Downhole casing external windowing experiment device and method

Abstract

The invention discloses a downhole casing pipe external windowing experiment device and method, and belongs to the technical field of downhole casing pipe windowing, the downhole casing pipe external windowing experiment device comprises an experiment bench, an angle control mechanism, a drilling mechanism and a drill column mechanism, the angle control mechanism is arranged on the experiment bench and used for adjusting the position of a casing pipe, and the drilling mechanism is arranged on the experiment bench and used for controlling the drilling mechanism; a first driving assembly of the drilling mechanism is used for driving a working plate to move in the direction close to the outer wall of the casing pipe, and a first pressure sensor is used for detecting thrust of the first driving assembly. A first servo motor of the drill string mechanism can drive a drill rod to drive a milling shoe to rotate so as to open a window from the outer wall of the casing pipe, a torque sensor is arranged between an output shaft of the first servo motor and the drill rod and used for detecting the cutting torque of the milling shoe, and a second pressure sensor is arranged on a working plate and used for detecting the cutting pressure of the milling shoe on the casing pipe. The underground casing pipe external windowing experiment method adopts the underground casing pipe external windowing experiment device. According to the method, data support is provided for an actual casing pipe external windowing process, and the windowing quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of downhole casing windowing, and in particular to a downhole casing external windowing experimental device and method. Background Art

[0002] As domestic oil and gas field development enters the mid-to-late stages, a large number of older wells are experiencing problems such as casing deformation, corrosion perforation, and interlayer crossflow due to long-term service. In severe cases, these problems can even lead to shallow water crossflow and environmental pollution. Furthermore, in gas storage construction and old well plugging projects, conventional perforation and cementing techniques struggle to meet long-term sealing requirements. However, external casing windowing technology, combined with rescue well re-entry procedures, has become an effective solution for complex well conditions. This technology places extremely high demands on windowing quality, and the rationality of its process parameters directly impacts the subsequent wellbore re-entry and plugging effectiveness.

[0003] However, the casing is a convex surface, with a significant difference in hardness between the formation and casing, and few drill bit constraints. Due to the lack of matching window-opening tools for different casing materials and the lack of parameters such as torque and cutting pressure at different angles between the window-opening tools and the casing, the success rate of direct mechanical window-opening outside the casing is extremely low. To obtain these key parameters through downhole experiments requires repeated downhole operations, which is costly and can easily cause accidents such as wellbore collapse, and in severe cases, even the abandonment of the wellbore.

[0004] Therefore, there is an urgent need to provide a downhole casing external window experimental device and method to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a downhole casing external window opening experimental device and method to simulate the downhole casing external window opening operation, obtain comprehensive and reliable experimental data, provide strong support for optimizing the actual window opening process, and improve the window opening quality.

[0006] As conceived above, the technical solution adopted by the present invention is:

[0007] Downhole casing external window experimental device, including:

[0008] Experimental bench;

[0009] An angle control mechanism includes two fixing components, which are sleeved on both ends of the sleeve, one of which is rotatable relative to the experimental bench, and the other is adjustably fixed to the experimental bench;

[0010] The drilling mechanism includes a first drive assembly, a working plate, and a first pressure sensor. The drive assembly is provided on the experimental bench and is used to drive the working plate to move toward the outer wall of the casing. The first pressure sensor is provided between the working plate and the first drive assembly and is used to detect the thrust of the first drive assembly.

[0011] The drill string mechanism includes a first servo motor, a drill rod, a mill shoe, a torque sensor and a second pressure sensor. The first servo motor is arranged on the working plate. One end of the drill rod is connected to the output shaft of the first servo motor through the torque sensor, and the mill shoe is installed on the other end. The first servo motor can drive the drill rod to drive the mill shoe to rotate to open a window from the outer wall of the casing. The torque sensor is used to detect the cutting torque of the mill shoe. The second pressure sensor is arranged on the working plate to detect the cutting pressure of the mill shoe on the casing.

[0012] Furthermore, the downhole casing external window experimental device also includes a cooling mechanism, which is arranged on the experimental bench and is used to spray cooling liquid onto the outer wall of the casing.

[0013] Furthermore, the angle control mechanism also includes a scale plate, which is fixed on the experimental bench and has a plurality of scale holes evenly spaced circumferentially around the rotation axis of one of the fixed components. A positioning hole is provided on the other fixed component. When the positioning hole is connected to different scale holes and fasteners are passed through, the angle of the casing relative to the drill rod is different.

[0014] Furthermore, a guide rail is provided on the experimental bench, the extension direction of the guide rail is set at an angle with the axial direction of the sleeve, and the working plate is slidably connected to the guide rail.

[0015] Furthermore, the drilling mechanism also includes a first fixing member and a second fixing member arranged at intervals on the experimental bench, the first drive assembly includes a second servo motor, a screw barrel and a screw, the second servo motor is arranged on the first fixing member, the two ends of the screw barrel are correspondingly connected to the first fixing member and the second fixing member, and one end is transmission-connected to the output shaft of the second servo motor, the screw is screwed to the screw barrel, and the first pressure sensor is clamped between the working plate and the screw.

[0016] Furthermore, the drill string mechanism also includes a sensor bracket, a bearing bracket, a small shaft and two couplings. The sensor bracket is fixed to the working plate, the bearing bracket is connected to the sensor bracket through the second pressure sensor, and the small shaft is sequentially passed through the bearing mounting holes of the sensor bracket and the bearing bracket. One end of the small shaft is connected to the output end of the torque sensor through one of the couplings, and the other end is connected to the drill rod. The input end of the torque sensor is connected to the output shaft of the first servo motor through the other coupling.

[0017] Furthermore, the drill string mechanism also includes a drill rod support, which is fixedly mounted on the experimental bench, and the drill rod is passed through the drill rod support.

[0018] Furthermore, the experimental bench includes a front frame and a rear frame connected to each other, the width of the front frame is smaller than the width of the rear frame, the drilling mechanism is arranged on the front frame, and the angle control mechanism is arranged on the rear frame.

[0019] Furthermore, the downhole casing external window experimental device also includes a protective cover, which is arranged around the outer periphery of the rear frame.

[0020] The downhole casing external window test method uses the above-mentioned downhole casing external window test device, including:

[0021] S1. Set the initial experimental parameters: select a specific material casing; adjust the angle control mechanism to set the initial angle between the casing and the moving direction of the working plate; select the initial specifications of the grinding shoe;

[0022] S2. Perform a single window opening experiment: Start the first drive assembly to push the working plate toward the outer wall of the casing; start the servo motor of the drill string mechanism to drive the drill rod to rotate the grinding shoe; detect the thrust force using the first pressure sensor, and detect the cutting torque and cutting pressure using the torque sensor and the second pressure sensor respectively; after completing the window opening, observe and record the window opening effect, as well as the thrust force, cutting torque, and cutting pressure;

[0023] S3, replace the grinding shoes of different specifications and repeat step S2;

[0024] S4, adjust the angle control mechanism to set a new angle, and repeat step S2;

[0025] S5. Replace the casing with a different material and repeat steps S2-S4;

[0026] S6. Summarize all experimental data and establish a window opening process parameter database.

[0027] Beneficial effects of the present invention:

[0028] The present invention proposes a downhole casing windowing experimental device. Two fixed components of an angle control mechanism are mounted and fixed at both ends of the casing. By rotating one fixed component relative to a test bench and adjusting the position of the other fixed component to the test bench, precise control of the casing at different angles is achieved. A first drive component of the drilling mechanism drives a working plate, which drives the drill string mechanism toward the outer wall of the casing. A first pressure sensor detects the thrust during this process, thereby determining the propulsion speed. A first servo motor of the drill string mechanism drives the drill rod, which in turn rotates the mill shoe to create a window on the outer wall of the casing. A torque sensor detects the cutting torque of the mill shoe, and a second pressure sensor detects the cutting pressure of the mill shoe on the casing. This allows the experimental environment to simulate the windowing process of casing of different materials and at different angles, and to determine the propulsion speed of the mill shoe, the torque matching the mill shoe with the casing, and the cutting pressure. This eliminates the need for downhole testing, avoids high costs and risks, and provides a reliable basis for actual operations, thereby addressing issues such as windowing size deviation and casing rupture.

[0029] The downhole casing external window opening experimental method provided by the present invention can systematically explore the influence of different factors on the window opening effect, and summarize all process parameter data to establish a process parameter database, providing an accurate reference basis for actual downhole casing external window opening operations, facilitating the rapid selection of optimal process parameters according to specific working conditions, improving operation efficiency and success rate, and reflecting the scientific nature and practicality of the experimental method. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of a downhole casing external window experimental device provided by an embodiment of the present invention;

[0031] Figure 2 This is a partial structural diagram of a downhole casing external window experimental device provided by an embodiment of the present invention;

[0032] Figure 3 This is a first partial enlarged view of the downhole casing external window experimental device provided by an embodiment of the present invention;

[0033] Figure 4 This is a second partial enlarged view of the downhole casing external window experimental device provided by an embodiment of the present invention;

[0034] Figure 5 It is a structural schematic diagram of a drilling mechanism provided by an embodiment of the present invention;

[0035] Figure 6 Schematic diagram of the structure of the drill string mechanism provided by an embodiment of the present invention;

[0036] Figure 7 It is a schematic structural diagram of a protective cover provided by an embodiment of the present invention.

[0037] In the picture:

[0038] 1. Experimental bench; 11. Front rack; 111. Connecting rack; 112. Bracket; 12. Rear rack;

[0039] 2. Angle control mechanism; 21. Fixing assembly; 211. Pressing member; 212. Pipe clamp; 22. Scale plate; 220. Scale hole; 23. Positioning plate; 24. Support beam; 25. Pressing beam; 26. Fastening bolts;

[0040] 3. Drilling mechanism; 31. First drive assembly; 311. Second servo motor; 312. Screw cylinder; 313. Screw; 314. First reducer; 32. Working plate; 33. First pressure sensor; 34. Guide rail; 35. First fixing member; 36. Second fixing member; 37. Tension and pressure plate; 38. Fixing plate; 39. First tripod; 310. Slider;

[0041] 4. Drill string mechanism; 41. First servo motor; 42. Drill rod; 43. Grinding shoe; 44. Torque sensor; 45. Second pressure sensor; 46. Sensor bracket; 47. Bearing bracket; 48. Small shaft; 49. Coupling; 410. Drill rod bracket; 411. Second reducer; 412. Reducer bracket; 413. Second tripod; 414. Collar; 415. Connector;

[0042] 5. Cooling mechanism; 51. Coolant tank; 52. Hose; 53. Liquid guide tube; 54. Nozzle;

[0043] 6. Protective cover; 61. Side panel; 62. Top panel; 63. Bracket plate; 64. Support member;

[0044] 100. Casing. DETAILED DESCRIPTION

[0045] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0046] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0047] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0048] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0049] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0050] like Figure 1-Figure 7 As shown, the present invention provides a downhole casing external window experimental device, including an experimental bench 1, an angle control mechanism 2, a drilling mechanism 3, and a drill string mechanism 4. The angle control mechanism 2 includes two fixing components 21, which are sleeved on both ends of the casing 100, one of which can rotate relative to the experimental bench 1, and the other fixing component 21 is adjustably fixed to the experimental bench 1; the drilling mechanism 3 includes a first driving component 31, a working plate 32 and a first pressure sensor 33. The driving component 31 is provided on the experimental bench 1 and is used to drive the working plate 32 to move toward the outer wall of the casing 100. The first pressure sensor 33 is provided between the working plate 32 and the first driving component. Components 31, used to detect the thrust of the first drive component 31; the drill string mechanism 4, including a first servo motor 41, a drill rod 42, a grinding shoe 43, a torque sensor 44 and a second pressure sensor 45, the first servo motor 41 is arranged on the working plate 32, one end of the drill rod 42 is connected to the output shaft of the first servo motor 41 through the torque sensor 44, and the other end is installed with the grinding shoe 43, the first servo motor 41 can drive the drill rod 42 to drive the grinding shoe 43 to rotate to open a window from the outer wall of the casing 100, the torque sensor 44 is used to detect the cutting torque of the grinding shoe 43, and the second pressure sensor 45 is arranged on the working plate 32, for detecting the cutting pressure of the grinding shoe 43 on the casing 100.

[0051] The two fixing components 21 of the angle control mechanism 2 are used to sleeve and fix the two ends of the casing 100. By rotating one of the fixing components 21 relative to the experimental bench 1 and fixing the other fixing component 21 to the experimental bench 1 in an adjustably positionable manner, precise control of different angles of the casing 100 is achieved; the first driving component 31 of the drilling mechanism 3 drives the working plate 32 to drive the drill string mechanism 4 close to the outer wall of the casing 100, and the first pressure sensor 33 can detect the thrust in the process to obtain the propulsion speed; the first servo motor 41 of the drill string mechanism 4 drives the drill rod 42 to rotate the mill shoe 43 to open a window on the outer wall of the casing 100, the torque sensor 44 detects the cutting torque of the mill shoe 43, and the second pressure sensor 45 detects the cutting pressure of the mill shoe 43 on the casing 100. In this way, the window opening process of casing 100 of different materials and at different angles can be simulated in an experimental environment, and the propulsion speed of the grinding shoe 43 and the torque and cutting pressure matched with the grinding shoe 43 and the casing 100 can be obtained without the need for downhole experiments, thus avoiding high costs and risks, providing a reliable basis for actual operations, and thus solving problems such as window opening size deviation and casing rupture.

[0052] Specifically, if Figure 1 and Figure 2 As shown, the test bench 1 includes a connected front frame 11 and a rear frame 12. The width of the front frame 11 is smaller than that of the rear frame 12. The drilling mechanism 3 is mounted on the front frame 11, and the angle control mechanism 2 is mounted on the rear frame 12. The front frame 11 provides a stable support for the drilling mechanism 3, adapting to the space required for driving the working plate 32 to move and the grinding shoe 43 to perform cutting operations. The wider width of the rear frame 12 provides ample installation and adjustment space for the two fixing components 21 of the angle control mechanism 2, facilitating stable fixing of the casing 100 and flexible adjustment of its angle, thereby preventing interference between the various mechanisms during operation.

[0053] In this embodiment, the top and bottom layers of the front frame 11 are each formed by four connecting frames 111 connected in sequence by bolts, and the top and bottom layers are connected and fixed by 12 brackets 112. The rear frame 12 is a rectangular ring structure, similarly divided into two layers, both of which are surrounded by connecting frames 111, and the two layers are connected and fixed by 18 brackets 112. The connecting frames 111 are composed of two single frames, with the two long sides of the top or bottom layer each being formed by three single frames connected in sequence by bolts, and the two short sides of the top or bottom layer each being formed by two connecting frames 111 connected in sequence by bolts.

[0054] Specifically, the angle control mechanism 2 also includes a scale plate 22, which is fixed to the test bench 1 and has a plurality of scale holes 220 evenly spaced circumferentially around the rotation axis of one of the fixed components 21. The other fixed component 21 is provided with a positioning hole. When the positioning hole is connected to different scale holes 220 and fasteners are inserted through it, the angle of the casing 100 relative to the drill rod 42 is different. The provision of the scale plate 22 in the angle control mechanism 2 further improves the accuracy of the angle adjustment of the casing 100. The scale plate 22 is centered on the rotation axis of one of the fixed components 21 and has a plurality of scale holes 220 evenly spaced circumferentially around it. When the positioning hole on the other fixed component 21 is connected to different scale holes 220 and fasteners are inserted through it, the casing 100 can be fixed at different angles relative to the drill rod 42. This design enables the experiment to accurately simulate the interaction scenarios of the casing 100 and the grinding shoe 43 at different angles. Combined with the detection functions of the first pressure sensor 33, the torque sensor 44, and the second pressure sensor 45, the torque and cutting pressure corresponding to different angles can be accurately obtained.

[0055] In this embodiment, two rows of scale holes 220 are distributed on the scale plate 22. In the same row, the arc spacing between two adjacent scale holes 220 is 1°. With the rotation axis as the center, the arc radius of the innermost row of scale holes 220 is 3m.

[0056] In this embodiment, the connecting member fastener may be a bolt or a pin.

[0057] More specifically, if Figure 3 As shown, the angle control mechanism 2 also includes a positioning plate 23, and each fixing assembly 21 is composed of a clamping member 211 and a pipe clamp 212. The positioning plate 23 is fixedly mounted on the experimental bench 1, wherein the pipe clamp 212 of one set of fixing assemblies 21 is rotatably connected to the center position of the positioning plate 23 via a rotating shaft, and one end of the sleeve 100 is clamped between the pipe clamp 212 and the clamping member 211 of the fixing assembly 21, and the clamping member 211 and the pipe clamp 212 are detachably connected; the pipe clamp 212 of another set of fixing assemblies 21 is provided with a positioning hole, and the other end of the sleeve 100 is clamped between the pipe clamp 212 and the clamping member 211 of the fixing assembly 21, and the clamping member 211 and the pipe clamp 212 are detachably connected. Each fixing assembly 21 is composed of a clamping part 211 and a pipe clamp 212. The cooperation of the two can firmly clamp the two ends of the casing 100, ensuring that the casing 100 will not loosen or move during the window opening experiment, providing a stable foundation for the experiment; the pipe clamps 212 of one group of fixing assemblies 21 are connected to the center of the positioning plate 23 through a rotating shaft, and combined with the positioning holes on the pipe clamps 212 of another group of fixing assemblies 21 and the scale holes 220 of the scale plate 22, the angle of the casing 100 relative to the drill rod 42 can be flexibly and accurately adjusted to meet the needs of window opening experiments at different angles.

[0058] Specifically, the angle control mechanism 2 also includes a support beam 24, a clamping beam 25, and two fastening bolts 26. The support beam 24 is fixedly mounted on the test bench 1 and is provided with two first sliding holes parallel to its length. The clamping beam 25 is located above the support beam 24 and is provided with two second sliding holes parallel to its length. The two fastening bolts 26 are passed through the two second sliding holes and the two first sliding holes in a one-to-one correspondence. The casing 100 is located between the two fastening bolts 26. By moving the fastening bolts 26 to adjust the clamping distance and tightening the nuts, the casing 100 can be fixed. By adjusting the position of the fastening bolts 26 in the first and second sliding holes, not only can casings 100 of different sizes be adapted, but the casing 100 can also be locked, further improving the stability of the casing 100 during window opening operations.

[0059] Specifically, if Figure 1 and Figure 4 As shown, the downhole casing external windowing experimental device also includes a cooling mechanism 5, which is arranged on the experimental bench 1 and is used to spray coolant onto the outer wall of the casing 100. When the mill shoe 43 performs a window cutting operation on the outer wall of the casing 100, a large amount of heat will be generated between the mill shoe 43 and the casing 100 due to high-speed friction. If the heat is not dissipated in time, the local temperature of the mill shoe 43 and the casing 100 may be too high. This will not only damage the mill shoe 43, reducing its cutting performance and service life, but may also change the material properties of the casing 100, affecting the accuracy of key parameters such as cutting torque and cutting pressure, and distorting the experimental data. The cooling mechanism 5 sprays coolant onto the outer wall of the casing 100, which can quickly take away the heat generated by cutting, effectively control the temperature of the mill shoe 43 and the casing 100, and avoid equipment loss and material property changes caused by high temperature. At the same time, the coolant can also wash away the debris generated during the cutting process, preventing the accumulation of debris from affecting the cutting action of the grinding shoe 43 and the smooth progress of the experiment, ensuring that the window opening process is stable and controllable, creating favorable conditions for accurately obtaining experimental parameters under different working conditions, and further improving the reliability of the experimental device and the validity of the experimental results.

[0060] More specifically, the cooling mechanism 5 includes a coolant tank 51, a hose 52, a liquid conduit 53, and a nozzle 54. Multiple coolant tanks 51 are provided, all installed within the test bench 1 and below the sleeve 100. Adjacent coolant tanks 51 are connected by hoses 52, and the nozzle 54 is connected to the water pump within the coolant tank 51 via the liquid conduit 53. Multiple coolant tanks 51 installed within the test bench 1 and below the sleeve 100 can store sufficient coolant to ensure continuous cooling. The connection between adjacent coolant tanks 51 via hoses 52 allows for flexible coolant allocation, ensuring stable liquid levels within each coolant tank 51 and preventing cooling continuity from being affected by insufficient capacity in a single coolant tank 51. The nozzle 54 is connected to the water pump within the coolant tank 51 via the liquid conduit 53. Driven by the water pump, the coolant is transported through the liquid conduit 53 to the nozzle 54 and precisely sprayed onto the cutting area on the outer wall of the sleeve 100.

[0061] In this embodiment, five coolant tanks 51 are provided.

[0062] In other embodiments, six coolant tanks 51 may be provided, and the number of the coolant tanks 51 is not specifically limited herein.

[0063] Specifically, if Figure 1 and Figure 5 As shown, the test bench 1 is equipped with a guide rail 34 extending at an angle to the axial direction of the casing 100. The working plate 32 is slidably connected to the guide rail 34. This structure enables the working plate 32 to move stably along a predetermined direction under the drive of the first drive assembly 31, ensuring that the grinding shoe 43 of the drill string mechanism 4 approaches and contacts the outer wall of the casing 100 at a precise angle. This directional guidance effectively prevents the working plate 32 from drifting or shaking during movement, ensures the consistency of the cutting path of the grinding shoe 43, and reduces problems such as inaccurate window size and casing cracking caused by movement deviation.

[0064] More specifically, two guide rails 34 are arranged in parallel on the experimental bench 1, and two sets of sliders 310 are correspondingly arranged at the bottom of the working plate 32. The two sets of sliders 310 are embedded in the guide rails 34 in a one-to-one correspondence, so that the working plate 32 can slide smoothly along the guide rails 34.

[0065] In this embodiment, each group of sliders 310 includes four sliders 310 spaced apart along the length direction of the working plate 32 .

[0066] In other embodiments, each group of sliders 310 also includes six sliders 310 spaced apart along the length direction of the working plate 32. The number of sliders 310 in each group is not specifically limited herein.

[0067] Specifically, the drilling mechanism 3 also includes a first fixing member 35 and a second fixing member 36 spaced apart on the experimental bench 1. The first drive assembly 31 includes a second servo motor 311, a screw barrel 312, and a screw 313. The second servo motor 311 is mounted on the first fixing member 35. The screw barrel 312 is rotatably connected to the first fixing member 35 and the second fixing member 36 at both ends, and one end is drivingly connected to the output shaft of the second servo motor 311. The screw 313 is screwed to the screw barrel 312. The first pressure sensor 33 is sandwiched between the working plate 32 and the screw 313. This screw drive method has the characteristics of high transmission accuracy and smooth operation. It can accurately control the movement distance and speed of the working plate 32, ensure that the grinding shoe 43 contacts the casing 100 at a stable feed rate, and avoid cutting pressure fluctuations caused by unstable feed.

[0068] More specifically, the first drive assembly 31 further includes a first reducer 314, which is mounted on the first fixing member 35 and connected to the output shaft of the second servo motor 311 and is in transmission connection with the screw barrel 312. The addition of the first reducer 314 further optimizes the transmission performance of the first drive assembly 31, converting the high speed of the second servo motor 311 into the low speed required by the screw barrel 312. This makes the process of the screw 313 pushing the working plate 32 more stable and controllable, avoids excessive rotation of the screw barrel 312 due to the excessive speed of the second servo motor 311, and thus prevents sudden changes in the movement speed of the working plate 32. This ensures a stable feed rate when the grinding shoe 43 contacts the casing 100 and reduces sudden fluctuations in cutting pressure.

[0069] More specifically, the first fixing member 35 is provided with a cavity, in which a driving pulley, a driven pulley and a transmission belt wound around the driving pulley and the driven pulley are provided. The driving pulley is connected to the output shaft of the first reducer 314, and the driven pulley is coaxially connected to the screw barrel 312.

[0070] Specifically, the drilling mechanism 3 also includes a tension and compression plate 37 and a fixed plate 38. The tension and compression plate 37 is connected to the end of the screw 313 away from the screw barrel 312. The first pressure sensor 33 is connected to the tension and compression plate 37 by screws. The fixed plate 38 is vertically mounted on the working plate 32, and the first pressure sensor 33 is fixedly mounted on the side of the fixed plate 38 facing the screw barrel 312. The tension and compression plate 37 can stably transmit the thrust of the screw 313 to the first pressure sensor 33; the fixed plate 38 can firmly support the first pressure sensor 33, thereby further optimizing the detection accuracy of the first pressure sensor 33.

[0071] More specifically, the drilling mechanism 3 further includes a first tripod 39, which is a right-angled tripod located on the side of the fixed plate 38 facing away from the screw barrel 312. One of its two right-angled sides is connected to the fixed plate 38, and the other is connected to the working plate 32. The stability of the triangular structure further enhances the secure connection between the fixed plate 38 and the working plate 32, preventing the fixed plate 38 from tilting or deforming due to excessive force, and ensuring that it always remains upright.

[0072] In this embodiment, two first tripods 39 are arranged at intervals.

[0073] In other embodiments, three first tripods 39 may also be provided, and the number of the first tripods 39 is not specifically limited herein.

[0074] Specifically, if Figure 1 and Figure 6 As shown, the drill string mechanism 4 also includes a sensor bracket 46, a bearing bracket 47, a small shaft 48, and two couplings 49. The sensor bracket 46 is fixed to the work plate 32, and the bearing bracket 47 is connected to the sensor bracket 46 via the second pressure sensor 45. The small shaft 48 passes through the bearing mounting holes of the sensor bracket 46 and the bearing bracket 47, respectively. One end of the small shaft 48 is connected to the output end of the torque sensor 44 via one of the couplings 49, and the other end is connected to the drill rod 42. The input end of the torque sensor 44 is connected to the output shaft of the first servo motor 41 via the other coupling 49. The sensor bracket 46 is fixed to the work plate 32, providing a stable mounting base for the second pressure sensor 45. The bearing bracket 47 is connected to the sensor bracket 46 via the second pressure sensor 45. It not only supports the small shaft 48 and the drill rod 42, but also enables the second pressure sensor 45 to accurately detect the axial cutting pressure of the drill rod 42, ensuring a clear pressure transmission path and reliable detection data. The two couplings 49 can effectively compensate for installation errors, reduce interference of additional torque generated by different shafts on torque detection, and ensure that the torque sensor 44 can accurately capture the cutting torque of the grinding shoe 43.

[0075] In this embodiment, two second pressure sensors 45 are provided, and the bearing bracket 47 is connected to the sensor bracket 46 via the two second pressure sensors 45 that are spaced apart.

[0076] In this embodiment, the small shaft 48 is connected to the drill rod 42 via a pin.

[0077] In this embodiment, the sensor bracket 46 is mounted on the working plate 32 via four second tripods 413 to improve stability.

[0078] More specifically, the drill string mechanism 4 also includes a second reducer 411 and a reducer bracket 412. The reducer bracket 412 is mounted on the work plate 32. The second reducer 411 is fixed to the reducer bracket 412 and connected to the output shaft of the first servo motor 41. The input end of the torque sensor 44 is connected to the output shaft of the second reducer 411 via one of the couplings 49. The reducer bracket 412 is mounted on the work plate 32, providing a stable mounting base for the second reducer 411, preventing displacement due to vibration or force during operation and ensuring a stable power transmission path. The second reducer 411 is fixed to the reducer bracket 412 and connected to the output shaft of the first servo motor 41. It converts the high speed of the first servo motor 41 to a suitable low speed, while also increasing the output torque. This ensures smoother torque transmission to the torque sensor 44 via the coupling 49, reduces torque fluctuations caused by excessively high speeds, and ensures that the torque sensor 44 can accurately detect torque during the cutting process.

[0079] In this embodiment, the reducer bracket 412 is mounted on the working plate 32 via four second tripods 413 to improve stability.

[0080] Specifically, the drill string mechanism 4 further includes a collar 414, which is fixed to the connection between the small shaft 48 and the coupling 49 by screws to prevent the small shaft 48 from falling off the coupling 49 during movement.

[0081] Specifically, the drill string mechanism 4 also includes a connector 415, one end of which is connected to the drill rod 42 and the other end is used to mount the mill shoe 43. The provision of the connector 415 makes the replacement of the mill shoe 43 more convenient and flexible. When simulating the window opening effect of mill shoes 43 of different models and materials, there is no need to adjust the drill rod 42; simply replace the corresponding mill shoe 43 with the connector 415, significantly reducing experimental preparation time and improving experimental efficiency.

[0082] Specifically, if Figure 3 As shown, the drill string mechanism 4 also includes a drill rod support 410, which is fixedly mounted on the experimental bench 1. The drill rod 42 is inserted into the drill rod support 410. The drill rod support 410 secures the drill rod 42, reducing the swing and bending of the drill rod 42 due to its own length or force during high-speed rotation and cutting operations. This allows the grinding shoe 43 to always accurately act on the preset cutting position of the casing 100, avoiding the deviation of the cutting trajectory caused by the shaking of the drill rod 42.

[0083] In this embodiment, two drill rod supports 410 are arranged at intervals to further enhance the stability of the drill rod 42 .

[0084] Specifically, if Figure 1 and Figure 7As shown, the downhole casing external window experimental device further includes a protective cover 6, which is disposed around the outer surface of the rear frame 12. The protective cover 6 is disposed around the outer surface of the rear frame 12 and can effectively block coolant, cutting chips, and other debris that may splash during the experiment, preventing these debris from splashing onto the surrounding environment or the operator, thereby reducing safety hazards and ensuring the personal safety of the operator.

[0085] More specifically, the protective cover 6 comprises side panels 61, a top panel 62, bracket panels 63, and support members 64. Multiple side panels 61 are arranged circumferentially around the rear frame 12 and bolted to the sides of the rear frame 12. Multiple bracket panels 63 are evenly spaced along the length of the rear frame 12 on the side panels 61 on opposite sides of the width. The bracket panels 63 on each of the side panels 61 correspond to each other. Each of the two opposing bracket panels 63 is provided with a support member 64, and both ends of the support member 64 are bolted to the two opposing bracket panels 63. Two sets of top panels 62 are hingedly connected to the side panels 61 on opposite sides of the width and rest on the support members 64, forming a complete protective top surface. This arrangement facilitates operators to quickly lift the top panels 62 to inspect or operate components above the rear frame 12 when needed, improving operational convenience. When closed, the top panels 62 and the side panels 61 can also form a complete protective space, blocking falling objects and splashing objects from above, further enhancing the protective effect.

[0086] In this embodiment, the top plate 62 is a foldable top plate.

[0087] The present invention also provides a downhole casing external window test method, which uses the above-mentioned downhole casing external window test device and includes:

[0088] S1. Setting initial experimental parameters: Select a sleeve 100 of a specific material; adjust the angle control mechanism 2 to set the initial angle between the sleeve 100 and the moving direction of the working plate 32; select the initial specifications of the grinding shoe 43;

[0089] S2. Perform a single window opening experiment: Start the first drive assembly 31 to push the working plate 32 toward the outer wall of the casing 100; start the servo motor 41 of the drill string mechanism 4 to drive the drill rod 42 to rotate the grinding shoe 43; detect the thrust through the first pressure sensor 33, and detect the cutting torque and cutting pressure through the torque sensor 44 and the second pressure sensor 45; after the window opening is completed, observe and record the window opening morphology characteristics as well as the thrust, cutting torque, and cutting pressure;

[0090] S3, replace the grinding shoes 43 of different specifications and repeat step S2;

[0091] S4, adjust the angle control mechanism 2 to set a new angle, and repeat step S2;

[0092] S5. Replace the sleeve 100 with a different material and repeat steps S2-S4;

[0093] S6. Summarize all experimental data and establish a window opening process parameter database.

[0094] This experimental method can systematically explore the impact of different factors on the window opening effect, and summarize all process parameter data to establish a process parameter database, providing an accurate reference basis for actual downhole casing external window opening operations, facilitating the rapid selection of optimal process parameters according to specific working conditions, improving operational efficiency and success rate, and reflecting the scientific nature and practicality of the experimental method.

[0095] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Downhole casing external window experimental device, characterized in that: include: Experimental bench (1); An angle control mechanism (2) includes two fixing assemblies (21), the two fixing assemblies (21) being sleeved on both ends of the sleeve (100), one of the fixing assemblies (21) being rotatable relative to the experimental bench (1), and the other fixing assembly (21) being positionally adjustable and fixed to the experimental bench (1); A drilling mechanism (3) comprises a first drive assembly (31), a working plate (32) and a first pressure sensor (33), wherein the first drive assembly (31) is arranged on the experimental bench (1) and is used to drive the working plate (32) to move toward the outer wall of the casing (100), and the first pressure sensor (33) is arranged between the working plate (32) and the first drive assembly (31) and is used to detect the thrust of the first drive assembly (31); A drill string mechanism (4) comprises a first servo motor (41), a drill rod (42), a grinding shoe (43), a torque sensor (44) and a second pressure sensor (45), wherein the first servo motor (41) is arranged on the working plate (32), one end of the drill rod (42) is connected to the output shaft of the first servo motor (41) through the torque sensor (44), and the other end is installed with the grinding shoe (43), the first servo motor (41) can drive the drill rod (42) to drive the grinding shoe (43) to rotate so as to open a window from the outer wall of the casing (100), the torque sensor (44) is used to detect the cutting torque of the grinding shoe (43), and the second pressure sensor (45) is arranged on the working plate (32) and is used to detect the cutting pressure of the grinding shoe (43) on the casing (100).

2. The downhole casing external window experimental device according to claim 1, characterized in that: The downhole casing external window experimental device further comprises a cooling mechanism (5), which is arranged on the experimental bench (1) and is used for spraying cooling liquid onto the outer wall of the casing (100).

3. The downhole casing external window experimental device according to claim 1, characterized in that: The angle control mechanism (2) further comprises a scale plate (22), the scale plate (22) being fixed on the experimental bench (1) and having a plurality of scale holes (220) uniformly spaced circumferentially around the rotation axis of one of the fixed components (21), and a positioning hole being provided on the other fixed component (21). When the positioning hole and the different scale holes (220) are connected and fasteners are passed through, the angle of the casing (100) relative to the drill rod (42) is different.

4. The downhole casing external window experimental device according to claim 1, characterized in that: A guide rail (34) is provided on the experimental bench (1), the extension direction of the guide rail (34) is arranged at an angle with the axial direction of the sleeve (100), and the working plate (32) is slidably connected to the guide rail (34).

5. The downhole casing external window experimental device according to claim 1, characterized in that: The drilling mechanism (3) further comprises a first fixing member (35) and a second fixing member (36) which are arranged at intervals on the experimental bench (1); the first driving assembly (31) comprises a second servo motor (311), a screw barrel (312) and a screw (313); the second servo motor (311) is arranged on the first fixing member (35); the two ends of the screw barrel (312) are correspondingly connected to the first fixing member (35) and the second fixing member (36), and one end is connected to the output shaft of the second servo motor (311); the screw (313) is screwed to the screw barrel (312); and the first pressure sensor (33) is clamped between the working plate (32) and the screw (313).

6. The downhole casing external window experimental device according to claim 1, characterized in that: The drill string mechanism (4) further comprises a sensor bracket (46), a bearing bracket (47), a small shaft (48) and two couplings (49), wherein the sensor bracket (46) is fixed to the working plate (32), the bearing bracket (47) is connected to the sensor bracket (46) via the second pressure sensor (45), the small shaft (48) passes through the bearing mounting holes of the sensor bracket (46) and the bearing bracket (47) in sequence, one end of the small shaft (48) is connected to the output end of the torque sensor (44) via one of the couplings (49), and the other end is connected to the drill rod (42), and the input end of the torque sensor (44) is connected to the output shaft of the first servo motor (41) via the other coupling (49).

7. The downhole casing external window experimental device according to claim 1, characterized in that: The drill string mechanism (4) further comprises a drill rod support (410), wherein the drill rod support (410) is fixedly mounted on the experimental bench (1), and the drill rod (42) is passed through the drill rod support (410).

8. The downhole casing external window experimental device according to any one of claims 1 to 7, characterized in that: The experimental bench (1) comprises a front frame (11) and a rear frame (12) connected to each other, the width of the front frame (11) being smaller than the width of the rear frame (12), the drilling mechanism (3) being arranged on the front frame (11), and the angle control mechanism (2) being arranged on the rear frame (12).

9. The downhole casing external window experimental device according to claim 8, characterized in that: The downhole casing external window experimental device further comprises a protective cover (6), and the protective cover (6) is arranged around the outer periphery of the rear frame (12).

10. A downhole casing external window test method, using the downhole casing external window test device according to any one of claims 1 to 9, comprising: S1. Setting initial experimental parameters: selecting a sleeve (100) of a specific material; adjusting the angle control mechanism (2) to set the initial angle between the sleeve (100) and the moving direction of the working plate (32); selecting a grinding shoe (43) of initial specifications; S2, performing a single window opening experiment: starting the first driving component (31) to push the working plate (32) toward the outer wall of the casing (100); starting the servo motor (41) of the drill string mechanism (4) to drive the drill rod (42) to drive the grinding shoe (43) to rotate; detecting the thrust through the first pressure sensor (33), and detecting the cutting torque and cutting pressure through the torque sensor (44) and the second pressure sensor (45); after completing the window opening, observing and recording the window opening effect as well as the thrust, cutting torque and cutting pressure; S3, replace the grinding shoes (43) of different specifications and repeat step S2; S4, adjusting the angle control mechanism (2) to set a new angle, and repeating step S2; S5, replace the sleeve (100) with a different material and repeat steps S2-S4; S6. Summarize all experimental data and establish a window opening process parameter database.

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