Rock breaking drill bit for unloading drilling resistance of bottom hole ground stress weakening stratum

Abstract

The utility model discloses a rock breaking drill bit capable of unloading drilling resistance of a ground stress weakening stratum at the bottom of a well, which belongs to the technical field of drilling equipment and comprises a drill bit body, blades are arranged on the drill bit body, and cutting teeth are arranged on the blades. A drilling fluid runner is arranged in the middle of the drill bit body, a rotating shaft is arranged in the middle of the drilling fluid runner, a rotating handle is coaxially and fixedly arranged at the lower end of the rotating shaft, and a supporting piece is arranged between the upper portion of the rotating shaft and the side wall of the drilling fluid runner and provided with a plurality of supporting runner holes. A plurality of impact teeth are evenly arranged on the bottom end face of the drilling fluid flow channel in the circumferential direction and downwards penetrate through the drill bit body in the axial direction. A driving assembly used for driving all the impact teeth to conduct synchronous reciprocating impact is arranged on the rotating handle. The impact teeth capable of impacting downwards in a reciprocating mode in the axial direction are arranged to impact rocks, then the pressure of the rocks is unloaded, the rock breaking difficulty of the cutting teeth is reduced, the rock breaking efficiency is improved, and the service life of the cutting teeth is prolonged.

Description

Technical Field

[0001] This utility model belongs to the field of drilling equipment technology, specifically relating to a rock-breaking drill bit that reduces formation resistance to drilling by unloading bottom-hole stress. Background Technology

[0002] In the exploration and development of deep and ultra-deep oil and gas resources, drilling is not only a necessary means, but also the only way. The geological conditions in this field are extremely harsh, and the complex environment with high temperature, high pressure, and high abrasiveness poses many hazards to drill bits.

[0003] Currently, commonly used drill bits rely mainly on the cutting teeth on the cutter wings to break rocks during drilling. However, the rock pressure in deep and ultra-deep layers is relatively high. During the drilling process, the cutting teeth of the drill bit have to withstand enormous rock pressure, which makes it difficult to break rocks and greatly affects the rock breaking efficiency. In addition, the cutting teeth on the cutter wings are easily damaged.

[0004] To improve rock breaking efficiency, this application proposes a rock breaking drill bit that reduces formation resistance by unloading bottom-hole stress. By setting impact teeth that can reciprocate downward along the axial direction, the drill bit impacts the rock, thereby unloading the rock pressure, reducing the difficulty of rock breaking by the cutting teeth, and improving rock breaking efficiency and the service life of the cutting teeth. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a rock-breaking drill bit that reduces the formation's resistance to drilling by unloading the bottom stress of the well.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A rock-breaking drill bit for unloading bottom-hole stress and weakening formation resistance to drilling includes a drill bit body, wherein the drill bit body is provided with a plurality of cutter wings arranged in a circumferential direction, and the cutter wings are provided with cutting teeth;

[0008] The drill bit body has a drilling fluid flow channel in the middle, and a rotating shaft is set in the middle of the drilling fluid flow channel. A cylindrical rotating handle is coaxially fixed at the lower end of the rotating shaft. A support member is set between the upper part of the rotating shaft and the side wall of the drilling fluid flow channel. The radial inner side of the support member is rotatably engaged with the rotating shaft, and the radial outer side of the support member is rotatably engaged with the side wall of the drilling fluid flow channel. A plurality of support flow channel holes are evenly arranged along the circumferential direction on the support member.

[0009] An annular space is left between the rotating shaft, the rotating handle and the side wall of the drilling fluid flow channel;

[0010] Several impact teeth are evenly arranged along the circumferential direction on the bottom end face of the drilling fluid flow channel, and the impact teeth penetrate the drill bit body axially downward.

[0011] The handle is equipped with a drive assembly for driving all impact teeth to perform synchronous reciprocating impacts.

[0012] Preferably, the drive assembly includes a plurality of strong magnets evenly arranged along the circumferential direction. The strong magnets are fixed to the lower end of the handle. The strong magnets include alternating first strong magnets and second strong magnets, with the N pole of the first strong magnet located at the lower end and the S pole of the second strong magnet located at the lower end.

[0013] A third strong magnet is fixedly installed at the top of the impact tooth, with the N pole or S pole of the third strong magnet located at the top.

[0014] The number of impact teeth is half the number of strong magnets.

[0015] Preferably, the drill bit body is provided with a through hole for the impact tooth to reciprocate axially, the top of the impact tooth is provided with a circular tooth shank, the circular tooth shank is located in the drilling fluid flow channel, and the diameter of the circular tooth shank is larger than the diameter of the through hole.

[0016] The third strong magnet is located on the circular toothed shank.

[0017] Preferably, a plurality of handle flow channel holes are evenly arranged on the handle along the circumferential direction, and the handle flow channel holes extend through the handle axially.

[0018] Preferably, the impact teeth extend axially through the blade wings, and the number of impact teeth is the same as the number of blade wings.

[0019] Preferably, the drilling fluid flow channel includes a first flow channel and a second flow channel connected axially, the diameter of the first flow channel is smaller than the diameter of the second flow channel, the rotating shaft is located in the first flow channel, and the rotating handle is located in the second flow channel.

[0020] Preferably, a drill bit connector is provided at the top of the drill bit body.

[0021] Preferably, the blade is provided with a nozzle flow channel, the upper end of the nozzle flow channel extends to the drilling fluid flow channel, and the lower end of the nozzle flow channel is provided with a nozzle.

[0022] The beneficial effects of this utility model are:

[0023] This invention achieves rock impact by setting impact teeth that can reciprocate downward along the axial direction, thereby relieving rock pressure, reducing the difficulty of rock breaking by the cutting teeth, improving rock breaking efficiency and the service life of the cutting teeth. Attached Figure Description

[0024] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0025] Figure 1 This is a schematic diagram of the rock-breaking drill bit of this utility model, which weakens the formation's resistance to drilling by unloading the bottom stress of the well.

[0026] Figure 2 This is a schematic diagram illustrating the principle of a single impact by the impact tooth in this utility model;

[0027] in:

[0028] 1. Drill bit body; 11. Drilling fluid flow channel; 12. Annular space; 13. Drill bit connector; 2. Cutting blade; 21. Nozzle flow channel; 3. Cutting teeth; 4. Shaft; 41. Support component; 42. Support flow channel hole; 5. Rotary shank; 51. Rotary shank flow channel hole; 6. Impact tooth; 61. Circular tooth shank; 7. First strong magnet; 8. Second strong magnet; 9. Third strong magnet; 10. Strong magnet. Detailed Implementation

[0029] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0030] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0031] In this utility model, terms such as "upper", "lower", "bottom", and "top" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the structural relationship between the various components or elements of this utility model and do not specifically refer to any component or element in this utility model. They should not be construed as limiting this utility model.

[0032] In this utility model, terms such as "connected" and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be determined according to the specific circumstances, and should not be construed as a limitation of this utility model.

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] Example 1:

[0035] like Figure 1 As shown, a rock-breaking drill bit that reduces formation resistance to drilling by unloading bottom stress includes a drill bit body 1, on which a plurality of cutter wings 2 are arranged in a circumferential direction, and cutting teeth 3 are provided on the cutter wings 2.

[0036] The drill bit body 1 has a drilling fluid channel 11 in the middle, and a rotating shaft 4 is provided in the middle of the drilling fluid channel 11. A cylindrical rotating handle 5 is coaxially fixed at the lower end of the rotating shaft 4. A support member 41 is provided between the upper part of the rotating shaft 4 and the side wall of the drilling fluid channel 11. The radial inner side of the support member 41 is rotatably engaged with the rotating shaft 4, and the radial outer side of the support member 41 is rotatably engaged with the side wall of the drilling fluid channel 11. A plurality of support channel holes 42 are evenly provided on the support member 41 along the circumferential direction.

[0037] An annular space 12 is left between the rotating shaft 4, the rotating handle 5 and the side wall of the drilling fluid flow channel 11;

[0038] A plurality of impact teeth 6 are evenly arranged along the circumferential direction on the bottom end surface of the drilling fluid flow channel 11, and the impact teeth 6 penetrate the drill bit body 1 axially downward.

[0039] The handle 5 is equipped with a drive assembly for driving all impact teeth 6 to perform synchronous reciprocating impacts.

[0040] Preferably, the drive assembly includes a plurality of strong magnets 10 evenly arranged along the circumferential direction. The strong magnets 10 are fixed to the lower end of the rotating handle 5. The strong magnets 10 include alternating first strong magnets 7 and second strong magnets 8. The N pole of the first strong magnet 7 is located at the lower end, and the S pole of the second strong magnet 8 is located at the lower end.

[0041] The top of the impact tooth 6 is fixedly provided with a third strong magnet 9, and the N pole or the S pole of the third strong magnet 9 is located at the top.

[0042] The number of impact teeth 6 is half the number of strong magnets.

[0043] like Figure 2 As shown, when the N pole of the third strong magnet 9 is at the upper end, relative rotation occurs between the drill bit body 1 and the rotating shaft 4. When the third strong magnet 9 rotates to directly below the second strong magnet 8, opposite poles attract each other, and the impact tooth 6 retracts upward. When the third strong magnet 9 rotates to directly below the first strong magnet 7, like poles repel each other, and the impact tooth 6 extends downward. Figure 2 The image shows the drill bit body 1 and the rotating shaft 4 both rotating clockwise.

[0044] When the S-pole of the third strong magnet 9 is at the top, the drill bit body 1 and the rotating shaft 4 rotate relative to each other. When the third strong magnet 9 rotates to the position directly below the first strong magnet 7, opposite poles attract each other and the impact tooth 6 retracts upward. When the third strong magnet 9 rotates to the position directly below the second strong magnet 8, like poles repel each other and the impact tooth 6 extends downward.

[0045] Preferably, the drill bit body 1 is provided with a through hole for the impact tooth 6 to reciprocate axially, and the top of the impact tooth 6 is provided with a circular tooth shank 61. The circular tooth shank 61 is located in the drilling fluid flow channel 11, and the diameter of the circular tooth shank 61 is larger than the diameter of the through hole to prevent the impact tooth 6 from slipping out of the through hole.

[0046] The third strong magnet 9 is located on the circular toothed shank 61.

[0047] Preferably, a plurality of handle flow channel holes 51 are uniformly arranged on the handle 5 along the circumferential direction, and the handle flow channel holes 51 penetrate the handle 5 axially.

[0048] Preferably, the impact teeth 6 penetrate the blade 2 along the axial direction, and the number of impact teeth 6 is the same as the number of blades 2.

[0049] That is, each blade 2 has an impact tooth 6 that slides along the axial direction. The upper end of the impact tooth 6 extends to the drilling fluid flow channel 11, and the lower end of the impact tooth 6 extends to the lower end of the blade 2.

[0050] Preferably, the drilling fluid flow channel 11 includes a first flow channel and a second flow channel connected along the axial direction. The diameter of the first flow channel is smaller than the diameter of the second flow channel, that is, the drilling fluid flow channel 11 has a stepped structure that is thinner at the top and thicker at the bottom. The rotating shaft 4 is located in the first flow channel, and the rotating handle 5 is located in the second flow channel.

[0051] Preferably, a drill bit connector 13 is provided at the top of the drill bit body 1.

[0052] Preferably, the blade 2 is provided with a nozzle flow channel 21, the upper end of the nozzle flow channel 21 extends to the drilling fluid flow channel 11, and the lower end of the nozzle flow channel 21 is provided with a nozzle.

[0053] Example 2:

[0054] A rock-breaking method for reducing formation drill resistance by unloading bottom-hole in-situ stress is implemented based on the rock-breaking drill bit for reducing formation drill resistance by unloading bottom-hole in-situ stress in Example 1. The rock-breaking method is as follows:

[0055] In use, the top of the rotating shaft 4 is connected to the rotor of the downhole power drilling tool, and the top of the drill bit body 1 is connected to the stator of the downhole power drilling tool; the downhole power drilling tool is existing technology, and its specific structure and working principle will not be described in detail here.

[0056] During drilling, the drill bit body 1 rotates along with the downhole power drill bit, driving the impact tooth 6 to rotate. At the same time, the shaft 4 rotates along with the rotor of the downhole power drill bit, driving the handle 5 to rotate. The rotational angular velocity of the shaft 4 is different from that of the drill bit body 1. When the impact tooth 6 rotates to the point where the third strong magnet 9 is directly below the strong magnet that attracts it, the impact tooth 6 retracts upward. When the impact tooth 6 rotates to the point where the third strong magnet 9 is directly below the strong magnet that repels it, the impact tooth 6 impacts downward.

[0057] The drill bit body 1 and the rotating shaft 4 rotate continuously, realizing the reciprocating impact of the impact teeth 6;

[0058] Impact tooth 6 reciprocates to impact the rock, relieving rock pressure, while cutting tooth 3 simultaneously assists in breaking the rock, achieving high-speed rock breaking.

[0059] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, they are not intended to limit the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the protection scope of the present utility model.

Claims

1. A rock-breaking drill bit for unloading bottom-hole stress and weakening formation resistance to drilling, comprising a drill bit body, wherein the drill bit body is provided with a plurality of cutter wings arranged in a circumferential direction, and the cutter wings are provided with cutting teeth; characterized in that, The drill bit body has a drilling fluid channel in the middle, and a rotating shaft is located in the middle of the drilling fluid channel. A cylindrical rotating handle is coaxially fixed at the lower end of the rotating shaft. A support member is provided between the upper part of the rotating shaft and the side wall of the drilling fluid channel. The radially inner side of the support member is rotatably engaged with the rotating shaft, and the radially outer side of the support member is rotatably engaged with the side wall of the drilling fluid channel. A plurality of support channel holes are evenly provided on the support member along the circumferential direction. An annular space is left between the rotating shaft, the rotating handle and the side wall of the drilling fluid flow channel; Several impact teeth are evenly arranged along the circumferential direction on the bottom end face of the drilling fluid flow channel, and the impact teeth penetrate the drill bit body axially downward. The handle is equipped with a drive assembly for driving all impact teeth to perform synchronous reciprocating impacts.

2. The rock-breaking drill bit for unloading bottom-hole stress and weakening formation drill resistance as described in claim 1, characterized in that, The drive assembly includes a plurality of strong magnets evenly arranged along the circumference. The strong magnets are fixed to the lower end of the handle. The strong magnets include alternating first strong magnets and second strong magnets. The N pole of the first strong magnet is located at the lower end, and the S pole of the second strong magnet is located at the lower end. A third strong magnet is fixedly installed at the top of the impact tooth, with the N pole or S pole of the third strong magnet located at the top. The number of impact teeth is half the number of strong magnets.

3. The rock-breaking drill bit for unloading bottom-hole stress and weakening formation drill resistance as described in claim 2, characterized in that, The drill bit body is provided with a through hole for the impact tooth to reciprocate axially. The top of the impact tooth is provided with a circular tooth shank, which is located in the drilling fluid flow channel. The diameter of the circular tooth shank is larger than the diameter of the through hole. The third strong magnet is located on the circular toothed shank.

4. The rock-breaking drill bit for unloading bottom-hole stress and weakening formation drill resistance as described in claim 2, characterized in that, The handle is provided with a plurality of handle flow channel holes evenly arranged along the circumferential direction, and the handle flow channel holes extend through the handle axially.

5. The rock-breaking drill bit for unloading bottom-hole stress and weakening formation drill resistance as described in claim 2, characterized in that, The impact teeth extend axially through the blade wings, and the number of impact teeth is the same as the number of blade wings.

6. The rock-breaking drill bit for unloading bottom-hole stress and weakening formation drill resistance as described in claim 2, characterized in that, The drilling fluid flow channel includes a first flow channel and a second flow channel connected along the axial direction. The diameter of the first flow channel is smaller than the diameter of the second flow channel. The rotating shaft is located in the first flow channel, and the rotating handle is located in the second flow channel.

7. The rock-breaking drill bit for unloading bottom-hole stress and weakening formation drill resistance as described in claim 2, characterized in that, The top of the drill bit body is provided with a drill bit connector.

8. The rock-breaking drill bit for unloading bottom-hole stress and weakening formation drill resistance as described in claim 2, characterized in that, The blade is provided with a nozzle flow channel, the upper end of which extends to the drilling fluid flow channel, and the lower end of which is provided with a nozzle.

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