Coring drill bit and coring drilling equipment

Abstract

The invention discloses a coring drill bit which comprises a cylindrical drill bit body (10) and a core guiding sleeve (20), and the cylindrical drill bit body (10) comprises a drilling end (11); the cylindrical drill bit main body (10) is provided with a cylindrical cavity (13); the core guiding sleeve (20) is fixed in the barrel cavity (13) and extends from the drilling end (11) to the connecting end (12) of the barrel-shaped drill bit main body (10); the core guiding sleeve (20) is provided with a bottom end port and a top end port which are distributed oppositely, the bottom end port is a rock core inlet (21), the top end port is communicated with a sleeve cavity (22) of the core guiding sleeve (20) and the barrel cavity (13), and a water channel (40) is defined by the outer wall of the core guiding sleeve (20) and the inner wall of the barrel-shaped drill bit body (10). According to the scheme, the problem that coring drilling equipment involved in the prior art is low in coring yield can be solved.

Description

Technical Field

[0001] This invention relates to the field of drill bit design technology, and in particular to a core drilling bit and core drilling equipment. Background Technology

[0002] In the field of oil and gas exploration, coring is a common method for obtaining formation samples, which is accomplished by coring drilling equipment. During coring drilling, it is necessary to ensure that the coring drilling equipment can guarantee a certain coring yield. A low coring yield means that less material is obtained from the core, which is detrimental to determining reserves and analyzing reservoir genesis.

[0003] Coring in fractured formations has long been a challenging and difficult area to overcome. Industry standards for coring in fractured formations generally require a core recovery rate of around 50%. However, in actual coring drilling, this is often difficult to achieve, severely hindering the efficient progress of exploration work.

[0004] Improving the core recovery rate of core drilling equipment is an urgent problem to be solved by technical personnel in related fields. Summary of the Invention

[0005] This invention discloses a coring drill bit and coring drilling equipment to solve the problem of low coring recovery rate in coring drilling equipment involved in related technologies.

[0006] To address the aforementioned technical problems, the present invention discloses the following technical solutions:

[0007] On one hand, embodiments of the present invention disclose a core drill bit, which includes a cylindrical drill bit body and a core guide sleeve. The cylindrical drill bit body includes a drilling end and a cylindrical cavity. The core guide sleeve is fixed inside the cylindrical cavity and extends from the drilling end to the connecting end of the cylindrical drill bit body. The core guide sleeve has a bottom end port and a top end port distributed opposite to each other. The bottom end port is a core inlet, and the top end port connects the cavity of the core guide sleeve with the cylindrical cavity. The outer wall of the core guide sleeve and the inner wall of the cylindrical drill bit body form a water channel.

[0008] In one embodiment, the mandrel sleeve is fixedly connected to the cylindrical drill bit body by a threaded connection. The outer peripheral wall of the mandrel sleeve is provided with a plurality of recesses, which are spaced apart along the circumferential direction of the mandrel sleeve. The plurality of recesses and the cylindrical drill bit body form a plurality of water channels distributed along the circumferential direction of the mandrel sleeve.

[0009] In one embodiment, the core drill bit further includes a plurality of nozzles, which are installed at the drilling end and located on the side of the water channel facing the drilling end in the drilling direction. The plurality of nozzles are respectively connected to the ends of the plurality of water channels facing the drilling direction. The water spray holes of the nozzles are connected to the corresponding water channels, and the diameter of the water spray holes of the nozzles is not equal to the diameter of the corresponding water channels.

[0010] In one embodiment, the diameter of the spray hole of the nozzle is larger than the diameter of the corresponding water channel.

[0011] In one embodiment, the diameter of the spray hole of the nozzle is smaller than the diameter of the corresponding water channel.

[0012] In one embodiment, the drilling end has multiple mounting slots, and the multiple nozzles are installed in the multiple mounting slots one by one.

[0013] In one embodiment, the wall of the mounting groove is provided with a retaining ring groove, and the nozzle is detachably mounted in the corresponding mounting groove by a retaining ring that cooperates with the retaining ring groove.

[0014] In one embodiment, the core drill bit further includes a core claw, which includes a base and a plurality of elastic claw bodies. The base is fixed to the inner wall of the core guide sleeve. The first end of the plurality of elastic claw bodies is connected to the base, and the second end of the plurality of elastic claw bodies bends and extends in a direction away from the drilling direction of the drilling end and close to the central axis of the sleeve cavity, so that the plurality of elastic claw bodies form a gradually narrowing guide space away from the drilling direction.

[0015] In one embodiment, the inner wall of the mandrel sleeve is provided with an annular groove extending around the central axis of the mandrel sleeve, and the base is an arc-shaped structure, the base being elastically positioned in the annular groove.

[0016] On the other hand, embodiments of the present invention also disclose a coring drilling device, which includes the coring drill bit described above.

[0017] The technical solutions disclosed in the embodiments of the present invention have the following technical effects:

[0018] The core drilling bit disclosed in this invention features an improved structure. A core guide sleeve is added inside the drilling end of the cylindrical drill bit body, with its bottom end forming a core inlet. Simultaneously, the outer wall of the core guide sleeve and the inner wall of the cylindrical drill bit body form a water channel. This structure allows for initial isolation between the core entering the casing through the core inlet and the drilling fluid transported in the water channel. This prevents adverse erosion of the core just entering the core drilling bit, ensuring core formation and continuous movement into the core drilling bit. When core drilling in fractured formations, the core guide sleeve guides, protects, and isolates the core to prevent drilling fluid erosion, ultimately reducing core loss from the core inlet and improving core recovery rate. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the core drill bit disclosed in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the core claw structure disclosed in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the nozzle structure disclosed in an embodiment of the present invention.

[0022] The components in the diagram are labeled as follows:

[0023] 10-Cylindrical drill bit body, 11-Drilling end, 111-Mounting groove, 112-Snap ring, 12-Connecting end, 13-Cylinder cavity, 14-Cutting blade,

[0024] 20-Core guide sleeve, 21-Core inlet, 22-Cavity,

[0025] 30 - Nozzle, 31 - Water spray hole

[0026] 40-Waterway,

[0027] 50-Core claw, 51-Base, 52-Elastic claw body, 53-Introduction space. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] The technical solutions disclosed in the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] Please refer to Figures 1 to 3 This invention discloses a coring drill bit. The disclosed coring drill bit belongs to coring drilling equipment. The coring drill bit disclosed in this invention includes a cylindrical drill bit body 10 and a core guide sleeve 20.

[0031] The cylindrical drill bit body 10 is the main structure of the core drill bit, and it is a hollow cylindrical structure. The cylindrical drill bit body 10 includes a drilling end 11 and a connecting end 12. The drilling end 11 is the end where the core drill bit drills, used for breaking rock formations. The connecting end 12 is the end where the cylindrical drill bit body 10 connects to the drill rod of the core drilling equipment. The connecting end 12 and the drilling end 11 are the two opposite ends of the cylindrical drill bit body 10. The connecting end 12 can be connected to the drill rod of the core drilling equipment through connectors, threaded connections, or other methods. This embodiment of the invention does not limit the specific connection method of the connecting end 12.

[0032] The main body 10 of the cylindrical drill bit has a cavity 13. A core guide sleeve 20 is used to guide the columnar rock core formed during core drilling. The core guide sleeve 20 is fixed inside the cavity 13. The core guide sleeve 20 extends from the drilling end 11 of the main body 10 to the connecting end 12 of the main body 10. The core guide sleeve 20 has a sleeve-like structure with a bottom end port and a top end port distributed opposite to each other. The bottom end port is the rock core inlet 21. The top end port connects the sleeve cavity 22 of the core guide sleeve 20 with the cavity 13.

[0033] The outer wall of the core sleeve 20 and the inner wall of the cylindrical drill bit body 10 form a water channel 40. During the drilling process, drilling fluid (such as water) flows into the water channel 40 along the inner wall of the cylinder cavity 13 and eventually flows out of the core drill bit through the water channel 40.

[0034] The core sleeve 20 is located inside the drill end 11 and plays a guiding role. It can also protect the rock core that has just entered the core drill bit. Since the water channel 40 is formed on the outside of the core sleeve 20, the core sleeve 20 can isolate the rock core that has just entered the core drill bit from the drilling fluid.

[0035] The core drill bit disclosed in this embodiment of the invention features an improved structure. A core guide sleeve 20 is added inside the drilling end 11 of the cylindrical drill bit body 10, forming a core inlet 21 at its bottom end. Simultaneously, the outer wall of the core guide sleeve 20 and the inner wall of the cylindrical drill bit body 10 form a water channel 40. This structure allows for initial isolation between the core entering the casing 22 through the core inlet 21 and the drilling fluid transported in the water channel 40. This prevents adverse erosion of the core just entering the core drill bit, ensuring core formation and continuous movement into the drill bit. When core drilling in fractured formations, the core guide sleeve 20 guides, protects, and isolates the core to prevent erosion by the drilling fluid, ultimately reducing core loss through the core inlet 21 and improving core recovery rate.

[0036] In this embodiment of the invention, the mandrel sleeve 20 is fixed inside the cylindrical drill bit body 10. Specifically, the mandrel sleeve 20 can be welded into the cylindrical drill bit body 10, or it can be fixed by interference fit or other methods. In one embodiment, the mandrel sleeve 20 and the cylindrical drill bit body 10 can be fixedly connected by a threaded connection. The outer peripheral wall of the mandrel sleeve 20 can be provided with multiple recesses, which can be a fitted structure and extend along the axial direction of the mandrel sleeve 20. The multiple recesses can be spaced apart along the circumferential direction of the mandrel sleeve 20. The multiple recesses and the cylindrical drill bit body 10 form multiple channels 40 distributed along the circumferential direction of the mandrel sleeve 20. By using a threaded connection for fixation, the mandrel sleeve 20 can be disassembled, thereby facilitating the disassembly, assembly, and maintenance of the mandrel sleeve 20 individually. At the same time, the use of threaded fit also facilitates the assembly of the core sleeve 20 and the cylindrical drill bit body 10. Moreover, this structure can form a structure of multiple water channels 40 by cooperating with the core sleeve 20 through multiple recesses distributed along the circumferential direction. It is also conducive to the uniform spraying of drilling fluid in the circumferential direction of the core drill bit, which is conducive to achieving more balanced flushing.

[0037] In a further embodiment, the core drilling bit disclosed in this invention may further include a plurality of nozzles 30. The plurality of nozzles 30 may be installed at the drill end 11 and located on the side of the water channel 40 facing the drill end 11 in the drilling direction. The plurality of nozzles 30 may be correspondingly connected to the ends of the water channels 40 facing the drilling direction. The water jet holes 31 of the nozzles 30 communicate with the corresponding water channels 40, and the diameter of the water jet holes 31 of the nozzles 30 is not equal to the diameter of the corresponding water channels 40. This structure allows for adjustment of the injection pressure of the drilling fluid flowing out of the water channels 40 by adding nozzles 30, thereby adapting to core drilling in different formations.

[0038] In one embodiment, the diameter of the nozzle 30's water jet 31 can be smaller than the diameter of the corresponding water channel 40. In this case, the smaller diameter of the nozzle 30's water jet 31 allows the drilling fluid in the water channel 40 to be accelerated after entering the water jet 31, which is beneficial for the core bit's drilling. This structure is more suitable for drilling in formations with high hardness.

[0039] In other embodiments, the diameter of the nozzle 30's spray hole 31 can be larger than the diameter of the corresponding waterway 40. In this case, the larger diameter of the nozzle 30's spray hole 31 allows the drilling fluid in the waterway 40 to be slowed down after entering the spray hole 31, thus preventing excessive drilling fluid impact that could wash away and transport away the fractured rock layers. This helps ensure core formation and entry into the core guide sleeve 20 from the core inlet 21, ultimately improving the core recovery rate.

[0040] In this embodiment of the invention, the plurality of nozzles 30 can be installed on the drilling end 11 in various ways. In one embodiment, the drilling end 11 may have a plurality of mounting slots 111, and the plurality of nozzles 30 can be installed in the plurality of mounting slots 111 in a one-to-one correspondence. Specifically, the plurality of nozzles 30 can be fixed in the mounting slots 111 by interference fit, or can be installed in the mounting slots 111 by threaded fit or other detachable methods.

[0041] As described above, the diameter of the nozzle 30 can be larger or smaller than the diameter of the corresponding water channel 40. Based on this, the core drill bit disclosed in this embodiment of the invention can be configured with two sets of nozzles 30 of different sizes. One set of nozzles 30 has a water jet hole 31 with a diameter smaller than the diameter of the corresponding water channel 40, while the other set of nozzles 30 has a water jet hole 31 with a diameter larger than the diameter of the corresponding water channel 40. For ease of replacement, the nozzle 30 is preferably detachably mounted on the drilling end 11. In one embodiment, the wall of the mounting groove 111 can be provided with a retaining spring groove. The nozzle 30 can be detachably mounted in the corresponding mounting groove 111 via a retaining spring 112 that mates with the retaining spring groove.

[0042] The drilling end 11 may be provided with multiple cutter wings 14, which may be evenly distributed on the drilling end 11 in the circumferential direction. Specifically, the multiple cutter wings 14 may be an integral structure with the drilling end 11, and cutting teeth may be installed on the cutter wings 14. During the drilling process, the cutter wings 14 will drive the cutting teeth to rotate, thereby breaking up the formation.

[0043] like Figure 1 and Figure 2As shown, the core drill bit disclosed in this embodiment of the invention may further include a core claw 50. The core claw 50 may include a base 51 and a plurality of elastic claw bodies 52. The base 51 is fixed to the inner wall of the core guide sleeve 20, and the first ends of the plurality of elastic claw bodies 52 may be connected to the base 51. The second ends of the plurality of elastic claw bodies 52 bend and extend in a direction away from the drilling direction of the drilling end 11 and close to the central axis of the sleeve 22 (e.g., Figure 2 As shown in the diagram, the multiple elastic claws 52 are arranged to form a gradually narrowing inlet space 53 opposite to the drilling direction. This structure creates a gradually narrowing inlet space 53. During drilling, the core enters the inlet space 53 from the core inlet 21. As the core moves upward, the elastic claws 52 expand, allowing it to pass through the core claws 50. After the core has completely passed through the core claws 50, the elastic claws 52 return to their original shape, thus blocking the core at the bottom. Therefore, the core claws 50 are a structure that allows the core to pass through and enter the core drill bit while preventing it from falling out. Thus, during drilling in fractured formations, the core claws 50 prevent the core from falling out of the core guide sleeve 20 after it enters, which helps improve the core recovery rate.

[0044] Furthermore, since the first ends of the multiple elastic claws 52 are connected to the base 51, and the second ends of the multiple elastic claws 52 bend and extend in a direction away from the drilling direction of the drilling end 11 and close to the central axis of the casing 22, it can be seen that the gradual extension of the second ends of the multiple elastic claws 52 enables the multiple elastic claws 52 to exert a lateral tightening force on the core entering the introduction space 53, thereby facilitating the formation of the core. Optionally, the first ends of the multiple elastic claws 52 can be connected to the base 51 by welding, bonding, or connecting with connectors, etc., and the embodiments of the present invention are not limited thereto.

[0045] In this embodiment of the invention, the base 51 serves as the foundation of the core claw 50, and the connection between the core claw 50 and the core sleeve 20 is achieved through connection with the core guide sleeve 20. There are various ways to connect the base 51 and the core sleeve 20. In one embodiment, the base 51 can be fixed inside the core sleeve 20 by welding or threaded connection. In other embodiments, the inner wall of the core sleeve 20 can be provided with an annular groove extending around the central axis of the core sleeve 20. The base 51 can be an arc-shaped structure, and the base 51 can be elastically positioned in the annular groove. In this structure, the base 51 is an arc-shaped structural component. After deformation, the base 51 is inserted into the annular groove. After entering the annular groove, the base 51 returns to its original shape and is locked in the annular groove, thereby achieving the installation of the base 51 in the core sleeve 20. This method is convenient and simple to operate.

[0046] Furthermore, the base 51 is located in the annular groove and does not protrude from the inner wall of the core sleeve 20, which helps to avoid obstructing the entry of the rock core into the core sleeve 20 due to the outward protrusion of the base 51.

[0047] In this embodiment of the invention, the core sleeve 20 can be made of materials with high hardness such as steel or iron, and the core claw 50 can be made of raw materials such as steel plate or iron plate. Of course, the core sleeve 20 and the core claw 50 can also be made of other materials suitable for core drilling. This embodiment of the invention does not limit their materials.

[0048] In this embodiment of the invention, the central axis of the core guide sleeve 20 can coincide with the central axis of the core drill bit. This structure makes it easier for the core guide sleeve 20 to center the core during the process of guiding the core in. The centering of the core is conducive to the stable entry of the core into the core drill bit, which in turn helps to improve the core recovery rate.

[0049] Based on the core drill bit disclosed in this embodiment of the invention, this embodiment of the invention discloses a core drilling device, which includes the core drill bit described in the above embodiment.

[0050] The core drilling equipment disclosed in this embodiment of the invention may further include a core cutting mechanism. The core cutting mechanism is a known technology, and its function and structure will not be described in detail here. The core cutting mechanism may also have a core claw. The core claw 50 located in the core guide sleeve 20 and the core claw in the core cutting mechanism can form a core claw combination, which is more conducive to protecting the core. It should be noted that the structure of the core claw in the core cutting mechanism and the core claw 50 located in the core guide sleeve 20 may be the same or different; this embodiment of the invention does not impose any limitations.

[0051] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A core bit, characterized in that The drill bit includes a cylindrical drill bit body (10) and a core sleeve (20). The cylindrical drill bit body (10) includes a drilling end (11). The cylindrical drill bit body (10) has a cylindrical cavity (13). The core sleeve (20) is fixed inside the cylindrical cavity (13) and extends from the drilling end (11) to the connecting end (12) of the cylindrical drill bit body (10). The core sleeve (20) has a bottom port and a top port distributed opposite to each other. The bottom port is a core inlet (21), and the top port connects the sleeve cavity (22) of the core sleeve (20) with the cylindrical cavity (13). The outer wall of the core sleeve (20) and the inner wall of the cylindrical drill bit body (10) form a water channel (40).

2. The core bit of claim 1, wherein, The mandrel sleeve (20) is fixedly connected to the cylindrical drill bit body (10) by a threaded connection. The outer peripheral wall of the mandrel sleeve (20) is provided with a plurality of recesses. The plurality of recesses are distributed at intervals along the circumferential direction of the mandrel sleeve (20). The plurality of recesses and the cylindrical drill bit body (10) form a plurality of water channels (40) distributed along the circumferential direction of the mandrel sleeve (20).

3. The core bit of claim 2, wherein, The core drill bit also includes a plurality of nozzles (30), which are installed on the drilling end (11) and located on the side of the water channel (40) facing the drilling end (11) in the drilling direction. The plurality of nozzles (30) are connected one-to-one with the ends of the plurality of water channels (40) facing the drilling direction. The water spray hole (31) of the nozzle (30) is connected to the corresponding water channel (40), and the diameter of the water spray hole of the nozzle (30) is not equal to the diameter of the corresponding water channel (40).

4. The core bit of claim 3, wherein, The diameter of the spray hole (31) of the nozzle (30) is larger than the diameter of the corresponding water channel (40).

5. The core bit of claim 3 wherein, The diameter of the spray hole (31) of the nozzle (30) is smaller than the diameter of the corresponding water channel (40).

6. The core bit of claim 3 wherein, The drilling end (11) has multiple mounting slots (111), and the multiple nozzles (30) are installed in the multiple mounting slots (111) one by one.

7. The core bit of claim 6 wherein, The mounting groove (111) has a retaining ring groove on its groove wall, and the nozzle (30) is detachably mounted in the corresponding mounting groove (111) by a retaining ring (112) that cooperates with the retaining ring groove.

8. The core bit of claim 1 wherein, The core drill bit also includes a core claw (50), which includes a base (51) and a plurality of elastic claw bodies (52). The base (51) is fixed to the inner wall of the core guide sleeve (20). The first end of the plurality of elastic claw bodies (52) is connected to the base (51), and the second end of the plurality of elastic claw bodies (52) bends and extends in a direction away from the drilling direction of the drilling end (11) and close to the central axis of the sleeve cavity (22), so that the plurality of elastic claw bodies (52) form a gradually narrowing guide space (53) away from the drilling direction.

9. The core bit of claim 8, wherein, The inner wall of the core sleeve (20) is provided with an annular groove extending around the central axis of the core sleeve (20), and the base (51) is an arc-shaped structure, and the base (51) is elastically positioned in the annular groove.

10. A core drilling device, characterized in that, The core drill bit includes any one of claims 1 to 9.

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