A combined construction method of directional drilling and reverse well drilling of a high-precision guide hole of an ultra-long steep-inclination inclined shaft

Abstract

The application discloses a kind of super-long steeply inclined angle inclined shaft high-precision guide hole directional drilling and reverse shaft drilling combination construction method, it is related to inclined shaft construction technical field, including in the process of guide hole drilling construction, the drilling trajectory of drill bit is obtained in real time using measurement-while-drilling system;Drilling trajectory of drill bit is compared with preset drilling trajectory, and tool face angle of drilling tool is corrected and analyzed when deviation exceeds threshold range;Based on the analysis result, the adjustment amount of tool face angle of drilling tool is obtained, and the adjustment amount obtained is used to adjust tool face angle;When guide hole construction is to last 60 meters, switch to rotating magnetic field ranging system to guide the drilling trajectory of drill bit until the construction of guide hole is completed;Reverse shaft drilling machine is used to ream the guide hole, and the construction of inclined shaft is completed and the like steps, the present application effectively overcomes the influence of gravity and formation in the prior art, and can realize accurate construction of guide hole, effectively improving the construction quality of inclined shaft project.

Description

Technical Field

[0001] This invention relates to the field of inclined shaft construction technology, specifically to a combined construction method for high-precision pilot hole directional drilling and reverse drilling of ultra-long steep-angle inclined shafts. Background Technology

[0002] In underground engineering projects such as hydropower and mining, inclined shafts are a key structural form, commonly used to connect tunnels at different elevations, install pressure pipelines, or provide ventilation and drainage channels. As engineering projects develop towards more complex geological conditions and larger scales, the design parameters of inclined shafts are becoming increasingly extreme, resulting in ultra-long, highly inclined shafts exceeding 250 meters in length and with inclination angles of 60° or higher. The construction safety, efficiency, and precision control of such inclined shafts face severe challenges.

[0003] Currently, the raised shaft drilling method has become the mainstream construction method for excavating the main shaft of such inclined shafts due to its advantages such as high safety and fast well completion speed. This process typically consists of two core stages: the first stage is "pilot hole drilling," which involves drilling a pilot hole from top to bottom using a small-diameter drill bit until precise penetration is achieved in the lower roadway; the second stage is "reaming," which involves replacing the pilot hole with a large-diameter reaming cutterhead in the lower roadway to enlarge the pilot hole to the designed pilot shaft size from bottom to top. The key to the success of the entire process lies in the high-precision penetration of the pilot hole in the first stage. The trajectory accuracy of the pilot hole directly determines whether the subsequent reaming can proceed smoothly along the designed axis, ultimately affecting the overall straightness, specifications, quality, project cost, and construction period of the shaft.

[0004] For pilot hole construction, the closest existing technology is to use a conventional directional drilling rig equipped with a standard roller cone drill bit or a stabilized drill string combination. Its directional control mainly relies on the rigidity of the drill string itself, combined with intermittent trajectory measurements for passive anti-deviation. Specifically, during construction, drilling needs to be stopped periodically, and all drill strings are pulled out of the wellhead one by one. Then, instruments such as gyro-inclinometers are used to measure the attitude of the last drill string or drill bit to assess the deviation of the borehole trajectory.

[0005] However, when applied to pilot hole construction in ultra-long, steeply inclined wells, this existing technology reveals the following significant drawbacks and limitations: Traditional pilot hole construction methods cannot monitor the drill bit's position and attitude in real time and continuously during drilling. Trajectory measurement is intermittent and delayed, constituting a "passive anti-deviation" approach. By the time deviation data reveals that the borehole has deviated from the designed trajectory, the deviation has often already formed and accumulated significantly. Under deep hole and steep inclination conditions, the drill bit is highly susceptible to "natural drooping" or deviation towards weak rock formations due to the strong influence of gravity, formation heterogeneity, and drill bit wear. By the time this is detected, it is difficult to effectively correct the deviation by simply adjusting process parameters such as drilling pressure and rotation speed, resulting in the pilot hole's construction accuracy failing to meet requirements. Summary of the Invention

[0006] This invention provides a combined construction method for high-precision pilot hole directional drilling and reverse drilling in ultra-long steep-angle inclined shafts. This method effectively overcomes the influence of gravity and formation in existing methods, enabling precise construction of the pilot hole and significantly improving the construction quality of inclined shaft projects.

[0007] A method for constructing ultra-long, steep-angle inclined wells using a combination of high-precision pilot hole directional drilling and reverse drilling includes the following steps:

[0008] S1, Use a directional drilling rig to perform directional drilling in a top-down manner to construct the pilot hole;

[0009] S2, During the drilling of the pilot hole, the drilling trajectory of the drill bit is obtained in real time using the measurement while drilling system;

[0010] S3 compares the drilling trajectory of the drill bit with the preset drilling trajectory, and performs correction analysis on the tool face angle of the drill when the deviation exceeds the threshold range;

[0011] S4. Based on the analysis results, the adjustment amount of the tool face angle of the drill bit is obtained, and the tool face angle is adjusted using the obtained adjustment amount;

[0012] S5, when the pilot hole is constructed to the last 60 meters, switch to the rotating magnetic field ranging system to guide the drilling trajectory of the drill bit until the construction of the pilot hole is completed;

[0013] S6. Use a reverse drilling rig to enlarge the pilot hole and complete the construction of the inclined shaft.

[0014] Furthermore, the directional drilling rig includes a drill string assembly connected to the drill string. The drill string assembly is used for directional drilling. The drill string assembly consists of a measurement and communication assembly, a bend, a screw motor, and a drill bit connected in series. The measurement and communication assembly is connected to a host computer and is connected to the drill string. The power output end of the screw motor is connected to the drill bit. The measurement and communication assembly is suitable for capturing and acquiring the directional data of the drill bit during the drilling of the pilot hole, and using a mud pulse generator to generate pulses in the mud to transmit the encoded directional data to the host computer on the ground for parameter analysis.

[0015] Furthermore, an anti-rotation stabilizer is required when adjusting the tool face angle. The anti-rotation stabilizer is mounted on the housing of the screw motor.

[0016] Furthermore, the anti-spin stabilizer includes a positioning ring integrated with the screw motor housing, at least four telescopic mechanisms are equally spaced along the circumferential direction of the positioning ring surface, and a guide plate is provided between the intervals of two telescopic mechanisms.

[0017] Furthermore, the surface of the guide plate has an arc-shaped portion.

[0018] Furthermore, the telescopic mechanism includes a telescopic member and a top foot connected to the telescopic end of the telescopic member. The surface of the top foot that abuts against the wall of the guide hole has a groove. The telescopic mechanism is communicatively connected to a measurement and communication component.

[0019] Furthermore, the anti-rotation stabilizer has two working states: 1. Deployed state: The measurement and communication component controls the telescopic component to push the top foot out and abut against the wall of the guide hole. When the telescopic component pushes the top foot out fully, the widest point of the guide plate's outer contour is located at two-thirds of the total length of the top foot; 2. Retracted state: The measurement and communication component controls the telescopic component to pull the top foot back. When the telescopic component fully retracts the top foot, the position of the top foot is within the outer contour range of the guide plate, and at this time, the top foot does not contact the inside of the guide hole.

[0020] Furthermore, the working process of the anti-spin stabilizer is as follows:

[0021] The ground-based host computer determines whether the guide hole trajectory deviates from the design axis by more than a preset threshold based on the data captured by the measurement and communication components;

[0022] When the threshold is exceeded, the directional drilling rig is switched from compound drilling mode to sliding drilling mode, the directional drilling rig stops rotating the drill string, and the tool face angle adjustment amount is obtained based on the deviation of the guide hole trajectory.

[0023] After the tool face angle is adjusted to the correct position, the tool face angle is defined as the reference tool face angle. The host computer sends a command to the measurement and communication component, which then controls the anti-spin stabilizer to enter the deployment state.

[0024] After the correction is completed, the host computer sends a command to the measurement and communication component, which then controls the anti-spin stabilizer to enter the retraction state.

[0025] Furthermore, the process by which the measurement and communication components control the anti-spin stabilizer to enter the deployment state includes:

[0026] The measurement and communication components control the deployment of the anti-spin stabilizer;

[0027] The host computer determines whether the tool surface deviates from the target angle based on the data collected by the measurement and communication components.

[0028] When it is determined that the tool face deviates from the target angle, the extension and retraction of each control extension and retraction mechanism is adjusted based on the offset to restore the tool face to the reference tool face angle.

[0029] Furthermore, the surface of the top foot is uniformly provided with multiple rows of sawtooth or conical frustums, and the cutting surface of the frustum is inclined in the opposite direction of rotation.

[0030] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0031] 1. The scheme adopts a dual guidance approach combining long-distance navigation of the measurement while drilling system and a rotating magnetic field ranging system, overcoming the cumulative error of inertial measurement by the measurement while drilling system alone over ultra-long distances. Especially in the last 60-meter closed section, the absolute positioning vector provided by the rotating magnetic field ranging system replaces relative measurement, greatly reducing the deviation between the final hole axis and the target point axis.

[0032] 2. During sliding drilling correction, the anti-rotation stabilizer extends and rigidly anchors to the wellbore, completely absorbing and balancing the reaction torque generated by the screw motor driving the drill bit. This completely eliminates unintended rotation of the drill string housing, ensuring that the tool face angle indicated by the bend remains constant throughout the correction process. This greatly improves the accuracy and reliability of the correction adjustment.

[0033] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0034] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0036] Figure 1 This is a flowchart of the combined construction method of directional drilling and reverse drilling for pilot holes disclosed in an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of a directional drilling rig constructing a pilot hole, as disclosed in an embodiment of the present invention.

[0038] Figure 3 This is a schematic diagram of the hole enlargement process of a reverse drilling rig disclosed in an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the anti-spin stabilizer disclosed in an embodiment of the present invention;

[0040] Figure 5 for Figure 4 A magnified structural diagram of point A in the middle.

[0041] Figure label:

[0042] 1. Drill tool assembly; 11. Drill bit; 12. Bend; 13. Screw motor; 2. Measurement and communication assembly; 3. Drill string; 4. Anti-rotation stabilizer; 41. Positioning ring; 42. Telescopic mechanism; 421. Telescopic component; 422. Top foot; 4221. Groove; 44. Guide plate. Detailed Implementation

[0043] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0044] This combined construction method consists of two parts: 1. A directional drilling rig uses drill assembly 1 to drill a pilot hole from top to bottom; 2. A raise boring machine uses a reamer to enlarge the pilot hole from bottom to top.

[0045] like Figures 4-5 As shown, in step 1 above, the structure of the drill assembly 1 adopts the same mechanism as the prior art. The parts that are the same as the prior art include the measurement and communication assembly 2, the bend 12, the screw motor 13 and the drill bit 11, which are connected in series with the drill string 3. The measurement and communication assembly 2, the screw motor 13, the bend 12 and the drill bit 11 all adopt the prior art.

[0046] Measurement and communication component 2 is a downhole measurement tool in the existing MWD (Measuring While Drilling) system. It has a built-in sensor group, including orientation sensors (triaxial accelerometer, triaxial magnetometer) for measuring well inclination angle, azimuth angle, and tool face angle; a mud pulse generator; a data transmission module; a mud turbine power generation module; and a control module. In general, measurement and communication component 2 is used to acquire orientation data of the drill bit 11 during pilot hole drilling via the orientation sensors. The control module encodes the acquired orientation data and uses the mud pulse generator to generate pulses in the mud, transmitting them to the host computer for specific parameter analysis. The mud turbine power generation module uses circulating drilling fluid to drive power generation to power the various components of measurement and communication component 2. The drilling fluid is generally mud. This combined construction method installs the MWD system in the drill string. In a specific embodiment of pilot hole construction, the process is as follows:

[0047] A high-precision directional drill with directional drilling capability is selected for hole opening and directional drilling. The hole is opened according to the designed inclination angle (e.g., 60°) with a diameter of ￠216mm, and a top-down drilling method is adopted.

[0048] like Figure 2As shown, a drilling fluid circulation is established using a mud pump. The circulating mud drives a mud turbine generator module to generate electricity, which is used to start the downhole measurement system.

[0049] During drilling, the sensors built into the measurement and communication component 2 (mainly a triaxial accelerometer and a triaxial magnetometer) directly measure three key parameters near the drill bit 11 behind it: 1. Well inclination angle: the angle between the borehole axis and the vertical line; 2. Azimuth angle: the angle between the projection of the borehole axis on the horizontal plane and the due north direction; 3. Tool face angle: the angular displacement indicating the bending direction of the bending screw motor 13, which is the direct basis for controlling the drilling direction.

[0050] The control module in measurement and communication component 2 packages and encodes the measured well inclination, azimuth, tool face angle, and other data into a specific binary digital string. The control module sends this encoded signal to the mud pulse generator, which generates regular pressure fluctuations (positive pulses, negative pulses, or continuous waves) in the flowing drilling fluid column by controlling the opening and closing of valves, thus modulating the digital signal into a physical signal that can be transmitted through the mud.

[0051] The pressure wave signal generated by the pulse generator propagates upward at the speed of sound along the mud channel inside drill string 3, using drilling fluid as the medium, and is eventually transmitted to the riser manifold on the surface. The entire process depends on continuous and stable mud circulation.

[0052] These subtle pressure fluctuations were detected by a high-precision pressure sensor installed on the surface riser. The sensor converted the pressure signal into an electrical signal and transmitted it to the surface host computer. The decoding unit in the host computer used a filtering algorithm to remove interference such as pump noise and restored the pressure waveform to the original well inclination, azimuth, tool face angle, and other data according to the encoding protocol agreed upon with the well.

[0053] Based on the decoded data and previous data, a 3D trajectory map of the borehole is calculated and plotted in real time. The operator can clearly see the real-time spatial position, extension trend, and deviation from the designed trajectory through a ground-based host computer.

[0054] The operator monitors the comparison between the real-time trajectory and the designed trajectory to analyze the deviation trend. If the trajectory deviates from the design, adjustments are required. The decision is mainly based on the tool face angle: In the sliding drilling mode where direction adjustment is required, the operator sends a command to the downhole via the host computer. The data transmission module of the measurement communication component 2 receives the command, and the control module uploads the preset tool face angle data to the host computer on the ground for display to the operator. The operator keeps the drill string 3 stationary and slowly twists the drill string 3 to the specified direction according to the displayed tool face angle to complete the tool face angle adjustment. At this time, the drill bit 11 driven by the screw motor 13 will drill in that direction, thereby correcting the trajectory. By repeating the above steps, it is ensured that the drilling trajectory can be monitored in real time and accurately controlled within the design range. The above-mentioned existing technology uses the measurement communication component 2 to acquire downhole data, and the host computer uses the acquired data to calculate the real-time trajectory of the drill bit 11 and compares it with the designed trajectory axis of the guide hole to determine whether the guide hole trajectory deviates from the designed axis by more than a preset threshold. The existing technology also uses the offset between the real-time trajectory of the drill bit 11 and the designed trajectory axis of the guide hole to calculate the adjustment amount of the tool face angle.

[0055] In the above steps, although the drill string 3 does not rotate during sliding drilling, it is affected by the reaction torque and the lateral stress of the formation. This is particularly evident in the construction of ultra-long steep-angle inclined wells. Specifically, the reaction force generated when the screw motor 13 drives the drill bit 11 to break the rock will try to make the entire screw motor 13 and the drill string 3 rotate in opposite directions. This will directly cause the tool face to drift, causing the drilling trajectory of the drill bit 11 to deviate. After accumulation, this will eventually cause the axis of the pilot hole to deviate from the target axis.

[0056] The difference between this solution and existing technologies lies in the following: To improve the accuracy of pilot hole drilling and ensure the construction quality of the final inclined well, this solution proposes an anti-rotation stabilizer 4. The implementation of this high-precision pilot hole directional drilling and reverse drilling combined construction method for ultra-long steep-angle inclined wells relies on this anti-rotation stabilizer 4. The anti-rotation stabilizer 4 includes a positioning ring 41, which is integrated with the housing of the screw motor 13. The positioning ring 41 is the basic mounting base of the anti-rotation stabilizer 4 and must withstand huge torque shear forces. The positioning ring 41 and the housing of the screw motor 13 are made of high-strength non-magnetic stainless steel or Monel alloy. The selection of these materials can provide a yield strength of over 800MPa and ensure a relative magnetic permeability u. r<1.005, to avoid magnetic interference to the magnetic sensor of the adjacent measurement and communication component 2 and ensure measurement accuracy, at least four telescopic mechanisms 42 are equally spaced along the circumferential direction of the positioning ring 41. A guide plate 44 is provided between the intervals of two telescopic mechanisms 42. There are at least four guide plates 44, the surface of which has an arc portion. Two guide plates 44 in symmetrical positions form a circular structure. The radius of the circular structure is slightly smaller than or equal to the radius of the guide hole. The guide plates 44 are made of wear-resistant non-magnetic steel or hard alloy with tungsten carbide overlay. Multiple guide plates 44 form a spherical structure to protect the telescopic mechanism 42 in the retracted state and prevent the telescopic mechanism 42 from scratching the hole wall of the guide hole in the retracted state. The telescopic mechanism 42 includes a telescopic component 421 and a top foot 422 connected to the telescopic end of the telescopic component 421. The telescopic component 421 uses an electric push rod and is made of non-magnetic stainless steel or titanium alloy. At the same time, the sealing component is made of high temperature resistant, oil resistant, and high pressure resistant fluororubber or tetrafluoroethylene. The top foot 422 is made of non-magnetic alloy steel and is made of fluoropolymer rubber. The surface of the top foot 422 has a groove 4221. In another embodiment, the surface of the top foot 422 does not have a groove 4221. The surface of the top foot 422 is uniformly provided with multiple rows of sawtooth or conical truncated pyramids. The cutting surface of the truncated pyramid is inclined in the opposite direction of rotation. The truncated pyramid design can more effectively embed into the well wall and provide a mechanical locking effect beyond pure friction, ensuring the anchoring effect. The telescopic mechanism 42 is used to extend the top plate and abut against the inside of the guide hole during sliding drilling, which can stabilize the screw motor 13 and prevent it from reversing. The telescopic component 421 of the telescopic mechanism 42 is electrically connected to the control module of the measurement and communication component 2 and the mud turbine power generation module. The mud turbine power generation module provides the electrical energy required for the telescopic component 421 of the telescopic mechanism 42 to work. After the data transmission module of the communication component 2 receives the instruction sent by the ground host computer, the control module drives and controls the telescopic component 421 of each telescopic mechanism 42 according to the received instruction to perform the extension or retraction action.

[0057] The anti-rotation stabilizer 4 has two working states: 1. Deployed state: The measurement and communication component 2 controls the telescopic component 421 to push the top foot 422 out to abut against the wall of the guide hole. When the telescopic component 421 pushes the top foot 422 out completely, the widest point of the outer contour of the guide plate 44 is located at two-thirds of the overall length of the top foot 422. 2. Retracted state: The measurement and communication component 2 controls the telescopic component 421 to pull the top foot 422 back. When the telescopic component 421 fully retracts the top foot 422, the position of the top foot 422 is within the outer contour range of the guide plate 44. At this time, the top foot 422 does not contact the inside of the guide hole.

[0058] The working process of the anti-spin stabilizer 4 is as follows:

[0059] During the drilling process of the directional drilling rig, the telescopic mechanism 42 of the anti-rotation stabilizer 4 is in the retracted state, the guide plate 44 plays a role in straightening and guiding, and the measurement and communication component 2 transmits well inclination angle and azimuth angle data to the ground in real time.

[0060] When the data captured by the measurement and communication component 2 shows that the guide hole trajectory deviates from the design axis by more than a preset threshold, the preset threshold is used to determine whether the guide hole trajectory deviates from the design axis of the guide hole. Alternatively, the operator decides to switch from compound drilling to sliding drilling for correction. At this time, the directional drilling rig stops rotating the drill string 3 and starts the mud pump circulation. The operator fine-tunes the angle of the drill string 3 according to the data captured by the measurement and communication component 2, aligns the bend angle 12 with the predetermined correction direction, and completes the tool face angle adjustment. At this time, the anti-rotation stabilizer 4 is activated. After the tool face angle is adjusted to the correct position, the operator sends a command to the measurement and communication component 2 from the ground host computer. The measurement and communication component 2 activates the anti-rotation stabilizer 4. At this time, the telescopic component 421 of the anti-rotation stabilizer 4 moves synchronously, pushing the top plate to extend radially and abut against the hole wall of the guide hole. At this time, the positioning ring 41, the screw motor 13 housing and the well wall form a rigid connection.

[0061] Keeping drill string 3 stationary, increase drilling pressure. The internal rotor of screw motor 13 rotates at high speed under mud drive, driving drill bit 11 to break rock. At this time, the reaction torque generated by drill bit 11 breaking rock acts entirely on the anchored screw motor 13 housing. Because the friction between the top plate and the well wall is much greater than the reaction torque, screw motor 13 housing cannot reverse, keeping the tool face angle data constant. Drill bit 11 drills precisely along the predetermined direction, effectively improving the hole-forming accuracy of pilot holes in existing technologies.

[0062] After the drilling trajectory returns to the design axis or the predetermined sliding advance is completed, drilling stops. The operator sends a release command from the ground via the host computer. After the measurement and communication component 2 receives the release command, the telescopic mechanism 42 drives the top plate to retract inward until it is lower than the outer contour of the guide plate 44. After the top plate is completely retracted, the ground drilling rig resumes rotary table rotation, and the system re-enters the composite drilling mode to continue the next stage of construction.

[0063] In the above process, after the tool face angle is adjusted to the correct position, the tool face angle is defined as the reference tool face angle.

[0064] The process by which the measurement and communication component 2 controls the anti-spin stabilizer 4 to enter the deployment state includes:

[0065] The measurement and communication component 2 controls the deployment of the anti-spin stabilizer 4;

[0066] The host computer determines whether the tool face deviates from the target angle based on the data collected by the measurement and communication component 2;

[0067] Specifically, the host computer calculates the current tool face angle based on the data collected by the measurement and communication component 2, compares the tool face angle with the reference tool face angle, and calculates the deviation value.

[0068] When it is determined that the tool face deviates from the target angle, the extension and retraction of each control extension and retraction mechanism is adjusted based on the offset to restore the tool face to the reference tool face angle.

[0069] Specifically, the host computer calculates the target extension amount required for each telescopic component 421 in each telescopic mechanism 42 based on the direction (clockwise or counterclockwise deviation) and magnitude of the deviation value.

[0070] The calculation process for the target scaling amount is as follows:

[0071] The required correction control quantity is calculated using existing PID algorithms:

[0072] ;

[0073] In the formula, This is the control quantity for corrective action (i.e., the required eccentric displacement). The control coefficient is obtained based on existing trial-and-error methods during actual construction. It determines the system's response speed. Increasing it will speed up the response, but will also increase overshoot and oscillation tendency. This determines the system's ability to eliminate residuals. Increasing this ability will eliminate residuals, but will slow down the system response and increase the likelihood of low-frequency oscillations. These parameters determine system stability. Increasing them will suppress overshoot and oscillations, but will amplify high-frequency noise. Fine-tuning these three parameters using a trial-and-error method aims to achieve optimal control performance with fast toolface angle response, zero steady-state error, and minimal overshoot. For tool face angle deviation, Tool face angle deviation rate of change For time Inner tool face angle deviation The area it occupies.

[0074] Using trigonometric functions to determine the corrective control quantity Mapped onto the telescopic components 421 in each telescopic mechanism 42: In the formula, For the increase in expansion and contraction, For corrective control quantity, The direction indicated by the current bend angle 12. Given the azimuth angle of the telescopic component 421, the telescopic increment of all telescopic mechanisms 42 can be calculated based on the parameters of different telescopic components 421.

[0075] Calculate the final target expansion / contraction amount for each expansion member 421: In the formula: For the initial telescopic extension amount of telescopic component 421, The final target expansion / contraction amount of expansion component 421, This represents the increment of the expansion / contraction amount.

[0076] The host computer sends the calculated control commands to the measurement and communication component 2. The measurement and communication component 2 controls the telescopic components 421 in each telescopic mechanism 42 to perform the final target telescopic amount, pushing the tool face angle back to the reference tool face angle.

[0077] During the above process, the radial extension height of the top foot 422 of the telescopic mechanism is significantly greater than the maximum radial height of the arc portion of the guide plate 44. This means that when anchoring and adjustment are required, the top foot 422 is the only point of contact with the force. It will directly contact the hole wall of the guide hole, passing over the outer contour of the guide plate 44. The guide plate 44 will not affect the operation of the anti-rotation stabilizer 4 in the deployed state or the micro-adjustment process.

[0078] like Figure 1 As shown, the measurement and communication component 2 also integrates a rotating magnetic field receiving probe, and the host computer also integrates a rotating magnetic field ranging system. During the construction process of the combined construction method, when the pilot hole is drilled to the last 60 meters, the MWD (Measuring While Drilling) system is switched to the rotating magnetic field ranging system to guide the final section of the drill bit 11's drilling process. The rotating magnetic field ranging system uses existing technology, and its specific operation process is as follows:

[0079] First, a magnetic beacon needs to be installed at the target point in the inclined shaft's lower horizontal tunnel. It must be installed in an area completely free from magnetic interference, far away from any reinforcing bars, tracks, or metal equipment. Simultaneously, the coordinate system of the magnetic beacon must be precisely aligned with the ground's engineering coordinate system through high-precision measurement. The magnetic beacon should be activated immediately after installation to generate a low-frequency, rotating AC magnetic field. The rotating magnetic field receives the magnetic field vector measured by the probe and transmits it to the host computer via the measurement communication component 2. The rotating magnetic field ranging system generates a correction command based on the data obtained from the probe and corrects the tool face angle based on the correction command, returning its axis to the design axis. During this process, sliding drilling is employed, and an anti-rotation stabilizer 4 prevents the screw motor 13 from rotating, maintaining the stability of the tool face angle and thus achieving the construction accuracy of the guide hole.

[0080] This invention discloses a construction method for ultra-long, steeply inclined wells with an inclination angle greater than 60°, aiming to solve industry problems such as large cumulative errors, severe tool face drift, and difficulty in guaranteeing final breakthrough accuracy in long-distance directional drilling. To completely solve the problem of tool face drift during sliding drilling at steep inclination angles, this solution innovatively introduces an anti-rotation stabilizer 4. This anti-rotation stabilizer 4 consists of a telescopic mechanism 42 arranged circumferentially along the housing of the screw motor 13. During sliding correction drilling, the anti-rotation stabilizer 4 extends and rigidly anchors to the well wall, absorbing all the reaction torque generated by the screw motor 13 driving the drill bit 11 to break rock. This ensures zero drift of the tool face angle defined by the bend angle 12 throughout the correction process, greatly improving the accuracy of the correction command execution. The anti-rotation stabilizer 4 is activated at the start of sliding drilling and deactivated after correction is completed. The construction process of the scheme includes: firstly, through the control of the measurement while drilling system and the rotating magnetic field ranging system and the anti-rotation stabilizer 4, the pilot hole is accurately connected, completely eliminating tool face drift during sliding drilling; and ensuring the wellbore quality and safety of subsequent back-expansion construction, providing reliable technical support for the construction quality of ultra-large underground projects.

[0081] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0082] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.

[0083] Those skilled in the art will also understand that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments herein can be implemented as electronic hardware, computer software, or a combination thereof. To clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in alternative ways for each specific application; however, such implementation decisions should not be construed as departing from the scope of this disclosure.

[0084] The steps of the methods or algorithms described in conjunction with the embodiments herein can be directly embodied in hardware, software modules executed by a processor, or a combination thereof. The software modules can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. The ASIC can reside in a user terminal. Alternatively, the processor and storage medium can exist as discrete components in the user terminal.

[0085] For software implementation, the techniques described in this application can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described in this application. This software code can be stored in memory units and executed by a processor. The memory units can be implemented within the processor or outside the processor; in the latter case, they are communicatively coupled to the processor via various means, as is well known in the art.

[0086] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that the various embodiments can be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A method for constructing ultra-long, steeply inclined wells using a combination of high-precision pilot hole directional drilling and reverse drilling, characterized in that: include: S1. A directional drilling rig is used to construct a pilot hole by drilling from top to bottom. The directional drilling rig includes a drill string assembly connected to the drill string. The drill string assembly is used for directional drilling and consists of a measurement and communication assembly, a bend, a screw motor, and a drill bit connected in series. The measurement and communication assembly is connected to a host computer and is connected to the drill string. The power output end of the screw motor is connected to the drill bit. The measurement and communication assembly is suitable for capturing and acquiring the directional data of the drill bit during the drilling of the pilot hole, and uses a mud pulse generator to generate pulses in the mud to transmit the encoded directional data to the host computer on the ground for parameter analysis. S2, During the drilling of the pilot hole, the drilling trajectory of the drill bit is obtained in real time using the measurement while drilling system; S3 compares the drilling trajectory of the drill bit with the preset drilling trajectory, and performs correction analysis on the tool face angle of the drill when the deviation exceeds the threshold range; S4. Based on the analysis results, the adjustment amount of the tool face angle of the drill bit is obtained. The tool face angle is adjusted using the obtained adjustment amount. When adjusting the tool face angle, an anti-rotation stabilizer is also required. The anti-rotation stabilizer is set on the housing of the screw motor. The anti-rotation stabilizer includes a positioning ring integrated with the housing of the screw motor. At least four telescopic mechanisms are evenly spaced along the circumferential direction of the positioning ring surface. A guide plate is provided between the intervals of two telescopic mechanisms. The telescopic mechanism includes a telescopic component and a top foot connected to the telescopic end of the telescopic component. The surface of the top foot that abuts against the guide hole wall is uniformly provided with multiple rows of sawtooth or conical truncated pyramids. The cutting surface of the truncated pyramid is inclined in the opposite direction of rotation. The telescopic mechanism is communicatively connected to the measurement and communication component. The anti-spin stabilizer has two operating modes:

1. Deployment State: The measurement and communication component controls the telescopic component to push the top foot out and abut against the hole wall of the guide hole. The rotor inside the screw motor rotates at high speed under the drive of mud, driving the drill bit to break the rock. During this process, the reaction torque generated by the drill bit breaking the rock is completely applied to the anchored screw motor housing. Since the screw motor housing cannot reverse, the tool face angle data remains constant, and the drill bit drills along the predetermined direction. When the telescopic component pushes the top foot out fully, the widest point of the guide plate's outer contour is located at two-thirds of the overall length of the top foot. The process of the measurement and communication component controlling the anti-rotation stabilizer to enter the deployment state includes: the measurement and communication component controlling the anti-rotation stabilizer to deploy; the host computer judging whether the tool face deviates from the target angle based on the data collected by the measurement and communication component; when it is judged that the tool face deviates from the target angle, the telescopic mechanism adjusts the telescopic amount based on the offset to restore the tool face to the reference tool face angle. The host computer calculates the target telescopic amount required for each telescopic component based on the direction and magnitude of the deviation value. The calculation process for the target scaling amount is as follows: ; In the formula, For corrective control quantity, For control coefficients, For tool face angle deviation, Tool face angle deviation rate of change For time Inner tool face angle deviation The area it occupies; Using trigonometric functions to determine the corrective control quantity Mapped onto the telescopic components in each telescopic mechanism: In the formula, For the increase in expansion and contraction, For corrective control quantity, The direction indicated by the current bend. The azimuth angle of the expansion joint; Calculate the final target expansion / contraction amount for each expansion component: In the formula: For the initial expansion and contraction of the expansion joint, The final target expansion / contraction amount of the expansion joint, This represents the increment of the expansion / contraction amount; The host computer sends the calculated control commands to the measurement and communication component, which then controls the telescopic components in each telescopic mechanism to execute the final target telescopic amount, pushing the tool face angle back to the reference tool face angle.

2. Retracted state: The measurement and communication component controls the telescopic component to pull the top foot back. When the telescopic component is fully retracted, the top foot is located within the outer contour of the guide plate. At this time, the top foot does not contact the inside of the guide hole. The anti-rotation stabilizer operates as follows: The ground-based host computer determines whether the guide hole trajectory deviates from the design axis by more than a preset threshold based on data captured by the measurement and communication component. If the threshold is exceeded, the directional drilling rig is switched from composite drilling mode to sliding drilling, and the directional drilling rig stops rotating the drill string. The tool face angle adjustment is obtained based on the deviation of the guide hole trajectory. After the tool face angle is adjusted to the correct position, it is defined as the reference tool face angle. The host computer sends a command to the measurement and communication component, which then controls the anti-rotation stabilizer to enter the deployment state. After the correction is completed, the host computer sends a command to the measurement and communication component, which then controls the anti-rotation stabilizer to enter the retraction state. S5, when the pilot hole is constructed to the last 60 meters, switch to the rotating magnetic field ranging system to guide the drilling trajectory of the drill bit until the construction of the pilot hole is completed; S6. Use a reverse drilling rig to enlarge the pilot hole and complete the construction of the inclined shaft.

2. The method as described in claim 1, characterized in that, The surface of the guide plate has an arc portion.

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