Intelligent coiled tubing drilling system and method

Abstract

An intelligent coiled tubing drilling system (100), comprising: an execution module (110), used for executing a drilling action of a drilling rig; a control module (120), used for controlling modules of the drilling rig and building a database; a circulation module (130), used for collecting physical parameters of mud in returned drilling cuttings and adjusting the flow of a circulating flushing liquid; a power module (140), used for providing driving force of the execution module, the control module, and the circulation module; and a transportation module (150), used for bearing and moving the execution module, the control module, the circulation module, and the power module. In the system, coiled tubing is used to replace a segmented drill pipe to implement an automatic and intelligent drilling process, and a plurality of functional modules are integrated, so that the system has the characteristics of high integration, full intelligence, multifunctionality, and platform universality, thereby providing a new operation platform for the fields of underground coal mine horizontal mining and geological measurement and control. Also disclosed is an intelligent coiled tubing drilling method.

Description

A coiled tubing intelligent drilling system and method Technical Field

[0001] The present application relates to the field of intelligent mining, and in particular to a continuous tubing intelligent drilling system and method. Background Art

[0002] my country is the world's largest coal producer and consumer. Coal has always been my country's main energy source and important industrial raw material, accounting for more than half of the country's primary energy production and consumption. Since the beginning of this century, my country's coal mining and transportation equipment have made rapid technological progress, the domestic production rate has increased significantly, and a relatively complete R&D and manufacturing system has been formed. Due to the special working conditions of coal mines, the development of underground coal drilling and geophysical exploration equipment has been slow, especially for highly integrated and intelligent equipment, which is basically non-existent. The continuous tubing drill, also known as the "universal operating machine," is the product of the fusion and integration of oil drilling technologies. It integrates traditional multi-link and multi-process operating methods through an equipment revolution, and can independently complete system drilling operations and drilling and completion processes in one go.

[0003] Currently, over 10% of oil wells in certain regions of the United States are being drilled using coiled tubing (CT) rigs. The rapid development of CT drilling technology fueled the rapid recovery of shale oil in the 1990s. This development also ushered in a period of rapid growth for CT technology. Within the decade since 2008, shale oil extraction efficiency in the United States has increased by 3-4 times. Schlumberger first proposed the use of CT rigs in western Venezuela in 1993, and over 300 wells have been drilled to date, demonstrating their high drilling efficiency.

[0004] However, existing coal mine drilling equipment requires constantly stopping the pump and connecting the drill rod to achieve continuous drilling. It generally has problems such as low automation level, single function, and complicated operation and maintenance.

[0005] Summary of the Invention

[0006] The purpose of the embodiments of the present application is to provide a coiled tubing intelligent drilling system, which aims to solve the problems of low automation level, single function, and complicated operation and maintenance.

[0007] The embodiment of the present application is implemented as follows: a coiled tubing intelligent drilling system, the system comprising: an execution module, comprising at least: a coiled tubing, the head of the coiled tubing being connected to a bottom hole assembly for completing a drilling action; a coiled tubing drum for storing the coiled tubing; the bottom hole assembly (Bottom Hole Assembly) The invention also includes a drilling rig assembly (BHA) for realizing coiled tubing horizontal directional drilling; a coiled tubing injection head for applying continuous propulsion force to the coiled tubing; a rotary drilling device for realizing rotational and translational drive; a pointing mechanism for adjusting the drilling direction; a coiled tubing delivery device for ensuring the discharge of the coiled tubing; a data display unit for displaying drilling data; a control module comprising at least: an electric hydraulic drive control unit and a drilling rig operation control unit, the electric hydraulic drive control unit for controlling electrical equipment and driving hydraulic equipment, and the drilling rig operation control unit for collecting drilling rig data and borehole geological data; a circulation module for collecting physical parameters of mud in the borehole return and adjusting the flow rate of the circulating flushing fluid; a power module for providing driving force for the execution module, the control module, and the circulation module; and a transport module for carrying and moving the execution module, the control module, the circulation module, and the power module.

[0008] Another object of an embodiment of the present application is to provide a continuous tubing intelligent drilling method, the method comprising: moving the drilling rig to a working position and securing it via a transport module; drilling a pilot hole using a rotary drilling device, drilling to 1 meter and then retracting the drill; installing a bottom drill assembly and measuring instruments, using a connecting pipe injection head instead, and starting work according to a set trajectory.

[0009] The embodiment of the present application provides a coiled tubing intelligent drilling system that achieves highly integrated packaging. The system's five modules, namely the control module, execution module, circulation module, power module, and transport module, are comprehensively planned and unitized in design. It possesses complete industrial Internet of Things elements, has a compact structure, a simple layout, and is fully sealed, with automatic start and stop, system self-checking, continuous operation, vehicle-to-vehicle interconnection, and system linkage. This reduces the frequency of on-site actions and reduces on-site operation and maintenance activities. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG1 is a structural block diagram of a coiled tubing intelligent drilling system provided in an embodiment of the present application;

[0011] FIG2 is a structural block diagram of an execution module of a coiled tubing intelligent drilling system according to an embodiment of the present application;

[0012] FIG3 is a structural block diagram of a control module of a coiled tubing intelligent drilling system according to an embodiment of the present application;

[0013] FIG4 is a schematic diagram of a drilling rig portion of a coiled tubing intelligent drilling system according to an embodiment of the present application;

[0014] FIG5 is a schematic diagram of a coiled tubing drum of a coiled tubing intelligent drilling system provided in an embodiment of the present application;

[0015] FIG6 is a force analysis diagram of the coiled tubing on the drum of the coiled tubing intelligent drilling system provided in an embodiment of the present application;

[0016] FIG7 is a schematic diagram of a bottom hole assembly of a coiled tubing intelligent drilling system according to an embodiment of the present application;

[0017] FIG8 is a schematic diagram showing the working principle of a directional rotary steerable tool of a coiled tubing intelligent drilling system according to an embodiment of the present application;

[0018] FIG9 is a schematic diagram of a bottom hole measurement while drilling device for a coiled tubing intelligent drilling system according to an embodiment of the present application;

[0019] FIG10 is a schematic diagram of a coiled tubing injection head of a coiled tubing intelligent drilling system according to an embodiment of the present application;

[0020] FIG11 is a schematic diagram of a rotary drilling device of a coiled tubing intelligent drilling system according to an embodiment of the present application;

[0021] FIG12 is a schematic diagram of a pointing mechanism of a coiled tubing intelligent drilling system according to an embodiment of the present application;

[0022] FIG13 is a schematic diagram of a coiled tubing delivery device of a coiled tubing intelligent drilling system according to an embodiment of the present application;

[0023] FIG14 is a schematic diagram of a transport module of a coiled tubing intelligent drilling system according to an embodiment of the present application;

[0024] FIG15 is a dynamic force analysis diagram of the coiled tubing intelligent drilling system provided in an embodiment of the present application;

[0025] FIG16 is a three-dimensional model of a coiled tubing intelligent drilling system according to an embodiment of the present application during drilling of a coiled tubing having a length of 500 m and a diameter of φ63.5 mm;

[0026] FIG17 is a diagram of axial force and torque during the drilling process of a 500 m long, φ63.5 mm diameter coiled tubing using the intelligent coiled tubing drilling system provided in an embodiment of the present application;

[0027] FIG18 is a three-dimensional model of a coiled tubing intelligent drilling system according to an embodiment of the present application during drilling of a coiled tubing having a length of 500 m and a diameter of φ50.0 mm;

[0028] FIG19 is a diagram of axial force and torque during the drilling process of a coiled tubing with a length of 500 m and a diameter of φ50.0 mm provided by the coiled tubing intelligent drilling system according to an embodiment of the present application;

[0029] FIG20 is a block diagram of the internal structure of the computer processing unit of the coiled tubing intelligent drilling system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first xx script may be referred to as a second xx script, and similarly, a second xx script may be referred to as a first xx script without departing from the scope of this application.

[0032] As shown in FIG1 , in one embodiment, a coiled tubing intelligent drilling system 100 is provided, which may specifically include:

[0033] The execution module 110 includes at least: an uphole drilling rig execution unit 111, a downhole while drilling instrument execution unit 112, and a downhole rotary steering execution unit 113. The uphole drilling rig execution unit 111 is used to execute coiled tubing drilling operations, the downhole while drilling instrument execution unit 112 is used to collect drilling trajectory parameters, geological parameters, and engineering parameters in real time, and the downhole rotary steering execution unit 113 is used to continuously and in real time control the drilling trajectory to ensure that the actual drilling trajectory is within a deviation range from the predetermined trajectory.

[0034] The trajectory parameters include inclination, azimuth and tool face angle, the geological parameters include natural gamma and resistivity, and the engineering parameters include bottom hole weight on bit, torque, drill bit speed, outer annulus pressure and temperature.

[0035] The control module 120 includes at least: an electric hydraulic drive control unit 121 and a drilling rig operation control unit 122, wherein the electric hydraulic drive control unit is used to control electrical equipment and drive hydraulic equipment, and the drilling rig operation control unit is used to collect drilling data and borehole geological data of the drilling rig;

[0036] The circulation module 130 is used to collect the physical parameters of the mud in the drilling slag and adjust the flow rate of the circulating flushing fluid;

[0037] The power module 140 is used to provide driving force for the execution module 110, the control module 120 and the circulation module 130;

[0038] The transport module 150 is used to carry and move the execution module 110 , the control module 120 , the circulation module 130 and the power module 140 .

[0039] In this embodiment, the hole drilling rig execution unit 111 also comprises a coiled tubing device, a tubing feeder, a gripping and propulsion device, a rotary make-up device, an instrument and tool storage and loading device, a wellhead stabilization device, a wellhead tubing storage and installation device, and a manipulator. It is a key unit for automated routing, make-up, drilling, self-regulation, and intelligent control of the downhole coiled tubing system.

[0040] The downhole instrument execution unit 112 is primarily used to collect real-time drilling trajectory parameters, geological parameters, and engineering parameters. Trajectory parameters include inclination, azimuth, and tool face angle. These parameters primarily serve to achieve spatial positioning of the drilling trajectory. Geological parameters, such as natural gamma and resistivity, primarily provide a basis for formation evaluation. Engineering parameters, such as bottomhole weight on bit, torque, drill bit speed, annular pressure, and temperature, primarily reflect the actual stress conditions on the bottomhole drill string. This measurement information is then uploaded to the computer processing unit via a data transmission channel for processing and analysis. This information determines the bottomhole drill string status and the characteristics of the encountered formations, providing a basis for precise drilling trajectory control and a reference for rapid formation evaluation. This ensures the effective extension of the drilling trajectory within the coal seam or target rock formation, improves the target formation penetration rate, and enhances drilling safety.

[0041] The bottom-hole rotary steering tool unit 113 continuously and in real time adjusts the drilling trajectory while the drill string rotates, ensuring that the actual drilling trajectory is within the deviation range from the planned trajectory. It offers high drilling efficiency, a smooth trajectory, strong reach, and high hole cleanliness, meeting the needs of ultra-long and ultra-large diameter downhole directional drilling. Geosteering drilling enables real-time measurement of geological parameters and formation evaluation. It relies on geological information measured while drilling (MWD) to continuously correct and precisely control the drilling trajectory to hit the target, achieving optimized steered drilling.

[0042] In one embodiment, coiled tubing (CT), also known as flexible tubing, serpentine tubing, or coiled tubing, refers to a seamless continuous tubing system wound onto a large-diameter reel. It is constructed from multiple steel strips joined together at an angle, then rolled, formed, and welded. This high-strength and high-toughness coiled tubing resembles a coiled cable over two meters high. Its enhanced automation and maneuverability make operations safer, more efficient, and more environmentally friendly.

[0043] In this embodiment, the primary function of the coiled tubing drum is to safely protect and store the coiled tubing. This is achieved by preventing excessive damage from tubing string fatigue (bending) or mechanical damage. To achieve a drilling depth of 500 meters, the coiled tubing length must be at least 500 meters. Therefore, the radius of the coiled tubing drum mandrel must be calculated. According to engineering experience, the mandrel radius is generally at least 20 times the diameter of the coiled tubing, meaning a mandrel with a radius of at least 50 inches is required. Further research on the relationship between the common mandrel radius and the outer diameter of the coiled tubing indicates that the corresponding mandrel radius for 2.5-inch coiled tubing does not exceed 58 inches, or 1.47 meters.

[0044] The theoretical capacity of a drum for continuous pipe can be calculated using the following formula. This assumes that the pipe is wound perfectly around the entire drum. In practice, this is difficult to achieve, and a margin must be left to keep the drum capacity within practical limits.

[0045] L=(A+C)ABK

[0046] Where L is the pipe capacity (feet); A is the pipe stack height (inches); B is the width between the flanges at both ends of the drum (inches); C is the diameter of the drum core (inches); K is the K value for different pipe sizes (feet / inches). 3 ).

[0047] For example, take L as 500m or 1640.4 feet, B as 1.5m or 59 inches, C as 116 inches, K as 0.032, and substitute into the above formula to obtain A as 7.1 inches, that is, the maximum outer diameter of the drum should be no less than 130.2 inches, or 3.3m.

[0048] In addition, to ensure that the coiled tubing can be coiled together more tightly during winding, the winding torque of the coiled tubing drum needs to be further designed. As shown in Figure 6, the stress at the yield point q of the coiled tubing is examined. Under the combined action of the axial force F and the cross-sectional bending moment M, the coiled tubing undergoes plastic deformation. At this time, the bending stress is equal to the yield stress of the material, which can be expressed as follows: M = W·σ y

[0049] The force on the coiled tubing during winding is shown in the figure. According to the force analysis in the figure, we can get: F·sinθ·R·tanθ=W·σ y

[0050] The roller torque can be expressed as follows:

[0051] Substituting into the above formula, it can be transformed into:

[0052] in, is the bending coefficient of the continuous pipe section, σ yis the yield stress of the material, d is the shortest distance between the yield point q and the outer ring of the coiled tubing, which characterizes the tightness of the winding.

[0053] For example, the outer diameter of the continuous tube is D = 63.5 mm, the inner diameter is d = 49.3 mm, and the bending coefficient of the continuous tube section is W = 1.6 × 10 -5 m 3 , material yield strength σ y =80000psi, i.e. 551.6MPa, tightness d = R20, roller radius R = 1.65m, and the roller torque is 9492.9N·m when substituted into the above formula. Taking a design margin of 50%, the maximum torque of the roller is required to be 20kN·m.

[0054] In this embodiment, the coiled tubing cannot rotate during the drilling process. To apply the coiled tubing to underground horizontal directional drilling operations in coal mines, a motor is required to drive the drill bit to achieve drilling; a direction finder is required to achieve tool face orientation; and a tractor or crawler is required to overcome the frictional resistance of the wellbore wall on the coiled tubing and apply drilling pressure to the drill bit.

[0055] Therefore, as shown in Figures 7-9, the bottom hole assembly (BHA) of the system of the present application must include the following four devices: a steering device, a measuring device, a traction device, and a safety device. The steering device may include a drill bit and a directional rotary steering tool to achieve more accurate and efficient directional drilling operations. The measuring device may include logging while drilling (LWD). The traction device is used to solve the problem of difficulty in applying weight on bit in the horizontal section of the coiled tubing. The safety device is used for emergency separation in special circumstances.

[0056] In this embodiment, the coiled tubing injection head can be integrated with the rotary drilling device, as shown in Figure 10. The coiled tubing injection head generally utilizes a chain clamping mechanism to achieve continuous propulsion of the coiled tubing. A double-lever design employs a shaking mechanism that amplifies the input thrust by several dozen times, driving the coiled tubing to vibrate at high frequencies under high thrust, effectively overcoming the loss of WOB caused by static friction between the coiled tubing and the wellbore wall. For example, the maximum feed force required in this application is 100 kN, of which the injection head accounts for 80%, or 80 kN.

[0057] In one embodiment, as shown in FIG11 , the rotary drilling device needs to be driven in both rotational and translational directions. The rotational drive is used to achieve bend-up and bend-down and rotary cutting, while the translational drive is used to achieve drilling. The rotary drilling device is divided into a power section and a storage section. The power section is similar in structure to the power section of a traditional downhole drilling rig, consisting of a stator and a rotor. The base of the rotor is connected to a slide rail, enabling it to rotate and translate at the same time. For example, the maximum rated torque of the rotary drilling device is 250 N·m. In addition, the maximum feed force required for continuous tubing drilling of 500 m in length is 100 kN, and the length of the BHA section is approximately 1 / 20 of the total length. Therefore, when the bit pressure limit is 25 kN, the feed force of the rotary drilling device only needs to be 28.75 kN.

[0058] The storage area is used to store the BHA and casing. During BHA drilling operations, the BHA unit pushes out each component in the correct sequence, connects them, and then begins rotary drilling. After completing a section of drilling, casing is injected. The above steps are then repeated to connect the next BHA component, begin drilling, and complete casing injection. This cycle repeats until the BHA is assembled and fully drilled into the hole. Finally, the rotary drilling unit is lowered and retracted, and the coiled tubing injection head is replaced. The coiled tubing is then connected to the end of the BHA and connected to the end of the BHA for subsequent continuous directional drilling.

[0059] The BHA is pushed through the storage section into the rotary drilling unit's work area, where it is then made up and installed for drilling. It's important to note that each column of the BHA storage section has a lift. The storage area translates to align the corresponding BHA segment with the work area, where it is then delivered into the work area by the independent lift for that column.

[0060] To prevent wellhead collapse, casing is run into the first 10-20 meters of the borehole to reinforce the wellhead. The casing is wrapped around the BHA and stored with the BHA in the rotary drilling unit's storage area. After being pushed into the rotary drilling unit's working area and made into the previous section of casing, it is pushed into the drilled wellhead by the rotary head.

[0061] In this embodiment, the pointing mechanism is responsible for adjusting the drilling direction of the drill rig. As shown in Figure 12, it has a degree of freedom in the pitch direction to meet the requirements of tunnel operations. The pointing mechanism can adjust the injection head angle within the range of -10° to 90°.

[0062] In this embodiment, as shown in Figure 13, the tube delivery device can exert a pulling force at the outlet of the coiled tubing, providing additional propulsion and ensuring smooth delivery of the coiled tubing. The continuous propulsion is achieved using rollers, with the propulsion force provided by the friction between the rollers and the coiled tubing. Therefore, given a given pressure tolerance for the coiled tubing, the greater the contact length, the greater the propulsion force.

[0063] In this embodiment, the data display unit displays the drilling rig status on a screen for inspection personnel. This screen is embedded in the casing to the right of the pipe feeder, an integrated design that meets the explosion-proof and dust-proof requirements of underground operations. The screen is 1 meter wide and 0.4 meters high. To ensure ergonomic design and facilitate observation and operation by underground inspectors, the highest point of the screen is 1.6 meters above the ground.

[0064] In one embodiment, the control module includes:

[0065] The control module is responsible for processing the entire machine's operating instructions and controlling the operating process, and is the foundation of the drilling rig system's intelligence. This application features unmanned operation and remote control, so a very powerful control system is required. The system consists of two major units: one is the "electric-hydraulic drive" control unit composed of electrical control and hydraulic drive, and the other is the drilling rig operation control unit composed of a computer processing unit and a geological guidance data processing unit. It follows the "overall-unit-overall" design concept, has the ability to integrate and process feedforward and feedback information, has the operation and maintenance characteristics of unit self-inspection, and has three control modes: manual, automatic, and remote control. It has the application flexibility of freely switching between multiple scenarios.

[0066] The control module relies on numerous digital sensors for real-time feedback from actuators, PLC control technology for full human-machine interaction, computer simulation technology for optimal system operation, and real-time data collected by the bottomhole measurement and control system for directional drilling and geological measurement and control. This allows for the establishment of a transparent three-dimensional geological database system based on the massive amount of data generated during actual drilling. The "electric hydraulic drive" control unit was selected according to existing technical standards.

[0067] The computer processing unit is equipped with an explosion-proof casing, base plate and explosion-proof glass according to the performance requirements of explosion-proof and computing. The main board model is GWSKY1-D4, the 220V power filter module model is EMI CW1B-6A single-channel 6A, used for connecting the screen line, power line, and various interface lines of the power supply board. The memory size is 8G, the hard disk capacity is 128G, 1553 communication forwarding is adopted, and it is equipped with a power switch, drilling rig hydraulic PLC control module, drilling rig power PLC control module, and drilling rig propulsion PLC control module.

[0068] The geosteering data processing unit includes a series of tasks such as sensor data acquisition, instrument data reading and processing, database establishment and maintenance, and well information import. The control module is divided into three layers: the bottom data interface layer, the middle business processing layer, and the top user interface layer.

[0069] The data interface layer includes a database interface, which is used to create, delete, and modify databases and data tables, add, delete, and modify data, and query multiple drilling data; a data acquisition interface, which includes the driver and interface functions of the acquisition card. The signals generated by the acquisition card include: 5-channel 24-bit precision analog (XDCR1-4, HOOKLOAD), 5-channel digital (PS1-4, IN-SLIP), and 4-channel forward and reverse encoders (DW1-4); a communication module interface, which includes the driver and interface functions of the communication card, the communication card 1553 interface data, the communication card voltage, current, etc.

[0070] The business processing layer includes: database-related services, used for data import and export, real-time data storage, curve addition, deletion and query; data acquisition-related services, used for pressure sensor data storage, digital filtering, data decoding, well depth tracking calculation, etc.; communication module-related services, used for equipment initialization, equipment query, data encoding, protocol analysis, equipment status control, etc.

[0071] User interface layer, database-related interface, used for well information management, trip number information management, instrument information management, data management, drawing or printing management; data acquisition-related interface, used for waveform display, DDU display, well depth display, decoding log display; communication-related interface, instrument parameter reading, etc.

[0072] In one embodiment, the circulation module is implemented in the form of an existing drilling rig, requiring it to adapt to the requirements of continuous tubing operations and the size of the drilling rig. It is then connected to a control module to achieve a mud unit that meets the requirements of automated and intelligent drilling operations. This module performs functions such as cleaning the bottom of the well, cooling the drill bit, and balancing wellbore pressure during drilling operations. Based on the drilling process and the differences in the formations encountered, it collects parameters such as the solid content, density, and viscosity of the drill slag in real time. Automatic control is then used to adjust and change the operating parameters of the centrifuge to ensure that the centrifuge is always in the optimal operating state. The treated flushing fluid can meet the needs of normal downhole drilling, thereby reducing flushing fluid consumption. Furthermore, the use of flushing fluid circulation can establish a pressure-controlled active wall protection mode, addressing the problem of wall instability in complex formations under near-horizontal directional drilling conditions without liquid column pressure.

[0073] In one embodiment, the power module is connected to the alternating current through a motor and is responsible for providing a power unit mainly based on electricity to each module of the drilling rig system; "hydraulic drive and electronic control" is adopted as the basic structure of the power system, which can not only give play to the advantages of hydraulic drive to achieve large torque and large thrust output, but also achieve automated and intelligent operation goals through electronic control.

[0074] In one embodiment, as shown in Figure 14, the transport module is the carrier of the various modules of the drilling rig system and is responsible for the overall movement of the drilling rig underground. A crawler chassis is used as the main component of the transport module. Compared with a wheeled chassis, the crawler chassis can adapt to the complex terrain of the tunnel and ensure the obstacle-crossing ability of the drilling rig underground. In addition, it has the ability to turn on the spot in a small space, which is particularly suitable for the environment of tunnel operations. The transport module has two working modes. In transport mode, due to the narrow tunnel space, the surrounding support frames are retracted to facilitate the relocation of the equipment in the tunnel. In drilling mode, the surrounding support frames are extended to provide better lateral stability for the operation process.

[0075] In one embodiment, a coiled tubing intelligent drilling method is provided, the method comprising:

[0076] Step S102: Move the drilling rig to a working position and fix it using the transport module;

[0077] Step S104: Drill a pilot hole using the rotary drilling device, and retract the drill after drilling to a depth of 1 meter.

[0078] Step S106: Install the bottom hole assembly and measuring instruments.

[0079] Step S108: Use the connecting pipe injection head instead and start working according to the set trajectory.

[0080] In this embodiment, the drilling rig is first transported to the work site according to the pre-set plan. The rig is then supported and secured. After securing, a full system self-check is performed, power and water are connected, and drilling preparations are made. A rotary drilling unit is retrieved from the reserve, and a pilot hole is drilled. After reaching 1 meter, the drill is retracted and the custom wellhead installation begins. The wellhead is retrieved from the reserve, anchored by a manipulator, and once in place, drilling resumes. The bottom hole assembly (BHA) and surveying equipment are connected sequentially according to the installation sequence. The wellhead casing is installed simultaneously based on the footage. Once the casing is installed to a position 10 meters from the wellhead and the BHA and surveying equipment are fully inserted into the hole, the rotary drilling unit is returned to the reserve and swapped with the injection head reserve. The injection head reserve is retrieved, and a manipulator completes the threading of the coiled tubing through the injection head and the connection to the surveying equipment. Drilling then begins according to the set trajectory. During drilling, measurement information is transmitted in real time to the surface computer processing unit, enabling real-time adjustments to the operational trajectory. Simultaneously, geological measurement and control data is transmitted back to the surface computer processing unit, and the establishment of the block geological database begins. The data display device on the roof displays the information collected from the bottom of the hole in real time, making it easier for managers in the mine to understand the operation information in a timely manner and make on-site judgments and decisions.

[0081] Real-time trajectory control during drilling ensures smooth boreholes and minimizes drill sticking. When the lifting force required to elevate the coiled tubing exceeds 80% of its yield strength, this condition is defined as a stuck coiled tubing event. Drill stuck accidents can be categorized as drill stuck due to hole collapse, drill stuck due to mudstone shrinkage, and drill stuck due to sediment, depending on the cause. In addition to traditional preventive measures such as proper drilling layout design, identifying and avoiding hazardous zones, designing a proper drilling structure, selecting appropriate drilling process parameters, and performing regular punching, the following steps can be used to address drill stuck accidents during coiled tubing drilling:

[0082] 1) Use high-frequency vibration of the injection head and traction of the bottom hole assembly to perform active unstuck. At this time, it is necessary to pay attention to the stress of the drill string to avoid coiled tubing breakage;

[0083] 2) Ensure that the pump is operating without stopping. If the drill is stuck due to a mechanical failure, inject lubricant to try to re-establish circulation and then use the active drill bit to try to unblock it.

[0084] 3) If the drill is stuck at the bottom hole assembly, forcefully disconnect the safety device and release it, then remove the coiled tubing and use the coiled tubing for fishing. If the drill is stuck at the coiled tubing, use a through-the-hole milling process to unstick the drill string. If the drill is stuck, the drill string can be unstuck by vibrating the entire vehicle or by increasing the drilling pressure to increase the traction force of the bottom hole traction device.

[0085] During drilling, coiled tubing may break, causing the bottom hole assembly to separate from the drill pipe. This is known as a drill drop accident. This accident may be caused by metal fatigue, mechanical damage, or accidental damage.

[0086] The system can monitor the stress status of coiled tubing in real time, effectively preventing fatigue and accidental damage. In the event of a drill bit drop, it can be handled by using methods such as milling and salvaging, male and female tapers, and drilling branches to avoid dropped drill bits.

[0087] After drilling is complete, the coiled tubing and bottom hole assembly are withdrawn. Once the coiled tubing reaches the hole mouth, a manipulator removes it and the measuring instruments. The tubing is then withdrawn to the injection head unit storage bay, where it is aligned with the rotary drilling unit storage bay. The rotary drilling unit is then withdrawn, and the measuring equipment and drill assembly are gradually removed and placed in the instrument bay. Finally, the unit is returned to the rotary drilling unit storage bay. Water and electricity are disconnected, the hydraulic support is retracted, and the vehicle is driven to the next work area.

[0088] For traditional rod-type drilling rigs, pure drilling time accounts for approximately 40% or even less of the total drilling time in underground coal mines. The remaining time is mostly spent on connecting drill rods and handling accidents. Assuming an average shift footage of 25 meters, drilling a 500-meter-deep hole requires 20 shifts, or 160 hours. Coiled tubing drilling rigs eliminate the need for connecting drill rods, reducing labor costs and potentially increasing the proportion of pure drilling time to over 80%. If the rig's mechanical penetration rate remains unchanged, the average footage per shift will reach 50 meters, and a 500-meter-deep hole will only require 10 shifts, or 80 hours, achieving a 100% increase in efficiency.

[0089] In one embodiment, as shown in FIG4 , the execution module, control module, circulation module, power module, and transport module in the present application are integrated into a drilling rig as a whole. For example, the length, width, and height dimensions of the drilling rig are 3.44 m × 1.52 m × 2.03 m, which can meet the working space requirements of existing underground tunnels. The drilling rig in the present application can be a 500-meter medium-deep hole directional drilling rig with the following parameters: a drilling depth of 500 meters, a maximum feed force of 100 kN, a pull-out force of 75 kN, a rated torque of 50-250 N·m, a rated speed of 70-240 rpm, and a curb weight of 9850 kg.

[0090] The main technical indicators of the bottom-hole measurement equipment are as follows: environmental characteristics include a maximum temperature of 70°C, a maximum pressure of 12 MPa, and a working time of more than 200 hours; wellbore trajectory data includes azimuth measurement range of 0°-360° with an accuracy of ±1.5°, well inclination measurement range of 0°-180° with an accuracy of ±0.2°, and tool face angle measurement range of 0°-360° with an accuracy of ±2.8°; formation evaluation data includes four resistivity parameters, including phase resistivity range of 0.05 to 2000Ω-M, amplitude resistivity range of 0.1 to 100Ω-M, and accuracy error of ±1% (10Ω-M); and three natural gamma parameters, with a measurement range of 0 to 380API and an accuracy error of ±3API.

[0091] In one embodiment, as shown in FIG15 , during horizontal drilling in a coal mine, the hole wall generates axial friction on the coiled tubing, consuming the feed force provided by the injection head and the tube feeder, causing the drilling pressure at the drill bit to decrease. This requires the injection head and the tube feeder to provide sufficient feed force.

[0092] In addition, if the coiled tubing buckles in the hole, the positive pressure it exerts on the wellbore wall will further increase, causing increased frictional resistance and making it impossible to transmit the drilling pressure to the drill bit. Therefore, during the design process, it is also necessary to select a coiled tubing of appropriate diameter to ensure that its bending stiffness meets the design requirements.

[0093] By building a multibody dynamics model and simulating the actual drilling process, we provide a design basis for the injector head, tubing feeder power, and coiled tubing diameter. For example, we used commonly used drill pipes of φ50.0mm (2”, 6.5mm wall thickness) and φ63.5mm (2-1 / 2”, 7.1mm wall thickness), a drill bit outer diameter of 95.25mm, a wellbore inner diameter of 100mm, and a coefficient of friction between the wellbore and the drill string of 0.3. The screw motor speed was set to 80rpm, and the weight on bit (WOB) was set to the maximum WOB of 25kN for a φ73mm screw motor, as per the Drilling Technology Manual.

[0094] Figure 16 shows a 3D model of a 500-meter-long, 63.5-mm-diameter coiled tubing drilled in a wellbore. The wellbore is magnified 300x for ease of visualization. The larger diameter cylinder represents the wellbore, while the smaller diameter cylinder represents the coiled tubing. The arrows indicate the contact force exerted by the wellbore wall on the coiled tubing. The coiled tubing does not buckle at this point.

[0095] Figure 17 shows the axial force and torque results for the coiled tubing. When the WOB reaches 25 kN, the wellbore friction loss is 24.4 kN, and the injection force provided by the orifice should be no less than 49.4 kN. To allow for sufficient margin, the injection force provided by the injector head and tubing feeder is designed to be 100 kN. Furthermore, the drill bit torque generated during drilling at this WOB is 0.24 kN·m. Because the wellbore is relatively curvy during the first few tens of meters of drilling, a significant margin is not required. Therefore, the maximum rated torque required for the rotary drilling unit is 250 N·m.

[0096] Figure 18 shows a 3D model of a φ50.0 mm coiled tubing drilled in a wellbore. The wellbore is magnified 300x for easier visualization. The larger diameter cylinder represents the wellbore, while the smaller diameter cylinder represents the coiled tubing. The arrows indicate the contact force exerted by the wellbore wall on the coiled tubing. At this point, the front half of the coiled tubing experiences helical buckling, causing the contact force exerted by the wellbore wall on the drill string to increase dramatically. A cross-section shows that the contact force is directed in all directions.

[0097] Figure 19 shows the axial force and torque results for the coiled tubing. When the weight on bit (WOB) reaches 25 kN, the wellbore friction loss is 37.9 kN, and the injection force provided by the orifice should be no less than 62.9 kN. Compared to the case where no buckling occurs, the frictional torque is greater, requiring a higher injection force and causing greater damage to the coiled tubing. Therefore, this size of coiled tubing is not suitable for 500 m horizontal drilling.

[0098] This application achieves automated directional drilling and remote control in underground coal mine tunnels by utilizing automatic control technology, sensor technology, directional drilling technology, measurement while drilling technology, remote monitoring technology, and efficient transmission and communication technology. It highly integrates equipment such as an automated directional drilling rig system, a rotary directional drilling system, a geo-steering drilling system, measurement while drilling tools, logging while drilling tools, and an automatic control system for flushing fluid circulation.

[0099] This application has the following effects:

[0100] 1) High integration

[0101] It achieves highly integrated packaging, with the five major modules of the system, namely control module, execution module, circulation module, power module and transport module, being comprehensively planned and unitized in design. It has complete industrial Internet of Things elements, compact structure and simple layout, and the whole vehicle is sealed, with automatic start and stop, system self-check, continuous operation, vehicle-to-vehicle interconnection and system linkage, which reduces the frequency of on-site actions and reduces on-site operation and maintenance behaviors.

[0102] 2) Fully intelligent

[0103] Based on the communication management of the system bus design, using a large number of sensors and electronic instruments as the means, and focusing on the integration of mechanical, electrical, hydraulic, and software systems, with the goal of establishing a complete self-detection system and a good adaptive learning system, we will build an intelligent system equipment with high standards of automation and intelligence. Based on the characteristics of coiled tubing with built-in cables and combined with the needs of underground coal mine drilling operations, the design includes three aspects of intelligence:

[0104] Drilling Rig Intelligence: Each module of the drilling rig is equipped with a self-checking function, facilitating the use and maintenance of the drilling rig. It also provides a basic platform for building a closed-loop system of "parameter measurement - intelligent decision-making - control execution".

[0105] Intelligent measurement: Utilizing the coiled tubing's built-in cable as a signal and power transmission channel, high-precision, low-latency front-end measurement equipment and digital sensors distributed throughout the drilling rig enable real-time monitoring of the status of each module. This enables real-time measurement of drilling trajectories and formation geological data, establishing a complete coalfield geological data system and laying a solid technical foundation for achieving geological transparency.

[0106] Intelligent control: By modeling the dynamics of the entire drilling rig system and adopting a comprehensive feedforward and feedback control strategy based on high-precision, low-latency measurement data, we achieve intelligent control of the drilling rig's borehole and bottomhole units, thereby achieving the goal of optimizing and expediting various downhole tasks centered on drilling.

[0107] Through the intelligent drilling rig, a drilling closed loop marked by rotary steering is realized; through the intelligent measurement, a measurement closed loop marked by geological steering is realized; through the intelligent control, an operation closed loop marked by unmanned operation and unmanned driving is realized, thus building a complete intelligent drilling system.

[0108] 3) Multifunctional

[0109] Give full play to the characteristics of the continuous tubing drill rig as a "universal operating machine", fully explore the application scenarios of coal mine tunnel operations, fully empower technical solutions for multi-scenario applications, achieve fast drilling, precise measurement, and automatic fracturing, and improve work efficiency and operational effectiveness.

[0110] Optimized and fast drilling embodies fully automated, continuous drilling. Because coiled tubing drilling requires no single connection, tripping and drilling speeds are high, shortening the drilling cycle. Automatic control of the drilling process, based on dynamic feedforward and measurement signal feedback, enables autonomous adjustment of operating modes and tool and instrument performance, significantly improving drilling efficiency and hole quality, and providing real-time, accurate wellbore information for rapid decision-making.

[0111] Precision measurement is based on the application of a large number of precise measuring instruments, which can realize the technical integration of conventional logging and logging while drilling, realize the precision of measurement level brought by the diversification of measurement methods, achieve the dual goals of directional measurement and geological measurement and control, and lay a data foundation for geological transparency.

[0112] Automatic fracturing was previously a blank spot in coal mine horizontal hole technology. The main reason was that there was no means to arrange fracturing tools in the horizontal borehole under the previous open hole state. The continuous tubing system of the continuous tubing drilling rig can effectively carry the fracturing tools into the hole and realize segmented and graded fracturing, which will allow the gas to change from the adsorbed state to the free state as soon as possible, accelerate the gas emission rate and increase the emission scale.

[0113] 4) Pan-platform

[0114] This drilling rig adopts a modular design, and different platform functions can be realized by replacing different modules. It includes a three-layer platform function design for production operations, data mining, and deep learning.

[0115] First of all, the system is a production operation platform, which mainly completes the whole system operations of gas fast extraction, including drilling operations, measurement operations, hole fixing operations, and fracturing operations in the gas extraction process.

[0116] Secondly, the system is a data mining platform that integrates geographic information system data of the operating environment and data from multiple monitoring sensors in the tunnel, generates wellbore trajectory data and three-dimensional geological data during the drilling process, establishes a 3D imaging system for coal and rock identification, generates coalfield fissure characteristic data formed by fracturing, and generates real-time monitoring data on gas displacement and gas displacement rate. If the deployment of deep coal seam monitoring sensors is completed on this basis, real-time coal seam pressure monitoring, temperature monitoring, concentration monitoring and other monitoring data will also be generated. Through these integrated and generated data, a powerful data mining platform will be built, and a complete geological transparent database system for undeveloped well fields will be constructed, laying the foundation for the realization of the coal mine industrial Internet of Things.

[0117] Thirdly, the system is a deep learning platform that fully leverages artificial intelligence, using bus communication technology as its main axis and electronic information technology as its secondary axis. While inherently highly intelligent, it also forms an intelligent operation system that integrates single-machine operations with multi-machine collaboration. Building on these platforms, and utilizing multi-data operations and Huawei's Kuanghong 5G technology system, a comprehensive coalfield drilling system integration platform and a gas extraction management information platform are being constructed. Furthermore, a coalfield geology expert database and knowledge base system are being established based on these platforms. This allows for in-depth research into coalfield development patterns and evolutionary characteristics, and the development of targeted development plans. This significantly enhances the system intelligence level of coal mine ventilation and geology professionals.

[0118] This invention refines the characteristics of the latest oil drilling technology and coal drilling technology, integrates and optimizes traditional drilling equipment technology and modern information technology through cross-disciplinary and cross-field technological innovation, and develops an internationally pioneering intelligent mining drilling system.

[0119] Through its highly integrated, fully intelligent, multifunctional, and platform-agnostic design, this system enables coal mine drills to seamlessly transition from semi-automated to fully automated development, ushering them in the era of intelligent drilling rigs. This system redefines and empowers the two disciplines of coal mine ventilation and geology, leading to three revolutions: technological, process, and management revolutions in underground coal mine gas control and geological measurement and control. It also achieves four innovations in intelligent drilling equipment: conceptual innovation, technological innovation, manufacturing innovation, and operational innovation, marking a historic leap for China's intelligent coal mine equipment industry.

[0120] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0121] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0122] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0123] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A coiled tubing intelligent drilling system, characterized in that: The system comprises: an execution module, which at least comprises: a borehole drilling rig execution unit, a bottom hole drilling instrument execution unit and a bottom hole rotary steering execution unit, wherein the borehole drilling rig execution unit is used to execute the continuous pipe drilling action, the bottom hole drilling instrument execution unit is used to collect the drilling trajectory parameters, geological parameters and engineering parameters in real time, and the bottom hole rotary steering execution unit is used to continuously and in real time control the drilling trajectory to ensure that the actual drilling trajectory is within the deviation range from the predetermined trajectory; wherein the trajectory parameters include the inclination angle, azimuth angle and tool face angle, the geological parameters include natural gamma and resistivity, and the engineering parameters include bottom hole drilling pressure, torque and relative humidity. torque, drill bit speed, outer annulus pressure, and temperature; a control module, comprising at least: an electric hydraulic drive control unit and a drilling rig operation control unit, wherein the electric hydraulic drive control unit is used to control electrical equipment and drive hydraulic equipment, and the drilling rig operation control unit is used to collect drilling data of the drilling rig and borehole geological data; a circulation module is used to collect physical parameters of mud in the borehole return residue and adjust the flow rate of the circulating flushing fluid; a power module is used to provide driving force for the execution module, the control module, and the circulation module; a transportation module is used to carry and move the execution module, the control module, the circulation module, and the power module.

2. The coiled tubing intelligent drilling system according to claim 1, characterized in that: The orifice drilling rig execution unit includes: a coiled tubing, the head of which is connected to a bottom drill assembly for completing drilling; the bottom drill assembly for realizing horizontal directional drilling of the coiled tubing; and a coiled tubing delivery device for ensuring the discharge of the coiled tubing.

3. The coiled tubing intelligent drilling system according to claim 2, characterized in that: The bottom drill assembly includes at least: a guide device for realizing directional drilling operation; a measuring device for acquiring drilling data and geological data; a traction device for increasing the drilling pressure of the horizontal section of the continuous pipe; and a safety device for emergency separation of the bottom drill assembly.

4. The coiled tubing intelligent drilling system according to claim 1, characterized in that: The bottom hole rotary steering execution unit comprises: a coiled tubing injection head for applying continuous propulsion force to the coiled tubing; and a rotary drilling device for realizing driving in rotation and translation directions.

5. The coiled tubing intelligent drilling system according to claim 4, characterized in that: The rotary drilling device comprises: a power part, which is composed of a stator and a rotor and is used to realize driving in rotation and translation directions; and a storage part, which is used to store a bottom drilling tool assembly and a casing.

6. The coiled tubing intelligent drilling system according to claim 1, characterized in that: The drilling rig operation control unit includes: a computer processing unit for providing a borehole data processing platform; a geological guidance data processing unit for collecting sensor data, establishing a database, and storing and processing data.

7. The coiled tubing intelligent drilling system according to claim 1, characterized in that: The circulation module includes: a mud unit, which is used to collect parameters such as solid content, density, viscosity, etc. in the drilling slag in real time according to the drilling construction process and the difference in the drilled strata, change the operating parameters of the centrifuge, and adjust the flow rate of the flushing liquid processed by the centrifuge.

8. The coiled tubing intelligent drilling system according to claim 1, characterized in that: The power module adopts a hydraulic-driven and electrically controlled working mode.

9. The coiled tubing intelligent drilling system according to claim 1, characterized in that: The transport module has a transport mode for facilitating the movement of the transport module and a drilling mode for providing lateral stability.

10. A coiled tubing intelligent drilling method, characterized in that: The method comprises: moving the drilling rig to the working position and fixing it by means of a transport module; drilling a guide hole according to a rotary drilling device, and retracting the drill after drilling to 1 meter; installing a bottom drilling tool assembly and a measuring instrument, using a connecting pipe injection head instead, and starting to work according to a set trajectory.

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