Dual-power system rope coring drill tool and method for ultra-deep hole directional drilling

Abstract

The present invention discloses a dual-power system rope coring drill tool and method for ultra-deep hole directional drilling. The drill tool includes a straight drill rod, a hollow motor, a power transmission tube, a hollow motor, a flexible drill rod, a drill bit, and a coring mechanism. The straight drill rod, the hollow motor, the power transmission tube, the hollow motor, the flexible drill rod, and the drill bit are all hollow cylindrical structures and are sequentially connected to form a channel for axial movement of the coring mechanism. One end of the straight drill rod is fixedly connected to the hollow motor, and the other end of the straight drill rod is a drilling rig connection end. The hollow motor is transmission-connected to the hollow motor via the power transmission tube, and the hollow motor is drive-connected to the flexible drill rod. The drill bit is fixedly connected to the flexible drill rod and can rotate synchronously under the drive of the hollow motor. The coring mechanism includes a detachable coring tube located within the flexible drill rod. The coring tube can be a flexible coring tube or a rigid coring tube. The present invention configures the drill tool with two power systems. The coordinated cooperation of the hollow motor and the hollow motor can effectively improve the drilling power.

Description

Technical Field

[0001] The present invention relates to the technical field of soil or rock drilling equipment, in particular to a dual-power system rope coring drill tool for ultra-deep hole directional drilling and a rope coring method for ultra-deep hole directional drilling. Background Art

[0002] Engineering drilling is the most commonly used surveying technique in engineering surveys and is widely used in industries such as transportation, municipal administration, water conservancy, and hydropower. Currently, common engineering drilling techniques include vertical drilling, inclined drilling, and horizontal drilling. Vertical drilling and inclined drilling are the most widely used due to their relatively low construction costs and relatively mature technical processes. However, both vertical drilling and inclined drilling can only drill in a fixed direction and cannot change the drilling direction during the drilling process, which has certain limitations in their application areas. For example, in cross-riverbed surveys, when the borehole needs to pass through the riverbed from one bank to the other bank, neither vertical drilling nor inclined drilling can be implemented. To address the limitations of vertical drilling and inclined drilling, research on directional drilling has been developed.

[0003] Currently, the commonly used method for directional drilling is to install an eccentric mechanism on the rigid drill pipe. The eccentric mechanism applies an eccentric force to the rigid drill pipe to cause slight bending deformation, thereby achieving a certain degree of directional drilling capability. However, since directional drilling currently uses a hole power drill to provide power for drilling, for ultra-deep hole drilling with deeper drilling depths, the power transmission distance between the drill rig and the drill bit becomes longer and longer as the drilling depth increases, and the power attenuation becomes more and more obvious. In addition, during the drilling process, the drill pipe is constantly affected by the friction of the borehole wall, which further leads to insufficient power provided by the drill rig. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a dual-power system rope coring drill tool for ultra-deep hole directional drilling, which can effectively reduce the attenuation degree of drilling power.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a dual-power system rope coring drill tool for ultra-deep hole directional drilling, including a straight drill rod, a hollow motor, a power transmission tube, a hollow motor, a flexible drill rod, a drill bit and a coring mechanism, the straight drill rod, the hollow motor, the power transmission tube, the hollow motor, the flexible drill rod and the drill bit are all hollow cylindrical structures and are connected in sequence to form a channel for axial movement of the coring mechanism; one end of the straight drill rod is fixedly connected to the hollow motor, and the other end of the straight drill rod is the drilling rig connection end; the hollow motor is transmission-connected to the hollow motor through the power transmission tube, the hollow motor is drive-connected to the flexible drill rod, the drill bit is fixedly connected to the flexible drill rod and can rotate synchronously under the drive of the hollow motor; the coring mechanism includes a detachable coring tube, which is located in the flexible drill rod; the coring tube is a flexible coring tube or a rigid coring tube.

[0006] As an improvement to the above scheme: the hollow motor includes a motor stator, a motor rotor and at least one connecting bearing, the motor stator is sleeved on the outside of the motor rotor and fixedly connected to the straight drill rod, the motor rotor forms a relative rotation fit with the motor stator through the connecting bearing, a plurality of turbine blades are fixedly provided on the outer wall of the motor rotor, and a gap is left between the motor stator and the motor rotor to communicate with the hollow part of the straight drill rod; the hollow motor includes an outer stator, an inner rotor and two rotating bearings, the outer stator is sleeved on the outside of the inner rotor and fixedly connected to the motor stator through a connecting pipe, the inner rotor forms a relative rotation fit with the outer stator through the rotating bearing, and the inner rotor is fixedly connected to the motor rotor through a force transmission tube; the two rotating bearings are respectively arranged near the two ends of the hollow motor, and the outer ends of the rotating bearings are fixed with sealing rings that form a sealing fit with the outer stator and the inner rotor.

[0007] As an improvement to the above solution: it also includes a protective tube that is sleeved on the outside of the straight drill rod, the protective tube extends axially to the outside of the hollow motor and the hollow motor, a limiting tube is fixedly connected to the outer stator, and the limiting tube and the end of the protective tube form an axial limiting fit; the force transmission tube is fixedly connected to the inner rotor through an extension tube, and the inner wall of the extension tube is provided with a fixing groove that forms a snap fit with the coring mechanism.

[0008] As an improvement to the above scheme: the flexible drill rod includes a spring tube, a filling body, a steel ring hose, a first connector and a second connector; the spring tube is a circular tube structure formed by spirally winding steel bars, the filling body is a circular tube structure formed by casting flexible rubber on the inside and outside of the spring tube, the steel ring hose is a circular tube structure formed by integrally casting flexible rubber and multiple axially arranged steel rings, the steel ring hose is coaxially arranged inside the filling body and abuts against the inner wall of the filling body; one end of the flexible drill rod is fixedly connected to the connecting ring fixed to the end of the inner rotor through the first connector, and the other end of the flexible drill rod is fixedly connected to the drill bit through the second connector.

[0009] As an improvement of the above scheme: the coring mechanism also includes a fishing head, a guide head, a fixing part and a single turner; one end of the fishing head is provided with a conical cap, the other end of the fishing head is fixedly connected to the fixing part, and a water-blocking plug is fixedly provided on the connection part between the fishing head and the fixing part, which forms a sealing fit with the inner wall of the motor rotor; the fixing part is snap-fitted into the fixing groove; the single turner is composed of two rotating units rotatably connected by a rotating shaft, one of which is fixedly connected to the fixing part, and the other is fixedly connected to the coring tube; one end of the guide head is fixedly connected to the coring tube, and the other end of the guide head is a conical cut end, and the guide head slides in fit with the channel for axial movement of the coring mechanism through a guide bearing.

[0010] As an improvement to the above solution: two fixing ears are provided on the fixing part, one end of the two fixing ears is rotatably connected to the fixing part through a fixing shaft, the other ends of the two fixing ears are respectively unfolded to both sides and inserted into the fixing groove to form a snap fit, and the two fixing ears are connected by a compression spring.

[0011] As an improvement to the above scheme: it also includes an electronic warehouse arranged between the single rotator and the coring tube; the two ends of the electronic warehouse are fixedly connected to the single rotator and the coring tube respectively; a three-dimensional positioning device is arranged in the electronic warehouse; the electronic warehouse slides with the channel for axial movement of the coring mechanism through a limit bearing.

[0012] As an improvement to the above scheme: the coring tube is a flexible coring tube, which is a flexible circular tube structure formed by integrally casting flexible rubber and multiple axially arranged steel rings, and an opening is provided on the steel ring; the two ends of the flexible coring tube form radial limiting fits with the electronic compartment and the guide head respectively through limiting cuts and are fixedly connected by bolts; the flexible coring tube bends and deforms synchronously with the flexible drill rod when the flexible drill rod is subjected to axial pressure.

[0013] As an improvement of the above scheme: the coring tube is a rigid coring tube, which is a rigid circular tube structure. The two ends of the rigid coring tube form radial limiting cooperation with the electronic warehouse and the guide head through limiting cuts and are fixedly connected by bolts; the rigid coring tube limits the bending deformation of the flexible drill rod when the flexible drill rod is subjected to axial pressure.

[0014] The present invention also discloses a wireline coring method for ultra-deep hole directional drilling, which uses the dual-power system wireline coring drill tool for ultra-deep hole directional drilling as described above and is carried out according to the following steps:

[0015] Step 1: Assemble the dual-power system rope coring drill tool for ultra-deep hole directional drilling. Select the coring tube according to the drilling purpose and the characteristics of the drilling section. Use a flexible coring tube for directional drilling and a rigid coring tube for linear drilling.

[0016] Step 2: The straight drill pipe is fixedly connected to the drilling rig, and the coring mechanism with the rigid coring tube installed is placed inside the drill tool and fixed through the fish catcher. The vertical force is applied to the straight drill pipe through the drilling rig, and drilling slurry is input at high pressure at the top of the drill tool. The hollow motor is driven by the drilling slurry to rotate. At the same time, the power of the hollow motor is turned on so that the hollow motor and the hollow motor rotate synchronously, driving the drill tool to continuously drill into the rock formation in a straight line, and the core enters the rigid coring tube. When the core capacity in the rigid coring tube is about to reach the upper limit, the drilling work of the drill tool is stopped, and the coring mechanism is fished out through the fish catcher to remove the core in the rigid coring tube;

[0017] Step 3: Repeat the linear drilling and coring work of step 2, and increase the number of straight drill rods assembled according to the change in drilling depth, until the linear drilling reaches the starting position of directional drilling;

[0018] Step 4: Remove the rigid coring tube from the coring mechanism and replace it with a flexible coring tube;

[0019] Step 5: Place the coring mechanism equipped with the flexible coring tube into the drill tool through the fishing device and fix it, apply an eccentric force opposite to the predetermined drilling direction to the straight drill rod through the drilling rig, so that the flexible drill rod and the flexible coring tube are synchronously bent and deformed in the direction of the designed trajectory curve, input high-pressure drilling slurry at the top of the drill tool, drive the hollow motor to rotate through the drilling slurry, and simultaneously connect the power supply of the hollow motor to make the hollow motor and the hollow motor rotate synchronously, drive the drill tool to continuously bend in a direction to drill into the rock formation, and the core enters the flexible coring tube. When the core capacity in the flexible coring tube is about to reach the upper limit, stop the drilling work of the drill tool, salvage the coring mechanism through the fishing device, and take out the core in the flexible coring tube;

[0020] Step 6: Repeat the directional drilling and coring work of step 5, and increase the number of straight drill rods assembled according to the change in drilling depth, until the directional drilling reaches the predetermined directional bending target point;

[0021] Step 7: Replace the flexible core tube with a rigid core tube, and repeat the linear drilling and coring work of step 2, and increase the number of straight drill rods assembled according to the change in drilling depth, until the linear drilling reaches the predetermined depth;

[0022] Step 8. Obtain the drilling trajectory of the drilling tool, analyze the actual drilling trajectory and determine the direction of directional drilling, compare the actual drilling trajectory curve with the designed drilling trajectory curve, determine the deviation direction and offset of the actual drilling trajectory, and correct the drilling direction; refer to the plumb bob profile of the actual drilling trajectory curve, if the drill bit in the actual drilling trajectory is located above the drill bit in the designed drilling trajectory, reduce the eccentric force applied by the drilling rig; if the drill bit in the actual drilling trajectory is located below the drill bit in the designed drilling trajectory, increase the eccentric force applied by the drilling rig; refer to the horizontal profile of the actual drilling trajectory curve, if the drill bit in the actual drilling trajectory is located to the left of the drill bit in the designed drilling trajectory, adjust the direction of the eccentric force applied by the drilling rig to the left; if the drill bit in the actual drilling trajectory is located to the right of the drill bit in the designed drilling trajectory, adjust the direction of the eccentric force applied by the drilling rig to the right; by adjusting the magnitude and direction of the eccentric force applied by the drilling rig, the actual drilling trajectory is returned to the designed drilling trajectory.

[0023] The beneficial effects of the present invention are:

[0024] 1. The present invention configures the drill tool with two power systems, a hollow motor and a hollow motor. The two power systems rotate synchronously to drive the flexible drill rod and the drill bit to rotate synchronously to achieve drilling. The coordinated cooperation of the hollow motor and the hollow motor can effectively improve the drilling power and is more suitable for ultra-deep hole drilling environments.

[0025] 2. The present invention places both the hollow motor and the hollow electric motor, which serve as drilling power components, close to the drill bit. The power system and the drill bit are connected by a flexible drill rod, thereby improving the existing hole-drilling power to bottom-hole drilling power. As the drilling depth increases, the distance between the power system and the drill bit remains constant, so there is no significant power attenuation, and the coring mechanism's core extraction work is not affected.

[0026] 3. The hollow motor of the present invention is driven by the high-pressure injected drilling slurry, while the hollow motor is powered by electricity. Although the injection pressure of the drilling slurry decreases with the increase of drilling depth, the hollow motor and the hollow motor can jointly provide power for the drilling work of the drill tool through the transmission connection. The hollow motor can supplement the weakened power of the hollow motor, ensuring that sufficient drilling power can be stably provided to the drill bit.

[0027] 4. The present invention provides a coring mechanism within the drill tool, and sequentially connects a straight drill rod, a hollow motor, a power transmission tube, a hollow motor, a flexible drill rod, and a drill bit to form a channel for axial movement of the coring mechanism. This does not affect the coring mechanism's core collection during the drilling process, thereby effectively improving the efficiency of core collection. The coring mechanism of the present invention can be selectively configured with a flexible coring tube or a rigid coring tube. The corresponding coring tube can be selected according to the characteristics of the drilling section during the drilling process, so that the core collection work can be adapted to the drilling work. The flexible coring tube can automatically adjust its own bending posture according to the drilling posture of the drill tool during directional drilling, while the rigid coring tube can limit the bending deformation of the flexible drill rod during straight drilling, thereby effectively improving the applicability of directional drilling work.

[0028] 5. The present invention disposes a flexible drill rod between the straight drill rod and the drill bit. The flexible drill rod has the characteristic of being fully deformable. When the pressure applied by the hole drill rig is transmitted to the flexible drill rod through the straight drill rod, the flexible drill rod will produce a corresponding bending deformation. Under different pressures of the hole drill rig, the flexible drill rod produces different degrees of bending deformation. This enables the present invention to have a wider range of deflection amplitudes and is applicable to directional drilling construction with different deflection amplitude requirements, effectively improving the deflection efficiency and drilling efficiency of directional drilling.

[0029] 6. The present invention can obtain the spatial trajectory of the drill tool during the entire drilling process in real time, thereby being able to guide the direction of the drill tool during directional bending drilling in real time, and correct the drilling direction through the acquired spatial trajectory. It has a while-drilling trajectory testing function, and is more convenient to control the drilling trajectory, thereby improving drilling efficiency by ensuring the accuracy of the drilling trajectory. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a cross-sectional structural diagram of the present invention in a natural state;

[0031] Figure 2 It is a cross-sectional structural diagram of the present invention in a directional drilling state;

[0032] Figure 3 This is a cross-sectional structural diagram of the present invention in a linear drilling state;

[0033] Figure 4 This is a schematic diagram of the structure of the present invention when the coring mechanism is not installed;

[0034] Figure 5 Schematic diagram of the structure of the flexible drill rod in the present invention;

[0035] Figure 6 for Figure 1 Cross-section at AA;

[0036] Figure 7 for Figure 1 Cross-section at BB.

[0037] The markings in the figure are: 100-straight drill pipe, 200-hollow motor, 210-motor stator, 220-motor rotor, 310-power transmission tube, 320-protection tube, 330-limiting tube, 340-extension tube, 350-connecting tube, 360-connecting ring, 400-hollow motor, 410-outer stator, 420-inner rotor, 430-rotating bearing, 440-sealing ring, 500-flexible drill pipe, 51 0-spring tube, 520-filling body, 530-steel ring hose, 540-first connector, 550-second connector, 600-drill bit, 700-coring mechanism, 710-coring tube, 720-fishing head, 730-guide head, 740-fixing part, 750-single turner, 760-water blocking plug, 770-fixing ear, 780-guide bearing, 790-limit bearing, 800-electronic compartment. DETAILED DESCRIPTION

[0038] To facilitate understanding of the present invention, the present invention will be further described below with reference to the accompanying drawings.

[0039] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as "front", "rear", "left", "right", "up", "down", and "inside" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of description. They do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0040] like Figures 1 to 3As shown, the disclosed dual-power system wireline coring drill tool for ultra-deep hole directional drilling includes a straight drill rod 100, a dual-power system, a flexible drill rod 500, a drill bit 600, and a coring mechanism 700. The dual-power system includes a hollow motor 200, a power transmission tube 310, and a hollow motor 400. The straight drill rod 100 is connected to a drilling rig at the borehole entrance. The drilling rig applies pressure to the straight drill rod 100, which is transmitted downward through the straight drill rod 100. Straight drill rods 100 can also be added and connected to extend the length of the drill tool. The dual-power system serves as the power component for drilling, providing power for the drilling tool. By placing the dual-power system near the bottom end of the drill bit 600, the power component is positioned closer to the bottom of the hole, rather than the conventional design where the power component is located at the borehole entrance. The distance between the dual-power system and the drill bit 600 remains constant. The hollow motor 200 and hollow motor 400 in the dual-power system each utilize different power sources. The hollow motor 200 is driven by high-pressure injected drilling slurry, while the hollow motor 400 is driven by electricity. The power transmission tube 310 connects the hollow motor 200 and hollow motor 400 of the dual-power system, thereby simultaneously combining the torque of the hollow motor 200 and the hollow motor 400 to enhance the drilling power of the drill tool. The flexible drill rod 500 rotates under the joint drive of the hollow motor 200 and the hollow motor 400, driving the drill bit 600 to rotate synchronously. The flexible drill rod 500 can bend and deform when subjected to a force from above. The flexible drill rod 500 bends accordingly based on the magnitude of the force applied, thereby achieving an appropriate deflection amplitude. The drill bit 600 cuts the rock in the borehole through its own rotation, allowing the drill tool to continuously drill deeper. In the present invention, the straight drill rod 100, hollow motor 200, power transmission tube 310, hollow motor 400, flexible drill rod 500 and drill bit 600 are all set as hollow cylindrical structures, and the hollow parts of the components are connected through the axial connection of the above components to form a channel for axial movement of the coring mechanism 700. The coring mechanism 700 realizes the collection of cores by axial movement in this channel; the coring mechanism 700 is equipped with a detachable coring tube 710, through which the cores are collected and stored during the drilling process of the drill tool.

[0041] Specifically, such as Figures 1 to 4As shown, the straight drill rod 100 of the present invention is a hollow cylindrical structure. The hollow portion of the straight drill rod 100 serves as a moving channel for the coring mechanism 700. Furthermore, the hollow portion of the straight drill rod 100 also provides a flow channel for the drilling slurry injected into the hollow motor 200. One end of the straight drill rod 100 is threadedly connected to the hollow motor 200, and the other end of the straight drill rod 100 serves as a drill rig connection end. The straight drill rod 100 can be threadedly connected to a borehole drill rig via the drill rig connection end, or it can be threadedly connected to other straight drill rods 100 via the drill rig connection end. As the drilling depth increases, the number of connected straight drill rods 100 can be increased, allowing multiple straight drill rods 100 to be threadedly connected in sequence, all the way from the bottom of the borehole to the borehole drill rig at the surface borehole. This allows the entire drilling tool to be extended to match the drilling depth. The straight drill rod 100 is a rigid structure, and the straight drill rod 100 can directly withstand the bit pressure and eccentric force applied by the hole drilling rig. The straight drill rod 100 serves as a force transmission component to transmit the force applied by the hole drilling rig downward.

[0042] Specifically, such as Figures 1 to 4 As shown, the dual power system of the present invention includes a hollow motor 200 and a hollow motor 400 , and the hollow motor 200 and the hollow motor 400 form a transmission fit through a power transmission tube 310 .

[0043] The hollow motor 200 consists of a motor stator 210, a motor rotor 220, and a connecting bearing. The motor stator 210 and motor rotor 220 are hollow cylindrical structures of different sizes. The hollow motor 200 is positioned between the straight drill rod 100 and the power transmission tube 310. The motor stator 210 is sleeved onto the exterior of the motor rotor 220. A threaded interface is provided on the inner side of the upper end of the motor stator 210, through which it is threadedly connected to the straight drill rod 100 above. A threaded interface is provided on the outer side of the lower end of the motor stator 210, through which it is threadedly connected to the connecting tube 350. The motor rotor 220 is located within the motor stator 210. A threaded interface is provided on the outer side of the lower end of the motor rotor 220, through which it is threadedly connected to the power transmission tube 310. The upper end of the motor rotor 220 is free. The motor stator 210 and the motor rotor 220 are clearance-fitted and achieve relative rotational engagement via a connecting bearing. The connecting bearing is sleeved on the outer wall of the motor rotor 220, with the inner ring of the connecting bearing fixedly connected to the motor rotor 220, and the outer ring of the connecting bearing fixedly connected to the motor stator 210. A plurality of turbine blades are fixedly mounted on the outer wall of the motor rotor 220. The gap between the motor stator 210 and the motor rotor 220 communicates with the hollow portion of the upper straight drill pipe 100. Drilling slurry injected downward through the straight drill pipe 100 can flow into the gap between the motor stator 210 and the motor rotor 220. The flow of drilling slurry from the inlet to the outlet then drives the turbine blades fixed to the outer wall of the motor rotor 220 to rotate, thereby driving the motor rotor 220 to rotate. The motor rotor 220 then transmits the rotational torque downward through the power transmission tube 310.

[0044] The hollow motor 400 consists of an outer stator 410, an inner rotor 420, and two rotating bearings 430. The outer stator 410 and inner rotor 420 are hollow cylindrical structures of different sizes. The hollow motor 400 receives the torque transmitted by the hollow motor 200 through the power transmission tube 310, increases the torque through its own rotation, and then transmits it downward to the flexible drill rod 500. The outer stator 410 is mounted on the outside of the inner rotor 420. The upper end of the outer stator 410 is threadedly connected to the motor stator 210 of the upper hollow motor 200 via the connecting tube 350. The upper end of the inner rotor 420 is threadedly connected to the motor rotor 220 of the upper hollow motor 200 via the power transmission tube 310. The outer stator 410 and inner rotor 420 are fitted with a clearance fit, and relative rotational engagement is achieved via a rotating bearing 430. The rotating bearing 430 is sleeved onto the outer wall of the inner rotor 420. The inner ring of the rotating bearing 430 is fixedly connected to the inner rotor 420, while the outer ring of the rotating bearing 430 is fixedly connected to the outer stator 410. Two rotating bearings 430 are positioned near each end of the hollow motor 400, creating a space between the two rotating bearings 430 to accommodate the electrical components of the hollow motor 400, including the motor magnets and coils. To protect the electrical components of the hollow motor 400, the present invention also includes a sealing ring 440 fixedly mounted on the outer end of each rotating bearing 430. The sealing ring 440 tightly abuts against both the inner wall of the outer stator 410 and the outer wall of the inner rotor 420, sealing the gap between the outer stator 410 and the inner rotor 420 to prevent groundwater from entering and damaging the hollow motor 400. This makes the hollow motor 400 waterproof and capable of operating normally in high-water-head groundwater environments.

[0045] The dual power system adopted in the present invention can increase the drilling power of the drill bit, and when drilling ultra-deep holes, when the drilling depth is too deep to provide the hollow motor 200 with drilling slurry with sufficient pressure, the power of the hollow motor 200 can be supplemented by the operation of the hollow motor 400, thereby ensuring that stable drilling power can always be provided to the drill bit.

[0046] Since the working environment in the borehole is complex and there are a lot of rock debris or groundwater, it is easy to cause damage to the dual power system of the present invention. Figures 1 to 4As shown, the present invention provides a protective tube 320 to protect the dual power system. The protective tube 320 is a hollow circular tube made of wear-resistant plastic. The upper end of the protective tube 320 is sleeved on the outside of the straight drill rod 100, and the lower end of the protective tube 320 extends axially downward to the outside of the hollow motor 400, enclosing both the hollow motor 200 and the hollow motor 400. A limit tube 330 is fixed to the outer stator 410. The limit tube 330 is a hollow cylindrical structure and is fixedly connected to the lower end of the outer stator 410 of the hollow motor 400. The outer diameter of the limit tube 330 is larger than the outer diameter of the outer stator 410, so that the limit tube 330 radially protrudes to the outside of the outer stator 410. An oblique cut is provided on the upper end of the limit tube 330, and a matching oblique cut is provided on the lower end of the protective tube 320. The limit tube 330 forms an axial limit fit on the lower end of the protective tube 320. In addition to limiting and securing the protective tube 320, the position limiting tube 330 also protects the lower portion of the hollow motor 400, preventing debris, rock fragments, and other impurities from entering the hollow motor 400. The present invention forms a protective layer on the outside of the dual-power system by providing the protective tube 320, thereby preventing the drill tool from contacting the borehole rock wall and causing wear during drilling. As the drilling depth increases, the number of straight drill rods 100 increases to extend the overall length of the drill tool. Accordingly, the number of protective tubes 320 can be increased, with multiple protective tubes 320 extending axially outside the drill tool and assembled using snap-fit connections or bolt connections.

[0047] In addition, an extension tube 340 is provided between the force transmission tube 310 and the inner rotor 420. The extension tube 340 is a hollow cylindrical structure. A threaded interface is provided on the inner side of the upper end of the extension tube 340. The extension tube 340 is threadedly connected to the force transmission tube 310 through the threaded interface at the upper end. The lower end face of the extension tube 340 is directly fixedly connected to the upper end face of the inner rotor 420. A fixing groove is provided on the inner wall of the extension tube 340. By providing the fixing groove, a snap fit can be formed with the coring mechanism 700 to achieve fixation of the coring mechanism 700 in the channel.

[0048] Specifically, such as Figures 1 to 4 as well as Figure 5 、 Figure 7As shown, the flexible drill rod 500 in the present invention is composed of a spring tube 510, a filling body 520, a steel ring hose 530, a first connector 540 and a second connector 550. The spring tube 510 is a circular tube structure formed by spirally winding steel bars. The steel bars used to prepare the spring tube 510 can be round steel bars or square steel bars. In the present invention, the spring tube 510 is used as the skeleton structure of the flexible drill rod 500. The flexible drill rod 500 can be flexible through the spring tube 510. After being subjected to the axial force transmitted from above, the spring tube 510 in the flexible drill rod 500 will bend and deform, driving the flexible drill rod 500 to bend as a whole, thereby providing sufficient deflection amplitude for the drill tool and realizing directional bending drilling of the drill tool. The filler 520 is a flexible circular tube structure formed by casting flexible wear-resistant rubber on the inner and outer sides of the spring tube 510 to fill the gap. The casting of the filler 520 makes the flexible drill rod 500 an integrated structure, and can make the outer wall of the flexible drill rod 500 a straight and smooth surface, which can effectively reduce the wear of the flexible drill rod 500 by the borehole wall. The present invention fills the inner wall of the flexible drill rod 500 by providing a steel ring hose 530; the steel ring hose 530 is a circular tube structure formed by integrally casting flexible rubber and multiple axially arranged steel rings. That is, multiple steel rings are arranged in axial intervals in sequence, and the gaps between the steel rings are then filled by casting flexible wear-resistant rubber to obtain the steel ring hose 530. The outer diameter of the steel ring hose 530 is adapted to the inner diameter of the spring tube 510 so that the steel ring hose 530 can be tightly attached to the spring tube 510; when the spring tube 510 is bent and deformed, the adjacent parts of the spring tube 510 will open, and due to the provision of the steel ring hose 530, the steel ring inside the steel ring hose 530 will not be deformed due to the axial arrangement, and the diameter of the steel ring remains unchanged. When the spring tube 510 is bent, the steel ring hose 530 remains in contact with the spring tube 510, and therefore will not cause deformation to the internal core tube 710.

[0049] The first connector 540 and the second connector 550 of the flexible drill pipe 500 are both hollow cylindrical structures. A tapered threaded interface is provided on the inner side of the upper end of the first connector 540, and a tapered threaded interface is provided on the outer side of the lower end of the second connector 550. The two ends of the spring tube 510 are welded to the first connector 540 and the second connector 550, respectively. One end of the flexible drill pipe 500 is threadedly connected to the connecting ring 360 fixed to the lower end of the inner rotor 420 through the first connector 540, and the other end of the flexible drill pipe 500 is threadedly connected to the drill bit 600 through the second connector 550. The upper and lower ends of the steel ring hose 530 are fixedly connected to the first connector 540 and the second connector 550, respectively.

[0050] Specifically, such as Figures 1 to 3 As shown, the coring mechanism 700 of the present invention includes, in addition to the coring tube 710 , a fishing head 720 , a guide head 730 , a fixing portion 740 and a single turner 750 .

[0051] The fishing head 720 of the coring mechanism 700 is used to connect with the fishing device. The fishing device can connect the coring mechanism 700 by fixing and releasing the fishing head 720. After the fishing device is connected to the fishing head 720, the coring mechanism 700 can be fished out to extract the core, or the coring mechanism 700 can be lowered into the drilling tool through the fishing device. One end of the fishing head 720 is provided with a conical cap, and the other end of the fishing head 720 is welded and fixed to the fixing part 740 by a round tube or other connecting parts. A fixing part 740 is also fixed on the connecting part between the fishing head 720 and the fixing part 740. A water-blocking plug 760 is provided. The water-blocking plug 760 adopts a flexible rubber sealing ring. The water-blocking plug 760 abuts against the inner wall of the motor rotor 220 of the hollow motor 200 to form a sealed fit. The water-blocking plug 760 can seal and isolate the inner wall of the motor rotor 220, so that the drilling slurry flowing out of the channel of the straight drill rod 100 cannot enter under the water-blocking plug 760, but can only flow into the gap between the motor rotor 220 and the motor stator 210, thereby ensuring that the drilling slurry is delivered to drive the motor rotor 220 and ensure the operation of the hollow motor 200.

[0052] The guide head 730 of the coring mechanism 700 is used to guide the movement of the coring mechanism 700 in the channel. One end of the guide head 730 is threadedly connected to the bottom end of the core tube 710 through a circular tubular guide tube with a tapered threaded interface, and the other end of the guide head 730 is a tapered cut end with a tapered cut. The tapered cut end of the guide head 730 can reduce the contact between the guide head 730 and the drill bit, so that the guide head 730 can more easily drive the entire core mechanism 700 to move in the drill bit; in addition, a guide bearing 780 is fixed to the outside of the guide head 730, and a ball is provided on the outside of the guide bearing 780. The ball of the guide bearing 780 slides in cooperation with the channel for axial movement of the core mechanism 700, and the guide bearing 780 can limit the movement of the guide head 730 in the channel to ensure smooth movement of the guide head 730, and the guide bearing 780 can be provided to enable the guide head 730 to form a relative rotation fit with the external mechanism to avoid synchronous rotation of the guide head 730 and the external mechanism.

[0053] The fixing portion 740 of the coring mechanism 700 is used to secure the coring mechanism 700 within the drill string. One end of the fixing portion 740 is welded to the fishing head 720 via a connecting component, and the other end of the fixing portion 740 is threadedly connected to the single turner 750. Two fixing lugs 770 are provided on the fixing portion 740. One end of each fixing lug 770 is rotatably connected to the fixing portion 740 via a fixed shaft, and the other ends of each fixing lug 770 extend to either side of the fixing portion 740. A fixing groove is provided on the inner wall of the extension tube 340. The extended ends of the two fixing lugs 770 can be inserted into the fixing groove and snap-fit with the fixing groove, thereby securing the fixing portion 740 and the entire coring mechanism 700 within the drill string. A compression spring is also connected between the two fixed ears 770, and the elasticity of the compression spring applies a compression force to the two fixed ears 770, pressing the two fixed ears 770 in the fixed groove; when the coring mechanism 700 needs to be fished, the fisher lifts the entire coring mechanism 700 through the fishing head 720, and the fixed ears 770 are subjected to the upward pulling force and shrink inward and compress the compression spring. The compression spring is compressed, and the fixed ears 770 are detached from the fixed groove.

[0054] The single-rotating device 750 of the coring mechanism 700 is composed of two rotating units, which are connected by a rotating shaft to form a relative rotation fit. The top of the rotating unit located at the top is provided with a tapered thread interface, and the bottom of the rotating unit located at the bottom is provided with a tapered thread interface. The two rotating units are respectively threadedly connected to the fixing part 740 and the coring tube 710. Figure 7 As shown, the single-rotating mechanism 750 is located inside the hollow motor 400. Because the two rotating units of the single-rotating mechanism 750 can rotate relative to each other, they rotate independently, ensuring that when the upper rotating unit connected to the fixing portion 740 rotates, the lower rotating unit connected to the coring tube 710 does not rotate. This prevents wear of the core inside the coring tube due to rotation, particularly wear on the core's structural surface.

[0055] Further, such as Figures 1 to 3As shown, the coring mechanism 700 of the present invention also includes an electronics compartment 800, which is positioned between the single-rotator 750 and the coring tube 710. A three-dimensional positioning device is installed within the electronics compartment 800, via an electronic device installation space. The electronics compartment 800 is a cylindrical structure, with the electronic device installation space located in its center. A tapered threaded interface is provided on the inner side of the upper end of the electronics compartment 800, which is threadedly connected to the lower rotating unit of the single-rotator 750. A right-angled notch is provided on the lower end of the electronics compartment 800, which forms a radial stop with the coring tube 710 and is fixedly connected via bolts. The three-dimensional positioning device installed within the electronics compartment 800 can locate the three-dimensional spatial coordinates of the drill tool during drilling to determine the tool's trajectory. This provides a positioning-while-drilling (LWD) capability. By analyzing the drilling trajectory, the direction of directional bending drilling can be determined in real time. By comparing the actual drilling trajectory with the planned drilling trajectory, the deviation direction and offset of the actual drilling trajectory can be determined, allowing for timely correction of the drilling direction. In addition, a limit bearing 790 is fixedly installed on the outer wall of the electronic warehouse 800, and a ball is provided on the outside of the limit bearing 790; the limit bearing 790 plays the same role as the guide bearing 780 installed on the guide head 730. The limit bearing 790 is used to limit the movement of the coring mechanism 700 in the drill bit and ensure the smooth movement of the coring mechanism 700. The limit bearing 790 can be set to enable the electronic warehouse 800 to form a relative rotation cooperation with the external mechanism to avoid synchronous rotation of the electronic warehouse 800.

[0056] The coring tube 710 configured for the coring mechanism 700 in the present invention can be disassembled and replaced. The coring tube 710 includes a flexible coring tube and a rigid coring tube. Different coring tubes can be selected according to the characteristics of different drilling sections during the drilling process. Flexible coring tubes are used when carrying out directional drilling, and rigid coring tubes are used when carrying out linear drilling.

[0057] like Figure 1 and Figure 2As shown, the coring tube 710 is a flexible coring tube. The flexible coring tube's skeleton structure is a flexible, wear-resistant hollow tube structure formed by integrally casting multiple steel rings spaced apart in the axial direction. The steel rings are provided with openings to allow for a certain degree of deformation. The ends of the flexible coring tube form radially limited engagements with the electronic compartment 800 and the guide head 730 through limiting cutouts and are fixedly connected by bolts. The flexible coring tube is provided with a steel ring with an opening. When a core is stored in the flexible coring tube, the opening of the steel ring can be opened to cause a certain degree of deformation. This is particularly true during directional bending drilling, where the core being drilled is curved. The adaptive deformation capability of the steel ring can prevent the core from being squeezed or worn. Furthermore, the steel ring has a certain strength and can also improve its grip on the core through its own deformation, thereby clamping the core. The flexible wear-resistant rubber used in casting the flexible core pipe can produce a certain amount of expansion deformation. When the flexible drill rod 500 is subjected to axial pressure, it can cooperate with the steel ring to deform the flexible core pipe and the flexible drill rod 500 together, and can subsequently return to its original shape under the action of its own elastic force.

[0058] like Figure 3 As shown, the coring tube 710 is a rigid coring tube. The rigid coring tube is a rigid circular tube structure that cannot bend or deform. The two ends of the rigid coring tube form radial limit fits with the electronics compartment 800 and the guide head 730 through limiting cutouts and are fixedly connected by bolts. Because the rigid coring tube cannot bend or deform, during linear drilling, the rigid coring tube's inherent rigidity can limit bending deformation of the flexible drill rod 500 when the flexible drill rod 500 is subjected to axial pressure, ensuring that the flexible drill rod 500 remains in a straight line.

[0059] The present invention also discloses a wireline coring method for ultra-deep hole directional drilling, which uses the dual-power wireline coring drill tool for ultra-deep hole directional drilling as described above and is carried out according to the following steps:

[0060] Step 1: Assemble the dual-power system rope coring drill tool for ultra-deep hole directional drilling. Select different coring tubes 710 according to the drilling purpose and the characteristics of the drilling section. Use a flexible coring tube for directional drilling and a rigid coring tube for linear drilling. The designed trajectory curve generally involves first conducting inclined hole linear drilling, then conducting directional drilling after drilling to a certain depth based on the drilling target. When the directional drilling reaches the predetermined directional bending target point, continue linear drilling to reach the designed predetermined position.

[0061] Step 2: The straight drill rod 100 is fixedly connected to the drilling rig, and the coring mechanism 700 equipped with the rigid coring tube is placed inside the drilling tool and fixed through the fish catcher. The vertical force is applied to the straight drill rod 100 through the drilling rig, and drilling slurry is input at high pressure at the top of the drilling tool. The hollow motor 200 is driven to rotate by the drilling slurry, and the power of the hollow motor 400 is turned on to make the hollow motor 400 and the hollow motor 200 rotate synchronously, driving the drilling tool to continuously drill into the rock formation in a straight line, and the core enters the rigid coring tube. When the core capacity in the rigid coring tube is about to reach the upper limit, the application of bit pressure and the input of drilling slurry to the hollow motor 200 are stopped, and the power of the hollow motor 400 is cut off at the same time, the drilling work of the drilling tool is stopped, and the coring mechanism is salvaged through the fish catcher to remove the core in the rigid coring tube;

[0062] Step 3: Repeat the linear drilling and coring work of step 2, and increase the number of assembled straight drill rods 100 according to the change in drilling depth, until the linear drilling reaches the starting position of directional drilling;

[0063] Step 4: Remove the rigid coring tube from the coring mechanism 700 and replace it with a flexible coring tube;

[0064] Step 5: Place the coring mechanism equipped with the flexible coring tube into the drill tool and fix it through the fisher. Apply an eccentric force opposite to the predetermined drilling direction to the straight drill rod 100 through the drilling rig, so that the flexible drill rod and the flexible coring tube are synchronously bent and deformed in the direction of the designed trajectory curve. Drilling slurry is input at high pressure at the top of the drill tool, and the hollow motor 200 is driven to rotate by the drilling slurry. At the same time, the power of the hollow motor 400 is turned on to make the hollow motor 400 rotate synchronously with the hollow motor 200, driving the drill tool to continuously bend and drill into the rock formation in a directional manner. The core enters the flexible coring tube. When the core capacity in the flexible coring tube is about to reach the upper limit, stop applying the bit pressure and inputting the drilling slurry to the hollow motor 200, and at the same time, cut off the power to the hollow motor 400, stop the drilling work of the drill tool, salvage the coring mechanism through the fisher, and take out the core in the flexible coring tube.

[0065] Step 6: Repeat the directional drilling and coring work of step 5, and increase the number of assembled straight drill rods 100 according to the change in drilling depth, until the directional drilling reaches the predetermined directional bending target point;

[0066] Step 7: Replace the flexible core pipe with a rigid core pipe, and repeat the linear drilling and coring work of step 2, and increase the number of assembled straight drill rods 100 according to the change in drilling depth, until the linear drilling reaches the predetermined depth;

[0067] Step 8: The drilling trajectory of the drilling tool is obtained through the three-dimensional positioning device installed in the electronic warehouse 800, the actual drilling trajectory is analyzed and the direction of directional drilling is determined, the actual drilling trajectory curve is compared with the designed drilling trajectory curve, the deviation direction and offset of the actual drilling trajectory are determined, and the drilling direction is corrected; referring to the plumb bob cross-section of the actual drilling trajectory curve, if the drill bit in the actual drilling trajectory is located above the drill bit in the designed drilling trajectory, the eccentric force applied by the drilling rig is reduced; if the drill bit in the actual drilling trajectory is located above the drill bit in the designed drilling trajectory, the eccentric force applied by the drilling rig is reduced; if the drill bit in the actual drilling trajectory is located above the drill bit in the designed drilling trajectory, the eccentric force applied by the drilling rig is reduced. If the drill head is located below the drill bit in the designed drilling trajectory, the eccentric force applied by the drill rig is increased; referring to the horizontal cross-section of the actual drilling trajectory curve, if the drill bit in the actual drilling trajectory is located to the left of the drill bit in the designed drilling trajectory, the direction of the eccentric force applied by the drill rig is adjusted to the left; if the drill bit in the actual drilling trajectory is located to the right of the drill bit in the designed drilling trajectory, the direction of the eccentric force applied by the drill rig is adjusted to the right; by adjusting the size and direction of the eccentric force applied by the drill rig, the actual drilling trajectory is returned to the designed drilling trajectory.

Claims

1. A dual-power system rope coring drill for ultra-deep hole directional drilling, characterized by: The invention comprises a straight drill rod (100), a hollow motor (200), a power transmission tube (310), a hollow motor (400), a flexible drill rod (500), a drill bit (600) and a coring mechanism (700). The straight drill rod (100), the hollow motor (200), the power transmission tube (310), the hollow motor (400), the flexible drill rod (500) and the drill bit (600) are all hollow cylindrical structures and are connected in sequence to form a channel for axial movement of the coring mechanism (700); one end of the straight drill rod (100) is fixedly connected to the hollow motor (200). The other end of the straight drill rod (100) is a drilling rig connection end; the hollow motor (200) is transmission-connected to the hollow motor (400) via a power transmission tube (310); the hollow motor (400) is drive-connected to the flexible drill rod (500); the drill bit (600) is fixedly connected to the flexible drill rod (500) and can rotate synchronously under the drive of the hollow motor (400); the coring mechanism (700) includes a detachable coring tube (710), which is located in the flexible drill rod (500); the coring tube (710) is a flexible coring tube or a rigid coring tube; The hollow motor (200) comprises a motor stator (210), a motor rotor (220) and at least one connecting bearing. The motor stator (210) is sleeved on the outside of the motor rotor (220) and fixedly connected to the straight drill rod (100). The motor rotor (220) forms a relative rotation fit with the motor stator (210) via the connecting bearing. A plurality of turbine blades are fixedly provided on the outer wall of the motor rotor (220). A gap is left between the motor stator (210) and the motor rotor (220) to communicate with the hollow part of the straight drill rod (100). The hollow motor (400) comprises an outer stator (410), an inner rotor (420) and a second rotor (420). ) and two rotating bearings (430), the outer stator (410) is sleeved on the outside of the inner rotor (420) and fixedly connected to the motor stator (210) through the connecting pipe (350), the inner rotor (420) forms a relative rotation fit with the outer stator (410) through the rotating bearing (430), and the inner rotor (420) is fixedly connected to the motor rotor (220) through the power transmission tube (310); the two rotating bearings (430) are respectively arranged near the two ends of the hollow motor (400), and the outer ends of the rotating bearings (430) are fixed with sealing rings (440) that form a sealing fit with the outer stator (410) and the inner rotor (420).

2. The dual-power system wireline coring drill tool for ultra-deep hole directional drilling according to claim 1, characterized in that: The invention also includes a protective tube (320) sleeved on the outside of the straight drill rod (100), the protective tube (320) extending axially to the outside of the hollow motor (200) and the hollow motor (400), a limiting tube (330) fixedly connected to the outer stator (410), and the limiting tube (330) and the end of the protective tube (320) forming an axial limiting fit; the power transmission tube (310) is fixedly connected to the inner rotor (420) through an extension tube (340), and a fixing groove forming a snap fit with the coring mechanism (700) is provided on the inner wall of the extension tube (340).

3. The dual-power system wireline coring drill for ultra-deep hole directional drilling according to claim 1, characterized in that: The flexible drill rod (500) comprises a spring tube (510), a filling body (520), a steel ring hose (530), a first connector (540), and a second connector; the spring tube (510) is a circular tube structure formed by spirally winding steel bars; the filling body (520) is a circular tube structure formed by casting flexible rubber on the inside and outside of the spring tube (510); the steel ring hose (530) is a circular tube structure formed by integrally casting flexible rubber and a plurality of axially arranged steel rings; the steel ring hose (530) is coaxially arranged inside the filling body (520) and abuts against the inner wall of the filling body (520); one end of the flexible drill rod (500) is fixedly connected to a connecting ring (360) fixed to the end of the inner rotor (420) via the first connector (540); the other end of the flexible drill rod (500) is fixedly connected to the drill bit (600) via the second connector (550).

4. The dual-power system wireline coring drill tool for ultra-deep hole directional drilling according to claim 2, characterized in that: The coring mechanism (700) further comprises a fishing head (720), a guide head (730), a fixing portion (740) and a single turner (750); one end of the fishing head (720) is provided with a conical cap, the other end of the fishing head is fixedly connected to the fixing portion (740), and a water-blocking plug (760) is fixedly provided at the connection portion between the fishing head (720) and the fixing portion (740) to form a sealing fit with the inner wall of the motor rotor (220); the fixing portion (740) is connected to the fixing groove. Snap fit; the single rotator (750) consists of two rotating units rotatably connected via a rotating shaft, wherein one rotating unit is fixedly connected to the fixing portion (740), and the other rotating unit is fixedly connected to the core tube (710); one end of the guide head (730) is fixedly connected to the core tube (710), and the other end of the guide head (730) is a tapered cut end, and the guide head (730) is slidably fitted with the axially movable channel of the core mechanism (700) via a guide bearing (780).

5. The dual-power system wireline coring drill tool for ultra-deep hole directional drilling according to claim 4, characterized in that: Two fixing ears (770) are provided on the fixing portion (740), one end of the two fixing ears (770) is rotatably connected to the fixing portion (740) via a fixing shaft, and the other ends of the two fixing ears (770) are respectively unfolded to both sides and inserted into the fixing groove to form a snap fit, and the two fixing ears (770) are connected via a compression spring.

6. The dual-power system wireline coring drill tool for ultra-deep hole directional drilling according to claim 4, characterized in that: It also includes an electronic bin (800) arranged between the single rotator (750) and the coring tube (710); the two ends of the electronic bin (800) are fixedly connected to the single rotator (750) and the coring tube (710), respectively; a three-dimensional positioning device is provided in the electronic bin (800); the electronic bin (800) is slidably matched with the channel for axial movement of the coring mechanism (700) through a limit bearing (790).

7. The dual-power system wireline coring drill tool for ultra-deep hole directional drilling according to claim 6, characterized in that: The coring tube (710) is a flexible coring tube, which is a flexible circular tube structure formed by integrally casting flexible rubber and a plurality of axially arranged steel rings, with openings provided on the steel rings; the two ends of the flexible coring tube respectively form radial limiting fits with the electronic compartment (800) and the guide head (730) through limiting cutouts and are fixedly connected by bolts; the flexible coring tube bends and deforms synchronously with the flexible drill rod (500) when the flexible drill rod (500) is subjected to axial pressure.

8. The dual-power system wireline coring drill tool for ultra-deep hole directional drilling according to claim 6, characterized in that: The coring tube (710) is a rigid coring tube having a rigid circular tube structure. The two ends of the rigid coring tube respectively form radial limiting fits with the electronic compartment (800) and the guide head (730) through limiting cutouts and are fixedly connected by bolts. The rigid coring tube limits the flexible drill rod (500) from bending deformation when the flexible drill rod (500) is subjected to axial pressure.

9. A wireline coring method for ultra-deep hole directional drilling, characterized by: Using the dual-power system wireline coring drill tool for ultra-deep hole directional drilling according to any one of claims 1 to 8, the following steps are performed: Step 1: assemble a dual-power system rope coring drill for ultra-deep hole directional drilling, select a coring tube (710) according to the drilling purpose and characteristics of the drilling section, use a flexible coring tube when performing directional drilling, and use a rigid coring tube when performing linear drilling; Step 2: The straight drill rod (100) is fixedly connected to the drilling rig, and the coring mechanism (700) equipped with the rigid coring tube is placed inside the drilling tool and fixed through the fishing device. A vertical force is applied to the straight drill rod (100) through the drilling rig, and a high-pressure drilling slurry is input to the top of the drilling tool. The hollow motor (200) is driven to rotate by the drilling slurry, and the power of the hollow motor (400) is turned on at the same time so that the hollow motor (400) and the hollow motor (200) rotate synchronously, driving the drilling tool to continuously drill into the rock formation in a straight line, and the core enters the rigid coring tube. When the core capacity in the rigid coring tube is about to reach the upper limit, the drilling work of the drilling tool is stopped, and the coring mechanism is salvaged through the fishing device to remove the core in the rigid coring tube; Step 3, repeat the linear drilling and coring work of step 2, and increase the number of assembled straight drill rods (100) according to the change in drilling depth, until the linear drilling reaches the starting position of the directional drilling; Step 4: Remove the rigid coring tube from the coring mechanism (700) and replace it with a flexible coring tube; Step 5: Place the coring mechanism equipped with the flexible coring tube into the drill tool through the fishing device and fix it, apply an eccentric force opposite to the predetermined drilling direction to the straight drill rod (100) through the drilling rig, so that the flexible drill rod and the flexible coring tube are synchronously bent and deformed in the direction of the designed trajectory curve, input high-pressure drilling slurry at the top of the drill tool, drive the hollow motor (200) to rotate through the drilling slurry, and simultaneously connect the power supply of the hollow motor (400) to make the hollow motor (400) and the hollow motor (200) rotate synchronously, drive the drill tool to continuously bend and drill into the rock formation, and the core enters the flexible coring tube. When the core capacity in the flexible coring tube is about to reach the upper limit, stop the drilling work of the drill tool, salvage the coring mechanism through the fishing device, and take out the core in the flexible coring tube; Step 6: Repeat the directional drilling and coring work of step 5, and increase the number of assembled straight drill rods (100) according to the change in drilling depth, until the directional drilling reaches the predetermined directional bending target point; Step 7: Replace the flexible core tube with a rigid core tube, and repeat the linear drilling and coring work of step 2, and increase the number of assembled straight drill rods (100) according to the change in drilling depth, until the linear drilling reaches the predetermined depth; Step 8. Obtain the drilling trajectory of the drilling tool, analyze the actual drilling trajectory and determine the direction of directional drilling, compare the actual drilling trajectory curve with the designed drilling trajectory curve, determine the deviation direction and offset of the actual drilling trajectory, and correct the drilling direction; refer to the plumb bob profile of the actual drilling trajectory curve, if the drill bit in the actual drilling trajectory is located above the drill bit in the designed drilling trajectory, reduce the eccentric force applied by the drilling rig; if the drill bit in the actual drilling trajectory is located below the drill bit in the designed drilling trajectory, increase the eccentric force applied by the drilling rig; refer to the horizontal profile of the actual drilling trajectory curve, if the drill bit in the actual drilling trajectory is located to the left of the drill bit in the designed drilling trajectory, adjust the direction of the eccentric force applied by the drilling rig to the left; if the drill bit in the actual drilling trajectory is located to the right of the drill bit in the designed drilling trajectory, adjust the direction of the eccentric force applied by the drilling rig to the right; by adjusting the magnitude and direction of the eccentric force applied by the drilling rig, the actual drilling trajectory is returned to the designed drilling trajectory.

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