Multi-angle drilling equipment for shale gas exploitation

Abstract

The invention provides multi-angle drilling equipment for shale gas exploitation, belongs to the technical field of shale gas exploitation equipment, and solves the problems that the existing drilling equipment is generally difficult to realize sharp turning drilling and is difficult to adjust the drilling direction. The multi-angle drilling equipment for shale gas exploitation comprises a hollow main body part which extends in the first direction and is provided with a first end and a second end in the first direction; the multiple drilling mechanisms are uniformly distributed at the first end in the circumferential direction of the main body part; the drilling mechanism comprises a support, an off-axis drill bit, a drill bit driving assembly and a direction adjusting assembly. The support is rotatably connected with the first end around a reference axis, and the reference axis is tangent to the circumferential direction of the main body part; the direction adjusting assembly drives the support to rotate relative to the first end. The off-axis drill bit is rotatably connected with the bracket; the axial direction of the drill bit is inclined to the extension direction of the bracket; the drill driving assembly drives the off-axis drill to rotate relative to the support. The drilling direction can be adjusted, and sharp turning drilling is achieved.

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. Therefore, fracturing is one of the main technologies for shale gas development.

[0003] Before fracturing a shale reservoir, it is necessary to use drilling equipment to drill holes into the shale reservoir and carry the fracturing equipment to the shale reservoir. During the drilling process, due to the influence of the formation development conditions and the later geological structure, the spatial distribution characteristics of the shale reservoir are not completely horizontal or approximately horizontal. For example, the thickness, inclination angle, faults and other sudden changes will occur in the local area of ​​the shale reservoir in 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 usually has difficulty in achieving 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, the present application aims to provide a multi-angle drilling device 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 comprises 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 and the other rotates outwardly relative to the main body.

[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 passed through 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 the 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; 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 greater 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 the embodiment of the present application, multiple drilling mechanisms are arranged along the circumference of the main body. When drilling in a straight line, the extension direction of the bracket is parallel to the first direction, and the main body pushes each drilling mechanism to move 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 inner side 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 and drive 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 equipment for shale gas extraction in the embodiment of the present application, thereby meeting the shale reservoir extraction and drilling under complex geological conditions.

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

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

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

[0021] Figure 2 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 A structural schematic diagram of a drilling mechanism of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application.

[0023] Figure 4 A structural schematic diagram of the main part of the multi-angle drilling equipment for shale gas extraction according to an embodiment of the present application.

[0024] Figure 5 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 Another schematic diagram of the structure of the multi-angle drilling equipment for shale gas extraction according to an embodiment of the present application.

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

[0028] Fig. 9 A schematic diagram of the dimensions of the main body of a multi-angle drilling device 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. eccentric drill bit; 23. drill bit driving 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 the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connected" should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection, or an integral connection can be a mechanical connection, or an electrical connection can be a direct connection, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] The terms "top", "bottom", "above", "lower", and "on" used throughout the description are relative to the relative positions of components of a device, such as the relative positions of the top and bottom substrates within a device. It is 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 will be 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, so 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, including a main body and a plurality of drilling mechanisms, wherein the plurality of drilling mechanisms are arranged along the circumference of the main body, the 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. When drilling in a straight line, the extension direction of the bracket is parallel to the first direction, and the main body pushes each drilling mechanism to move 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 inner side 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 and drive 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 realizing multi-angle drilling of the multi-angle drilling device for shale gas extraction in the embodiment of the present application.

[0039] Figure 1 A schematic diagram of the structure of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application. Figure 2 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 The embodiment of the present application provides a multi-angle drilling device 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 arranged 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 driving 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 driving 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. There are multiple drilling mechanisms 2, which are evenly arranged at the first end along the circumference of the main body 1. The structure of each drilling mechanism 2 is consistent. The bracket 21 is rotatably connected to the first end of the main body 1, and the bracket 21 rotates around the reference axis relative to the first end of the main body 1. The reference axis is parallel to the tangent of the connection between the bracket 21 and the first end. The direction adjustment component 24 drives the bracket 21 to rotate relative to the first end, so the bracket 21 can rotate toward the inside or outside of the main body 1 relative to the main body 1. The axis of the eccentric drill bit 22 is at an obtuse angle to the extension direction of the bracket 21, so the tip of the eccentric drill bit 22 is not completely facing the first direction. The drill bit driving component 23 drives the eccentric drill bit 22 to rotate relative to the bracket 21. When drilling in a straight line, the extension direction of the bracket 21 can be made parallel to the first direction, and the force can be transferred along the first direction. At the same time, multiple eccentric drill bits 22 rotate simultaneously, which can break the shale rock mass in front of the straight drilling direction and move forward in a straight line together 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. As a whole, 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 the multi-angle drilling device of the embodiment of the present application is used for drilling operations, the drilling direction can be adjusted in real time according to the underground rock formation conditions actually detected during the drilling process, thereby reducing the probability of return, improving the drilling efficiency, and reducing the drilling cost. At the same time, small radius turning drilling can also be completed, which is more conducive to the planning of the drilling path.

[0044] Figure 3 A structural schematic diagram of a drilling mechanism of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application.

[0045] For further information, 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 which 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 needs to provide a sufficiently large supporting force for the drill bit, in the embodiment of the present application, the direction adjustment component 24 is in the form of a hydraulic cylinder to drive the support 21 to rotate relative to the first end, and the hydraulic cylinder is also used to fix the relative angle between the extension direction of the support 21 and the first direction. The hydraulic cylinder, the protrusion 211 and the main body 1 can form a triangular support structure, which can provide stable support for the support 21 and can also make the extension direction of the support 21 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 eccentric drill bit 22 can facilitate the eccentric drill bit 22 to drill into the shale rock mass, and the threaded protrusion can guide the rock cuttings generated after the eccentric drill bit 22 drills into the shale rock mass backwards, and can be guided out through the main body 1 to avoid blocking the drilling hole. In addition, the axial direction of the eccentric drill bit 22 forms an obtuse angle with the inner side of the bracket 21, so that the rock cuttings can be guided to the inner side of the main body 1 for easy guidance. The drill bit drive assembly 23 is arranged on the inner side of the bracket 21, which can prevent the drill bit drive assembly 23 from interfering with the advancement of the multi-angle drilling device of the embodiment of the present application.

[0049] Further, see Figures 1 to 3 There are four drilling mechanisms 2, and among the two drilling mechanisms 2 opposite to each other along the circumferential direction 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 rotate as a whole 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 the straight drilling state. Among the four drilling mechanisms 2, the bracket 21 of each drilling mechanism 2 remains parallel to the first direction. As the eccentric drill bit 22 rotates, the drilling can be carried out along the direction. The second state corresponds to the turning drilling state. The four drilling mechanisms 2 form two pairs. Among the two pairs of drilling mechanisms 2, the brackets 21 of the two adjacent drilling mechanisms 2 corresponding to the inner side of the outer side rotate outward relative to the main body 1, and the brackets 21 of the other two drilling mechanisms 2 rotate inward relative to the outer side of the main body 1.

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

[0054] Figure 4 A structural schematic diagram of the main part of the multi-angle drilling equipment for shale gas extraction according to an embodiment of the present application. Figure 5 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] For further information, 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 component 3, the control component 3 includes a first signal line 31 and a second signal line 32, the drill driving component 23 and the control component 3 are electrically connected through the first signal line 31, the direction adjustment component 24 and the control component 3 are electrically connected through the second signal line 32, and the first signal line 31 and the second signal line 32 are both arranged in the flexible sealing tube 4. The flexible sealing tube 4 can be arranged in 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 through a first signal line 31, and the direction adjustment assembly 24 is electrically connected to the control assembly 3 through a second signal line 32. The first signal line 31 and the second signal line 32 are both passed through the flexible sealing tube 4, which can protect the first signal line 31 and the second signal line 32 and prevent the first signal line 31 and the second signal line 32 from being damaged by fracturing fluid or rock cuttings.

[0057] For further information, 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 a plurality of connecting parts 15; a liquid supply part connected between the outer tube 12 and the inner tube 11; and a liquid extraction part 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 proceeds, and part of the shale gas can be recovered to facilitate the analysis of the shale gas distribution, and 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 extraction 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 the rock cuttings, the liquid extraction part can extract the fracturing fluid mixed with the shale gas and the rock cuttings from the inner tube 11 to facilitate the recovery of the shale gas and the cleaning of the rock cuttings.

[0059] Figure 7 Another schematic diagram of the structure of the multi-angle drilling equipment for shale gas extraction according to an embodiment of the present application. Figure 8 A structural schematic diagram of a first outer casing and a second outer casing of a multi-angle drilling device 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 a 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 inwardly relative to the main body 1 and the other two drilling mechanisms 2 rotate outwardly 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 connected to the outer tube 12 and fixedly connected. The second outer sleeve 14 is sleeved on the outer side of the outer tube 12, and the second outer sleeve 14 is rotatably connected to the first outer sleeve 13, that is, although the second outer sleeve 14 is sleeved on the outer side of the outer tube 12, it can rotate relative to the outer tube 12. Exemplarily, a plurality of micro motors are provided at one end of the first outer sleeve 13 facing the second outer sleeve 14, and a gear ring is provided at one end of the second outer sleeve 14 facing the first outer sleeve 13, and meshes with the output gears of the plurality of micro motors, so that the second outer sleeve 14 can rotate relative to the first outer sleeve 13. Since the bracket 21 is connected to the second outer sleeve 14, the circumferential positions 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 the 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 first outer sleeve 13 from rotating relative to the shale rock mass, so 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, and when the second outer sleeve 14 rotates relative to the first outer sleeve 13, the protrusion of the first outer sleeve 13 can be prevented from circumferentially slipping off the shale rock mass.

[0064] Fig. 9 A schematic diagram of the dimensions of the main body of a multi-angle drilling device for shale gas extraction according to an embodiment of the present application.

[0065] For further information, see Fig. 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 from 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, so that D1>(D3-D2) / 2. The inner diameter of the inner tube 11 is larger than the ring 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 embodiment of the present application provides a multi-angle drilling device for shale gas extraction, in which multiple drilling mechanisms are arranged along the circumference of the main body. When drilling in a straight line, the extension direction of the bracket is parallel to the first direction, and the main body pushes each drilling mechanism to move 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 inner side relative to the main body. At this time, the eccentric drill bit can crush the shale rock mass in the turning direction and drive 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 in the shale gas extraction process, thereby meeting the shale reservoir extraction drilling requirements under complex geological conditions.

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

Claims

1. A multi-angle drilling device for shale gas extraction, characterized in that: include: A hollow main body portion extending along a first direction and having a first end and a second end along the first direction; A plurality of drilling mechanisms are evenly distributed at the first end along the circumference of the main body; the drilling mechanism comprises 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 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 driving assembly can drive the eccentric drill bit to rotate relative to the bracket.

2. The multi-angle drilling equipment for shale gas extraction according to claim 1, characterized in that: The bracket includes a protruding portion, 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 protruding portion.

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 driving 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: There are four drilling mechanisms, and among the two drilling mechanisms opposite to each other along the circumferential direction of the main body, one rotates inwardly and the other rotates outwardly relative to the main body.

5. The multi-angle drilling equipment for shale gas extraction according to claim 4, characterized in that: 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 inwardly relative to the main body, and the other two drilling mechanisms rotate outwardly relative to the main body.

6. 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.

7. 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, and the inner tube and the outer tube are connected via a plurality of connecting parts; a liquid supply portion, connected between the outer tube and the inner tube; The liquid extraction part is communicated with the inner tube.

8. The multi-angle drilling equipment for shale gas extraction according to claim 7, characterized in that: The main body also includes: A first outer sleeve, which is sleeved on the outer side of the outer tube and fixedly connected to the outer tube; The second outer sleeve is sleeved on the outer side 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.

9. The multi-angle drilling equipment for shale gas extraction according to claim 8, 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 greater than the outer diameter of the first outer sleeve.

10. The multi-angle drilling equipment for shale gas extraction according to claim 7, 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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