Continuous deflection coring drilling tool and method

Abstract

The present invention discloses a continuous deflection coring drill tool and method, which relates to the field of drilling soil or rock, and solves the problems of the existing drilling device in that the deflection direction is difficult to control and the core recovery rate is low. The technical solution adopted by the present invention is: a continuous deflection coring drill tool and method, including a deflection drill rod, a hollow motor and a drill bit. The deflection drill rod is divided into two sections, namely a first deflection drill rod and a second deflection drill rod. The first deflection drill rod, the deflection mechanism, the hollow motor and the drill bit are connected in series in sequence to form a coring cavity; the deflection mechanism includes an inner tube and an outer tube, an annular cavity is formed between the inner tube and the outer tube, and the two ends of the annular cavity are respectively sealed. A direction adjustment motor for driving the outer tube to rotate around the inner tube is installed between the inner tube and the outer tube, and the inner wall of the outer tube is installed with a deflection motor and an ejection device. The ejection device is provided with an ejection member driven by the deflection motor and can be ejected to the outside of the outer wall of the outer tube and retracted into the outer wall of the outer tube. The present invention can perform both linear drilling and directional deflection drilling.

Description

Technical Field

[0001] The present invention relates to the field of soil or rock drilling, in particular to a device for extracting undisturbed rock cores, specifically to a continuous deflection coring drill tool and method. Background Art

[0002] Commonly used engineering drilling methods include vertical drilling, inclined drilling, and horizontal drilling. These three types of drilling technologies all fall under the category of linear drilling. Linear drilling has been widely used due to its relatively low construction cost and simple structure. However, due to its simple structure, it lacks components that create inclination and cannot bend during drilling. It can only be used for linear drilling and has a limited scope of application. With the development of my country's water conservancy, hydropower, railway and other infrastructure projects, there is a need to conduct curved drilling across rivers or drilling along the axis of hydraulic tunnels. Research on directional coring technology that can achieve curved drilling has gradually begun.

[0003] Curved drilling technology has made some progress in the field of petroleum engineering exploration. However, petroleum engineering exploration is drilling without taking cores, which is essentially different from drilling in water conservancy and hydropower projects that require taking cores. Therefore, this technology cannot be applied to drilling that requires taking cores.

[0004] At present, the existing directional coring drilling equipment mainly achieves directional coring drilling by adding an eccentric component to the outside of the drill pipe. The eccentric component has a protrusion that pushes the wall of the drill hole. The reaction force of the hole wall causes the rigid drill pipe to bend slightly, thereby achieving directional coring drilling. There are many problems with the directional deflection coring drilling device, which mainly include: first, the eccentric component is coaxial with the drill pipe. When the drill pipe is lowered, the eccentric component and the drill pipe rotate synchronously. Due to the lack of measures to position and control the direction of the eccentric component, it is difficult to ensure that the protrusion is in the preset position, resulting in the wrong bending direction of the drill pipe; second, the volume of the eccentric component is relatively large, and engineering drilling also requires core sampling, and the eccentric component causes the coring channel to be extremely small; third, the structure of the eccentric component is complex. Since the drilling that requires core sampling is water drilling, the eccentric component is easily damaged in drilling environments such as water, rock chips, and mud; fourth, the protrusion of the eccentric component is limited in length, the deflection amplitude is small, and the deflection efficiency is low; fifth, drilling uses orifice power. When the drilling depth is large, the drilling power is insufficient and the drill pipe is severely worn; sixth, there is no special rope coring device in the drill pipe for directional deflection drilling, the core sampling rate is low, and the core is easily broken and damaged. Summary of the Invention

[0005] The present invention firstly provides a continuous deflection coring drill tool, which solves the problems of difficult control of deflection direction and low core sampling rate of existing drilling devices.

[0006] The technical solution adopted by the present invention is: a continuous deflection coring drill tool, including a deflection drill rod, a deflection mechanism, a hollow motor and a drill bit, the deflection drill rod is divided into two sections, namely a first deflection drill rod and a second deflection drill rod, the central axes of the two sections of the deflection drill rod are set vertically, the deflection drill rod includes a spring tube in the middle, and an upper joint tube and a lower joint tube fixedly connected to the upper and lower ends of the spring tube, the spring tube includes a flexible tube body and a skeleton embedded in the flexible tube body, or the spring tube includes a skeleton and a stainless steel woven mesh layer fixed to the skeleton, the skeleton is a spring-shaped pipe formed by tightly winding or intermittently winding steel bars; the lower joint tube of the first deflection drill rod and the upper joint tube of the second deflection drill rod are connected by the deflection mechanism, the lower joint tube of the second deflection drill rod is connected to the hollow motor, the lower end of the hollow motor is an output end and is connected to the drill bit, and the interior of the first deflection drill rod, the deflection mechanism, the second deflection drill rod, the hollow motor and the drill bit form a continuous and cylindrical coring cavity;

[0007] The inclination mechanism includes an inner tube and an outer tube, both of which are hollow tubular structures. The upper end of the inner tube is provided with an upper joint tube and is connected to the lower joint tube of the first inclination drill rod, and the lower end of the inner tube is provided with a lower joint tube and is connected to the upper joint tube of the second inclination drill rod; an annular cavity is formed between the inner tube and the outer tube, and sealing members are respectively provided at the upper and lower ends of the annular cavity, a first bearing is provided between the inner tube and the outer tube, and a direction adjustment motor for driving the outer tube to rotate around the inner tube is installed between the inner tube and the outer tube; an inclination motor and an ejection device are installed on the inner wall of the outer tube, and the drive shaft of the inclination motor is in transmission connection with the ejection device, and the ejection device is provided with an ejection member driven by the inclination motor, which can be ejected to the outside of the outer wall of the outer tube and retracted into the outer wall of the outer tube.

[0008] In order to facilitate the connection between the deflection drill rod and the straight drill rod, the connection between the deflection drill rod and the inner tube of the deflection mechanism, and the connection between the deflection drill rod and the hollow motor, it is further provided that: the upper and lower ends of the skeleton of the spring tube of the deflection drill rod are fixedly connected to the upper joint tube and the lower joint tube respectively, the upper joint tube and the lower joint tube of the deflection drill rod are adapted to each other, the upper joint tube and the lower joint tube at the upper and lower ends of the inner tube of the deflection mechanism are adapted to each other, and one of the mutually adapted upper joint tube and lower joint tube is an externally threaded joint tube, and the other is an internally threaded joint tube.

[0009] The directional adjustment motor is used to adjust the direction of the ejection mechanism, thereby adjusting the bending direction of the deflection drill pipe when the ejection member pushes against the borehole wall. Specifically, the directional adjustment motor is fixedly mounted on the outer wall of the inner tube of the deflection mechanism. A ring gear is fixed horizontally to the inner wall of the outer tube. The drive shaft of the directional adjustment motor is equipped with a gear that meshes with the ring gear.

[0010] In order to facilitate monitoring the direction of the ejection device, further: a direction monitor is fixedly installed on the inner wall of the outer tube.

[0011] In order to reduce the requirements for the slanting motor, further: the slanting motor is fixedly installed on the inner wall of the outer tube, the transmission shaft of the slanting motor is transmitted and matched with the ejector of the ejection device through a reduction gear set, the outer tube is provided with an ejection hole adapted to the ejection part, the ejection part is located in the ejection hole and sealed with the hole wall of the ejection hole, and the ejection part is arranged along the radial direction of the outer tube.

[0012] The hollow motor is directly connected to the drill bit and drives its rotation, reducing power loss through bottomhole power. Specifically, the hollow motor consists of a stator and a rotor outside the stator. The stator is a hollow tubular structure with open ends. The upper end of the stator is provided with a stator joint and is fixedly connected to the lower joint pipe of the second deflection drill pipe. The lower end of the rotor is provided with a rotor joint and is fixedly connected to the drill bit. A sealing ring and a second bearing are provided between the stator and rotor. The second bearing is located in the sealed cavity formed by the stator, rotor, and sealing ring.

[0013] The coring chamber is used to accommodate a rope coring device for obtaining cores. Furthermore, the continuous deflection coring drill tool also includes a rope coring device installed in the coring chamber. The rope coring device includes a coring tube and a limiting mechanism connected to the upper end of the coring tube. The coring tube includes a flexible tube body and a frame embedded in the flexible tube body. The frame is a spiral steel wire. The limiting mechanism is provided with a fishing head at the top, and the outer periphery of the limiting mechanism is provided with a latch for engaging with a slot on the inner side of the straight drill pipe.

[0014] In order to facilitate the sliding and removal of the rope coring device in the coring cavity, further: at least one slide is provided on the outside of the coring tube, the slide is provided with a ball groove, balls are installed in the ball groove, and the balls roll with the cavity wall of the coring cavity; the lower end of the coring tube is fixedly connected to the guide tube, and a slide and balls are provided on the outside of the guide tube.

[0015] The present invention also provides a continuous deflection coring method, which also solves the problems of difficulty in controlling the deflection direction and low core recovery rate of existing drilling devices. The technical solution adopted by the present invention is that the continuous deflection coring method, using any of the above-mentioned continuous deflection coring drill tools to drill and coring, includes the following steps:

[0016] S1. Securely connect the upper end of the straight drill pipe to the orifice drill rig, securely connect the lower end of the straight drill pipe to the upper joint of the first deflection drill pipe, and place the rope coring device in the coring cavity and secure it. To facilitate securing and removing the rope coring device, a retaining groove is provided on the inner side of the lower end of the straight drill pipe. The rope coring device includes a coring tube and a limiting mechanism connected to the upper end of the coring tube. The limiting mechanism has a fishing head at the top and latches on the outer periphery of the limiting mechanism. Once the rope coring device is placed in the coring cavity, the latches automatically snap into the retaining grooves.

[0017] S2. Adjust the orientation of the ejector device using the directional motor, control the two sections of the deflection drill pipe to form a straight or curved shape using the deflection motor, apply pressure to the straight drill pipe using the orifice drill rig, and use the hollow motor to drive the drill bit to rotate, causing the drill bit to break through the rock and drill. When the core fills the core tube of the wireline coring device, stop drilling, remove the wireline coring device, and obtain the core.

[0018] S3. Place the rope coring device into the coring cavity and secure it, and repeat step S2 until the target position is reached.

[0019] In order to control the actual drilling trajectory to be consistent with the predetermined drilling trajectory, further steps are as follows: before placing the rope coring device into the coring cavity, in step S3, a drilling inclinometer is placed into the coring cavity and the drilling trajectory from the hole mouth to the bottom of the hole is tested, and the posture of the two sections of the deflection drill rod is adjusted accordingly through the deflection motor.

[0020] The present invention has the following beneficial effects: a continuous-deflection coring drill tool can perform both linear and directional deflection drilling, enabling a single set of drill tools to simultaneously perform both drilling functions. The deflection motor can control the ejector assembly to retract back into the outer wall of the outer tube, where it does not push against the borehole wall. The centerline of the two sections of deflection drill rod forms a straight line, enabling linear drilling. The deflection motor can also control the ejector assembly to extend beyond the outer wall of the outer tube, where it pushes against the borehole wall. The centerline of the two sections of deflection drill rod forms a curved line, enabling directional deflection drilling.

[0021] The spring tube of the deflection drill pipe is bent into an arc or near-arc shape, minimizing the impact on coring operations, reducing the risk of core breakage, facilitating coring, and improving core recovery efficiency. The deflection motor controls both the bending of the two sections of the deflection drill pipe and the degree of bending. This simple operation ensures a stable posture for the two sections, allowing for quick adjustment of the bending degree. The directional adjustment motor controls the direction of the ejection device, facilitating adjustment of the bending direction of the two sections to meet various directional deflection drilling requirements.

[0022] The hollow motor is connected to the lower end of the second deflection drill rod. The hollow motor has a hollow tubular structure and has no effect on coring operations. It directly drives the drill bit at the bottom of the borehole, minimizing power loss. This avoids the significant friction between the drill rod and the borehole wall, which can lead to significant wear and tear, as well as significant power loss, during the drilling process when the drill rod and drill bit are rotated by a hole drill. Therefore, the present invention can be used for ultra-deep hole drilling and achieves high drilling efficiency.

[0023] During the drilling process, the deflection drill rod, deflection mechanism and drill bit do not need to be taken out of the borehole. The deflection drill rod, deflection mechanism and drill bit are only taken out when the drill bit needs to be replaced. The entire drilling process is simple to operate and has low implementation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of an embodiment of the continuous deflection coring drilling tool of the present invention in a natural state.

[0025] Figure 2 yes Figure 1 An enlarged view of the tilting mechanism in the illustrated embodiment.

[0026] Figure 3 yes Figure 1 Schematic diagram of the embodiment shown in section AA.

[0027] Figure 4 yes Figure 1 The illustrated embodiment is a schematic structural diagram in a directional drilling state.

[0028] Figure markings: first deflection drill pipe 1a, second deflection drill pipe 1b, upper joint pipe 1-1, spring tube 1-2, lower joint pipe 1-3, deflection mechanism 2, inner tube 2-1, outer tube 2-2, seal 2-3, first bearing 2-4, direction adjustment motor 2-5, deflection motor 2-6, ejection device 2-7, ring gear 2-8, direction monitor 2-9, reduction gear set 2-10, hollow motor 3, stator 3-1, rotor 3-2, stator joint 3-3, rotor joint 3-4, sealing ring 3-5, second bearing 3-6, drill bit 4, core pipe 5-1, limit mechanism 5-2, fishing head 5-2-1, ear 5-2-2, slide 5-3, ball 5-4, guide pipe 5-5, straight drill pipe 6, protective tube 7. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] The first subject of the present invention is a continuous deflection coring tool. Figure 1 and Figure 4 The continuous deflection coring drill tool includes a deflection drill rod, a deflection mechanism 2, a hollow motor 3, and a drill bit 4. The deflection drill rod is divided into two sections, namely the first deflection drill rod 1a and the second deflection drill rod 1b, which are connected by the deflection mechanism 2. The continuous deflection coring drill tool has two states: a natural state and a directional drilling state. In the natural state, the central axes of the first deflection drill rod 1a, the deflection mechanism 2, and the second deflection drill rod 1b are straight and coincident. Figure 1 In the directional drilling state, the central axis of the first deflection drill rod 1a, the deflection mechanism 2 and the second deflection drill rod 1b is a curve, see Figure 2. For the convenience of description, it is assumed that in the natural state, the central axes of the two sections of the deflection drill rod are both vertical, that is, the central axes of the two sections of the deflection drill rod are both vertical and coincident, and the deflection drill rod includes a spring tube 1-2 in the middle, and an upper joint tube 1-1 and a lower joint tube 1-3 fixedly connected to the upper and lower ends of the spring tube 1-2. The upper and lower ends of the deflection mechanism 2 are also respectively provided with an upper joint tube and a lower joint tube, and the upper joint tube 1-1 and the lower joint tube 1-3 of the deflection drill rod, as well as the upper joint tube and the lower joint tube of the deflection mechanism 2 all play a connecting role. The upper joint tube 1-1 of the first deflection drill rod 1a is used to connect with the straight drill rod 6, the lower joint tube 1-3 of the first deflection drill rod 1a is connected to the upper joint tube of the deflection mechanism 2, the lower joint tube of the deflection mechanism 2 is connected to the upper joint tube 1-1 of the second deflection drill rod 1b, and the lower joint tube 1-3 of the second deflection drill rod 1b is connected to the hollow motor 3. To facilitate the connection of the deflection drill pipe to the straight drill pipe 6, the connection of the deflection drill pipe to the deflection mechanism 2, specifically the connection of the deflection drill pipe to the inner tube 2-1 of the deflection mechanism 2, and the connection of the deflection drill pipe to the hollow motor 3, the upper joint pipe 1-1 and the lower joint pipe 1-3 of the deflection drill pipe are mutually adapted, and the upper and lower joint pipes at the upper and lower ends of the deflection mechanism 2 are mutually adapted. Generally, one of the mutually adapted upper and lower joint pipes is an externally threaded joint pipe, and the other is an internally threaded joint pipe. The upper and lower ends of the two sections of deflection drill pipe can be interchanged.

[0031] The deflection drill rod is a hollow circular tube structure with both ends open. The main part of the deflection drill rod is a spring tube 1-2, which includes a flexible tube body and a skeleton embedded in the flexible tube body. The skeleton is a spring-shaped tube formed by spirally winding steel bars. The steel bars can be tightly wound when they are spirally wound, that is, there is no gap between two adjacent circles of steel bars. In the natural state, there is no gap between two adjacent circles of steel bars and they are directly in contact. The steel bars can also be wound at intervals when they are spirally wound, that is, a gap is reserved between two adjacent circles of steel bars. In the natural state, there is a gap between two adjacent circles of steel bars and they are not directly in contact. The flexible tube body plays the role of closing the gaps and cracks of the skeleton, so that the spring tube 1-2 will not leak when the central axis is a straight line or a curve. The flexible tube body is arranged on the inside or outside of the skeleton, or on both the inside and outside of the skeleton. When the flexible tube body is only arranged on the inner side of the skeleton, the inner wall of the spring tube 1-2 is flat; when the flexible tube body is only arranged on the outer side of the skeleton, the outer wall of the spring tube 1-2 is flat; when the flexible tube body is arranged on the outer side and the outer side of the skeleton, the inner and outer walls of the spring tube 1-2 are both flat. The flexible tube body is generally combined with the skeleton by injection molding to form a complete spring tube 1-2. The flexible tube body is generally made of a polymer material with good wear resistance, such as rubber. During drilling, the straight drill rod 10 needs to apply pressure to the first deflection drill rod 1a and transmit it to the drill bit 4. In order to make the first deflection drill rod 1a transmit pressure more stably, the skeleton of the spring tube 1-2 is preferably tightly wound with steel bars. The upper joint tube 1-1 and the lower joint tube 1-3 at the upper and lower ends of the spring tube 1-2 both play a connecting role. In order to firmly connect the spring tube 1-2 to the upper joint tube 1-1 and to firmly connect the spring tube 1-2 to the lower joint tube 1-3, the upper and lower ends of the skeleton are fixedly connected to the upper joint tube 1-1 and the lower joint tube 1-3 respectively, for example, by welding.

[0032] Another embodiment of the spring tube 1-2 for making an inclined drill pipe is provided below. The spring tube 1-2 includes a skeleton and a stainless steel braided mesh layer fixed to the skeleton. The skeleton is a spring-shaped tube formed by spirally winding steel bars. The steel bars can be tightly wound or spaced apart during spiral winding. The stainless steel braided mesh layer is fixed to the inside or outside of the skeleton, or to both the inside and outside of the skeleton. The upper and lower ends of the stainless steel braided mesh layer are preferably fixedly connected to the upper joint tube 1-1 and the lower joint tube 1-3, respectively. The stainless steel braided mesh layer can produce synchronous deformation when the skeleton is bent and deformed. The stainless steel braided mesh layer on the outside of the skeleton can also withstand friction with the borehole wall during drilling, reducing the wear of the skeleton. The stainless steel braided mesh layer also plays an isolating role to prevent the movement of materials inside and outside the skeleton in the gaps of the spring tube.

[0033] The lower joint pipe 1-3 of the first deflection drill pipe 1a is connected to the upper joint pipe 1-1 of the second deflection drill pipe 1b via a deflection mechanism 2. The deflection mechanism 2 pushes against the borehole wall, which generates a reaction force on the deflection mechanism 2. The first deflection drill pipe 1a, the deflection mechanism 2, and the second deflection drill pipe 1b bend under the action of this reaction force, thereby achieving directional deflection drilling. Figure 1 、 Figure 3 and Figure 4 As shown, the deflection mechanism 2 includes an inner tube 2-1 and an outer tube 2-2. Both inner tube 2-1 and outer tube 2-2 are hollow tubular structures. The inner tube 2-1 is longer than the outer tube 2-2. The upper end of the inner tube 2-1 is provided with an upper joint pipe and is connected to the lower joint pipe 1-3 of the first deflection drill pipe 1a. The lower end of the inner tube 2-1 is provided with a lower joint pipe and is connected to the upper joint pipe 1-1 of the second deflection drill pipe 1b. The upper and lower ends of the inner tube 2-1 are generally connected by a threaded connection. The inner diameter of the outer tube 2-2 is larger than the outer diameter of the inner tube 2-1. An annular cavity is formed between the inner tube 2-1 and the outer tube 2-2. That is, the axes of the inner tube 2-1 and the outer tube 2-2 coincide, forming an annular cavity. Seals 2-3 are provided at the upper and lower ends of the annular cavity. The seals 2-3 are generally sealing rings, but can also be sealing end caps. For example, the seals 2-3 are rubber sealing rings. A first bearing 2-4 is provided between the inner tube 2-1 and the outer tube 2-2, allowing the outer tube 2-2 to rotate about the inner tube 2-1. For example, the first bearing 2-4 is a deep groove ball bearing. There are one or more first bearings 2-4, typically two, arranged at the upper and lower ends of the annular cavity. The first bearings 2-4 are preferably located inside the seal 2-3, that is, within the sealed annular cavity formed by the outer wall of the inner tube 2-1, the inner wall of the outer tube 2-2, and the seal 2-3.

[0034] A steering motor 2-5 is installed between the inner tube 2-1 and the outer tube 2-2 of the deflection mechanism 2 to drive the outer tube 2-2 to rotate around the inner tube 2-1. The steering motor 2-5 is located in a sealed annular cavity surrounded by the outer wall of the inner tube 2-1, the inner wall of the outer tube 2-2, and the sealing member 2-3. The steering motor 2-5 is used to adjust the direction of the outer tube 2-2 and the ejection device 2-7 installed on the inner wall of the outer tube, thereby adjusting the bending direction of the deflection drill pipe during directional drilling. The steering motor 2-5 is installed on the outer wall of the inner tube 2-1 or the inner wall of the outer tube 2-2. For example, see Figure 1 、 Figure 3 and Figure 4 The outer wall of the inner tube 2-1 of the inclination mechanism 2 is fixedly installed with a steering motor 2-5, and the inner wall of the outer tube 2-2 is fixed with a circle of ring gear 2-8 in the horizontal direction. The transmission shaft of the steering motor 2-5 is provided with a gear and meshes with the ring gear 2-8.

[0035] A slanting motor 2-6 and an ejector 2-7 are mounted on the inner wall of the outer tube 2-2 of the slanting mechanism 2. The drive shaft of the slanting motor 2-6 is in driving connection with the ejector 2-7. The ejector 2-7 includes an ejector member, whose extension and retraction are controlled by the slanting motor 2-6. The ejector member can be ejected out of the outer wall of the outer tube 2-2 or retracted into the outer wall of the outer tube 2-2. The ejector is retracted into the outer wall of the outer tube 2-2. There is no force between the ejector and the wall of the borehole. The central axes of the first deflection drill rod 1a, the deflection mechanism 2, and the second deflection drill rod 1b are straight and coincident. At this time, it is suitable for linear drilling. The ejector is ejected outside the outer wall of the outer tube 2-2. The ejector pushes the wall of the borehole. The wall of the borehole generates a reaction force on the ejector. The first deflection drill rod 1a, the deflection mechanism 2, and the second deflection drill rod 1b bend under the action of the reaction force. At this time, it is suitable for directional deflection drilling. The outer tube 2-2 is provided with a push hole adapted for the ejector. The ejector is located in the push hole and is sealed with the wall of the push hole. The ejector is arranged along the radial direction of the outer tube 2-2. The drive shaft of the deflection motor 2-6 can directly drive or indirectly drive the ejector. In order to reduce the requirements for the deflection motor 2-6, the drive shaft of the deflection motor 2-6 is connected through a reduction transmission structure. See Figure 1 、 Figure 3 and Figure 4 The inclination motor 2-6 is fixedly mounted on the inner wall of the outer tube 2-2, and the transmission shaft of the inclination motor 2-6 is matched with the ejector of the ejection device 2-7 through the reduction gear set 2-10. For example, the reduction gear set 2-10 is two meshing bevel gears.

[0036] In order to facilitate monitoring the direction of the ejection device 2-7, a direction monitor 2-9 is fixedly installed on the inner wall of the outer tube 2-2. The direction monitor 2-9 is preferably arranged radially with the ejection device 2-7, such as Figure 1 and Figure 4 As shown, the direction monitor 2-9 is conventional, and for example, primarily comprises a triaxial accelerometer, a triaxial magnetic field meter, and a gyroscope. The direction monitor 2-9 is used to measure its spatial coordinates, thereby reflecting the orientation of the ejector of the ejection device 2-7. The direction monitor 2-9, in conjunction with the steering motor 2-5, accurately rotates the ejector of the ejection device 2-7 to the desired orientation and deflection direction.

[0037] The lower joint pipe 1-3 of the second deflection drill rod 1b is connected to the hollow motor 3, the lower end of which is the output end and is connected to the drill bit 4. The hollow motor 3 provides power for drilling. The middle part of the hollow motor 3 is a hollow structure to avoid affecting the coring. Figure 1 、 Figure 3 and Figure 4The hollow motor 3 includes a stator 3-1 and a rotor 3-2 outside the stator 3-1. Components such as magnets and coils are also provided between the stator 3-1 and the rotor 3-2. The stator 3-1 is a hollow tubular structure. The inner diameter of the stator 3-1 is consistent with the inner diameter of the lower joint tube 1-3 of the second deflection drill pipe 1b. The upper and lower ends of the stator 3-1 are both open. A stator joint 3-3 is provided at the upper end of the stator 3-1. The stator joint 3-3 is fixedly connected to the lower joint tube 1-3 of the second deflection drill pipe 1b. The stator joint 3-3 is generally connected to the lower joint tube 1-3 of the second deflection drill pipe 1b by a threaded connection. The stator joint 3-3 can be a part of the stator 3-1 or a joint fixedly installed at the upper end of the stator 3-1. A sealing ring 3-5 and a second bearing 3-6 are provided between the stator 3-1 and the rotor 3-2. The sealing ring 3-5 comprises an upper sealing ring and a lower sealing ring. The second bearing 3-6 is located within the sealed cavity formed by the stator 3-1, the rotor 3-2, and the sealing ring 3-5. The sealing ring 3-5 is used to prevent groundwater, mud, and other objects from entering the interior of the hollow motor 3. For example, the sealing ring 3-5 may be a rubber sealing ring. An alternative to the sealing ring 3-5 is to provide sealing end caps at the top and bottom of the hollow motor 3. The second bearing 3-6 ensures smooth rotation of the rotor 3-2 and must be able to withstand axial pressure. A rotor joint 3-4 is provided at the lower end of the rotor 3-2 and is fixedly connected to the drill bit 4. The rotor joint 3-4 can be a part of the rotor 3-2 or a joint fixedly mounted at the lower end of the rotor 3-2. The upper end of the drill bit 4 is provided with a threaded interface that mates with the rotor joint 3-4, and the lower end of the drill bit 4 is provided with cutting teeth for grinding rock. The drill bit 4 is a hollow cylindrical structure, and the function of the drill bit 4 is to grind the rock to separate the rock inside and outside the drill bit 4.

[0038] In a natural state, a continuous and cylindrical coring cavity is formed inside the first deflection drill rod 1a, the deflection mechanism 2, the second deflection drill rod 1b, the hollow motor 3 and the drill bit 4. The coring cavity is used to place a rope coring device to obtain rock cores. The continuous deflection coring drill tool of the present invention also includes a rope coring device installed in the coring cavity. The rope coring device includes a coring tube 5-1 and a limiting mechanism 5-2 connected to the upper end of the coring tube 5-1. The coring tube 5-1 is directly or indirectly fixedly connected to the limiting mechanism 5-2. For example, an upper guide tube is fixed to the upper end of the coring tube 5-1, and the upper guide tube is threadedly connected to the limiting mechanism 5-2, such as Figure 1 and Figure 4As shown. The core tube 5-1 is used to store cores. The core tube 5-1 has a certain strength and can be deformed to adapt to the posture changes of the first deflection drill rod 1a, the deflection mechanism 2 and the second deflection drill rod 1b, solve the problem of easy breakage and damage of cores in directional deflection drilling, and improve the core recovery rate. The outer diameter of the core tube 5-1 is smaller than the diameter of the core cavity, ensuring that the core tube 5-1 can be smoothly placed in and taken out of the core cavity. The lower end of the core tube 5-1 is a free end, which is placed on the base of the inner wall of the drill bit 4. For example, the core tube 5-1 includes a flexible tube body and a skeleton embedded in the flexible tube body. The skeleton is a spiral steel wire, which is formed by injection molding on the inside and outside of the spiral skeleton through a mold. The flexible tube body of the core tube 5-1 is generally a polymer material, such as rubber. The inner and outer walls of the core tube 5-1 are straight and smooth, and can bend and deform with the bending changes of the two sections of the deflection drill rod. The flexible tube body keeps the coring tube 5-1 closed at all times, preventing the core from being exposed outside the coring tube 5-1. The limiting mechanism 5-2 is used to lower and remove the coring tube 5-1 and to secure it in a suitable position. A fishing head 5-2-1 is provided on the top of the limiting mechanism 5-2. The fishing head 5-2-1 is used to lower the rope coring device into the coring chamber and secure it. The fishing head 5-2-1 is generally a conical head, and can be salvaged and released using a fishing device. The outer periphery of the limiting mechanism 5-2 is provided with a clamping ear 5-2-2 for engaging with the clamping groove on the inner side of the straight drill pipe 6. The clamping ears 5-2-2 are generally two and symmetrically arranged. The clamping ears 5-2-2 are equipped with components such as a rotating shaft and an opening spring. The opening spring can open the clamping ear 5-2-2, and the rotating shaft can rotate the clamping ear 5-2-2.

[0039] In order to facilitate the sliding and removal of the rope coring device in the coring cavity, at least one slide 5-3 is set on the outside of the coring tube 5-1. The slide 5-3 is arranged in a ring shape and has a ball groove. The ball 5-4 is installed in the ball groove. The ball 5-4 rolls with the cavity wall of the coring cavity. In order to facilitate the lowering of the coring tube 5-1, the lower end of the coring tube 5-1 is fixedly connected to the guide tube 5-5, and the slide 5-3 and the ball 5-4 are set on the outside of the guide tube 5-5. For example, see Figure 1 and Figure 4 , a circle of slides 5-3 are respectively provided at the upper and lower ends of the core tube 5-1, and a circle of slides 5-3 includes at least three slides 5-3. The guide tube 5-5 at the lower end of the core tube 5-1 can also prevent the core tube 5-1 from rotating synchronously when the hollow motor 3 rotates. In order to facilitate the lowering of the core tube 5-1 into the core cavity, a tapered cutout is provided on the outer side of the lower end of the guide tube 5-5 at the lower end of the core tube 5-1, such as Figure 1 and Figure 4As shown, the upper end of the coring tube 5-1 can be directly or indirectly connected to the limiting mechanism 5-2. For example, an upper guide tube can be provided at the upper end of the coring tube 5-1, which is threadedly connected to the limiting mechanism 5-2. A sliding seat 5-3 is provided around the outer circumference of the upper guide tube. Furthermore, the upper end of the coring tube 5-1 and the limiting mechanism 5-2 can be connected via a single-rotator. The function of the single-rotator is to prevent the limiting mechanism 5-2 from rotating even if the coring tube 5-1 rotates.

[0040] The second subject of the present invention is a continuous deflection coring method. The continuous deflection coring method utilizes the continuous deflection coring drill tool described in the first subject to perform drilling and coring, and includes the following steps.

[0041] S1. The upper end of the straight drill rod 6 is fixedly connected to the hole drill rig, the lower end of the straight drill rod 6 is fixedly connected to the upper joint pipe 1-1 of the first deflection drill rod 1a, and the rope coring device is placed in the coring cavity and fixed.

[0042] The drill rod 6 is a hollow rod that can undergo minor bending deformation under external forces. The upper and lower ends of the drill rod 6 are provided with mutually compatible threaded interfaces. Depending on the depth of the drill hole, there may be one or more drill rods 6. When there are multiple drill rods 6, the rods are connected in series. The drill rod 6 primarily transmits tension and compression. The wires for the directional motor 2-5, the deflection motor 2-6, the direction monitor 2-9, and the hollow motor 3 can pass through the drill rod 6 and exit the hole from the upper end, or they can be located outside the drill rod 6 and exit the hole. To better protect the wires, a protective tube is placed on the outside of the drill rod 6, with the wires located between the inner wall of the protective tube and the outer wall of the drill rod 6. The drill rod 6 also forms a channel for the flow of drilling slurry and for wireline coring. The outer diameter of the drill rod 6 is less than or equal to the outer diameter of the deflection drill rod, and the inner diameter of the drill rod 6 is equal to the diameter of the coring cavity. In order to facilitate the positioning of the direction of the straight drill rod 6, vertical stripes are preferably provided on the outer wall of the straight drill rod 6.

[0043] To facilitate the attachment and removal of the wireline coring device, a slot for engaging the wireline coring device is provided on the inner side of the lower end of the straight drill rod 6, which is directly connected to the first deflection drill rod 1a. The wireline coring device comprises a coring tube 5-1 and a stopper mechanism 5-2 connected to the upper end of the coring tube 5-1. A fishing head 5-2-1 is located at the top of the stopper mechanism 5-2, and latches 5-2-2 are located on the outer periphery of the stopper mechanism 5-2. Once the wireline coring device is placed in the coring chamber, the latches 5-2-2 automatically engage with the slots.

[0044] S2. Adjust the orientation of the ejection device 2-7 by adjusting the direction motor 2-5, control the two sections of the deflection drill pipe to be straight or curved by the deflection motor 2-6, then apply pressure to the straight drill pipe 6 by the hole drilling rig, and use the hollow motor 3 to drive the drill bit 4 to rotate, so that the drill bit 4 breaks the rock and drills; when the core fills the core tube 5-1 of the wireline coring device, stop drilling, remove the wireline coring device, and obtain the core.

[0045] There are two drilling processes: linear drilling and directional drilling. During linear drilling, the central axes of the straight drill rod 6, the first deflection drill rod 1a, the deflection mechanism 2, the second deflection drill rod 1b, the hollow motor 3, and the drill bit 4 coincide. During directional drilling, the first deflection drill rod 1a, the deflection mechanism 2, the second deflection drill rod 1b, and the hollow motor 3 are adjusted to a curved shape by adjusting the position of the ejection device 2-7 of the directional motor 2-5 and adjusting the posture of the first deflection drill rod 1a, the deflection mechanism 2, and the second deflection drill rod 1b via the deflection motor 2-6.

[0046] S3. Place the rope coring device into the coring cavity and secure it, and repeat step S2 until the target position is reached.

[0047] To ensure that the actual drilling trajectory aligns with the planned trajectory, in step S3, before placing the wireline coring device into the coring chamber, a borehole inclinometer is placed into the coring chamber to measure the drilling trajectory from the hole mouth to the bottom. Based on this measurement, the deflection motor 2-6 adjusts the posture of the two sections of deflection drill rod. The measured drilling trajectory is compared with the planned trajectory. If the drilling direction deviates, the deflection motor 2-6 is adjusted to rotate forward or reverse to increase or decrease the bending of the two sections of deflection drill rod accordingly, thereby correcting the deviation during drilling.

Claims

1. A continuous deflection coring drill tool, comprising a deflection drill rod, a deflection mechanism (2), a hollow motor (3) and a drill bit (4), characterized in that: The deflection drill rod is composed of two sections, namely a first deflection drill rod (1a) and a second deflection drill rod (1b). The central axes of the two sections of the deflection drill rod are set vertically. The deflection drill rod includes a spring tube (1-2) in the middle, and an upper joint tube (1-1) and a lower joint tube (1-3) fixedly connected to the upper and lower ends of the spring tube (1-2). The spring tube (1-2) includes a flexible tube body and a skeleton embedded in the flexible tube body, or the spring tube (1-2) includes a skeleton and a stainless steel braided mesh layer fixed to the skeleton. The skeleton is a steel bar tightly wound or spaced wound shape. The spring-shaped pipe is formed; the lower joint pipe (1-3) of the first deflection drill rod (1a) and the upper joint pipe (1-1) of the second deflection drill rod (1b) are connected via a deflection mechanism (2); the lower joint pipe (1-3) of the second deflection drill rod (1b) is connected to a hollow motor (3); the lower end of the hollow motor (3) is an output end and is connected to a drill bit (4); the first deflection drill rod (1a), the deflection mechanism (2), the second deflection drill rod (1b), the hollow motor (3) and the drill bit (4) form a continuous and cylindrical coring cavity inside; The deflection mechanism (2) comprises an inner tube (2-1) and an outer tube (2-2), both of which are hollow tubular structures. The upper end of the inner tube (2-1) is provided with an upper joint tube and is connected to the lower joint tube (1-3) of the first deflection drill rod (1a), and the lower end of the inner tube (2-1) is provided with a lower joint tube and is connected to the upper joint tube (1-1) of the second deflection drill rod (1b); an annular cavity is formed between the inner tube (2-1) and the outer tube (2-2), and sealing members (2-3) are respectively provided at the upper and lower ends of the annular cavity. The inner tube (2-1) and the outer tube (2-2) are provided with a plurality of sealing members. A first bearing (2-4) is provided between the inner tube (2-1) and the outer tube (2-2); a direction adjustment motor (2-5) for driving the outer tube (2-2) to rotate around the inner tube (2-1) is installed between the inner tube (2-1) and the outer tube (2-2); a deflection motor (2-6) and an ejection device (2-7) are installed on the inner wall of the outer tube (2-2); a transmission shaft of the deflection motor (2-6) is transmission-connected to the ejection device (2-7); the ejection device (2-7) is provided with an ejection member, which is driven by the deflection motor (2-6) and ejected to the outside of the outer wall of the outer tube (2-2) and retracted into the outer wall of the outer tube (2-2).

2. The continuous deflection coring drill according to claim 1, characterized in that: The upper and lower ends of the skeleton of the spring tube (1-2) of the deflection drill pipe are fixedly connected to the upper joint pipe (1-1) and the lower joint pipe (1-3) respectively. The upper joint pipe (1-1) and the lower joint pipe (1-3) of the deflection drill pipe are adapted to each other. The upper joint pipe and the lower joint pipe at the upper and lower ends of the inner tube (2-1) of the deflection mechanism (2) are adapted to each other. One of the mutually adapted upper joint pipe and lower joint pipe is an externally threaded joint pipe, and the other is an internally threaded joint pipe.

3. The continuous deflection coring drill according to claim 1, characterized in that: A steering motor (2-5) is fixedly mounted on the outer wall of the inner tube (2-1) of the deflection mechanism (2); a ring gear (2-8) is fixedly mounted on the inner wall of the outer tube (2-2) in the horizontal direction; and a transmission shaft of the steering motor (2-5) is provided with a gear that meshes with the ring gear (2-8).

4. The continuous deflection coring drill according to claim 1, characterized in that: A direction monitor (2-9) is also fixedly mounted on the inner wall of the outer tube (2-2).

5. The continuous deflection coring drilling tool according to claim 1, characterized in that: The deflection motor (2-6) is fixedly mounted on the inner wall of the outer tube (2-2); the transmission shaft of the deflection motor (2-6) is coupled with the ejector of the ejection device (2-7) through a reduction gear set (2-10); the outer tube (2-2) is provided with an ejection hole adapted to the ejection hole; the ejection hole is located in the ejection hole and is sealed with the hole wall of the ejection hole; and the ejection hole is arranged radially along the outer tube (2-2).

6. The continuous deflection coring drilling tool according to claim 1, characterized in that: The hollow motor (3) includes a stator (3-1) and a rotor (3-2) outside the stator (3-1). The stator (3-1) is a hollow tubular structure. The upper and lower ends of the stator (3-1) are both open. A stator joint (3-3) is provided at the upper end of the stator (3-1) and is fixedly connected to the lower joint pipe (1-3) of the second deflection drill rod (1b). A rotor joint (3-4) is provided at the lower end of the rotor (3-2) and is fixedly connected to the drill bit (4). A sealing ring (3-5) and a second bearing (3-6) are provided between the stator (3-1) and the rotor (3-2). The second bearing (3-6) is located in a sealed cavity formed by the stator (3-1), the rotor (3-2) and the sealing ring (3-5).

7. The continuous deflection coring drill according to any one of claims 1 to 6, characterized in that: The continuous deflection coring drill tool also includes a rope coring device installed in the coring cavity, the rope coring device includes a coring tube (5-1) and a limiting mechanism (5-2) connected to the upper end of the coring tube (5-1), the coring tube (5-1) includes a flexible tube body and a skeleton embedded in the flexible tube body, the skeleton is a spiral steel wire, a fishing head (5-2-1) is provided on the top of the limiting mechanism (5-2), and a clamping ear (5-2-2) is provided on the outer periphery of the limiting mechanism (5-2) for clamping with the clamping groove on the inner side of the straight drill rod (6).

8. The continuous deflection coring drilling tool according to claim 7, characterized in that: At least one slide seat (5-3) is provided on the outer side of the coring tube (5-1), the slide seat (5-3) is provided with a ball groove, a ball (5-4) is installed in the ball groove, and the ball (5-4) is in rolling engagement with the cavity wall of the coring cavity; the lower end of the coring tube (5-1) is fixedly connected to the guide tube (5-5), and the slide seat (5-3) and the ball (5-4) are provided on the outer side of the guide tube (5-5).

9. Continuous deflection coring method, characterized in that: Drilling and coring using the continuous deflection coring drill tool according to any one of claims 1 to 8 comprises the following steps: S1. The upper end of the straight drill rod (6) is fixedly connected to the orifice drill rig, the lower end of the straight drill rod (6) is fixedly connected to the upper joint pipe (1-1) of the first deflection drill rod (1a), and the rope coring device is placed in the coring cavity and fixed; S2. The orientation of the ejection device (2-7) is adjusted by the directional motor (2-5), and the two sections of the deflection drill rod are controlled to be straight or curved by the deflection motor (2-6). Then, pressure is applied to the straight drill rod (6) by the orifice drilling rig, and the drill bit (4) is driven to rotate by the hollow motor (3), so that the drill bit (4) breaks the rock and drills; when the core fills the core tube (5-1) of the wireline coring device, the drilling is stopped, the wireline coring device is removed, and the core is obtained; S3. Place the rope coring device into the coring cavity and secure it, and repeat step S2 until the target position is reached.

10. The continuous deflection coring method according to claim 9, characterized in that: A slot is provided on the inner side of the lower end of the straight drill rod (6); the rope coring device comprises a coring tube (5-1) and a limiting mechanism (5-2) connected to the upper end of the coring tube (5-1); a fishing head (5-2-1) is provided on the top of the limiting mechanism (5-2); and a clamping ear (5-2-2) is provided on the outer periphery of the limiting mechanism (5-2); after the rope coring device is placed in the coring cavity, the clamping ear (5-2-2) is automatically clamped into the slot; In step S3, before placing the rope coring device into the coring cavity, a borehole inclinometer is placed into the coring cavity to test the drilling trajectory from the hole mouth to the hole bottom, and the postures of the two sections of the deflection drill rod are adjusted accordingly through the deflection motor (2-6).

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