Downhole torque controllable type horizontal well coring tool and method

Abstract

The invention relates to an underground torque controllable type horizontal well coring tool and method. The tool comprises a torque control structure, and the second end of the torque control structure is sequentially connected with a measurement-while-drilling structure, a screw drill structure, an automatic pitching structure and a coring structure; the torque control structure can be connected with the upper pipe column and the measurement-while-drilling structure so as to transmit the torque of the upper pipe column, or the torque control structure can be separated from the upper pipe column and the measurement-while-drilling structure so as to break the torque transmission of the upper pipe column; the automatic ball throwing structure can release the steel ball according to a pressure wave signal sent by the ground, and the steel ball can block the first end of the coring inner cylinder so that the coring inner cylinder can extend outwards to complete directional coring operation after the pump pressure rises. A coring drilling tool combination of a torque control structure, a measurement-while-drilling structure, a screw drilling tool structure, an automatic ball throwing structure and a coring structure is applied, continuous rotation of an upper tubular column above the torque control structure is achieved, and directional coring operation of a horizontal section is achieved through combination of the screw drilling tool structure and the coring structure.

Description

Technical Field

[0001] The present invention relates to the field of drilling coring technology in the field of petroleum and natural gas, in particular to horizontal well coring technology, and more particularly to a downhole torque-controllable horizontal well coring tool and method. Background Art

[0002] As the development of major domestic oil fields enters the middle and late stages, horizontal wells are increasingly used, but the reservoir heterogeneity is strong, so it is particularly important to analyze and study the physical properties of the horizontal section. The conventional vertical well coring data in the past did not provide sufficient guidance for the potential of remaining oil. It is urgent to carry out coring of the horizontal section of horizontal wells and subsequent analysis on site to accurately grasp the distribution law of the reservoir and provide theoretical basis and technical support for the overall effective development of the later oil reservoir. In addition, thin layers of 0.5-1 meters are always restricted areas for horizontal coring, and new horizontal cores are urgently needed on site.

[0003] Horizontal well construction is known as "threading a needle a thousand meters underground" because of its great construction difficulty, high technical requirements and many uncertain factors. Among them, the control of the horizontal wellbore trajectory is the key to coring. At present, a variety of drilling tool combinations are mostly used on site to optimize technical parameters and accurate software calculations to achieve precise landing of the inclined well section, improve the single-barrel footage and stable recovery rate of ultra-deep horizontal well coring. Horizontal well coring mostly adopts a composite drive (screw + top drive turntable) method to coring. Different from the stress conditions of conventional coring in vertical wells, composite drilling coring has more complex stress conditions for drill tools and uncertainty in the control ability of drill tool trajectory, which seriously affects the effective recovery rate of coring. In addition, due to the large friction torque and common support pressure in horizontal well coring, the drilling pressure cannot be effectively transmitted to the drill bit, the mechanical drilling speed is unstable, which is not conducive to core feeding and affects the integrity of the core.

[0004] Therefore, the inventor, relying on many years of experience and practice in related industries, proposes a downhole torque-controllable horizontal well coring tool and method to overcome the defects of the prior art. Summary of the invention

[0005] The purpose of the present invention is to provide a downhole torque-controllable horizontal well coring tool and method, so as to overcome the problems of difficult trajectory control, low coring mechanical drilling speed, low coring recovery rate and the like in the existing horizontal well coring, and apply a coring drill tool combination of a torque control structure + a measurement while drilling structure + a screw drill tool structure + an automatic ball throwing structure + a coring structure, so as to realize continuous rotation of the upper tubing above the torque control structure, and the combination of the screw drill tool structure and the coring structure realizes directional coring operations in the horizontal section.

[0006] The object of the present invention is achieved in this way. A downhole torque-controllable horizontal well coring tool comprises a torque control structure, wherein the first end of the torque control structure is used to connect the upper tubular column, and the second end of the torque control structure is sequentially connected to a measurement while drilling structure, a screw drill structure, an automatic ball throwing structure and a coring structure; the torque control structure can connect the upper tubular column and the measurement while drilling structure to transmit the torque of the upper tubular column, or the torque control structure can separate the upper tubular column and the measurement while drilling structure to disconnect the torque transmission of the upper tubular column; the torque control structure is When leaving the upper tubular column and the measurement while drilling structure, the screw drill tool structure can drive the measurement while drilling structure, the automatic ball-dropping structure and the coring structure to rotate synchronously; the coring structure includes a coaxially arranged coring outer cylinder and a coring inner cylinder, the first end of the coring outer cylinder is connected to the automatic ball-dropping structure, and the second end of the coring outer cylinder is connected to the coring drill bit; the automatic ball-dropping structure can release the steel ball according to the pressure wave signal sent from the ground, and the steel ball can block the first end of the coring inner cylinder so that the coring inner cylinder can extend outward after the pump pressure increases to complete the directional coring operation.

[0007] In a preferred embodiment of the present invention, the torque control structure includes a first shell, in which a torque controller, a torque control actuator, an upper clutch and a lower clutch are arranged, the torque controller is fixedly connected to the first shell; the torque control actuator is circumferentially fixedly connected to the torque controller; the upper clutch is circumferentially fixedly connected to the torque control actuator, and the torque control actuator can drive the upper clutch to move axially; the lower clutch and the first shell are arranged to be able to rotate circumferentially relative to each other, and the lower clutch is connected to the measurement while drilling structure; the torque controller controls the movement of the torque control actuator to make the upper clutch engage the lower clutch to transmit torque or to make the upper clutch disengage the lower clutch to disconnect torque transmission.

[0008] In a preferred embodiment of the present invention, a first pressure sensor is arranged in the first shell, and a first battery compartment and a torque control circuit are arranged in the torque controller. The first battery compartment is used to supply electric energy, and the torque control circuit is connected with the electrical signal of the first pressure sensor. The first pressure sensor receives the pressure wave signal transmitted from the ground and transmits it to the torque control circuit. The torque control circuit controls the torque control actuator according to the pressure wave signal to drive the upper clutch to move axially.

[0009] In a preferred embodiment of the present invention, the measurement while drilling structure includes a non-magnetic drill collar, in which a measurement while drilling instrument is arranged; the end of the lower clutch away from the upper clutch is connected to the center axis, the center axis is connected to the first end of the non-magnetic drill collar through a lower joint, and the second end of the non-magnetic drill collar is connected to the screw drill tool structure.

[0010] In a preferred embodiment of the present invention, the screw drill tool structure is a single-bend screw drill tool.

[0011] In a preferred embodiment of the present invention, the automatic pitching structure includes a second shell, in which a pitching controller is arranged, and the pitching controller is connected to a variable ball seat that can slide axially and extend radially, and the variable ball seat can shrink to fix the steel ball or radially open to release the steel ball.

[0012] In a preferred embodiment of the present invention, a second pressure sensor is arranged in the second shell, and the second pressure sensor receives the pressure wave signal transmitted from the ground and transmits it to the pitching controller. The pitching controller includes a telescopic rod, one end of which is connected to the variable ball seat. The pitching controller can control the telescopic rod to extend and push the variable ball seat until it opens radially to release the steel ball.

[0013] In a preferred embodiment of the present invention, a core cutting ball seat is provided at the first end of the core cutting inner cylinder, and the core cutting ball seat is connected to the core cutting outer cylinder through a shear pin; the steel ball can seal the core cutting ball seat, and the pump pressure at one end of the core cutting ball seat close to the automatic ball throwing structure is increased. After the pump pressure increases to a level greater than the shear force of the shear pin, the core cutting inner cylinder moves axially outward under the action of the pump pressure.

[0014] In a preferred embodiment of the present invention, the second end of the coring inner barrel is connected to a core claw and a clamp, the core claw is moved outward and tightened to complete the core cutting operation, and the clamp is used to clamp the core.

[0015] The object of the present invention can also be achieved in this way. A downhole torque-controllable horizontal well coring method comprises: lowering the downhole torque-controllable horizontal well coring tool into the well through an upper pipe string; under normal working conditions, a torque control structure connects the upper pipe string and a while-drilling measurement structure to transmit torque, and the while-drilling measurement structure, a screw drill tool structure, an automatic ball throwing structure and a coring structure rotate synchronously with the upper pipe string;

[0016] According to the pressure monitoring result, a pressure wave signal is sent from the ground to the wellbore, and the torque control structure separates the upper tubing and the measurement while drilling structure. The upper tubing continues to rotate continuously, and the measurement while drilling structure, the automatic ball-dropping structure and the coring structure rotate under the drive of the screw drill tool structure, and the coring drill bit drills the footage. After the drilling is completed, another wave of pressure wave signal is sent from the ground to the wellbore, and the automatic ball-dropping structure releases the steel ball, which seals the first end of the coring inner barrel. The coring inner barrel moves outward after the pump pressure increases, the core claw contracts to cut the core, the clamp clamps the core, and the entire coring tubing is lifted to the drilling platform to complete the coring.

[0017] As described above, the downhole torque controllable horizontal well coring tool and method of the present invention have the following beneficial effects:

[0018] The present invention adopts a coring drill tool combination of a torque control structure + a measurement while drilling structure + a screw drill tool structure + an automatic ball-dropping structure + a coring structure, which solves the problems of difficult trajectory control, low mechanical drilling speed of coring, and low coring recovery rate in horizontal well coring, and realizes continuous rotation of the upper pipe string above the torque control structure, which has the effect of reducing friction and drag and effectively transmitting drilling pressure; the coring operation is controllable through the automatic ball-dropping structure, and the screw drill tool structure and the coring structure are combined to realize directional coring operations in the horizontal section, and the coring structure can accurately and directional coring under the drive of the screw drill tool structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0020] in:

[0021] Figure 1 : It is a schematic diagram of the downhole torque controllable horizontal well coring tool of the present invention.

[0022] Figure 2a : is a schematic diagram of the torque control structure of the present invention when it is in a separated state.

[0023] Figure 2b : is a schematic diagram of the torque control structure of the present invention when it is in an engaged state.

[0024] Figure 3a : is a schematic diagram of the initial state of the automatic pitching structure of the present invention.

[0025] Figure 3b : It is a schematic diagram of the pitching state of the automatic pitching structure of the present invention.

[0026] In the figure:

[0027] 1. First housing; 2. Torque controller; 3. First pressure sensor; 4. First battery compartment; 5. Torque control circuit; 6. Torque control actuator; 7. Upper clutch; 8. Lower clutch; 9. Center shaft; 10. Lower joint; 11. Non-magnetic drill collar; 12. Drilling while drilling instrument; 13. Screw drill tool structure; 14. Second housing; 15. Second pressure sensor; 16. Ball throwing controller; 17. Variable ball seat; 18. Steel ball; 19. Core cutting ball seat; 20. Shear pin; 21. Coring outer cylinder; 22. Coring inner cylinder; 23. Clamp; 24. Core claw; 25. Coring drill bit. DETAILED DESCRIPTION

[0028] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0029] The specific embodiments of the present invention described herein are only used to explain the purpose of the present invention and cannot be understood as limiting the present invention in any way. Under the guidance of the present invention, technicians can conceive of any possible variations based on the present invention, which should be considered to belong to the scope of the present invention. It should be noted that when an element is referred to as "arranged on" another element, it can be directly on the other element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a central element at the same time. The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two elements, it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation method.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0031] like Figure 1 As shown, the present invention provides a downhole torque-controllable horizontal well coring tool, including a torque control structure, a first end of the torque control structure is used to connect the upper pipe string, and a second end of the torque control structure is sequentially connected to a measurement while drilling structure, a screw drill tool structure 13, an automatic ball throwing structure and a coring structure;

[0032] The torque control structure can connect the upper tubular string and the measurement while drilling structure to transmit the torque of the upper tubular string, or the torque control structure can separate the upper tubular string and the measurement while drilling structure (MWD / LWD) to disconnect the torque transmission of the upper tubular string;

[0033] When the torque control structure separates the upper pipe string and the measurement while drilling structure, the screw drill tool structure 13 can drive the measurement while drilling structure, the automatic ball throwing structure and the coring structure to rotate synchronously; at this time, the upper pipe string (existing technology) can be rotated continuously in the forward direction through the turntable (existing technology), which has the effect of reducing friction and drag and effectively transmitting drilling pressure;

[0034] The coring structure includes a coaxially arranged coring outer cylinder 21 and a coring inner cylinder 22, the first end of the coring outer cylinder 21 is connected to the automatic ball throwing structure, and the second end of the coring outer cylinder 21 is connected to the coring drill bit 25; the automatic ball throwing structure can release the steel ball 18 according to the pressure wave signal sent from the ground, and the steel ball 18 can block the first end of the coring inner cylinder 22 so that the coring inner cylinder 22 extends outward after the pump pressure increases to complete the directional coring operation. The screw drill structure 13 is combined with the coring structure to realize the directional coring operation of the horizontal section.

[0035] The present invention solves the problems of poor borehole quality and difficulty in cleaning cuttings in horizontal wells: In the prior art, during the drilling of inclined well sections and horizontal sections, the drill bit rotates and slides against the high side or bottom side of the well wall, which easily forms irregular boreholes such as keyways and candied haws, resulting in poor borehole quality. During the drilling cycle, due to the effect of gravity, cuttings are deposited on the bottom of the wellbore and accumulate to form a cuttings bed. Since the bottom cuttings bed can only move a certain distance and then accumulate again, the thickness of the cuttings bed becomes thinner, and a new cuttings bed height is formed again, resulting in greater difficulty in cleaning cuttings in the wellbore. The torque control structure can effectively control the torque transmission. When the torque control structure is in a disconnected state, the upper pipe string can rotate continuously in the forward direction to avoid the deposition of cuttings in the wellbore, thus solving the problems of poor borehole quality and difficulty in cleaning cuttings in horizontal wells.

[0036] The present invention solves the problem of difficulty in controlling the coring trajectory: In the prior art, when coring directional wells and horizontal wells (dense formations), composite drive (screw + top drive / rotary table) is often used for coring. Therefore, the stress conditions of composite drilling coring tools are different from those of conventional power-driven coring tools. The stress conditions of the composite drilling coring tools are complex, and the deflection capacity of the tools is uncertain. When the torque control structure is disconnected, the screw drill tool structure 13 can drive the measurement while drilling structure, the automatic ball throwing structure and the coring structure to rotate synchronously. The coring tool is simply stressed and the coring trajectory can be effectively controlled.

[0037] The present invention solves the problem of low drilling speed of coring machinery: in the prior art, when coring directional wells and horizontal wells, the friction between the drill and the well wall is large, and the drilling pressure and torque cannot be effectively applied to the drill bit when the rotary table / top drive is used, resulting in large losses of drilling pressure and torque, resulting in low drilling speed of the coring machine. When the torque control structure is in a disconnected state, the screw drill structure 13 can drive the measurement while drilling structure, the automatic ball throwing structure and the coring structure to rotate synchronously, and the drilling speed of the coring machinery is stable and controllable.

[0038] The downhole torque-controllable horizontal well coring tool of the present invention adopts a coring drill tool combination of a torque control structure + a measurement while drilling structure (MWD / LWD instrument) + a screw drill tool structure (low-speed screw) + an automatic ball-dropping structure + a coring structure, which solves the problems of difficult trajectory control, low mechanical drilling speed of coring, and low coring recovery rate in horizontal well coring, and realizes continuous rotation of the upper pipe string above the torque control structure, which has the effect of reducing friction and drag and effectively transmitting drilling pressure; the coring operation is controllable through the automatic ball-dropping structure, and the screw drill tool structure and the coring structure are combined to realize directional coring operations in the horizontal section, and the coring structure can accurately and directional coring under the drive of the screw drill tool structure.

[0039] Further, if Figure 1 As shown, the torque control structure includes a first shell 1, in which a torque controller 2, a torque control actuator 6, an upper clutch 7 and a lower clutch 8 are arranged, the torque controller 2 is fixedly connected to the first shell 1; the torque control actuator 6 is circumferentially fixedly connected to the torque controller 2; the upper clutch 7 is circumferentially fixedly connected to the torque control actuator 6, and the torque control actuator 6 can drive the upper clutch 7 to move axially; the lower clutch 8 and the first shell 1 are arranged to be circumferentially rotatable relative to each other, and the lower clutch 8 is connected to the measurement while drilling structure; the torque controller 2 controls the movement of the torque control actuator 6 to make the upper clutch 7 engage the lower clutch 8 to transmit torque or to make the upper clutch 7 disengage the lower clutch 8 to disconnect the torque transmission.

[0040] Further, if Figure 1 As shown, a first pressure sensor 3 is arranged in the first shell 1, and a first battery compartment 4 and a torque control circuit 5 are arranged in the torque controller 2. The first battery compartment 4 is used to supply electric energy. The torque control circuit 5 is connected with the first pressure sensor 3 by electrical signals. The first pressure sensor 3 receives the pressure wave signal transmitted from the ground and transmits it to the torque control circuit 5. The torque control circuit 5 controls the torque control actuator 6 according to the pressure wave signal to drive the upper clutch 7 to move axially.

[0041] Further, if Figure 1 As shown, the measurement while drilling structure includes a non-magnetic drill collar 11, in which a measurement while drilling instrument 12 (MWD / LWD instrument) is arranged; the end of the lower clutch 8 away from the upper clutch 7 is connected to the central axis 9, and the central axis 9 is connected to the first end of the non-magnetic drill collar 11 through the lower joint 10, and the second end of the non-magnetic drill collar 11 is connected to the screw drilling tool structure 13.

[0042] Furthermore, the screw drill structure 13 is a single-bend screw drill.

[0043] The ground sends a group of signals in the form of mud pressure waves, and the first pressure sensor 3 in the first housing 1 receives the pressure wave signal transmitted from the ground. The downhole electro-hydraulic system is powered by the first battery compartment 4, and the system drives the torque control actuator 6 through the torque control circuit 5 to perform the engagement of the upper and lower clutches. Figure 2b As shown, and separated as Figure 2a As shown, the torque is transmitted / disconnected from the upper pipe string to the measurement while drilling structure, the screw drilling tool structure 13, the automatic ball throwing structure and the coring structure (lower pipe string). When the torque is disconnected, the upper pipe string can be rotated forward by the turntable (existing technology), which has the effect of reducing friction and resistance and effectively transmitting drilling pressure. The measurement while drilling structure, the automatic ball throwing structure and the coring structure perform horizontal section coring operations under the drive of the low-speed single-bend screw drilling tool (screw drilling tool structure 13).

[0044] Further, if Figure 1 As shown, the automatic pitching structure includes a second shell 14, in which a pitching controller 16 is arranged. The pitching controller 16 is connected to a variable ball seat 17 which can slide axially and extend radially. The variable ball seat 17 can shrink and fix the steel ball 18 or radially expand and release the steel ball 18.

[0045] Further, if Figure 1 As shown, a second pressure sensor 15 is arranged in the second shell 14. The second pressure sensor 15 receives the pressure wave signal transmitted from the ground and transmits it to the pitching controller 16. The pitching controller 16 includes a telescopic rod, one end of which is connected to a variable ball seat 17. The pitching controller 16 can control the telescopic rod to extend and push the variable ball seat until it opens radially to release the steel ball.

[0046] The variable ball seat 17 is initially in a state where the ball is not released. Figure 3a As shown, the steel ball 18 is preset in the variable ball seat 17; when the steel ball 18 needs to be released, the ground sends a set of mud pressure wave instructions, the second pressure sensor 15 in the second shell 14 receives the pressure wave signal transmitted from the ground, the telescopic rod of the ball throwing controller 16 extends, the front end of the telescopic rod is connected to the variable ball seat 17, the telescopic rod pushes the variable ball seat 17 to move axially, the second shell 14 is provided with an inner diameter expansion area, the variable ball seat 17 opens radially, the steel ball 18 is released, and the steel ball 18 moves down to the core inner cylinder 22, as shown in FIG. Figure 3b shown.

[0047] Further, if Figure 1 As shown, a core cutting ball seat 19 is provided at the first end of the core cutting inner cylinder 22, and the core cutting ball seat 19 is connected to the core cutting outer cylinder 21 through a shear pin 20; the steel ball 18 can block the core cutting ball seat 19, and the pump pressure at one end of the core cutting ball seat 19 close to the automatic ball throwing structure increases. After the pump pressure increases to a level greater than the shear force of the shear pin 20, the core cutting inner cylinder 22 moves axially outward under the action of the pump pressure.

[0048] Further, if Figure 1 As shown, the second end of the coring inner tube 22 is connected to the core claw 24 and the clamp 23. The core claw 24 is moved outward and tightened to complete the core cutting operation, and the clamp 23 is used to clamp the core.

[0049] The torque control structure is in the separated state, and the normal coring operation is carried out. After the coring drill bit 25 is drilled, the steel ball 18 is released into the core cutting ball seat 19, the pump pressure is increased and the shear pin 20 is cut off, the core claw 24 is moved outward and tightened, the core cutting operation is completed, the clamp 23 clamps the core, and the entire coring string is lifted to the drilling platform to complete the coring. At this point, the entire torque controllable horizontal well coring operation is completed.

[0050] The present invention also provides a downhole torque controllable horizontal well coring method, comprising:

[0051] The aforementioned downhole torque controllable horizontal well coring tool is lowered into the well through the upper tubing string; under normal working conditions, the torque control structure connects the upper tubing string and the while drilling measurement structure to transmit torque, and the while drilling measurement structure, the screw drill tool structure 13, the automatic ball throwing structure and the coring structure rotate synchronously with the upper tubing string;

[0052] When the pressure support problem becomes more and more serious, orientation becomes more and more difficult. According to the pressure monitoring result, a pressure wave signal (mud pressure wave pulse signal) is sent from the ground to the wellbore, and the torque control structure separates the upper pipe string and the while drilling measurement structure. The upper pipe string continues to rotate continuously, and the while drilling measurement structure, the automatic ball throwing structure and the coring structure rotate under the action of the screw drill tool structure 13, and the coring drill bit 25 drills the footage; after the drilling is completed, the ground sends another wave of pressure wave signal (mud pressure wave pulse signal) to the wellbore, and the automatic ball throwing structure releases the steel ball 18, and the steel ball 18 blocks the first end of the coring inner tube 22. The coring inner tube 22 moves outward after the pump pressure increases, the core claw 24 contracts to cut the core, and the clamp 23 clamps the core, and the entire coring pipe string is lifted to the drilling platform to complete the coring.

[0053] In a specific embodiment of the present invention,

[0054] For long horizontal wells, large displacement wells, and five-section directional wells, the downhole torque-controllable horizontal well coring tool is installed in the coring string (the upper string above the tool) when conventional coring operations are used. When the pressure problem becomes more and more serious, orientation becomes more and more difficult. At this time, the ground sends a mud pressure wave pulse signal to the downhole, and the torque control structure starts to work, so that the upper and lower torques of the torque control structure are separated. At this time, the turntable can drive the upper string to rotate continuously at a speed of 30r / min, and the screw drill structure applies a small drilling pressure to perform coring drilling. When the footage is completed, the ground sends another wave of mud pressure wave pulse signals to the downhole, and the automatic ball throwing structure pushes the variable ball seat 17 to release the steel ball 18, and the steel ball 18 falls into the core cutting ball seat 19, and the pressure of 8MPa is held to cut the shear pin 20, the core inner tube 22 moves outward, and the core claw 24 contracts to cut the core, and the core cutting operation is completed by lifting 10 tons. The entire coring string is pulled out and the core is taken out on the ground.

[0055] As described above, the downhole torque controllable horizontal well coring tool and method of the present invention have the following beneficial effects:

[0056] The present invention adopts a coring drill tool combination of a torque control structure + a measurement while drilling structure + a screw drill tool structure + an automatic ball-dropping structure + a coring structure, which solves the problems of difficult trajectory control, low mechanical drilling speed of coring, and low coring recovery rate in horizontal well coring, and realizes continuous rotation of the upper pipe string above the torque control structure, which has the effect of reducing friction and drag and effectively transmitting drilling pressure; the coring operation is controllable through the automatic ball-dropping structure, and the screw drill tool structure and the coring structure are combined to realize directional coring operations in the horizontal section, and the coring structure can accurately and directional coring under the drive of the screw drill tool structure.

[0057] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A downhole torque controllable horizontal well coring tool, characterized in that: The invention comprises a torque control structure, wherein the first end of the torque control structure is used to connect the upper tubular column, and the second end of the torque control structure is sequentially connected to a measurement while drilling structure, a screw drill structure, an automatic ball dropping structure and a coring structure; the torque control structure can connect the upper tubular column and the measurement while drilling structure to transmit the torque of the upper tubular column, or the torque control structure can separate the upper tubular column and the measurement while drilling structure to disconnect the torque transmission of the upper tubular column; When the torque control structure separates the upper tubular column and the measurement while drilling structure, the screw drill tool structure can drive the measurement while drilling structure, the automatic ball-dropping structure and the coring structure to rotate synchronously; the coring structure includes a coaxially arranged coring outer cylinder and a coring inner cylinder, the first end of the coring outer cylinder is connected to the automatic ball-dropping structure, and the second end of the coring outer cylinder is connected to the coring drill bit; the automatic ball-dropping structure can release a steel ball according to a pressure wave signal sent from the ground, and the steel ball can block the first end of the coring inner cylinder so that the coring inner cylinder extends outward after the pump pressure increases to complete the directional coring operation.

2. The downhole torque controllable horizontal well coring tool according to claim 1, characterized in that: The torque control structure comprises a first housing, in which a torque control instrument, a torque control actuator, an upper clutch and a lower clutch are arranged, the torque control instrument is fixedly connected to the first housing; the torque control actuator is circumferentially fixedly connected to the torque control instrument; the upper clutch is circumferentially fixedly connected to the torque control actuator, and the torque control actuator can drive the upper clutch to move axially; the lower clutch and the first housing are arranged to be circumferentially rotatable relative to each other, and the lower clutch is connected to the measurement while drilling structure; The torque controller controls the torque control actuator to move so that the upper clutch engages with the lower clutch to transmit torque or the upper clutch disengages from the lower clutch to stop torque transmission.

3. The downhole torque controllable horizontal well coring tool according to claim 2, characterized in that: A first pressure sensor is arranged in the first shell, and a first battery compartment and a torque control circuit are arranged in the torque controller. The first battery compartment is used to supply electric energy. The torque control circuit is connected with the electrical signal of the first pressure sensor. The first pressure sensor receives the pressure wave signal transmitted from the ground and transmits it to the torque control circuit. The torque control circuit controls the torque control actuator according to the pressure wave signal to drive the upper clutch to move axially.

4. The downhole torque controllable horizontal well coring tool according to claim 2, characterized in that: The measurement while drilling structure includes a non-magnetic drill collar, in which a measurement while drilling instrument is arranged; the end of the lower clutch away from the upper clutch is connected to the central axis, the central axis is connected to the first end of the non-magnetic drill collar through a lower joint, and the second end of the non-magnetic drill collar is connected to the screw drilling tool structure.

5. The downhole torque controllable horizontal well coring tool according to claim 2, characterized in that: The screw drill tool structure is a single-bend screw drill tool.

6. The downhole torque controllable horizontal well coring tool according to claim 2, characterized in that: The automatic pitching structure includes a second shell, in which a pitching controller is arranged. The pitching controller is connected to a variable ball seat that can slide axially and expand radially. The variable ball seat can shrink and fix the steel ball or expand radially to release the steel ball.

7. The downhole torque controllable horizontal well coring tool according to claim 6, characterized in that: A second pressure sensor is arranged in the second shell, and the second pressure sensor receives the pressure wave signal transmitted from the ground and transmits it to the pitching controller. The pitching controller includes a telescopic rod, one end of which is connected to the variable ball seat. The pitching controller can control the telescopic rod to extend and push the variable ball seat until it opens radially to release the steel ball.

8. The downhole torque controllable horizontal well coring tool according to claim 1, characterized in that: A core cutting ball seat is arranged at the first end of the core cutting inner cylinder, and the core cutting ball seat is connected to the core cutting outer cylinder through a shear pin; the steel ball can seal the core cutting ball seat, and the pump pressure at one end of the core cutting ball seat close to the automatic ball throwing structure increases. After the pump pressure increases to a level greater than the shear force of the shear pin, the core cutting inner cylinder moves outward along the axial direction under the action of the pump pressure.

9. The downhole torque controllable horizontal well coring tool according to claim 8, characterized in that: The second end of the coring inner cylinder is connected to a core claw and a clamp. The core claw is moved outward and tightened to complete the core cutting operation, and the clamp is used to clamp the core.

10. A downhole torque controllable horizontal well coring method, characterized in that: include: Lowering the downhole torque controllable horizontal well coring tool according to any one of claims 1 to 9 into the well through an upper pipe string; Under normal working conditions, the torque control structure connects the upper pipe string and the measurement while drilling structure to transmit torque, and the measurement while drilling structure, the screw drill structure, the automatic ball throwing structure and the coring structure rotate synchronously with the upper pipe string; According to the pressure monitoring result, a pressure wave signal is sent from the ground to the wellbore, and the torque control structure separates the upper tubing and the measurement while drilling structure. The upper tubing continues to rotate continuously, and the measurement while drilling structure, the automatic ball-dropping structure and the coring structure rotate under the drive of the screw drill tool structure, and the coring drill bit drills the footage. After the drilling is completed, another wave of pressure wave signal is sent from the ground to the wellbore, and the automatic ball-dropping structure releases the steel ball, which seals the first end of the coring inner barrel. The coring inner barrel moves outward after the pump pressure increases, the core claw contracts to cut the core, the clamp clamps the core, and the entire coring tubing is lifted to the drilling platform to complete the coring.

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