1 to lower the steel wire rope 4 to lower the welding gun 605 to the bottom position of the damaged well section, and then the control cabinet 1 controls the electric hydraulic cylinder 607 to extend through the downhole welding system working equipment control box 602, so that the extension of the centralizing telescopic block 606 is resisted against the inner wall of the well to realize the centralization and temporary fixation of the multi-arm welding system 6 in the well, and then the control cabinet 1 controls the driving motor to rotate through the downhole welding system working equipment control box 602 to drive the base 608 to rotate and drive the welding machine arm 604 to rotate, so that the welding gun 605 is aligned with the corrosion leakage position of the casing, a position is welded, the control cabinet 1 controls the centralizing telescopic block 606 to retract, and then the steel wire rope 4 is pulled up, and each corrosion position is sequentially welded and repaired from bottom to top until the whole corrosion well section is treated;

[0045] Step 4, after the welding repair of the corrosion leakage position of the whole wellbore is completed, the engineering logging instrument is used again to detect the welded and repaired well section again, secondary three-dimensional modeling is carried out, and the welding repair effect of the corrosion leakage well section is evaluated by comparing the detection data before and after the treatment;

[0046] Step 5, if the repair does not meet the continued use requirement, steps 3 and 4 are repeated until the repair meets the requirement, and if the repair meets the continued use requirement, the screw motor and the milling cone are lowered by using the workover rig power to expand the milling of the welded and repaired corrosion leakage well section, and the wellbore drift diameter is ensured.

[0047] In step 1, the winch 2 is fixed to the ground through the grounding long bolt, and the direction of the steel wire rope is adjusted by using the fixed pulley; the control cabinet 1 is in two-way signal communication with the engineering logging instrument and the multi-arm welding system through wires, and the rotation parameters of the internal motor of the winch are controlled, including the rotation speed and direction, and the lifting speed of the engineering logging instrument and the multi-arm welding system is adjusted;

[0048] When the engineering logging instrument 5 is explored, three cameras are used to form an equiangular distribution ring-shaped monitoring, and a fill light, an ultrasonic sensor and a temperature and humidity sensor are installed at the position of each camera; a high-definition camera capable of rotating 360 degrees is adopted, three cameras are wide-angle shooting, and three cameras are used for cooperative shooting, so that no dead angle shooting is formed when the exploration equipment is lifted, the shooting range is improved, video data is continuously acquired during lifting, the light brightness is improved by cooperating with the fill light, the clarity of shooting is ensured, the distance of the damaged point is detected by using the ultrasonic sensor, and the temperature and humidity change during lifting is detected by using the temperature and humidity sensor, so as to lay a foundation for subsequent accurate control of the multi-arm welding system.

[0049] The application establishes a three-dimensional model of the oilfield casing damage well, and the three-dimensional model includes the following data: three-dimensional data of the oilfield casing damage well and temperature and humidity distribution of the oilfield casing damage well; the three-dimensional model including the spatial three-dimensional data and the temperature and humidity data can effectively and quickly locate any point of the casing damage position when the casing is damaged subsequently, and the temperature adjustment during welding repair can be performed according to the temperature and humidity conditions.

[0050] In the casing damage treatment of the oilfield, the engineering logging instrument rechecks the monitoring data of the monitoring equipment, and then the multi-arm welding system sequentially performs welding on the casing damage position in the oilfield casing damage well.

[0051] According to the rechecking result of the engineering logging instrument, the first three-dimensional model generated by the insertion equipment can ensure the accuracy of the welding position of the multi-arm welding system, and then the welding operation is sequentially performed, which can effectively ensure the repair completion of the casing damage position after welding.

[0052] When comparing the first three-dimensional modeling and the second three-dimensional modeling, and according to the comparison of the two modeling data, the completion degree of the casing damage welding repair can be more directly reflected, and it is convenient to determine whether the treatment method needs to be supplemented according to the completion degree of the single welding repair.

[0053] Embodiment 3

[0054] Based on the embodiments 1 and 2, in the oil-water well casing corrosion leakage well section treatment device based on downhole welding, the multi-arm welding system 6 includes a downhole welding system working equipment control box 602 fixed below the engineering logging instrument 5, at least three centralizing telescopic structures 601 are fixedly connected around the top of the downhole welding system working equipment control box 602, the downhole welding system working equipment control box 602 is connected with a base structure 603, the base structure 603 can drive the welding machine arm 604 to rotate, the base structure 603 is provided with the welding machine arm 604, and the lower part of the welding machine arm 604 is provided with a welding gun 605.

[0055] The downhole welding system working equipment control box 602 serves as the control equipment of the multi-arm welding system 6, before welding, the longitudinal position of the multi-arm welding system 6 in the wellbore is adjusted through the steel wire rope 4, the position and centralization degree of the downhole welding system working equipment control box 602 are controlled in combination with the adjustment of the centralizing telescopic structure 601, then the downhole welding system working equipment control box 602 controls the base structure 603 to perform 360° rotation operation, when rotated to a certain position, the welding machine arm 604 is controlled to move by the controller, the welding machine arm 604 accurately controls the welding gun 605 to the casing damage position A by controlling the movement of the joints, and prepares for the next step of welding.

[0056] Embodiment 4

[0057] On the basis of embodiment 1 and embodiment 2, during the operation of the downhole welding oil-water well casing corrosion leakage well section treatment device, first, a fixed pulley is fixed above the well head 3 to perform the steering work of the steel wire rope 4, then the winch 2 is controlled to rotate by the control cabinet 1, and the steel wire rope 4 is released, at this time, the engineering logging instrument 5 and the multi-arm welding system 6 below the steel wire rope 4 are lowered synchronously, and the engineering logging instrument 5 reaches the casing damage position A to realize detection;

[0058] Then the multi-arm welding system 6 reaches the casing damage position A to realize welding repair, specifically: before welding, the longitudinal position of the multi-arm welding system 6 in the wellbore is adjusted by winding and unwinding the steel wire rope 4, the position and centering degree of the downhole welding system working equipment control box 602 are controlled in combination with the adjustment of the centralizing telescopic structure 601, then the downhole welding system working equipment control box 602 controls the rotation of the base structure 603 and the movement of the welding machine arm 604, and then the welding gun 605 reaches the casing damage position to complete welding, so that the welding repair treatment work of the casing damage position of the oilfield well can be completed.

Claims

1. A device for treating a corroded section of a casing of an oil and water well based on downhole welding, characterized in that, Including the winch (2) fixedly installed beside the well mouth (3) on the ground, the winch (2) is electrically connected with the control cabinet (1) through the wire, the well mouth (3) is fixedly installed with a fixed pulley (7) directly above, the winch (2) is used for lifting and the steel wire rope (4) below is extended to the well mouth (3) after being turned around the fixed pulley (7) and is fixedly connected with the engineering logging instrument (5), the engineering logging instrument (5) is in two-way signal communication with the control cabinet (1) through the wire, a multi-arm welding system (6) is fixed below the engineering logging instrument (5), the multi-arm welding system (6) is in two-way signal communication with the control cabinet (1) through the wire; Three cameras (501) are uniformly installed on the engineering logging instrument (5) around the inner wall of the well to form annular monitoring, a light supplementing lamp (502), an ultrasonic sensor (503) and a temperature and humidity sensor (504) are installed on each camera (501), the camera (501), the light supplementing lamp (502), the ultrasonic sensor (503) and the temperature and humidity sensor (504) are connected with the control cabinet (1) through the wire.

2. The downhole welding based oil well casing corrosion leak section treatment device according to claim 1, characterized in that, The multi-arm welding system (6) includes a downhole welding system working equipment control box (602) fixed below the engineering logging instrument (5), the downhole welding system working equipment control box (602) is in two-way signal communication with the control cabinet (1) through the wire, at least three righting telescopic structures (601) are fixedly connected around the well mouth center on the top of the downhole welding system working equipment control box (602), a rotatable base structure (603) is fixedly connected to the bottom of the downhole welding system working equipment control box (602), a welding machine arm (604) is fixed to the bottom of the base structure (603), a welding gun (605) is fixed to one side of the bottom of the welding machine arm (604), the welding gun (605) is electrically connected with the downhole welding system working equipment control box (602) through the wire, the welding machine arm (604) and the downhole welding system working equipment control box (602) are electrically connected through the wire.

3. The downhole welding based oil well casing corrosion leak section remediation device of claim 2, wherein, The righting telescopic structure (601) includes a righting telescopic block (606) and an electric hydraulic cylinder (607), the electric hydraulic cylinder (607) is fixedly connected around the well mouth center on the top of the downhole welding system working equipment control box (602), the righting telescopic block (606) is fixed to the telescopic end of the telescopic piston rod of the electric hydraulic cylinder (607), the electric hydraulic cylinder is electrically connected with the downhole welding system working equipment control box (602) through the wire.

4. The downhole welding based oil well casing corrosion leak section remediation device of claim 3, wherein, The base structure (603) comprises a driving motor (609) fixed at the bottom of the downhole welding system working equipment control box (602), the output end of the driving motor (609) is away from the downhole welding system working equipment control box (602) and is connected with a rotating shaft, a base (608) is fixed on the rotating shaft, the base (608) is fixedly connected with the welding machine arm (604), and the driving motor (609) is connected with the downhole welding system working equipment control box (602) through a wire electrical signal.

5. The method for treating the corrosion leakage section of the casing of the oil-water well based on the downhole welding, characterized in that, The oil and water well casing corrosion leakage well section treatment device based on downhole welding comprises a control cabinet (1), a winch (2), a lifting steel wire rope (4), an engineering logging instrument (5) and a multi-arm welding system (6).

6. The downhole welding-based oil and gas well casing corrosion leak section remediation method of claim 5, wherein, The specific implementation steps are as follows: Step 1, preparation before construction: install the oil and water well casing corrosion leakage well section treatment device based on downhole welding; Step 2, control the winch (2) to lift and lower the lifting steel wire rope (4) through the control cabinet (1), adjust the downhole depth of the engineering logging instrument (5), use the engineering logging instrument (5) to detect the accurate position and damage degree of casing damage, and return the detection data to the control cabinet (1) to establish a three-dimensional model of the casing damage well in the oilfield; Step 3, according to the bottom position of the damaged well section detected in step 2, lower the welding torch (605) to the bottom position of the damaged well section by controlling the winch (2) to lower the steel wire rope (4) through the control cabinet (1), then control the electric hydraulic cylinder (607) to extend through the downhole welding system working equipment control box (602) to control the control cabinet (1), so that the extension of the centralizing telescopic block (606) is resisted against the inner wall of the well to realize the centralizing and temporary fixing of the multi-arm welding system (6) in the well, then control the driving motor to rotate through the downhole welding system working equipment control box (602) to drive the base (608) to rotate and drive the welding machine arm (604) to rotate, align the welding torch (605) with the casing corrosion leakage position, control the centralizing telescopic block (606) to retract after welding at one position, then lift the steel wire rope (4), and sequentially weld and repair each corrosion position from bottom to top until the treatment of the entire corrosion well section is completed; Step 4, after completing the welding and repair of the corrosion leakage position of the entire wellbore, use the engineering logging instrument again to detect the welded and repaired well section, perform secondary three-dimensional modeling, compare the detection data before and after the treatment, and evaluate the welding and repair effect of the corrosion leakage well section; Step 5, if the repair does not meet the continuous use requirement, repeat steps 3 and 4 until the repair meets the requirement, if the repair meets the continuous use requirement, use the workover rig power to lower the screw motor and milling cone to expand the welded and repaired corrosion leakage well section and ensure the wellbore drift diameter.

7. The downhole welding-based oil and gas well casing corrosion leak section remediation method of claim 6, wherein, The step 2 utilizes the engineering logging instrument (5) to detect the precise position and damage degree of the corrosion leakage section of the oil-water well, and the detection data is returned to the control cabinet (1) and introduced into the modeling software, specifically: when the engineering logging instrument (5) is lowered into the well, the fill light (502) and the camera (501) are turned on, the camera (501), the ultrasonic sensor (503) and the temperature and humidity sensor (504) all return the collected information to the control cabinet (1) in real time, and then a three-dimensional space structure about the damage of the inner wall of the well is drawn according to the image information returned by the camera (501) and the ultrasonic information returned by the ultrasonic sensor (503) by using computer modeling, and a three-dimensional model of the casing damage well in the oil field is constructed, and the three-dimensional model further includes the temperature and humidity distribution of the casing damage well in the oil field.

8. The downhole welding-based oil and gas well casing corrosion leak section remediation method of claim 7, wherein, In step 3, when the casing corrosion leakage section of the oil-water well is treated, the control cabinet (1) controls the lifting and lowering of the steel wire rope according to the three-dimensional model of the casing damage well in the oil field established for the first time, so that the multi-arm welding system (6) is aligned with the casing corrosion leakage position, and then welding repair is sequentially performed from bottom to top.

Images