A multi-angle drilling device for shale gas extraction

Abstract

The present application provides a multi-angle drilling device for shale gas extraction, which belongs to the technical field of shale gas extraction equipment and solves the problem that existing drilling equipment is generally difficult to achieve sharp turn drilling and difficult to adjust the drilling direction. Among them, the multi-angle drilling device for shale gas extraction includes: a hollow main body extending along a first direction, having a first end and a second end along the first direction; a plurality of drilling mechanisms, evenly distributed at the first end along the circumference of the main body; the drilling mechanism includes a bracket, an eccentric drill bit, a drill bit drive assembly and a direction adjustment assembly; the bracket is rotatably connected to the first end around a reference axis, and the reference axis is tangent to the circumference of the main body; the direction adjustment assembly drives the bracket to rotate relative to the first end; the eccentric drill bit is rotatably connected to the bracket, and the axial direction of the drill bit is inclined with respect to the extension direction of the bracket; the drill bit drive assembly drives the eccentric drill bit to rotate relative to the bracket. The present application can adjust the drilling direction and achieve sharp turn drilling.

Description

Technical Field

[0001] The present application relates to the technical field of shale gas extraction equipment, and in particular to a multi-angle drilling equipment for shale gas extraction. Background Art

[0002] The porosity and matrix permeability of plateau continental shale gas reservoirs are extremely low, with basically no natural production capacity. In addition, they are deeply buried and have high formation pressure. They must be developed economically and efficiently through fracturing, so fracturing is one of the main technologies for shale gas development.

[0003] Before fracturing a shale reservoir, drilling equipment is required to drill a hole into the shale reservoir and carry the fracturing equipment to the shale reservoir. During the drilling process, due to the influence of formation development conditions and subsequent geological structures, the spatial distribution characteristics of the shale reservoir are not completely horizontal or nearly horizontal. For example, the shale reservoir may experience sudden changes in thickness, inclination angle, faults, etc. in local areas of the spatial plane distribution. This requires adjusting the drilling angle according to the changes in the shale reservoir during the drilling process.

[0004] However, existing drilling equipment is usually difficult to achieve sharp turn drilling and can usually only make large radius turns. It is difficult to adjust the drilling direction in real time and cannot meet the needs of shale gas extraction in shale reservoirs with complex geological conditions. Summary of the Invention

[0005] In view of the above analysis, this application aims to provide a multi-angle drilling equipment for shale gas extraction, which solves the problem that drilling equipment in the prior art is usually difficult to achieve small radius sharp turn drilling and difficult to adjust the drilling direction in real time.

[0006] The purpose of this application is mainly achieved through the following technical solutions:

[0007] An embodiment of the present application provides a multi-angle drilling device for shale gas extraction, comprising: a hollow main body extending in a first direction, having a first end and a second end along the first direction; a plurality of drilling mechanisms evenly distributed at the first end along the circumference of the main body; the drilling mechanism comprising a bracket, an eccentric drill bit, a drill bit drive assembly and a direction adjustment assembly; the bracket is rotatably connected to the first end around a reference axis, and the reference axis is tangent to the circumference of the main body; the direction adjustment assembly drives the bracket to rotate relative to the first end; the eccentric drill bit is rotatably connected to the bracket, and the axial direction of the drill bit is inclined to the extension direction of the bracket; the drill bit drive assembly can drive the eccentric drill bit to rotate relative to the bracket.

[0008] In an embodiment of the present application, the bracket includes a protrusion, which faces the inner side of the main body; the direction adjustment assembly includes a hydraulic cylinder, one end of the hydraulic cylinder is connected to the inner side of the main body, and the other end is connected to the protrusion.

[0009] In the embodiment of the present application, the eccentric drill bit is conical in shape and has a threaded protrusion on the side. The axial direction of the eccentric drill bit forms an obtuse angle with the inner side of the bracket; the drill drive assembly is arranged on the inner side of the bracket.

[0010] In the embodiment of the present application, there are four drilling mechanisms. Among the two drilling mechanisms opposite to each other along the circumference of the main body, one rotates inwardly relative to the main body, and the other rotates outwardly.

[0011] In the embodiment of the present application, it also includes a first state and a second state; in the first state, the extension direction of each bracket is parallel to the first direction; in the second state, two adjacent drilling mechanisms rotate inward relative to the main body, and the other two drilling mechanisms rotate outward relative to the main body.

[0012] In an embodiment of the present application, a flexible sealing tube and a control component are also included. The control component includes a first signal line and a second signal line. The drill drive component and the control component are electrically connected through the first signal line, and the direction adjustment component and the control component are electrically connected through the second signal line. The first signal line and the second signal line are both arranged in the flexible sealing tube.

[0013] In an embodiment of the present application, the main body includes: an inner tube and an outer tube arranged coaxially, the inner tube and the outer tube being connected by multiple connecting parts; a liquid supply part, connected between the outer tube and the inner tube; and a liquid extraction part, connected to the inner tube.

[0014] In an embodiment of the present application, the main body also includes: a first outer sleeve, which is sleeved on the outside of the outer tube and fixedly connected to the outer tube; a second outer sleeve, which is sleeved on the outside of the outer tube, the second outer sleeve is rotatably connected to the first outer sleeve, and the second outer sleeve is located on the side of the first outer sleeve close to the first end; and the bracket is connected to the second outer sleeve.

[0015] In the embodiment of the present application, the first outer sleeve is provided with a protrusion extending along the first direction, and the outer diameter of the protrusion is larger than the outer diameter of the first outer sleeve.

[0016] In the embodiment of the present application, the inner diameter of the inner tube is D1, the outer diameter of the inner tube is D2, and the inner diameter of the outer tube is D3, wherein D1>(D3-D2) / 2.

[0017] In the multi-angle drilling equipment for shale gas extraction provided in an embodiment of the present application, multiple drilling mechanisms are arranged along the circumference of the main body. During straight-line drilling, the bracket extends in a direction parallel to the first direction, and the main body pushes each drilling mechanism forward in the first direction. At this time, the eccentric drill bit can crush the shale rock mass in front. During turning, the bracket rotates inward relative to the main body. At this time, the eccentric drill bit can crush the shale rock mass in the turning direction, driving the main body to turn. Because multiple drilling mechanisms are provided, small-radius turns can be achieved in various directions relative to the first direction, enabling multi-angle drilling in the multi-angle drilling equipment for shale gas extraction of the embodiment of the present application, thereby meeting the requirements for shale reservoir extraction and drilling under complex geological conditions.

[0018] In this application, the above-mentioned technical solutions can be combined with each other to achieve more preferred combination solutions. Other features and advantages of this application will be described in the subsequent description, and some advantages will become apparent from the description or be understood by practicing this application. The objectives and other advantages of this application can be achieved and obtained through the contents particularly pointed out in the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered as limiting the present application. Like reference symbols denote like components throughout the drawings.

[0020] Figure 1 This is a structural schematic diagram of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application.

[0021] Figure 2 This is a schematic diagram of the internal structure of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application.

[0022] Figure 3 This is a structural schematic diagram of the drilling mechanism of the multi-angle drilling equipment used for shale gas extraction in an embodiment of the present application.

[0023] Figure 4 This is a structural schematic diagram of the main body of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application.

[0024] Figure 5 This is a cross-sectional view of the main body of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application.

[0025] Figure 6 A control schematic diagram of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application.

[0026] Figure 7 This is another structural schematic diagram of the multi-angle drilling equipment for shale gas extraction according to an embodiment of the present application.

[0027] Figure 8 This is a structural schematic diagram of the first outer casing and the second outer casing of the multi-angle drilling equipment for shale gas extraction in an embodiment of the present application.

[0028] Figure 9 This is a schematic diagram of the dimensions of the main body of the multi-angle drilling equipment for shale gas extraction according to an embodiment of the present application.

[0029] Reference numerals:

[0030] 1. Main body; 11. Inner tube; 12. Outer tube; 13. First outer sleeve; 14. Second outer sleeve; 15. Connecting part;

[0031] 2. Drilling mechanism; 21. Bracket; 211. Protrusion; 22. Off-axis drill bit; 23. Drill bit drive assembly; 24. Direction adjustment assembly;

[0032] 3. Control component; 31. First signal line; 32. Second signal line;

[0033] 4. Flexible sealing tube. DETAILED DESCRIPTION

[0034] The preferred embodiments of the present application are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present application and are used together with the embodiments of the present application to illustrate the principles of the present application, and are not used to limit the scope of the present application.

[0035] In the description of the embodiments of this application, it should be noted that, unless otherwise expressly specified or limited, the term "connected" should be understood in a broad sense. For example, it can mean a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection, an electrical connection, a direct connection, or an indirect connection through an intermediate medium. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0036] The terms "top," "bottom," "above," "below," and "on" used throughout the description refer to relative positions of components of a device, such as the relative positions of top and bottom substrates within a device. It will be understood that devices are multifunctional regardless of their orientation in space.

[0037] The applicant discovered that when using drilling equipment to extract shale gas, the extraction equipment is inserted into the underground shale reservoir through the drilling equipment. The drill bit of the drilling equipment is usually set at the head of the drilling equipment, and the shale reservoir is excavated through the drill bit. Considering that the drill bit is usually fixed to the end of the drilling equipment, the drilling equipment can usually only form a straight hole or an arc hole with a large radius. Therefore, it is necessary to explore the spatial distribution characteristics of the underground rock formation in advance and determine the drilling path based on the spatial distribution characteristics of the target shale reservoir. When encountering a shale reservoir with complex geological conditions, once it becomes difficult to continue drilling in the middle, it is necessary to retreat and adjust the drilling path again, which reduces the efficiency of drilling and greatly increases the cost.

[0038] In view of the above problems, the applicant has proposed a multi-angle drilling device for shale gas extraction, comprising a main body and multiple drilling mechanisms. The multiple drilling mechanisms are arranged along the circumference of the main body, a direction adjustment assembly drives the bracket to rotate relative to the first end, and the drill bit drive assembly can drive the eccentric drill bit to rotate relative to the bracket. During straight drilling, the extension direction of the bracket is parallel to the first direction, and the main body pushes each drilling mechanism forward in the first direction. At this time, the eccentric drill bit can crush the shale rock mass in front; when turning, the bracket rotates toward the inside of the turning direction relative to the main body. At this time, the eccentric drill bit can crush the shale rock mass in the turning direction, driving the main body to turn. Since there are multiple drilling mechanisms, small radius turns can be achieved in various directions relative to the first direction, realizing multi-angle drilling of the multi-angle drilling device for shale gas extraction of the embodiment of the present application.

[0039] Figure 1 This is a structural schematic diagram of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application. Figure 2 This is a schematic diagram of the internal structure of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application.

[0040] See also Figure 1 and Figure 2 , an embodiment of the present application provides a multi-angle drilling equipment for shale gas extraction, comprising: a hollow main body 1, extending along a first direction, having a first end and a second end along the first direction; a plurality of drilling mechanisms 2, uniformly distributed at the first end along the circumference of the main body 1; the drilling mechanism 2 comprises a bracket 21, an eccentric drill bit 22, a drill bit drive assembly 23 and a direction adjustment assembly 24; the bracket 21 is rotatably connected to the first end around a reference axis, and the reference axis is tangent to the circumference of the main body 1; the direction adjustment assembly 24 drives the bracket 21 to rotate relative to the first end; the eccentric drill bit 22 is rotatably connected to the bracket 21, and the axial direction of the drill bit is inclined to the extension direction of the bracket 21; the drill bit drive assembly 23 can drive the eccentric drill bit 22 to rotate relative to the bracket 21.

[0041] In the embodiment of the present application, the main body 1 is generally cylindrical in shape, and its axial direction is the first direction. The direction from the second end to the first end is the forward direction of the multi-angle drilling device in the embodiment of the present application.

[0042] The drilling mechanism 2 is used for drilling and excavation. Multiple drilling mechanisms 2 are evenly distributed along the circumference of the main body 1 at the first end. Each drilling mechanism 2 has the same structure. A bracket 21 is rotatably connected to the first end of the main body 1 and rotates relative to the first end of the main body 1 about a reference axis parallel to a tangent to the bracket 21's connection with the first end. A direction adjustment assembly 24 drives the bracket 21 to rotate relative to the first end, allowing the bracket 21 to rotate inward or outward relative to the main body 1. The axis of the eccentric drill bit 22 forms an obtuse angle with the extension direction of the bracket 21, so the tip of the eccentric drill bit 22 is not fully oriented in the first direction. The drill bit drive assembly 23 drives the eccentric drill bit 22 to rotate relative to the bracket 21. During linear drilling, the extension direction of the bracket 21 can be aligned parallel to the first direction, allowing the applied force to be transferred in the first direction. Simultaneously, the simultaneous rotation of multiple eccentric drill bits 22 can break up the shale ahead of the linear drilling direction, advancing in a straight line with the main body 1. When it is necessary to drill a hole in a turn, the bracket 21 can be rotated toward the inside of the bend, that is, among the multiple drilling mechanisms 2, the bracket 21 of the drilling mechanism 2 located on the inside of the bend is rotated toward the outside of the main body 1, and the bracket 21 of the drilling mechanism 2 located on the outside of the bend is rotated toward the inside of the main body 1. From a holistic perspective, the multiple drilling mechanisms 2 rotate toward the inside of the bend. As the drilling excavation continues, the multi-angle drilling equipment of the embodiment of the present application can be flexibly turned to form a curved borehole.

[0043] When using the multi-angle drilling equipment of the present invention to perform drilling operations, the drilling direction can be adjusted in real time based on the actual underground rock conditions detected during the drilling process, thereby reducing the probability of backtracking, improving drilling efficiency, and reducing drilling costs. It can also complete small-radius turning drilling, which is more conducive to drilling path planning.

[0044] Figure 3 This is a structural schematic diagram of the drilling mechanism of the multi-angle drilling equipment used for shale gas extraction in an embodiment of the present application.

[0045] Further, see Figure 3 , and combined with Figure 1 and Figure 2 The bracket 21 includes a protrusion 211, which faces the inner side of the main body 1; the direction adjustment component 24 includes a hydraulic cylinder, one end of the hydraulic cylinder is connected to the inner side of the main body 1, and the other end is connected to the protrusion 211.

[0046] Considering that the support 21 must provide sufficient support for the drill bit, in this embodiment of the present application, the direction adjustment assembly 24 utilizes a hydraulic cylinder to drive the support 21 to rotate relative to the first end. The hydraulic cylinder also serves to fix the angle between the extension direction of the support 21 and the first direction. The hydraulic cylinder, the protrusion 211, and the main body 1 form a triangular support structure, providing stable support for the support 21 and enabling the extension direction of the support 21 to be parallel to or intersecting with the first direction.

[0047] Further, see Figures 1 to 3 The eccentric drill bit 22 is conical and has a threaded protrusion on the side. The axial direction of the eccentric drill bit 22 forms an obtuse angle with the inner side of the bracket 21; the drill bit driving assembly 23 is arranged on the inner side of the bracket 21.

[0048] The conical shape of the off-axis drill bit 22 facilitates drilling into shale rock. The threaded protrusions guide the rock debris generated by the off-axis drill bit 22 backwards, allowing it to be discharged through the main body 1 to prevent blockage of the drill hole. Furthermore, the axial direction of the off-axis drill bit 22 forms an obtuse angle with the inner side of the bracket 21, directing the rock debris inside the main body 1 for easy discharge. The drill drive assembly 23 is located inside the bracket 21, preventing it from interfering with the forward movement of the multi-angle drilling apparatus of this embodiment.

[0049] Further, see Figures 1 to 3 There are four drilling mechanisms 2. Among the two drilling mechanisms 2 opposite to each other along the circumference of the main body 1, one rotates inwardly and the other rotates outwardly relative to the main body 1.

[0050] In the embodiment of the present application, the number of drilling mechanisms 2 can be but is not limited to four. The four drilling mechanisms 2 are opposite to each other in pairs, and the two opposite drilling mechanisms 2 can rotate synchronously, and one rotates inward and the other rotates outward, so that the two drilling mechanisms 2 as a whole rotate toward the inner side of the turning drilling.

[0051] Furthermore, the multi-angle drilling equipment of the embodiment of the present application also includes a first state and a second state; in the first state, the extension direction of each bracket 21 is parallel to the first direction; in the second state, two adjacent drilling mechanisms 2 rotate inward relative to the main body 1, and the other two drilling mechanisms 2 rotate outward relative to the main body 1.

[0052] The first state corresponds to a straight drilling state. The bracket 21 of each of the four drilling mechanisms 2 remains parallel to the first direction. As the eccentric drill bit 22 rotates, drilling and excavation can proceed along the axis. The second state corresponds to a curved drilling state. The four drilling mechanisms 2 form two pairs. Within the two pairs of drilling mechanisms 2, the brackets 21 of the two adjacent drilling mechanisms 2 on the inner side of the outermost portion rotate outward relative to the main body 1, while the brackets 21 of the other two drilling mechanisms 2 rotate inward relative to the outermost portion 1.

[0053] It should be emphasized that when drilling in a turning process, each drilling mechanism 2 affects the rotation, rather than one pair rotating while the other pair does not. Otherwise, the pair of drilling mechanisms 2 that does not rotate will interfere with the turning process.

[0054] Figure 4 This is a structural schematic diagram of the main body of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application. Figure 5 This is a cross-sectional view of the main body of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application. Figure 6 A control schematic diagram of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application.

[0055] Further, see Figures 4 to 6 The multi-angle drilling device of the embodiment of the present application further includes a flexible sealing tube 4 and a control assembly 3. The control assembly 3 includes a first signal line 31 and a second signal line 32. The drill drive assembly 23 and the control assembly 3 are electrically connected via the first signal line 31, and the direction adjustment assembly 24 and the control assembly 3 are electrically connected via the second signal line 32. The first signal line 31 and the second signal line 32 are both provided through the flexible sealing tube 4. The flexible sealing tube 4 can be provided within the main body 1.

[0056] The control assembly 3 is used to control the drill drive assembly 23 and the direction adjustment assembly 24. The drill drive assembly 23 and the control assembly 3 are electrically connected via a first signal line 31, and the direction adjustment assembly 24 and the control assembly 3 are electrically connected via a second signal line 32. The first signal line 31 and the second signal line 32 are both installed in a flexible sealing tube 4, which protects the first signal line 31 and the second signal line 32 from damage caused by fracturing fluid or rock debris.

[0057] Further, see Figures 4 to 6 The main body 1 includes: an inner tube 11 and an outer tube 12 arranged coaxially, the inner tube 11 and the outer tube 12 are connected by multiple connecting parts 15; a liquid supply part, which is connected between the outer tube 12 and the inner tube 11; and a liquid extraction part, which is connected to the inner tube 11.

[0058] The inner tube 11 and the outer tube 12 are coaxially arranged, and the inner tube 11 and the outer tube 12 are connected by a plurality of connecting parts 15. At this time, an annular tube is formed between the inner tube 11 and the outer tube 12. In the process of drilling using the multi-angle drilling equipment of the embodiment of the present application, fracturing fluid can be injected into the borehole as the drilling operation progresses. In addition to recovering part of the shale gas for analyzing the shale gas distribution, the rock cuttings can also be led out together to avoid blocking the borehole. The liquid supply part is connected to the outer tube 12 and the inner tube 11, and the liquid pumping part is connected to the inner tube 11. The liquid supply part can pump the fracturing fluid to the first end of the main body 1. After the fracturing fluid is mixed with part of the shale gas and rock cuttings, the liquid pumping part can pump the fracturing fluid mixed with the shale gas and rock cuttings back from the inner tube 11 to recover the shale gas and clean up the rock cuttings.

[0059] Figure 7 This is another structural schematic diagram of the multi-angle drilling equipment for shale gas extraction according to an embodiment of the present application. Figure 8 This is a structural schematic diagram of the first outer casing and the second outer casing of the multi-angle drilling equipment for shale gas extraction in an embodiment of the present application.

[0060] For further information, see Figure 7 and Figure 8 The main body 1 also includes: a first outer sleeve 13, which is sleeved on the outside of the outer tube 12 and fixedly connected to the outer tube 12; a second outer sleeve 14, which is sleeved on the outside of the outer tube 12, and the second outer sleeve 14 is rotatably connected to the first outer sleeve 13, and the second outer sleeve 14 is located on the side of the first outer sleeve 14 close to the first end; the bracket 21 is connected to the second outer sleeve 14.

[0061] Considering that during the turning drilling process, two adjacent drilling mechanisms 2 rotate inward relative to the main body 1 and the other two drilling mechanisms 2 rotate outward relative to the main body 1, the circumferential positions of the four drilling mechanisms 2 relative to the turning point must be adjusted before turning.

[0062] The first outer sleeve 13 is fixedly connected to the outer tube 12. The second outer sleeve 14 is sleeved on the outside of the outer tube 12 and is rotatably connected to the first outer sleeve 13. In other words, although the second outer sleeve 14 is sleeved on the outside of the outer tube 12, it can rotate relative to the outer tube 12. For example, the end of the first outer sleeve 13 facing the second outer sleeve 14 is provided with multiple micromotors, and the end of the second outer sleeve 14 facing the first outer sleeve 13 is provided with a ring gear that meshes with the output gears of the multiple micromotors to enable the second outer sleeve 14 to rotate relative to the first outer sleeve 13. Because the bracket 21 is connected to the second outer sleeve 14, the circumferential position of the four drilling mechanisms 2 relative to the turning point can be adjusted by rotating the second outer sleeve 14.

[0063] Further, see Figure 7 and Figure 8The first outer sleeve 13 is provided with a protrusion extending in a first direction, and the outer diameter of the protrusion is larger than the outer diameter of the first outer sleeve 13. When the second outer sleeve 14 rotates relative to the first outer sleeve 13, the protrusion of the first outer sleeve 13 can hinder the rotation of the first outer sleeve 13 relative to the shale rock mass, thereby ensuring that the rotation angle of the second outer sleeve 14 relative to the first outer sleeve 13 is equal to the rotation angle of the second outer sleeve 14 relative to the shale rock mass. The outer diameter of the protrusion is larger than the outer diameter of the first outer sleeve 13, which prevents the protrusion of the first outer sleeve 13 from circumferentially slipping from the shale rock mass when the second outer sleeve 14 rotates relative to the first outer sleeve 13.

[0064] Figure 9 This is a schematic diagram of the dimensions of the main body of the multi-angle drilling equipment for shale gas extraction according to an embodiment of the present application.

[0065] Further, see Figure 9 The inner diameter of the inner tube 11 is D1, the outer diameter of the inner tube 11 is D2, and the inner diameter of the outer tube 12 is D3, wherein D1>(D3-D2) / 2.

[0066] The fracturing fluid is injected into the borehole between the outer tube 12 and the inner tube 11. After being mixed with rock cuttings and shale gas, the fracturing fluid is extracted from the inner tube 11, making D1>(D3-D2) / 2. The inner diameter of the inner tube 11 is larger than the annular width of the annular tube, so the rock cuttings in the fracturing fluid can enter the inner tube 11, but it is difficult to enter the annular tube.

[0067] In summary, the embodiments of the present application provide a multi-angle drilling device for shale gas extraction, in which multiple drilling mechanisms are arranged along the circumference of the main body. During straight drilling, the extension direction of the bracket is parallel to the first direction, and the main body pushes each drilling mechanism forward in the first direction. At this time, the eccentric drill bit can crush the shale rock mass in front; when turning, the bracket rotates inward relative to the main body. At this time, the eccentric drill bit can crush the shale rock mass in the turning direction, driving the main body to turn. Since there are multiple drilling mechanisms, small radius turns can be achieved in various directions relative to the first direction, thereby achieving more flexible multi-angle drilling during shale gas extraction, thereby meeting the requirements of shale reservoir extraction and drilling under complex geological conditions.

[0068] The above is only a preferred specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the scope of protection of the present application.

Claims

1. A multi-angle drilling device for shale gas extraction, characterized in that: include: a hollow main body extending along a first direction and having a first end and a second end along the first direction; A plurality of drilling mechanisms are uniformly arranged at the first end along the circumference of the main body; the drilling mechanism includes a bracket, an eccentric drill bit, a drill bit driving assembly and a direction adjustment assembly; the bracket is rotatably connected to the first end about a reference axis, and the reference axis is tangent to the circumference of the main body; the direction adjustment assembly drives the bracket to rotate relative to the first end; the eccentric drill bit is rotatably connected to the bracket, and the axial direction of the drill bit is inclined to the extension direction of the bracket; the drill bit driving assembly is capable of driving the eccentric drill bit to rotate relative to the bracket; there are four drilling mechanisms, and of the two drilling mechanisms facing each other along the circumference of the main body, one rotates inwardly relative to the main body, and the other rotates outwardly relative to the main body; It also includes a first state and a second state; in the first state, the extension direction of each bracket is parallel to the first direction; in the second state, two adjacent drilling mechanisms rotate inward relative to the main body, and the other two drilling mechanisms rotate outward relative to the main body.

2. The multi-angle drilling equipment for shale gas extraction according to claim 1, characterized in that: The bracket includes a protrusion, which faces the inner side of the main body; the direction adjustment component includes a hydraulic cylinder, one end of the hydraulic cylinder is connected to the inner side of the main body, and the other end is connected to the protrusion.

3. The multi-angle drilling equipment for shale gas extraction according to claim 1, characterized in that: The eccentric drill bit is conical and has a threaded protrusion on the side. The axial direction of the eccentric drill bit forms an obtuse angle with the inner side of the bracket; the drill bit drive assembly is arranged on the inner side of the bracket.

4. The multi-angle drilling equipment for shale gas extraction according to claim 1, characterized in that: It also includes a flexible sealing tube and a control component, the control component includes a first signal line and a second signal line, the drill drive component and the control component are electrically connected through the first signal line, the direction adjustment component and the control component are electrically connected through the second signal line, and the first signal line and the second signal line are both passed through the flexible sealing tube.

5. The multi-angle drilling equipment for shale gas extraction according to claim 1, characterized in that: The main body comprises: An inner tube and an outer tube are coaxially arranged, wherein the inner tube and the outer tube are connected via a plurality of connecting portions; a liquid supply portion, communicating with the outer tube and the inner tube; The liquid extraction part is communicated with the inner tube.

6. The multi-angle drilling equipment for shale gas extraction according to claim 5, characterized in that: The main body also includes: a first outer sleeve, sleeved on the outer side of the outer tube and fixedly connected to the outer tube; The second outer sleeve is sleeved on the outside of the outer tube, the second outer sleeve is rotatably connected to the first outer sleeve, and the second outer sleeve is located on the side of the first outer sleeve close to the first end; the bracket is connected to the second outer sleeve.

7. The multi-angle drilling equipment for shale gas extraction according to claim 6, characterized in that: The first outer sleeve is provided with a protrusion extending along the first direction, and the outer diameter of the protrusion is larger than the outer diameter of the first outer sleeve.

8. The multi-angle drilling equipment for shale gas extraction according to claim 5, characterized in that: The inner diameter of the inner tube is D1, the outer diameter of the inner tube is D2, and the inner diameter of the outer tube is D3, wherein D1>(D3-D2) / 2.

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