Full-period management and control accurate penetration construction method for ultra-long large-dip-angle inclined shaft

Abstract

The invention discloses a full-period management and control accurate penetration construction method for a super-long large-dip-angle inclined shaft, which comprises the following steps of: sequentially executing five stages, namely, gestational deviation, deviation inducing, deviation forming, deviation rectifying and deviation preventing, so as to form a full-period closed-loop management and control system covering the design, construction and operation and maintenance of the inclined shaft; in the gestational deviation stage, a gestational deviation risk grade is divided by constructing a three-dimensional geologic model and calculating a drilling impedance difference value, and a quantitative basis is provided for subsequent construction; equipment type selection, parameter sensitivity analysis and system joint debugging are completed in the biased stage; in the deviation forming stage, the prediction model and the real-time monitoring system are used for dynamically pre-judging deviation and early warning; in the deviation rectification stage, closed-loop deviation rectification is achieved through track fitting and parameter adjustment; in the deviation prevention stage, track checking, data summarization and long-term monitoring are carried out. The method is suitable for inclined shaft engineering with the length of hundreds of meters and the inclination angle larger than 45 degrees, the penetrating precision can be effectively improved, the deflection risk is reduced, and precise control and full-period data tracing in the construction process are achieved.

Description

Technical Field

[0001] This invention relates to the field of ultra-long inclined shaft construction technology, specifically a method for precise and complete construction of ultra-long inclined shafts with full-cycle control. Background Technology

[0002] With the rapid advancement of deep resource development, hydraulic tunnel construction, and infrastructure projects in steep mountainous areas, ultra-long, steeply inclined shafts have become key structures in scenarios such as underground mine ventilation and transportation, hydropower station water diversion systems, underground powerhouse auxiliary cavern excavation, and geological exploration directional drilling. They undertake the core functions of connecting pilot tunnels, constructing connecting passages, and efficiently acquiring resources. Especially in the construction of ultra-long inclined shafts with lengths exceeding several hundred meters and inclination angles greater than 45°, the structural characteristics bring increasingly stringent requirements for trajectory control, deviation correction, and breakthrough accuracy, making traditional construction methods unable to meet the engineering needs.

[0003] Current deviated well construction technologies largely rely on conventional drilling processes, using roller cone bits, PDC bits, and ordinary drill pipe combinations, with trajectory control achieved only through surface surveying and a limited number of downhole directional methods. As deviated well lengths increase and formation conditions become more complex, the limitations of traditional technologies become increasingly apparent: Regarding trajectory measurement, traditional equipment such as optical guidance systems, gyroscopes, high-frequency electromagnetic signals, and inertial navigation systems are prone to signal attenuation, attitude drift, and amplified cumulative errors in high-angle, long-distance, and high-impedance formations, leading to decreased reliability of trajectory data and an inability to support high-precision breakthroughs. In terms of deviation control and correction, current technologies largely rely on the experience of construction personnel, passively correcting deviations by adjusting drilling pressure, pump volume, rotation speed, or replacing stabilizers. This lack of systematic analysis of the deviation generation mechanism makes early identification and proactive intervention difficult, often resulting in corrections only after deviations have accumulated to a significant level, missing the optimal correction window and increasing construction risks and repetitive work costs.

[0004] Some projects have attempted to improve accuracy using advanced directional drilling technologies such as Measurement While Drilling (MWD), LWD, and self-aligning drill strings. However, these devices are expensive and complex to maintain, limiting their application in non-oil and gas sectors such as hydraulic tunnels and large-scale infrastructure projects. Furthermore, their size and weight increase wellbore friction, easily leading to new problems like drill string jamming, slippage, and torque amplification at steep inclination angles, affecting construction stability. In complex, fractured, alternating soft and hard, or water-bearing formations, current technologies cannot identify deviation factors caused by abrupt formation changes in real time. Risk assessment is only possible through lagging, indirect indicators such as decreased drilling speed and increased torque, further exacerbating the difficulty of deviation control.

[0005] During the final breakthrough stage of an inclined shaft, traditional methods rely on endpoint measurement and drill string azimuth adjustment to achieve trajectory convergence. However, due to the complexity of the geology ahead, the accumulation of measurement errors, and the randomness of drill string stress, breakthrough deviation is difficult to control precisely. Some projects compensate for insufficient accuracy by "reserving deviation space" or "enlarging the target chamber," which not only increases the amount of construction work but also raises safety risks.

[0006] In summary, existing technologies have significant shortcomings in the construction of ultra-long and steeply inclined shafts: a lack of systematic analysis of deviation-causing mechanisms, discontinuous and limited monitoring of deviation-causing factors, reliance on experience-based correction methods without quantitative indicators, unclear correction windows, lack of multi-source data fusion and verification for breakthrough control, and a lack of a unified control strategy covering the entire construction cycle. Therefore, there is an urgent need for a comprehensive management and control method covering the entire cycle of deviation-causing identification, deviation-causing monitoring, deviation inversion, correction control, and breakthrough verification. This method would enable proactive and precise control over the entire process of ultra-long and steeply inclined shaft construction, addressing many problems inherent in traditional technologies and improving construction quality, breakthrough accuracy, and operational safety. Summary of the Invention

[0007] The purpose of this invention is to provide a precise and complete construction method for ultra-long inclined shafts with full-cycle control, addressing the shortcomings of existing technologies. This method utilizes technologies such as risk identification, parameter pre-setting, real-time monitoring, deviation prediction, closed-loop correction, and post-completion anti-deviation monitoring to achieve high-precision and high-stability inclined shaft pilot hole construction. It ensures that the connection error is stably controlled within the centimeter range and establishes a replicable and reusable construction standard system. This method is applicable to inclined shaft projects hundreds of meters long with an inclination greater than 45°, effectively improving connection accuracy, reducing deviation risk, and achieving precise control and full-cycle data traceability throughout the construction process.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a precise and complete construction method for full-cycle control of ultra-long inclined shafts, comprising five stages executed sequentially: S1 deviation induction stage, S2 deviation initiation stage, S3 deviation formation stage, S4 deviation correction stage, and S5 deviation prevention stage. The five stages constitute a closed-loop control system covering the entire cycle of inclined shaft design, construction, and operation and maintenance.

[0009] The S1 deviation stage includes: collecting geological data of the deviated well area and constructing a three-dimensional geological model; calculating the drilling impedance difference based on the difference in elastic modulus of the surrounding rocks of adjacent strata to classify the deviation risk level and divide the area; and pre-setting drilling parameters and drill string combinations according to the risk level.

[0010] The S2 deviation stage includes: selecting drilling tools and monitoring equipment, determining the control range of key construction parameters through parameter sensitivity analysis, and completing personnel training and equipment system commissioning.

[0011] The S3 deviation stage includes: establishing a drilling trajectory prediction model based on geological and construction parameter data to dynamically predict deviation trends, and identifying deviation types and triggering early warnings through a real-time monitoring system;

[0012] The S4 correction stage includes: determining the correction amount through trajectory fitting, adjusting the drill bit attitude and construction parameters to perform closed-loop correction, and verifying the correction effect.

[0013] The S5 anti-deviation stage includes: verifying the trajectory of the completed guide hole, establishing a deviation correction database and forming standardized operation documents, and deploying a long-term monitoring system to achieve full-cycle data traceability and risk warning.

[0014] To further optimize this invention, the following technical solutions may be preferred:

[0015] Preferably, the S1 stage of pregnancy specifically includes:

[0016] S101: Collect geological survey reports, topographic mapping data, hydrological monitoring records and structural drilling results of the area where the inclined shaft is located, and construct a three-dimensional geological model containing information on surrounding rock bedding, joints, faults, weak interlayers and lithological change zones;

[0017] S102: Based on the three-dimensional geological model, the elastic modulus of the surrounding rock of different strata is calculated by borehole sampling. The difference in elastic modulus between adjacent strata is defined as the drilling impedance difference. According to the magnitude of the drilling impedance difference, high, medium and low risk levels of deviation are divided along the axial direction of the inclined shaft, and a deviation risk zoning map is generated.

[0018] S103: Based on the risk level of the deviation, the deviated well is divided into sections and zones along the axial direction, and corresponding drilling parameters and drill string combinations are preset for different risk zones;

[0019] S104: Import the three-dimensional geological model, risk zoning data and preset parameters into the drilling rig attitude monitoring system, initialize the deviation early warning model and set the early warning threshold for each risk zone.

[0020] Preferably, the S2 polarization stage includes:

[0021] S201: Based on the design inclination angle and depth of the inclined shaft, high-rigidity drill pipe and adjustable-angle hydraulic directional drill bit are selected, and an automatic deviation correction system and real-time trajectory monitoring device are configured.

[0022] S202: Through parameter sensitivity analysis, determine the influence weights of drilling pressure, rotation speed, and mud properties on borehole trajectory deviation, and formulate parameter control ranges for different risk zones accordingly.

[0023] S203: Provide operators with training on identifying potential deviation factors and emergency response, and establish standardized construction procedures;

[0024] S204: Complete the calibration of drilling equipment and the joint debugging of the monitoring system before drilling.

[0025] Preferably, the S3 biasing stage includes:

[0026] S301: Using drilling depth, geological impedance, drilling pressure, and rotation speed as input variables, a BP neural network is used to establish a drilling trajectory prediction model to dynamically predict deviation trends.

[0027] S302: It adopts a three-dimensional inertial inclination system and a ground positioning system for bidirectional correction, monitors and calculates the borehole trajectory in real time, and automatically alarms when the deviation exceeds the set threshold.

[0028] S303: The system automatically identifies the type of deviation, which includes axial deviation, radial deviation, circumferential deviation, and azimuth deviation;

[0029] S304: Records drilling parameters, deviation changes, and correction response data throughout the entire process and displays them dynamically.

[0030] Preferably, the S4 correction stage includes:

[0031] S401: Use a multi-point inclinometer to collect spatial coordinate data of the deflection segment, and use the least squares method to fit the trajectory curve to determine the location of the correction point and the angle adjustment amount.

[0032] S402: The automatic correction system fine-tunes the angle of the directional drill bit and simultaneously optimizes the drilling pressure and pump pressure parameters;

[0033] S403: Periodically collect trajectory data after correction, compare it with the preset trajectory to calculate the residual deviation, and correct the drilling parameters based on the residual feedback to form a closed-loop control cycle;

[0034] S404: After the correction is completed, the borehole trajectory is re-measured using a laser inclinometer to verify the correction effect.

[0035] Preferably, the S5 anti-deviation stage includes:

[0036] S501: After the completion of each section of the pilot hole in the inclined shaft, the trajectory is checked by combining laser scanning and inertial measurement to generate a three-dimensional trajectory point cloud model of the pilot hole, and the overall deviation is calculated by comparing it with the design trajectory.

[0037] S502: Based on the data from the correction phase, establish a database with dimensions of "geological surrounding rock - deviation type - correction parameters - correction effect", and extract the optimal combination of correction parameters through cluster analysis to form a correction operation standard.

[0038] S503: Permanent monitoring nodes, including strain sensors and tilt sensors, are installed on the borehole wall to monitor and warn of deviation in real time during the lining, breakthrough and operation and maintenance stages.

[0039] S504: Integrate full-cycle data to construct a full-cycle closed-loop control system, enabling full data traceability and sharing for inclined shaft path optimization, construction guidance, and long-term maintenance.

[0040] Preferably, this method is applicable to directional drilling and precision breakthrough operations of inclined shafts with a length of over several hundred meters and an inclination angle greater than 45° in water diversion systems, hydraulic tunnels, and mine inclined shafts in high-altitude areas.

[0041] Beneficial effects:

[0042] The precise breakthrough construction method for ultra-long inclined shafts with full-cycle control provided by this invention systematically solves the core problems in existing technologies, such as difficulty in predicting deviation risks, difficulty in controlling deviation-causing factors, reliance on experience for deviation correction operations, insufficient breakthrough accuracy, and lack of full-cycle control, by constructing a closed-loop control system covering the entire process of "deviation initiation-deviation-deviation formation-deviation correction-deviation prevention". This method achieves the following significant beneficial effects:

[0043] (1) Precise full-cycle management and control, significantly improving breakthrough accuracy: This invention breaks through the limitations of traditional construction that only focuses on the drilling process, extending the scope of management and control to geological risk identification before design, dynamic control during construction, and long-term monitoring during operation and maintenance, forming a full-chain management of "design-construction-operation and maintenance". By quantifying risk zoning through geological impedance difference, dynamically predicting deviation trends through BP neural network, and accurately correcting the trajectory through closed-loop correction process, combined with dual-core laser scanning and inertial measurement, the breakthrough error of the inclined well is stably controlled at the centimeter level, which is significantly better than the breakthrough accuracy level of existing technologies, effectively avoiding rework or functional failure due to excessive deviation.

[0044] (2) Risk prediction is made in advance, and the deviation rate is significantly reduced: In the stage of deviation initiation, the geological risks are visualized and graded by three-dimensional geological modeling and drilling impedance difference quantitative analysis. Drilling tool combinations and drilling parameters adapted to different risk areas are preset in advance to avoid deviation caused by geological factors from the source. In the stage of deviation, the influence weight of key construction parameters is clarified by parameter sensitivity analysis. Combined with standardized personnel training and precise equipment calibration, the construction factors are systematically controlled, and the external deviation risks such as human operation and equipment error are greatly reduced, transforming from passive deviation correction to active deviation prevention.

[0045] (3) Dual optimization of correction efficiency and stability: In the deviation formation stage, a two-way correction of "three-dimensional inertial inclinometer system + ground positioning system" is adopted. Combined with automatic identification of deviation type and real-time early warning, the deviation position and type are accurately locked, providing accurate basis for correction. In the correction stage, the optimal correction parameters are determined by least squares trajectory fitting, and a closed-loop process of "inclinometer measurement-correction-optimization-verification-re-inclinometer measurement" is constructed to realize multi-dimensional parameter coupling correction, avoid the defects of traditional single-parameter correction which is easy to repeat and inefficient, greatly shorten the correction time, and reduce construction risks and costs.

[0046] (4) Standardized construction experience and strong replicability of projects: By establishing a multi-dimensional database of "geological surrounding rock - deviation type - correction parameters - correction effect", and combining cluster analysis to extract the optimal correction scheme under different scenarios, a reusable operation standard is formed, which effectively reduces the trial and error cost of similar projects and shortens the construction cycle; the full-cycle data traceability and sharing provides data support for subsequent inclined shaft path optimization, construction parameter adjustment and operation and maintenance, significantly improving the standardization and intelligence level of ultra-long inclined shaft construction.

[0047] (5) Wide applicability, outstanding practicality and economy: This invention does not rely on expensive special directional drilling equipment. By combining conventional equipment with precise control strategies, it can meet the construction needs of ultra-long inclined shafts with lengths exceeding hundreds of meters and inclination angles greater than 45° in various scenarios such as water diversion systems in high-altitude areas, hydraulic tunnels, and mine inclined shafts. In practical applications, it can significantly reduce rework, shorten the construction period, and reduce construction costs, while ensuring construction safety and long-term stability, and has significant engineering application value and economic and social benefits. Attached Figure Description

[0048] Figure 1 This is a flowchart illustrating the overall construction method. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0051] Example 1:

[0052] A precise and complete construction method for the full-cycle management of ultra-long inclined shafts includes five stages executed sequentially: S1 deviation induction stage, S2 deviation initiation stage, S3 deviation formation stage, S4 deviation correction stage, and S5 deviation prevention stage. These five stages constitute a closed-loop management system covering the entire cycle of inclined shaft design, construction, and operation and maintenance.

[0053] The S1 deviation stage includes: collecting geological data of the deviated well area and constructing a three-dimensional geological model; calculating the drilling impedance difference based on the difference in elastic modulus of the surrounding rocks of adjacent strata to classify the deviation risk level and divide the area; and pre-setting drilling parameters and drill string combinations according to the risk level.

[0054] The S2 deviation stage includes: selecting drilling tools and monitoring equipment, determining the control range of key construction parameters through parameter sensitivity analysis, and completing personnel training and equipment system commissioning.

[0055] The S3 deviation stage includes: establishing a drilling trajectory prediction model based on geological and construction parameter data to dynamically predict deviation trends, and identifying deviation types and triggering early warnings through a real-time monitoring system;

[0056] The S4 correction phase includes: determining the correction amount through trajectory fitting, adjusting the drill bit attitude and construction parameters to perform closed-loop correction, and verifying the correction effect.

[0057] The S5 anti-deviation stage includes: verifying the trajectory of completed guide holes, establishing a deviation correction database and forming standardized operation documents, and deploying a long-term monitoring system to achieve full-cycle data traceability and risk warning.

[0058] As a preferred embodiment, the S1 pregnancy stage specifically includes:

[0059] S101: Collect geological survey reports, topographic mapping data, hydrological monitoring records and structural drilling results of the area where the inclined shaft is located, and construct a three-dimensional geological model containing information on surrounding rock bedding, joints, faults, weak interlayers and lithological change zones;

[0060] S102: Based on a three-dimensional geological model, the elastic modulus of the surrounding rock of different strata is calculated by borehole sampling. The difference in elastic modulus between adjacent strata is defined as the drilling impedance difference. According to the magnitude of the drilling impedance difference, high, medium and low risk levels of deviation are divided along the axial direction of the inclined shaft, and a deviation risk zoning map is generated.

[0061] S103: Based on the risk level of deviation, the deviated well is divided into sections and zones along the axial direction, and corresponding drilling parameters and drill string combinations are preset for different risk zones;

[0062] S104: Import the three-dimensional geological model, risk zoning data and preset parameters into the drilling rig attitude monitoring system, initialize the deviation early warning model and set the early warning threshold for each risk zone.

[0063] In a preferred embodiment, the S2 biasing stage includes:

[0064] S201: Based on the design inclination angle and depth of the inclined shaft, high-rigidity drill pipe and adjustable-angle hydraulic directional drill bit are selected, and an automatic deviation correction system and real-time trajectory monitoring device are configured.

[0065] S202: Through parameter sensitivity analysis, determine the influence weights of drilling pressure, rotation speed, and mud properties on borehole trajectory deviation, and formulate parameter control ranges for different risk zones accordingly.

[0066] S203: Provide operators with training on identifying potential deviation factors and emergency response, and establish standardized construction procedures;

[0067] S204: Complete the calibration of drilling equipment and the joint debugging of the monitoring system before drilling.

[0068] Preferably, the S3 biasing stage includes:

[0069] S301: Using drilling depth, geological impedance, drilling pressure, and rotation speed as input variables, a BP neural network is used to establish a drilling trajectory prediction model to dynamically predict deviation trends.

[0070] S302: It adopts a three-dimensional inertial inclination system and a ground positioning system for bidirectional correction, monitors and calculates the borehole trajectory in real time, and automatically alarms when the deviation exceeds the set threshold.

[0071] S303: The system automatically identifies the type of deviation, which includes axial deviation, radial deviation, circumferential deviation, and azimuth deviation.

[0072] S304: Records drilling parameters, deviation changes, and correction response data throughout the entire process and displays them dynamically.

[0073] As a preferred implementation, the S4 correction stage includes:

[0074] S401: Use a multi-point inclinometer to collect spatial coordinate data of the deflection segment, and use the least squares method to fit the trajectory curve to determine the location of the correction point and the angle adjustment amount.

[0075] S402: The automatic correction system fine-tunes the angle of the directional drill bit and simultaneously optimizes the drilling pressure and pump pressure parameters;

[0076] S403: Periodically collect trajectory data after correction, compare it with the preset trajectory to calculate the residual deviation, and correct the drilling parameters based on the residual feedback to form a closed-loop control cycle;

[0077] S404: After the correction is completed, the borehole trajectory is re-measured using a laser inclinometer to verify the correction effect.

[0078] Preferably, the S5 anti-deviation stage includes:

[0079] S501: After the completion of each section of the pilot hole in the inclined shaft, the trajectory is checked by combining laser scanning and inertial measurement to generate a three-dimensional trajectory point cloud model of the pilot hole, and the overall deviation is calculated by comparing it with the design trajectory.

[0080] S502: Based on the data from the correction phase, establish a database with dimensions of "geological surrounding rock - deviation type - correction parameters - correction effect", and extract the optimal combination of correction parameters through cluster analysis to form a correction operation standard.

[0081] S503: Permanent monitoring nodes, including strain sensors and tilt sensors, are installed on the borehole wall to monitor and warn of deviation in real time during the lining, breakthrough and operation and maintenance stages.

[0082] S504: Integrate full-cycle data to construct a full-cycle closed-loop control system, enabling full data traceability and sharing for inclined shaft path optimization, construction guidance, and long-term maintenance.

[0083] As a preferred embodiment, this method is applicable to directional drilling and precision breakthrough operations of inclined shafts with a length of over several hundred meters and an inclination angle greater than 45° in water diversion systems, hydraulic tunnels, and mine inclined shafts in high-altitude areas.

[0084] Based on the above technical solution, the construction of an ultra-long inclined shaft in a water diversion system in a high-altitude area is taken as an application scenario. The inclined shaft is 800m long, with an inclination angle of 52°, and traverses strata containing weak interlayers and fault structures. It belongs to a typical ultra-long inclined shaft project with complex geological conditions and an inclination angle. The full-cycle control and precise breakthrough construction method described in this invention is adopted, and the specific implementation steps are as follows:

[0085] I. Geological Risk Precipitation Stage: Geological Risk Quantification Zoning and Parameter Prediction

[0086] (1) Geological data collection and 3D modeling (S101):

[0087] We collected 1:5000 topographic mapping data, detailed geological survey reports, hydrological monitoring records from the past five years, and results from three structural drilling profiles for the area where the inclined shaft is located. The focus was on extracting the bedding attitude, joint density, spatial location and fracture zone width of three faults, and the thickness and lithological parameters of two weak interlayers in the surrounding rock. Using Midas GTS NX geological modeling software, we constructed a three-dimensional geological model containing the aforementioned key structural information. The model achieved an accuracy of 0.5m, clearly marking the spatial coordinates and physical and mechanical properties of each geological structure, thus enabling transparent analysis of the surrounding rock environment.

[0088] (2) Calculation of drilling impedance difference and risk classification (S102): Six borehole sampling points were set up along the axis of the inclined shaft, with a spacing of 150m. The elastic modulus of the surrounding rock of each stratum was determined by indoor rock mechanics test: the elastic modulus of sandstone strata was 28-32GPa, that of shale strata was 12-15GPa, that of weak interlayers was 3-5GPa, and that of fault fracture zone was 1-3GPa. The arithmetic difference of the elastic modulus of adjacent strata was defined as the drilling impedance difference. The impedance difference of each section was calculated along the axis of the inclined shaft: the impedance difference of the section where the fault fracture zone and the adjacent strata intersected reached 27GPa, that of the section where the weak interlayer and the sandstone intersected reached 20GPa, and the impedance difference of the pure sandstone section was less than 5GPa. Based on this, the risk levels are divided as follows: impedance difference > 20 GPa is a high-risk area (cumulative length 180 m), 10-20 GPa is a medium-risk area (cumulative length 220 m), and < 10 GPa is a low-risk area (cumulative length 400 m). A color-coded risk zoning map is drawn to clarify the risk distribution pattern.

[0089] (3) Risk zone parameters and drill string combination preset (S103): For high-risk areas (fault fracture zone, weak interlayer junction), select a drill string combination of Φ127mm high-rigidity drill pipe (elastic modulus ≥210GPa) + adjustable angle hydraulic directional drill bit (adjustment range ±3°) + dual stabilizer. The preset drilling pressure is controlled at 12-15MPa, rotation speed is 60-80r / min, and mud density is 1.2-1.3g / cm³. For medium-risk areas, select the same drill pipe with a single stabilizer, drilling pressure is 15-18MPa, rotation speed is 80-100r / min, and mud density is 1.1-1.2g / cm³. For low-risk areas, select a conventional drill string combination, drilling pressure is 18-22MPa, rotation speed is 100-120r / min, and mud density is 1.0-1.1g / cm³, so as to achieve precise matching of parameters and geological risks.

[0090] (4) Data import and early warning model initialization (S104): Import the three-dimensional geological model, risk zoning data and preset parameters into the ZJ30DB drilling rig attitude monitoring system, and build an initial deviation early warning model in the system: set the deviation early warning threshold for high-risk areas to 3cm, medium-risk areas to 5cm, and low-risk areas to 8cm, to provide data support for subsequent drilling early warning.

[0091] II. Deviation Stage: Construction Factor Control and System Preparation

[0092] (1) Selection of drilling tools and equipment (S201): Based on the design parameters of 52° inclination angle and 800m depth of the inclined well, in addition to the preset drilling tool combination, an automatic deviation control system (response time ≤0.5s), a three-dimensional inertial inclinometer (measurement accuracy ±0.1°) and a ground GPS positioning system (positioning accuracy ±2cm) are configured to realize real-time perception and closed-loop control of drilling tool attitude.

[0093] (2) Parameter sensitivity analysis (S202): Parameter sensitivity tests were conducted in the FLAC3D simulation system, using drilling pressure, rotation speed, and mud properties as variables, and deviation as the response value. The controlled variable method was adopted: when the rotation speed and mud properties were fixed, the deviation increased by an average of 1.2 cm for every 3 MPa increase in drilling pressure; when the drilling pressure and mud properties were fixed, the deviation increased by an average of 0.8 cm for every 20 r / min increase in rotation speed; when the drilling pressure and rotation speed were fixed, the deviation increased by an average of 1.5 cm for every 0.1 g / cm³ decrease in mud density. It was determined that mud properties had the greatest impact on deviation (42%), followed by drilling pressure (35%) and rotation speed (23%). Based on this, the allowable range of parameter fluctuations for each risk zone was determined: parameter fluctuations in high-risk zones should not exceed ±10%, and those in medium- and low-risk zones should not exceed ±15%.

[0094] (3) Personnel training and standardization (S203): Three days of specialized training were conducted for eight operators, including identification of deviation factors, judgment of deviation types, and emergency response procedures. After the training, they passed a theoretical and practical assessment (100% pass rate). Establish construction behavior standards: It was clarified that two people must verify and confirm before parameter adjustment, and that the machine must be stopped immediately after a deviation alarm is triggered for investigation. An emergency response procedure of "stop-analysis-adjustment-verification" was formulated.

[0095] (4) Equipment calibration and system integration (S204): Before drilling, complete the equipment calibration: the zero point correction error of the inclinometer is ≤0.05°, the calibration accuracy of the pressure sensor is ±0.1MPa, and the positioning error of the mechanical parts of the drilling rig is ≤0.2cm; carry out system integration, test the communication link between the monitoring system and the drilling tools, ensure that the monitoring data is transmitted back in real time (transmission delay ≤1s), the control commands are issued accurately, and there are no signal interruptions or false triggering problems.

[0096] III. Skew Formation Stage: Skew Prediction and Real-time Monitoring

[0097] (1) Construction of Deviation Trend Prediction Model (S301): A BP neural network was used to establish a drilling trajectory prediction model. The input layer variables were set as four parameters: drilling depth, geological impedance, drilling pressure, and rotation speed. The output layer variables were axial deviation, radial deviation, circumferential deviation, and azimuth deviation. Ten sets of complete construction data (a total of 8000 samples) from similar projects were selected to train the model. The model used three hidden layers (with 12, 8, and 6 neurons respectively). Iterative optimization was performed using the backpropagation algorithm. Training stopped when the prediction error was ≤0.3cm, thus realizing the dynamic calculation of deviation trend.

[0098] (2) Dual-system real-time monitoring and alarm (S302): During drilling, the three-dimensional inertial inclinometer collects drill bit attitude data every 5m, and performs trajectory correction every 10m in conjunction with the ground GPS positioning system to eliminate cumulative errors. When drilling reaches 320m (high-risk area, fault fracture zone), the radial deviation is detected to be 3.2cm, exceeding the warning threshold. The system immediately triggers an audible and visual alarm, and the ground monitoring interface pops up a window to indicate the deviation location (320m) and deviation type (radial deviation).

[0099] (3) Automatic identification of deviation type (S303): The system automatically identifies the deviation type through trajectory data fitting analysis: axial deviation is a linear offset of the trajectory along the axis direction, radial deviation is a lateral offset perpendicular to the axis, circumferential deviation is an angular offset of the drill rotation direction, and azimuth deviation is an azimuth deviation in the horizontal direction. The deviation at 320m in this case was identified as radial deviation, and the radial deviation parameter combination preset in the deviation correction strategy library was matched.

[0100] (4) Data recording and visualization (S304): Record drilling parameters, deviation change data and correction response curves throughout the process and store them in the local database. At the monitoring end, generate a dynamic visualization interface using LabVIEW software: display the deviation between the drilling trajectory and the preset trajectory in real time with three-dimensional graphics (red is the actual trajectory and green is the preset trajectory), and display the trend of deviation with depth with a line graph, so that operators can trace the cause of deviation.

[0101] IV. Corrective Phase: Closed-Loop Correction and Effectiveness Verification

[0102] (1) Deviation data fitting and correction parameter calculation (S401): In the 320m deviation section, five deviation data points were collected using a multi-point inclinometer to obtain the spatial coordinates of the drill string axis (X1,Y1,Z1) to (X5,Y5,Z5). The least squares method was used to fit the data points to obtain the trajectory curve equation of the deviation section: y=0.002x²+0.015x-0.5 (x is the drilling depth, y is the radial deviation). The deviation curvature was determined to be 0.004 / m, and the trend direction was radially outward. The correction point was determined to be at 325m, the required angle adjustment was 1.8°, and the displacement adjustment was 3.5cm.

[0103] (2) Drill bit attitude and parameter adjustment (S402): The angle of the guide drill bit is finely adjusted by 1.8° through the automatic correction system so that the cutting direction points to the preset trajectory; synchronously optimize parameters: the drilling pressure is reduced from 14MPa to 12MPa, the mud density is increased from 1.25g / cm³ to 1.3g / cm³, and the pump pressure is kept constant at 25MPa to ensure a stable transition of the drill bit attitude.

[0104] (3) Closed-loop parameter optimization (S403): Track data after correction is collected every 3m, and the residual deviation is calculated: the residual deviation at 328m is 1.5cm, at 331m it is 0.8cm, and at 334m it is 0.3cm, all within the allowable range; when drilling to 340m (medium risk zone), the residual deviation rises to 0.6cm, and the system automatically reduces the rotation speed from 70r / min to 65r / min. After correction, the residual deviation is reduced to 0.2cm, forming a rapid cycle of "deviation detection - parameter response - correction execution - effect verification".

[0105] (4) Retest of correction effect (S404): After the correction is completed (at 350m), start the laser inclinometer to retest the borehole trajectory, obtain three-dimensional coordinate data, compare it with the preset trajectory model, the deviation residual is 0.2cm, which meets the allowable error (≤0.5cm), confirm that the correction is successful, and restore the preset drilling parameters of the high-risk area.

[0106] V. Deviation Prevention Phase: Standardized Management and Full-Cycle Monitoring

[0107] (1) Segmented Trajectory Dual Replication Kernel (S501): After each segment of the inclined shaft (each segment is 200m) is completed, a laser scanning system is used to perform a full-section scan of the inner wall of the guide hole to generate a three-dimensional point cloud model. At the same time, an inertial measurement instrument collects attitude data along the axis of the guide hole. The two are fused to generate the three-dimensional trajectory of the guide hole. The trajectory is compared with the design trajectory, and the overall deviation is calculated: the overall deviations of the four segments are 0.3cm, 0.4cm, 0.2cm, and 0.3cm, respectively. The deviation change at the segment connection is ≤0.1cm, which meets the accuracy requirements.

[0108] (2) Establishment of Correction Database and Standard Formulation (S502): Based on the correction data throughout the process, a database is established according to "geological surrounding rock - deviation type - correction parameters - correction effect", containing 12 sets of typical scenario data (such as radial deviation of fault fracture zone, axial deviation of weak interlayer, etc.). Through K-means cluster analysis, the optimal combination of correction parameters under different scenarios is extracted to form the "Standard for Correction Operation of Ultra-long Inclined Shafts", which clarifies the adjustment angle, parameter optimization range and verification standards for each type of deviation, for reuse in subsequent similar projects.

[0109] (3) Deployment of permanent monitoring nodes (S503): One permanent monitoring node is deployed every 50m along the borehole wall, for a total of 16 nodes. Each node includes a strain sensor (measurement range 0-2000με) and an inclination sensor (measurement accuracy ±0.05°). The nodes are connected to the ground monitoring system via a LoRa wireless transmission module with a transmission distance ≥1000m. Monitoring data is collected in real time during the lining stage, the breakthrough stage, and the operation and maintenance stage. An early warning is triggered when the deformation exceeds 1cm.

[0110] (4) Construction of a closed-loop system for the whole cycle (S504): Integrate the data of each stage of deviation, deviation, deviation formation, deviation correction and deviation prevention, and construct a full cycle control system of "design-construction-operation and maintenance": In the design stage, use deviation risk data to optimize the deviated shaft path and avoid one secondary fault; in the construction stage, use parameters and deviation correction standards to guide the operation and reduce trial and error costs; in the operation and maintenance stage, use monitoring data to formulate maintenance plans (a comprehensive inspection is carried out every six months) to achieve full data traceability and sharing.

[0111] This embodiment, through the above-mentioned full-cycle control method, ultimately achieves a shaft breakthrough error of 0.4cm, meeting the centimeter-level precision breakthrough requirement. The construction cycle is shortened by 25% compared to traditional methods, and the rework rate is reduced to 0, significantly improving construction efficiency and accuracy, and verifying the practicality and reliability of the method of this invention.

[0112] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for precise and continuous construction of ultra-long inclined shafts with full-cycle control, characterized in that, It includes five stages executed sequentially: S1 deviation induction stage, S2 deviation initiation stage, S3 deviation formation stage, S4 deviation correction stage, and S5 deviation prevention stage. These five stages constitute a closed-loop management and control system covering the entire lifecycle of inclined shaft design, construction, and operation and maintenance. The S1 deviation stage includes: collecting geological data of the deviated well area and constructing a three-dimensional geological model; calculating the drilling impedance difference based on the difference in elastic modulus of the surrounding rocks of adjacent strata to classify the deviation risk level and divide the area; and pre-setting drilling parameters and drill string combinations according to the risk level. The S2 deviation stage includes: selecting drilling tools and monitoring equipment, determining the control range of key construction parameters through parameter sensitivity analysis, and completing personnel training and equipment system commissioning. The S3 deviation stage includes: establishing a drilling trajectory prediction model based on geological and construction parameter data to dynamically predict deviation trends, and identifying deviation types and triggering early warnings through a real-time monitoring system; The S4 correction stage includes: determining the correction amount through trajectory fitting, adjusting the drill bit attitude and construction parameters to perform closed-loop correction, and verifying the correction effect. The S5 anti-deviation stage includes: verifying the trajectory of the completed guide hole, establishing a deviation correction database and forming standardized operation documents, and deploying a long-term monitoring system to achieve full-cycle data traceability and risk warning.

2. The method for precise connection construction of ultra-long inclined shafts with full-cycle control according to claim 1, characterized in that, The S1 stage of partial pregnancy specifically includes: S101: Collect geological survey reports, topographic mapping data, hydrological monitoring records and structural drilling results of the area where the inclined shaft is located, and construct a three-dimensional geological model containing information on surrounding rock bedding, joints, faults, weak interlayers and lithological change zones; S102: Based on the three-dimensional geological model, the elastic modulus of the surrounding rock of different strata is calculated by borehole sampling. The difference in elastic modulus between adjacent strata is defined as the drilling impedance difference. According to the magnitude of the drilling impedance difference, high, medium and low risk levels of deviation are divided along the axial direction of the inclined shaft, and a deviation risk zoning map is generated. S103: Based on the risk level of the deviation, the deviated well is divided into sections and zones along the axial direction, and corresponding drilling parameters and drill string combinations are preset for different risk zones; S104: Import the three-dimensional geological model, risk zoning data and preset parameters into the drilling rig attitude monitoring system, initialize the deviation early warning model and set the early warning threshold for each risk zone.

3. The method for precise connection construction of ultra-long inclined shafts with full-cycle control according to claim 1, characterized in that, The S2 biasing stage includes: S201: Based on the design inclination angle and depth of the inclined shaft, high-rigidity drill pipe and adjustable-angle hydraulic guide drill bit are selected, and an automatic deviation correction system and real-time trajectory monitoring device are configured. S202: Through parameter sensitivity analysis, determine the influence weights of drilling pressure, rotation speed, and mud properties on borehole trajectory deviation, and formulate parameter control ranges for different risk zones accordingly. S203: Provide operators with training on identifying potential deviation factors and emergency response, and establish standardized construction procedures; S204: Complete the calibration of drilling equipment and the joint debugging of the monitoring system before drilling.

4. The method for precise connection construction of ultra-long inclined shafts with full-cycle control according to claim 1, characterized in that, The S3 biasing stage includes: S301: Using drilling depth, geological impedance, drilling pressure, and rotation speed as input variables, a BP neural network is used to establish a drilling trajectory prediction model to dynamically predict deviation trends. S302: It adopts a three-dimensional inertial inclination system and a ground positioning system for bidirectional correction, monitors and calculates the borehole trajectory in real time, and automatically alarms when the deviation exceeds the set threshold. S303: The system automatically identifies the type of deviation, which includes axial deviation, radial deviation, circumferential deviation, and azimuth deviation; S304: Records drilling parameters, deviation changes, and correction response data throughout the entire process and displays them dynamically.

5. The method for precise connection construction of ultra-long inclined shafts with full-cycle control according to claim 1, characterized in that, The S4 correction phase includes: S401: Use a multi-point inclinometer to collect spatial coordinate data of the deflection segment, and use the least squares method to fit the trajectory curve to determine the location of the correction point and the angle adjustment amount. S402: The automatic correction system fine-tunes the angle of the directional drill bit and simultaneously optimizes the drilling pressure and pump pressure parameters; S403: Periodically collect trajectory data after correction, compare it with the preset trajectory to calculate the residual deviation, and correct the drilling parameters based on the residual feedback to form a closed-loop control cycle; S404: After the correction is completed, the borehole trajectory is re-measured using a laser inclinometer to verify the correction effect.

6. The method for precise connection construction of ultra-long inclined shafts with full-cycle control according to claim 1, characterized in that, The S5 anti-deviation stage includes: S501: After the completion of each section of the pilot hole in the inclined shaft, the trajectory is checked by combining laser scanning and inertial measurement to generate a three-dimensional trajectory point cloud model of the pilot hole, and the overall deviation is calculated by comparing it with the design trajectory. S502: Based on the data from the correction phase, establish a database with dimensions of "geological surrounding rock - deviation type - correction parameters - correction effect", and extract the optimal combination of correction parameters through cluster analysis to form a correction operation standard; S503: Permanent monitoring nodes, including strain sensors and tilt sensors, are installed on the borehole wall to monitor and warn of deviation in real time during the lining, breakthrough and operation and maintenance stages. S504: Integrate full-cycle data to construct a full-cycle closed-loop control system, enabling full data traceability and sharing for inclined shaft path optimization, construction guidance, and long-term maintenance.

7. The method for precise connection construction of ultra-long inclined shafts with full-cycle control according to claim 1, characterized in that, This method is applicable to directional drilling and precision breakthrough operations in water diversion systems, hydraulic tunnels, and mine inclined shafts with a length exceeding several hundred meters and an inclination angle greater than 45° in high-altitude areas.

Images