Continuous deflecting coring drilling tool and method

Abstract

The invention discloses a continuous deflecting coring drilling tool and a continuous deflecting coring method, relates to the field of drilling of soil layers or rocks, and solves the problems that an existing drilling device is high in deflecting direction control difficulty and low in core recovery rate. According to the technical scheme, the continuous deflecting coring drilling tool comprises a deflecting drill rod, a hollow motor and a drill bit, the two sections of deflecting drill rods are the first deflecting drill rod and the second deflecting drill rod respectively, and the first deflecting drill rod, a deflecting mechanism, the hollow motor and the drill bit are sequentially connected in series to form a coring cavity; the deflecting mechanism comprises an inner pipe and an outer pipe, an annular cavity is formed between the inner pipe and the outer pipe, the two ends of the annular cavity are sealed, a direction adjusting motor used for driving the outer pipe to rotate around the inner pipe is installed between the inner pipe and the outer pipe, and a deflecting motor and an ejection device are installed on the inner wall of the outer pipe. The ejection device is provided with an ejection piece which is driven by a deflecting motor and can be ejected out of the outer wall of the outer pipe and retracted into the outer wall of the outer pipe. According to the invention, not only can linear drilling be carried out, but also directional deflecting drilling can be carried out.

Description

Technical Field

[0001] The present invention relates to the field of drilling in soil layers or rocks, and in particular to a device for extracting undisturbed core, specifically a continuous deflecting coring drill and method. Background Technique

[0002] Common engineering drilling means are vertical drilling, inclined drilling, and horizontal drilling, and these three types of drilling techniques all belong to the category of straight-line drilling. Straight-line drilling has been widely used due to its relatively low construction cost and simple structure. However, because of its simple structure and no components for generating deflection, it cannot generate bending during drilling and can only be used in the field of straight-line drilling, with limited application scope. With the development of infrastructure projects such as water conservancy and hydropower, and railways in China, it is necessary to carry out curved drilling across rivers or along the axis of hydraulic tunnels, and gradually the research on directional coring technology that can perform curved drilling has begun.

[0003] The technology that can perform curved drilling has achieved certain development in the field of petroleum engineering exploration. However, petroleum engineering exploration belongs to non-core-taking drilling, which is essentially different from the drilling in water conservancy and hydropower and other projects that require taking cores, and its technology cannot be applied to the drilling that requires taking cores.

[0004] At present, the existing directional deflecting coring drilling device mainly adds an eccentric component outside the drill pipe. The eccentric component has a protruding part, and the protruding part pushes against the hole wall of the borehole. The reaction force of the hole wall causes the rigid drill pipe to generate a small degree of bending, thereby realizing directional deflecting coring drilling. This directional deflecting coring drilling device has many problems, mainly including: First, the eccentric component is coaxial with the drill pipe. During the lowering of the drill pipe, the eccentric component rotates synchronously with the drill pipe. Due to the lack of measures for positioning and controlling the direction of the eccentric component, it is difficult to ensure that the protruding part is located at 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 needs to take cores. The eccentric component results in a very small coring channel; Third, the structure of the eccentric component is complex. Since the drilling that requires taking cores is water drilling, the eccentric component is easily damaged in the drilling environment of water, cuttings, mud, etc.; Fourth, the length of the protruding part of the eccentric component is limited, the deflecting amplitude is small, and the deflecting efficiency is low; Fifth, the drilling uses hole-opening power. When the drilling depth is relatively large, the drilling power is insufficient and the drill pipe is severely worn; Sixth, there is no dedicated wireline coring device for directional deflecting drilling inside the drill pipe, the core recovery rate is low, and the core is easily fractured and damaged. Summary of the Invention

[0005] The present invention first provides a continuous deflecting coring drill to solve the problems of difficult control of the deflecting direction of the existing drilling device and low core recovery rate.

[0006] The technical solution adopted by the present invention is as follows: a continuous whipstock coring drill tool, including a whipstock drill pipe, a whipstock mechanism, a hollow motor, and a drill bit. The whipstock drill pipe is divided into two sections, namely the first whipstock drill pipe and the second whipstock drill pipe. It is set that the central axes of the two sections of whipstock drill pipes are both vertical. The whipstock drill pipe includes a spring tube in the middle, and an upper joint pipe and a lower joint pipe fixedly connected to the upper and lower ends of the spring tube respectively. 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 braided mesh layer fixed to the skeleton. The skeleton is a spring-shaped pipe fitting formed by tightly winding or intermittently winding steel bars; the lower joint pipe of the first whipstock drill pipe is connected to the upper joint pipe of the second whipstock drill pipe through the whipstock mechanism. The lower joint pipe of the second whipstock drill pipe is connected to the hollow motor. The lower end of the hollow motor is the output end and is connected to the drill bit. A continuous and cylindrical coring cavity is formed inside the first whipstock drill pipe, the whipstock mechanism, the second whipstock drill pipe, the hollow motor, and the drill bit; The whipstock mechanism includes an inner tube and an outer tube. Both the inner tube and the outer tube are hollow tubular structures. The upper end of the inner tube is provided with an upper joint pipe and is connected to the lower joint pipe of the first whipstock drill pipe. The lower end of the inner tube is provided with a lower joint pipe and is connected to the upper joint pipe of the second whipstock drill pipe; an annular cavity is formed between the inner tube and the outer tube. Seals are respectively arranged at the upper and lower ends of the annular cavity. A first bearing is arranged between the inner tube and the outer tube. A steering motor for driving the outer tube to rotate around the inner tube is installed between the inner tube and the outer tube; a whipstock motor and an ejection device are installed on the inner wall of the outer tube. The transmission shaft of the whipstock motor is in transmission connection with the ejection device. The ejection device is provided with an ejection member that can be ejected outside the outer wall of the outer tube and retracted inside the outer wall of the outer tube driven by the whipstock motor.

[0007] In order to facilitate the connection between the whipstock drill pipe and the straight drill pipe, the connection between the whipstock drill pipe and the inner tube of the whipstock mechanism, and the connection between the whipstock drill pipe and the hollow motor, further: the upper and lower ends of the skeleton of the spring tube of the whipstock drill pipe are respectively fixedly connected to the upper joint pipe and the lower joint pipe. The upper joint pipe and the lower joint pipe of the whipstock drill pipe are mutually adapted. The upper joint pipe and the lower joint pipe at the upper and lower ends of the inner tube of the whipstock mechanism are mutually adapted. One of the mutually adapted upper joint pipe and lower joint pipe is an external thread joint pipe, and the other is an internal thread joint pipe.

[0008] The steering motor is used to adjust the direction of the ejection device, and further adjust the bending direction of the whipstock drill pipe when the ejection member pushes against the hole wall of the drilled hole. Specifically: the steering motor is fixedly installed on the outer wall of the inner tube of the whipstock mechanism. A ring gear is fixedly arranged along the horizontal direction on the inner wall of the outer tube. The transmission shaft of the steering motor is provided with a gear and meshes with the ring gear.

[0009] In order to facilitate the monitoring of the direction of the ejection device, further: a direction monitor is also fixedly installed on the inner wall of the outer tube.

[0010] In order to reduce the requirements for the whipstock motor, further: the whipstock motor is fixedly installed on the inner wall of the outer pipe, the transmission shaft of the whipstock motor is in transmission cooperation with the ejector of the ejecting device through a speed reduction gear set, the outer pipe is provided with a pushing hole adapted to the ejector, the ejector is located in the pushing hole and is in sealing cooperation with the hole wall of the pushing hole, and the ejector is arranged along the radial direction of the outer pipe.

[0011] The hollow motor is directly connected to the drill bit and drives the drill bit to rotate, reducing power loss through the downhole power mode. Specifically: the hollow motor includes a stator and a rotor outside the stator. The stator is a hollow tubular structure, and both the upper and lower ends of the stator are open. A stator joint is arranged at the upper end of the stator and is fixedly connected to the lower joint pipe of the second whipstock drill pipe. A rotor joint is arranged at the lower end of the rotor and is fixedly connected to the drill bit. A sealing ring and a second bearing are arranged between the stator and the rotor, and the second bearing is located in the sealing cavity formed by the stator, the rotor, and the sealing ring.

[0012] The coring chamber is used to place the wireline coring device to obtain the core. Further: the continuous whipstock coring tool further includes a wireline coring device installed in the coring chamber. The wireline coring device includes a coring pipe and a limiting mechanism connected to the upper end of the coring pipe. The coring pipe includes a flexible pipe body and a skeleton embedded in the flexible pipe body. The skeleton is a helical steel wire. A fishing head is arranged at the top of the limiting mechanism, and a clamping ear for clamping with the card slot inside the straight drill pipe is arranged on the outer periphery of the limiting mechanism.

[0013] In order to facilitate the sliding and removal of the wireline coring device in the coring chamber, further: at least one sliding seat is arranged on the outer side of the coring pipe. The sliding seat is provided with a ball groove, and balls are installed in the ball groove. The balls are in rolling cooperation with the chamber wall of the coring chamber; a guiding pipe is fixedly connected to the lower end of the coring pipe, and sliding seats and balls are arranged on the outer side of the guiding pipe.

[0014] The present invention also provides a continuous whipstock coring method, which also solves the problems of difficult control of the whipstock direction and low core recovery rate of the existing drilling devices. The technical solution adopted by the present invention is that the continuous whipstock coring method uses any one of the above continuous whipstock coring tools for drilling and coring, including the following steps: S1. Fix the upper end of the straight drill pipe to the hole rig, fix the lower end of the straight drill pipe to the upper joint pipe of the first whipstock drill pipe, and place the wireline coring device in the coring chamber and fix it. In order to facilitate the fixing and extraction of the wireline coring device, further: a card slot is arranged on the inner side of the lower end of the straight drill pipe. The wireline coring device includes a coring pipe and a limiting mechanism connected to the upper end of the coring pipe. A fishing head is arranged at the top of the limiting mechanism, and a clamping ear is arranged on the outer periphery of the limiting mechanism. After the wireline coring device is placed in the coring chamber, the clamping ear automatically snaps into the card slot.

[0015] S2. Adjust the orientation of the ejection device through the orientation adjustment motor, control the two steerable drill pipes to be straight or bent through the build motor, then apply pressure to the straight drill pipe through the orifice drill rig, and drive the drill bit to rotate by using the hollow motor to make the drill bit break through the rock for drilling; when the core fills the core barrel of the wireline coring device, stop drilling, take out the wireline coring device and obtain the core.

[0016] S3. Place the wireline coring device into the core chamber and fix it, and repeat step S2 until drilling reaches the target position.

[0017] In order to control the actual drilling trajectory to be consistent with the predetermined drilling trajectory, further: before placing the wireline coring device into the core chamber in step S3, place a borehole inclinometer into the core chamber and test the drilling trajectory from the orifice to the bottom of the hole, and accordingly adjust the attitude of the two steerable drill pipes through the build motor.

[0018] The beneficial effects of the present invention are: the continuous build coring drill can not only perform straight drilling but also perform directional build drilling, enabling a set of drill to have two drilling functions at the same time. The build motor can control the ejector of the ejection device to retract inside the outer wall of the outer pipe. At this time, the ejector does not push against the hole wall of the borehole, and the center lines of the two steerable drill pipes are straight for straight drilling; the build motor can also control the ejector of the ejection device to eject outside the outer wall of the outer pipe. At this time, the ejector will push against the hole wall of the borehole, and the center lines of the two steerable drill pipes are curved for directional build drilling.

[0019] After the spring tube of the steerable drill pipe is bent, it is in an arc shape or a shape close to an arc, with little influence on the coring operation, reducing the risk of core fracture, facilitating the coring operation and improving the core recovery rate. The build motor can control whether the two steerable drill pipes are bent and can also control the degree of bending of the two steerable drill pipes. The operation is simple, and the attitude of the two steerable drill pipes is stable, facilitating the quick adjustment of the degree of bending of the two steerable drill pipes. The orientation adjustment motor can control the direction of the ejection device, facilitating the adjustment of the bending direction of the two steerable drill pipes according to needs, so as to meet various requirements for directional build drilling.

[0020] The hollow motor is connected to the lower end of the second steerable drill pipe. The hollow motor is of a hollow tubular structure and has no influence on the coring operation. The hollow motor directly drives the drill bit at the bottom of the borehole, with little power loss, avoiding the problems of large friction between the drill pipe and the hole wall of the borehole and large wear of the drill pipe during the drilling process of driving the drill pipe and the drill bit to rotate by the orifice drill rig, as well as the problem of large power loss. Therefore, the present invention can be used for ultra-deep hole drilling and has a high drilling efficiency.

[0021] During the drilling process, the steerable drill pipes, the build mechanism and the drill bit do not need to be lifted out of the borehole. Only when the drill bit needs to be replaced, the steerable drill pipes, the build mechanism and the drill bit are lifted out. The whole drilling process has simple operation and low implementation cost. Brief Description of the Drawings

[0022] Figure 1 FIG. 5 is a schematic structural diagram of an embodiment of the continuous whipstock coring drill of the present invention in a natural state.

[0023] Figure 2 is Figure 1 an enlarged view of the whipstock mechanism in the illustrated embodiment.

[0024] Figure 3 is Figure 1 a schematic diagram of the illustrated embodiment in the A-A cross-section.

[0025] Figure 4 is Figure 1 a schematic structural diagram of the illustrated embodiment in the directional drilling state.

[0026] Reference numerals: first whipstock drill pipe 1a, second whipstock drill pipe 1b, upper joint pipe 1-1, spring pipe 1-2, lower joint pipe 1-3, whipstock mechanism 2, inner pipe 2-1, outer pipe 2-2, seal 2-3, first bearing 2-4, steering motor 2-5, whipstock motor 2-6, ejecting 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, seal ring 3-5, second bearing 3-6, drill bit 4, coring pipe 5-1, limiting mechanism 5-2, fishing head 5-2-1, ear 5-2-2, sliding seat 5-3, ball 5-4, guide pipe 5-5, straight drill pipe 6, protection pipe 7. Detailed Description of the Invention

[0027] The present invention will be further described below with reference to the accompanying drawings.

[0028] The first subject of the present invention is a continuous whipstock coring drill. Referring to Figure 1 and Figure 4 , the continuous whipstock coring drill includes whipstock drill pipes, a whipstock mechanism 2, a hollow motor 3 and a drill bit 4. The whipstock drill pipes are two sections, namely a first whipstock drill pipe 1a and a second whipstock drill pipe 1b, and the first whipstock drill pipe 1a and the second whipstock drill pipe 1b are connected by the whipstock mechanism 2. The continuous whipstock coring drill has two states, namely a natural state and a directional drilling state. In the natural state, the central axes of the first whipstock drill pipe 1a, the whipstock mechanism 2 and the second whipstock drill pipe 1b are straight lines and coincide, referring to Figure 1 ; in the directional drilling state, the central axes of the first whipstock drill pipe 1a, the whipstock mechanism 2 and the second whipstock drill pipe 1b are curves, referring to Figure 2For ease of description, it is assumed that in the natural state, the central axes of the two inclined drill pipes are both vertical, that is, the central axes of the two inclined drill pipes are both vertical and coincident. The inclined drill pipe includes a spring tube 1-2 in the middle, and an upper joint pipe 1-1 and a lower joint pipe 1-3 fixedly connected to the upper and lower ends of the spring tube 1-2. Upper joint pipes and lower joint pipes are also respectively provided at the upper and lower ends of the inclination mechanism 2. The upper joint pipe 1-1 and the lower joint pipe 1-3 of the inclined drill pipe, as well as the upper joint pipe and the lower joint pipe of the inclination mechanism 2, all play a connecting role. The upper joint pipe 1-1 of the first inclined drill pipe 1a is used to connect with the straight drill pipe 6. The lower joint pipe 1-3 of the first inclined drill pipe 1a is connected to the upper joint pipe of the inclination mechanism 2. The lower joint pipe of the inclination mechanism 2 is connected to the upper joint pipe 1-1 of the second inclined drill pipe 1b. The lower joint pipe 1-3 of the second inclined drill pipe 1b is connected to the hollow motor 3. In order to facilitate the connection between the inclined drill pipe and the straight drill pipe 6, the connection between the inclined drill pipe and the inclination mechanism 2, specifically the connection between the inclined drill pipe and the inner pipe 2-1 of the inclination mechanism 2, and the connection between the inclined drill pipe and the hollow motor 3, the upper joint pipe 1-1 and the lower joint pipe 1-3 of the inclined drill pipe are mutually adapted, and the upper joint pipes and the lower joint pipes at the upper and lower ends of the inclination mechanism 2 are mutually adapted. Generally, one of the mutually adapted upper joint pipe and lower joint pipe is an external thread joint pipe, and the other is an internal thread joint pipe. The upper and lower ends of the two inclined drill pipes can be replaced.

[0029] The whipstock drill pipe has a hollow circular tube structure with both upper and lower ends open. The main part of the whipstock drill pipe is the coil pipe 1-2, which includes a flexible tube body and a skeleton embedded in the flexible tube body. The skeleton is a spring-shaped pipe fitting formed by helically winding steel bars. When the steel bars are helically wound, they can be wound tightly, that is, there is no gap between adjacent turns of steel bars, and in the natural state, adjacent turns of steel bars have no gap and are in direct contact; when the steel bars are helically wound, they can also be wound at intervals, that is, a gap is reserved between adjacent turns of steel bars, and in the natural state, there is a gap between adjacent turns of steel bars and they are not in direct contact. The flexible tube body serves to close the gaps and crevices of the skeleton, so that the coil pipe 1-2 will not leak whether its central axis is straight or curved. The flexible tube body is arranged on the inner side or the outer side of the skeleton, or is arranged on both the inner side and the outer side of the skeleton at the same time. When the flexible tube body is only arranged on the inner side of the skeleton, the inner wall of the coil pipe 1-2 is flat; when the flexible tube body is only arranged on the outer side of the skeleton, the outer wall of the coil pipe 1-2 is flat; when the flexible tube body is arranged on both the outer side and the inner side of the skeleton, both the inner wall and the outer wall of the coil pipe 1-2 are flat. The flexible tube body is generally combined with the skeleton to form a complete coil pipe 1-2 by injection molding. The flexible tube body is generally made of a polymer material and has good wear resistance, such as rubber. During drilling, the straight drill pipe 10 needs to apply pressure to the first whipstock drill pipe 1a and transmit it to the drill bit 4. In order to make the first whipstock drill pipe 1a transmit pressure more stably, the skeleton of the coil pipe 1-2 is preferably wound tightly with steel bars. The upper joint pipe 1-1 and the lower joint pipe 1-3 at both ends of the coil pipe 1-2 both play a connecting role. In order to firmly connect the coil pipe 1-2 with the upper joint pipe 1-1 and firmly connect the coil pipe 1-2 with the lower joint pipe 1-3, the upper and lower ends of the skeleton are fixedly connected to the upper joint pipe 1-1 and the lower joint pipe 1-3 respectively, such as by welding.

[0030] Another embodiment of the coil pipe 1-2 of the whipstock drill pipe is provided below. The coil pipe 1-2 includes a skeleton and a stainless steel braided mesh layer fixed to the skeleton. The skeleton is a spring-shaped pipe fitting formed by helically winding steel bars. When the steel bars are helically wound, they can be wound tightly or at intervals. The stainless steel braided mesh layer is fixed to the inner side or the outer side of the skeleton, or is fixed to both the inner side and the outer side of the skeleton at the same time. The upper and lower ends of the stainless steel braided mesh layer are preferably fixedly connected to the upper joint pipe 1-1 and the lower joint pipe 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 outer side of the skeleton can also withstand the friction with the borehole wall during drilling, reduce the wear of the skeleton, and the stainless steel braided mesh layer also plays an isolation role to prevent the substances inside and outside the skeleton from moving in the gaps of the spring pipe fitting.

[0031] The lower joint pipe 1-3 of the first whipstock drill pipe 1a is connected to the upper joint pipe 1-1 of the second whipstock drill pipe 1b through a whipstock mechanism 2. The whipstock mechanism 2 pushes against the borehole wall, and the borehole wall generates a reaction force on the whipstock mechanism 2. The first whipstock drill pipe 1a, the whipstock mechanism 2, and the second whipstock drill pipe 1b bend under the action of this reaction force, thereby achieving directional whipstock drilling. As Figure 1 , Figure 3 and Figure 4 shown, the whipstock mechanism 2 includes an inner pipe 2-1 and an outer pipe 2-2. Both the inner pipe 2-1 and the outer pipe 2-2 are hollow tubular structures. The length of the inner pipe 2-1 is greater than that of the outer pipe 2-2. The upper end of the inner pipe 2-1 is provided with an upper joint pipe and is connected to the lower joint pipe 1-3 of the first whipstock drill pipe 1a. The lower end of the inner pipe 2-1 is provided with a lower joint pipe and is connected to the upper joint pipe 1-1 of the second whipstock drill pipe 1b. The connection methods at the upper and lower ends of the inner pipe 2-1 are generally threaded connections. The inner diameter of the outer pipe 2-2 is greater than the outer diameter of the inner pipe 2-1. A ring cavity is formed between the inner pipe 2-1 and the outer pipe 2-2, that is, the axes of the inner pipe 2-1 and the outer pipe 2-2 coincide to form an annular chamber. Seals 2-3 are respectively arranged at the upper and lower ends of the ring cavity. The seals 2-3 are generally sealing rings and can also be sealing end caps. For example, the seal 2-3 is a rubber sealing ring. A first bearing 2-4 is provided between the inner pipe 2-1 and the outer pipe 2-2, enabling the outer pipe 2-2 to rotate around the inner pipe 2-1. For example, the first bearing 2-4 is a deep groove ball bearing. The first bearing 2-4 is one or more, generally two and arranged at the upper and lower ends of the ring cavity. The first bearing 2-4 is preferably located inside the seal 2-3, that is, the first bearing 2-4 is preferably located in the sealed ring cavity formed by the outer wall of the inner pipe 2-1, the inner wall of the outer pipe 2-2, and the seal 2-3.

[0032] A steering motor 2-5 for driving the outer pipe 2-2 to rotate around the inner pipe 2-1 is installed between the inner pipe 2-1 and the outer pipe 2-2 of the whipstock mechanism 2. The steering motor 2-5 is located in the sealed ring cavity formed by the outer wall of the inner pipe 2-1, the inner wall of the outer pipe 2-2, and the seal 2-3. The steering motor 2-5 is used to adjust the direction of the outer pipe 2-2 and the ejection device 2-7 installed on the inner wall of the outer pipe, thereby adjusting the bending direction of the whipstock drill pipe during directional drilling. The steering motor 2-5 is installed on the outer wall of the inner pipe 2-1 or the inner wall of the outer pipe 2-2. For example, referring to Figure 1 , Figure 3 and Figure 4 , a steering motor 2-5 is fixedly installed on the outer wall of the inner pipe 2-1 of the whipstock mechanism 2, and a ring gear 2-8 is fixedly arranged in a circle along the horizontal direction on the inner wall of the outer pipe 2-2. A gear is provided on the transmission shaft of the steering motor 2-5 and meshes with the ring gear 2-8.

[0033] An inclination-making motor 2-6 and an ejection device 2-7 are installed on the inner wall of the outer tube 2-2 of the inclination-making mechanism 2. The transmission shaft of the inclination-making motor 2-6 is in transmission connection with the ejection device 2-7. The ejection device 2-7 includes an ejector. The ejection and retraction of the ejector are controlled by the inclination-making motor 2-6, and the ejector can be ejected outside the outer wall of the outer tube 2-2 or retracted inside the outer wall of the outer tube 2-2. When the ejector is retracted inside the outer wall of the outer tube 2-2, there is no acting force between the ejector and the hole wall of the drill hole. The central axes of the first inclination-making drill pipe 1a, the inclination-making mechanism 2, and the second inclination-making drill pipe 1b are straight lines and coincide. At this time, straight drilling is suitable; when the ejector is ejected outside the outer wall of the outer tube 2-2, the ejector pushes against the hole wall of the drill hole, and the hole wall of the drill hole generates a reaction force on the ejector. Under the action of this reaction force, the first inclination-making drill pipe 1a, the inclination-making mechanism 2, and the second inclination-making drill pipe 1b are bent. At this time, directional inclination-making drilling is suitable. The outer tube 2-2 is provided with a push hole adapted to the ejector. The ejector is located in the push hole and is in sealed cooperation with the hole wall of the push hole. The ejector is arranged along the radial direction of the outer tube 2-2. The transmission shaft of the inclination-making motor 2-6 can directly drive or indirectly drive the ejector. In order to reduce the requirements for the inclination-making motor 2-6, the transmission shaft of the inclination-making motor 2-6 is connected through a speed reduction transmission structure. Refer to Figure 1 , Figure 3 and Figure 4 , the inclination-making motor 2-6 is fixedly installed on the inner wall of the outer tube 2-2. The transmission shaft of the inclination-making motor 2-6 is in transmission cooperation with the ejector of the ejection device 2-7 through a speed reduction gear set 2-10. For example, the speed reduction gear set 2-10 is two meshing bevel gears.

[0034] In order to facilitate monitoring the direction of the ejection device 2-7, a direction monitor 2-9 is also 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, as shown in Figure 1 and Figure 4 . The direction monitor 2-9 is an existing one. For example, the direction monitor 2-9 mainly includes a three-axis accelerometer, a three-axis magnetometer, and a gyroscope. The direction monitor 2-9 is used to measure the position coordinates of the space it is in, and thus can reflect the orientation of the ejector of the ejection device 2-7. The direction monitor 2-9 cooperates with the direction-adjusting motor 2-5 to accurately rotate the ejector of the ejection device 2-7 to the direction required for directional inclination-making.

[0035] The lower joint pipe 1-3 of the second inclination-making drill pipe 1b is connected to a hollow motor 3. The lower end of the hollow motor 3 is the output end and is connected to a 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 coring. Refer to Figure 1 , Figure 3 and Figure 4, the 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 arranged between the stator 3-1 and the rotor 3-2. The stator 3-1 is a hollow tubular structure, and the inner diameter of the stator 3-1 is the same as the inner diameter of the lower joint pipe 1-3 of the second whipstock drill pipe 1b. Both the upper and lower ends of the stator 3-1 are open. A stator joint 3-3 is arranged at the upper end of the stator 3-1, and the stator joint 3-3 is fixedly connected to the lower joint pipe 1-3 of the second whipstock drill pipe 1b. The connection method between the stator joint 3-3 and the lower joint pipe 1-3 of the second whipstock drill pipe 1b is generally 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 arranged between the stator 3-1 and the rotor 3-2. The sealing ring 3-5 includes an upper sealing ring and a lower sealing ring. The second bearing 3-6 is located in the sealing 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 objects such as groundwater and mud from entering the interior of the hollow motor 3. For example, the sealing ring 3-5 is a rubber sealing ring. Another alternative for the sealing ring 3-5 is that sealing end caps are respectively arranged at the top and bottom of the hollow motor 3. The function of the second bearing 3-6 is to enable the rotor 3-2 to rotate smoothly, and the second bearing 3-6 also needs to be able to bear axial pressure. A rotor joint 3-4 is arranged 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 installed at the lower end of the rotor 3-2. The upper end of the drill bit 4 is provided with a threaded interface adapted to the rotor joint 3-4, and the lower end of the drill bit 4 is provided with cutting teeth for grinding rocks. The drill bit 4 is a hollow circular tube structure, and the function of the drill bit 4 is to grind rocks to separate the rocks inside and outside the drill bit 4.

[0036] In the natural state, a continuous and cylindrical coring cavity is formed inside the first whipstock drill pipe 1a, the whipstock mechanism 2, the second whipstock drill pipe 1b, the hollow motor 3, and the drill bit 4. The coring cavity is used to place a wireline coring device to obtain core samples. The continuous whipstock coring drill of the present invention further includes a wireline coring device installed in the coring cavity. The wireline 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 at 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 in the figure. The core barrel 5-1 is used to store the core. The core barrel 5-1 has a certain strength and can be deformed to adapt to the attitude changes of the first whipstock drill pipe 1a, the whipstock mechanism 2, and the second whipstock drill pipe 1b, solving the problem that the core is easily fractured and damaged during directional whipstock drilling and improving the core recovery rate. The outer diameter of the core barrel 5-1 is smaller than the diameter of the core chamber, ensuring that the core barrel 5-1 can be smoothly placed into and taken out of the core chamber. The lower end of the core barrel 5-1 is a free end and is placed on the inner wall base of the drill bit 4. For example, the core barrel 5-1 includes a flexible tube body and a skeleton embedded in the flexible tube body. The skeleton is a helical steel wire, and is formed by injection molding on the inner and outer sides of the helical skeleton through a mold. The flexible tube body of the core barrel 5-1 is generally made of a polymer material, such as rubber. The inner and outer side walls of the core barrel 5-1 are straight and smooth, and can be bent and deformed along with the bending changes of the two whipstock drill pipes. The flexible tube body keeps the core barrel 5-1 always closed, preventing the core from being exposed outside the core barrel 5-1. The limiting mechanism 5-2 is used to lower and take out the core barrel 5-1 and fix the core barrel 5-1 in a suitable position. A fishing head 5-2-1 is provided at the top of the limiting mechanism 5-2. The fishing head 5-2-1 is used to lower the wireline coring device into the core chamber and fix it. The fishing head 5-2-1 is generally a conical head, and the fishing head 5-2-1 can be fished and released by a fishing tool. A lug 5-2-2 for engaging with the card slot on the inner side of the straight drill pipe 6 is provided on the outer periphery of the limiting mechanism 5-2. Generally, there are two lugs 5-2-2 and they are symmetrically arranged. The lugs 5-2-2 are equipped with components such as a rotating shaft and an opening spring. The opening spring can make the lugs 5-2-2 open, and the rotating shaft can make the lugs 5-2-2 rotate.

[0037] To facilitate the sliding and taking out of the wireline coring device in the core chamber, at least one sliding seat 5-3 is provided on the outer side of the core barrel 5-1. The sliding seats 5-3 are arranged in a ring shape. The sliding seats 5-3 are provided with ball grooves, and balls 5-4 are installed in the ball grooves. The balls 5-4 are in rolling fit with the wall of the core chamber. To facilitate the lowering of the core barrel 5-1, a guide tube 5-5 is fixedly connected to the lower end of the core barrel 5-1, and sliding seats 5-3 and balls 5-4 are provided on the outer side of the guide tube 5-5. For example, see Figure 1 and Figure 4 , a ring of sliding seats 5-3 are respectively provided at the upper and lower ends of the core barrel 5-1. A ring of sliding seats 5-3 includes at least three sliding seats 5-3. The guide tube 5-5 at the lower end of the core barrel 5-1 can also prevent the core barrel 5-1 from rotating synchronously when the hollow motor 3 rotates. To facilitate the lowering of the core barrel 5-1 into the core chamber, a conical cut is provided on the outer side of the lower end of the guide tube 5-5 at the lower end of the core barrel 5-1, as shown in 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 is provided at the upper end of the coring tube 5-1, and the upper guide tube is threadedly connected to the limiting mechanism 5-2. A circle of sliding seats 5-3 is provided on the outer periphery of the upper guide tube. In addition, the upper end of the coring tube 5-1 and the limiting mechanism 5-2 can also be connected through a single turner. The function of the single turner is that even if the coring tube 5-1 rotates, the limiting mechanism 5-2 will not be driven to rotate.

[0038] The second subject of the present invention is a continuous deflection coring method, which utilizes the continuous deflection coring drill tool described in the first subject to perform drilling and coring, and includes the following steps.

[0039] 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.

[0040] The straight drill rod 6 is a hollow rod, and the straight drill rod 6 can produce a small bending deformation under the action of external force. The upper and lower ends of the straight drill rod 6 are respectively provided with mutually adapted threaded interfaces. According to the depth of the borehole, the number of the straight drill rods 6 is one or more. When there are multiple straight drill rods 6, each is connected in series. The straight drill rod 6 mainly transmits tension and pressure. The wires of the adjustment motor 2-5, the wires of the deflection motor 2-6, the wires of the direction monitor 2-9, and the wires of the hollow motor 3 can pass through the straight drill rod 6 and pass out of the hole from the upper end of the straight drill rod 6, or can be located on the outside of the straight drill rod 6 and pass out of the hole. In order to better protect the wires, a protective tube is sleeved on the outside of the straight drill rod 6, and the wires are located between the inner wall of the protective tube and the outer wall of the straight drill rod 6. The straight drill rod 6 also forms a channel for the circulation of drilling slurry and rope coring. The outer diameter of the straight drill rod 6 is less than or equal to the outer diameter of the deflection drill rod, and the inner diameter of the straight 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, the outer wall of the straight drill rod 6 is preferably provided with vertical stripes.

[0041] In order to facilitate the fixing and extraction of the rope coring device, a slot for cooperating with the rope coring device is provided on the inner side of the lower end of the straight drill rod 6 directly connected to the first deflection drill rod 1a. 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. A fishing head 5-2-1 is provided on the top of the limiting mechanism 5-2. 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 clamping slot.

[0042] S2. Adjust the orientation of the ejection device 2-7 through the steering motor 2-5, control the two inclined drilling pipes to be straight or bent through the inclination motor 2-6, then apply pressure to the straight drill pipe 6 through the orifice drill, and drive the drill bit 4 to rotate by using the hollow motor 3 to make the drill bit 4 break through the rock and drill; when the core fills the core barrel 5-1 of the wireline coring device, stop drilling, take out the wireline coring device and obtain the core.

[0043] The drilling process is divided into two types, namely straight drilling and directional drilling. During straight drilling, the central axes of the straight drill pipe 6, the first inclined drilling pipe 1a, the inclination mechanism 2, the second inclined drilling pipe 1b, the hollow motor 3 and the drill bit 4 coincide; during directional drilling, adjust the orientation of the ejection device 2-7 through the steering motor 2-5, and adjust the postures of the first inclined drilling pipe 1a, the inclination mechanism 2 and the second inclined drilling pipe 1b through the inclination motor 2-6, and the first inclined drilling pipe 1a, the inclination mechanism 2 and the second inclined drilling pipe 1b are bent.

[0044] S3. Place the wireline coring device into the coring cavity and fix it, and repeat step S2 until drilling reaches the target position.

[0045] In order to control the actual drilling trajectory to be consistent with the predetermined drilling trajectory, before placing the wireline coring device into the coring cavity in step S3, place a borehole inclinometer into the coring cavity and test the drilling trajectory from the orifice to the bottom of the hole, and accordingly adjust the postures of the two inclined drilling pipes through the inclination motor 2-6. Compare the tested drilling trajectory with the designed drilling trajectory. When the drilling direction deviates, adjust the inclination motor 2-6 to rotate forward or backward to increase or decrease the bending degree of the two inclined drilling pipes accordingly, so as to correct the drilling direction during drilling.

Claims

1. Continuous deflecting and coring drill string, comprising a deflecting drill pipe, a deflecting mechanism (2), a hollow motor (3) and a drill bit (4), characterized in that: The whipstock drill pipe is divided into two sections, namely the first whipstock drill pipe (1a) and the second whipstock drill pipe (1b). It is set that the central axes of the two sections of whipstock drill pipes are both vertical. The whipstock drill pipe includes a spring tube (1-2) in the middle, and an upper joint pipe (1-1) and a lower joint pipe (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 spring-shaped pipe fitting formed by tightly winding or spaced winding of steel bars; the lower joint pipe (1-3) of the first whipstock drill pipe (1a) is connected to the upper joint pipe (1-1) of the second whipstock drill pipe (1b) through an inclinometer mechanism (2). The lower joint pipe (1-3) of the second whipstock drill pipe (1b) is connected to a hollow motor (3). The lower end of the hollow motor (3) is the output end and is connected to a drill bit (4). A continuous and cylindrical core-taking cavity is formed inside the first whipstock drill pipe (1a), the inclinometer mechanism (2), the second whipstock drill pipe (1b), the hollow motor (3) and the drill bit (4). The inclinometer mechanism (2) includes an inner tube (2-1) and an outer tube (2-2). Both the inner tube (2-1) and the outer tube (2-2) are hollow tubular structures. 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 whipstock 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 whipstock drill pipe (1b); an annular cavity is formed between the inner tube (2-1) and the outer tube (2-2). Seals (2-3) are respectively arranged at the upper and lower ends of the annular cavity. A first bearing (2-4) is arranged between the inner tube (2-1) and the outer tube (2-2). A steering 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); an inclinometer motor (2-6) and an ejecting device (2-7) are installed on the inner wall of the outer tube (2-2). The transmission shaft of the inclinometer motor (2-6) is in transmission connection with the ejecting device (2-7). The ejecting device (2-7) is provided with an ejecting member that can be ejected outside the outer wall of the outer tube (2-2) and retracted inside the outer wall of the outer tube (2-2) driven by the inclinometer motor (2-6).

2. The continuous whipstock coring drill tool according to claim 1, characterized in that: The upper and lower ends of the skeleton of the spring tube (1-2) of the whipstock drill pipe are respectively fixedly connected to the upper joint pipe (1-1) and the lower joint pipe (1-3). The upper joint pipe (1-1) and the lower joint pipe (1-3) of the whipstock drill pipe are mutually adapted. The upper and lower joint pipes at the upper and lower ends of the inner tube (2-1) of the inclinometer mechanism (2) are mutually adapted. One of the mutually adapted upper joint pipe and lower joint pipe is an external thread joint pipe, and the other is an internal thread joint pipe.

3. The continuous whipstock coring drill tool according to claim 1, characterized in that: A steering motor (2-5) is fixedly installed on the outer wall of the inner tube (2-1) of the inclinometer mechanism (2). A circular gear (2-8) is fixed in a circle along the horizontal direction on the inner wall of the outer tube (2-2). The transmission shaft of the steering motor (2-5) is provided with a gear and meshes with the circular gear (2-8).

4. The continuous whipstock coring drill tool according to claim 1, wherein: A direction monitor (2-9) is also fixedly installed on the inner wall of the outer tube (2-2).

5. The continuous whipstock coring drill tool according to claim 1, characterized in that: The whipstock motor (2-6) is fixedly installed on the inner wall of the outer pipe (2-2). The transmission shaft of the whipstock motor (2-6) is in transmission cooperation with the ejecting member of the ejecting device (2-7) through a reduction gear set (2-10). The outer pipe (2-2) is provided with a pushing hole adapted to the ejecting member. The ejecting member is located in the pushing hole and is in sealing cooperation with the hole wall of the pushing hole. The ejecting member is arranged radially along the outer pipe (2-2).

6. The continuous whipstock coring drill 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. Both the upper and lower ends of the stator (3-1) are 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 whipstock drill pipe (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 arranged between the stator (3-1) and the rotor (3-2). The second bearing (3-6) is located in the sealing cavity formed by the stator (3-1), the rotor (3-2) and the sealing ring (3-5).

7. The continuous whipstock coring drill tool according to any one of claims 1 to 6, characterized in that: The continuous whipstock coring drill also includes a wireline coring device installed in the coring cavity. The wireline coring device includes a coring pipe (5-1) and a limiting mechanism (5-2) connected to the upper end of the coring pipe (5-1). The coring pipe (5-1) includes a flexible pipe body and a skeleton embedded in the flexible pipe body. The skeleton is a helical steel wire. A fishing head (5-2-1) is provided at the top of the limiting mechanism (5-2). A clamping ear (5-2-2) for clamping with a card slot inside the straight drill pipe (6) is provided on the outer periphery of the limiting mechanism (5-2).

8. The continuous whipstock coring drill tool according to claim 7, wherein: At least one sliding seat (5-3) is arranged on the outer side of the coring pipe (5-1). The sliding seat (5-3) is provided with a ball groove. A ball (5-4) is installed in the ball groove. The ball (5-4) is in rolling cooperation with the cavity wall of the coring cavity. The lower end of the coring pipe (5-1) is fixedly connected to a guide pipe (5-5), and sliding seats (5-3) and balls (5-4) are provided on the outer side of the guide pipe (5-5).

9. Continuous deviation and coring method, characterized in that, Using the continuous whipstock coring drill according to any one of claims 1 to 8 above for drilling and coring includes the following steps: S1. Fix the upper end of the straight drill pipe (6) to the orifice drill rig, fix the lower end of the straight drill pipe (6) to the upper joint pipe (1-1) of the first whipstock drill pipe (1a), and place the wireline coring device into the coring cavity and fix it; S2. Adjust the orientation of the ejecting device (2-7) through the steering motor (2-5), control the two whipstock drill pipes to be straight or bent through the whipstock motor (2-6), then apply pressure to the straight drill pipe (6) through the orifice drill rig, and drive the drill bit (4) to rotate by using the hollow motor (3) to make the drill bit (4) break through the rock and drill. When the core fills the coring pipe (5-1) of the wireline coring device, stop drilling, take out the wireline coring device and obtain the core; S3. Place the wireline coring device into the coring cavity and fix it, and repeat step S2 until drilling reaches the target position.

10. The continuous whipstock coring method according to claim 9, characterized in that: A card slot is provided on the inner side of the lower end of the straight drill pipe (6). The wireline coring device includes a core barrel (5-1) and a limiting mechanism (5-2) connected to the upper end of the core barrel (5-1). A fishing head (5-2-1) is provided at the top of the limiting mechanism (5-2), and a lug (5-2-2) is provided on the outer periphery of the limiting mechanism (5-2). After the wireline coring device is placed into the coring cavity, the lug (5-2-2) automatically snaps into the card slot. Before the wireline coring device is placed into the coring cavity in step S3, a borehole inclinometer is placed into the coring cavity and the borehole trajectory from the hole mouth to the hole bottom is tested, and accordingly, the attitudes of the two sections of the deflecting drill pipes are adjusted by the deflecting motor (2-6).

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