Eccentric casing drilling tool

Abstract

The eccentric casing drilling tool comprises a drill bit, a guide part, a drilling part, a neck rod part and a connecting part, the guide part, the drilling part, the neck rod part and the connecting part are sequentially connected in the axis direction of the drill bit, the guide part is specifically of a conical structure, and the outer diameter of the guide part is gradually increased in the axial direction of the drill bit; the eccentric sleeve is arranged on the outer side of the neck rod part in a sleeving manner and is rotationally connected with the neck rod part; and the rod stabilizer is sleeved on the outer side of the connecting part and is fixedly connected with the connecting part. Compared with the prior art, the eccentric casing-following drilling tool has the advantages that damage to the eccentric casing-following drilling tool in the using process can be reduced, and the service life of the eccentric casing-following drilling tool is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of drilling tools, and more specifically, to an eccentric tubing drilling tool. Background Art

[0002] Existing eccentric drills typically consist of an eccentric drill bit, an eccentric sleeve, and a stabilizer. The eccentric drill bit and the eccentric sleeve are mounted on the stabilizer and are fixedly connected to the stabilizer. During use, the stabilizer drives the eccentric drill bit, which in turn drives the eccentric sleeve. During use, the drilling rotation torque is concentrated entirely at the connection between the eccentric drill bit and the stabilizer. Due to the uneven force applied to the eccentric sleeve, an eccentric load occurs at the connection between the eccentric drill bit and the stabilizer. This, combined with the impact force, can easily damage the connection between the eccentric drill bit and the stabilizer.

[0003] Therefore, there is an urgent need for an eccentric follow-up drill tool that can reduce damage during use and increase the service life of the eccentric drill tool. Utility Model Content

[0004] In order to solve the above technical problems, the present application provides an eccentric follow-up drill bit, which can reduce damage during use and increase the service life of the eccentric drill bit.

[0005] The technical solutions provided in this application are as follows:

[0006] An eccentric tubing drilling tool, comprising:

[0007] A drill bit, comprising a guide portion, a drilling portion, a neck portion, and a connecting portion sequentially connected along the axial direction of the drill bit, wherein the guide portion is specifically a tapered structure, and the outer diameter of the guide portion gradually increases along the axial direction of the drill bit;

[0008] An eccentric sleeve is sleeved on the outside of the neck portion and is rotatably connected to the neck portion;

[0009] A rod stabilizer is sleeved on the outside of the connecting portion and fixedly connected to the connecting portion.

[0010] Preferably, the tapered angle of the guide portion is no greater than 30°.

[0011] Preferably, the outer surface of the connecting portion is provided with an external thread, the front end of the stabilizer is provided with a mounting hole, the inner surface of the mounting hole is provided with an internal thread, and the connecting portion and the mounting hole are connected by threads.

[0012] Preferably, it also includes:

[0013] first alloy teeth, the first alloy teeth being arranged at intervals on the front end surface of the guide portion;

[0014] second alloy teeth, the second alloy teeth being arranged at intervals on the front end surface of the drilling portion;

[0015] The third alloy teeth are arranged at intervals on the front end surface and the side surface of the eccentric sleeve.

[0016] Preferably, it also includes:

[0017] a first groove provided on the stabilizer, wherein the first groove extends along the radial direction of the stabilizer;

[0018] a second groove provided on the connecting portion and used in conjunction with the first groove, wherein a columnar hole is formed between the first groove and the second groove;

[0019] A positioning rod is arranged in the cylindrical hole and is loosely matched with the cylindrical hole.

[0020] Preferably, at least two positioning rods are provided, and the positioning rods are arranged at intervals in the circumferential direction around the rod stabilizer.

[0021] Preferably, it also includes:

[0022] A positioning groove provided on the circumference of the neck portion;

[0023] A positioning key is provided on the eccentric sleeve, and the positioning key is slidably connected to the positioning slot so that the eccentric sleeve has an eccentric state and a retracted state. When the positioning key is located at the first end of the positioning slot, the eccentric sleeve is in the eccentric state. When the positioning key is rotated to the second end of the positioning slot, the eccentric sleeve is in the retracted state.

[0024] Preferably, the length of the neck portion is greater than the length of the eccentric sleeve, and a first positioning surface and a second positioning surface are provided at both ends of the neck portion. When the eccentric sleeve is in an eccentric state, the rear end surface of the eccentric sleeve abuts against the second positioning surface, and when the eccentric sleeve is in a retracted state, the front end surface of the eccentric sleeve abuts against the first positioning surface.

[0025] Preferably, a first air duct is provided in the stabilizer, and the first air duct extends along the axial direction of the stabilizer. A second air duct and a third air duct are provided in the drill bit, and the two ends of the second air duct are respectively connected with the first air duct and the third air duct. The third air duct is inclined and extends to the front end face of the guide part, the side opening of the guide part, and the side of the drill bit are provided with a slag discharge channel, and the opening is used to connect the third air duct and the slag discharge channel.

[0026] Preferably, the slag discharge channel comprises:

[0027] a first slag discharge groove provided on the front end surface of the drilling portion, the first slag discharge groove being in communication with the third air passage through the opening;

[0028] a second slag discharge groove provided in the circumference of the drilling portion and connected to the first slag discharge groove, wherein the second slag discharge grooves are provided in a one-to-one correspondence with the first slag discharge grooves, and a third slag discharge groove is provided between adjacent second slag discharge grooves;

[0029] A fourth slag discharge groove is provided on the outer circumferential surface of the eccentric sleeve.

[0030] The eccentric pipe drilling tool provided by the present invention is provided with a drill bit, an eccentric sleeve and a rod stabilizer, wherein a guide portion, a drilling portion, a neck portion and a connecting portion are sequentially connected along the axial direction of the drill bit, wherein the guide portion is used for guiding, the drilling portion is used for drilling, the guide portion is provided at the front end of the drilling portion and can guide the drilling process of the drill bit, the eccentric sleeve is provided on the outside of the neck portion, and the eccentric sleeve is rotatably connected to the drill bit, the rod stabilizer is provided on the outside of the connecting portion, and the rod stabilizer is fixedly connected to the connecting portion. In the prior art, the eccentric sleeve is not provided with a guide portion at the front end of the drill bit during the hole expansion process, and the eccentric sleeve is subjected to uneven force, which makes it easy for an eccentric load to appear at the connection between the connecting portion and the rod stabilizer, and the added impact force easily causes damage or even breakage of the connection between the connecting portion and the rod stabilizer. However, the eccentric pipe drill provided by the present invention has a guide at the front end of the drill bit. Under the action of impact force, the guide is inserted into the bottom of the hole to stabilize the front end of the drill bit. The rear end of the drill bit is stabilized by a stabilizer, which prevents the eccentric sleeve from being overloaded during rotation and increases the service life of the drill bit. It can be seen that compared with the prior art, the eccentric pipe drill provided by the present invention can reduce damage during use and increase the service life of the eccentric drill bit. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] Figure 1 A schematic structural diagram of an eccentric tubing drill provided by an embodiment of the present utility model;

[0033] Figure 2 A schematic diagram of a three-dimensional structure of an eccentric pipe drilling tool provided by an embodiment of the utility model;

[0034] Figure 3A schematic diagram of a three-dimensional connection mechanism for a drill bit provided in an embodiment of the present utility model;

[0035] Figure 4 for Figure 3 A schematic cross-sectional view of

[0036] Figure 5 A structural schematic diagram of an eccentric sleeve provided in an embodiment of the utility model.

[0037] Figure markings: 1. guide part; 2. drilling part; 3. neck part; 4. connecting part; 5. eccentric sleeve; 6. stabilizer; 71. first alloy tooth; 72. second alloy tooth; 73. third alloy tooth; 8. positioning rod; 91. positioning groove; 92. positioning key; 61. first air duct; 41. second air duct; 42. third air duct; 11. opening; 21. first slag discharge trough; 22. second slag discharge trough; 23. third slag discharge trough; 51. fourth slag discharge trough. DETAILED DESCRIPTION

[0038] In order to help those skilled in the art better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of this application.

[0039] It should be noted that when an element is referred to as being “fixed on” or “set on” another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being “connected to” another element, it can be directly connected to the other element or indirectly connected to the other element.

[0040] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout the description of this application, "plurality" or "several" means two or more, unless otherwise specifically defined.

[0042] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which this application can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in this application without affecting the efficacy and purpose that can be achieved by this application.

[0043] The embodiments of the present invention are written in a progressive manner.

[0044] like Figures 1 to 5 As shown, an embodiment of the utility model provides an eccentric follow-up drill tool, comprising: a drill bit, a guide part 1, a drilling part 2, a neck part 3 and a connecting part 4 connected in sequence along the axial direction of the drill bit, the guide part 1 is specifically a conical structure, and the outer diameter of the guide part 1 gradually increases in the direction of the drilling part 2; an eccentric sleeve 5 is sleeved on the outside of the neck part 3 and rotatably connected to the drill bit; a stabilizer 6 is sleeved on the outside of the connecting part 4 and fixedly connected to the connecting part 4.

[0045] Existing eccentric drills typically consist of an eccentric drill bit, an eccentric sleeve, and a stabilizer. The eccentric drill bit and the eccentric sleeve are mounted on the stabilizer and are fixedly connected to the stabilizer. During use, the stabilizer drives the eccentric drill bit, which in turn drives the eccentric sleeve. During use, the drilling rotation torque is concentrated entirely at the connection between the eccentric drill bit and the stabilizer. Due to the uneven force applied to the eccentric sleeve, an eccentric load occurs at the connection between the eccentric drill bit and the stabilizer. This, combined with the impact force, can easily damage the connection between the eccentric drill bit and the stabilizer.

[0046] The head of the eccentric drill bit in the prior art is used for drilling holes. No guide part 1 is provided to support the eccentric drill bit, and the eccentric drill bit is supported only by the stabilizer at the rear end. Therefore, when the eccentric drill bit rotates, it is easy to generate an eccentric load, and the eccentric load force can easily cause damage to the connection between the eccentric drill bit and the stabilizer.

[0047] The eccentric pipe drill provided by the present invention is provided with a drill bit, an eccentric sleeve 5 and a stabilizer 6, wherein a guide portion 1, a drilling portion 2, a neck portion 3 and a connecting portion 4 are sequentially connected along the axial direction of the drill bit, wherein the guide portion 1 is used for guiding, and the drilling portion 2 is used for drilling. The guide portion 1 is provided at the front end of the drilling portion 2 and can guide the drilling process of the drill bit. The eccentric sleeve 5 is sleeved on the outside of the neck portion 3 and is rotatably connected to the drill bit. The stabilizer 6 is sleeved on the outside of the connecting portion 4 and is fixedly connected to the connecting portion 4. In the prior art, the eccentric sleeve 5 is not provided with a guide portion 1 at the front end of the drill bit during the hole expansion process, and the eccentric sleeve 5 is subjected to uneven force, which makes it easy for an eccentric load to occur at the connection between the connecting portion 4 and the stabilizer 6. The added impact force easily causes damage or even breakage of the connection between the connecting portion 4 and the stabilizer 6. However, the eccentric pipe drill provided by the embodiment of the present invention has a guide portion 1 provided at the front end of the drill bit. Under the action of the impact force, the guide portion 1 is inserted into the bottom of the hole to stabilize the front end of the drill bit. The rear end of the drill bit is stabilized by the stabilizer 6, which prevents the eccentric sleeve 5 from being overloaded during rotation, thereby extending the service life of the drill bit. As can be seen from this, compared with the prior art, the eccentric pipe drill provided by the embodiment of the present invention can reduce damage during use and extend the service life of the eccentric drill bit.

[0048] In the above structure, as one implementation mode, the taper angle of the guide portion 1 in the embodiment of the present invention is not greater than 30°.

[0049] Specifically, the guide portion 1 in the embodiment of the present invention is a conical structure. The diameter of the guide portion 1 gradually increases toward the drilling portion 2. The guide portion 1 has a large end and a small end. The taper angle of the guide portion 1 is arctan((D 大端 -D 小端 ) / H); where D 大端 D is the outer diameter of the large end of the guide part 1 小端 is the outer diameter of the small end of the guide part 1, and H is the length of the guide part 1.

[0050] Furthermore, as one of the specific implementation methods, the outer surface of the connecting part 4 in the embodiment of the utility model is provided with an external thread line, the front end of the stabilizer 6 is provided with a mounting hole, the inner surface of the mounting hole is provided with an internal thread line, and the connecting part 4 and the mounting hole are connected by threads.

[0051] The connecting portion 4 is fixedly connected to the mounting hole of the rod stabilizer 6, and the rod stabilizer 6 provides the drill bit with axial rotation and axial impact.

[0052] Furthermore, since the front end face of the drill bit is often worn during the drilling process, the life of the drill bit is reduced, and the drill bit needs to be replaced in time. In order to extend the life of the drill bit and improve the drilling efficiency, as one of the implementation methods, the eccentric follow-up drill bit in the embodiment of the utility model also includes a first alloy tooth 71, a second alloy tooth 72 and a third alloy tooth 73, wherein a plurality of first alloy teeth 71 are arranged at intervals on the front end face of the guide part 1. When drilling, the front end face of the guide part 1 is in direct contact with the ground and is prone to wear. By arranging the first alloy teeth 71 on the front end face of the guide part 1, the wear resistance of the front end face of the guide part 1 is increased. A plurality of second alloy teeth 72 are arranged at intervals on the front end face of the drilling part 2. When drilling, it is mainly the front end face of the drilling part 2 that is in direct contact with the rock formation. A plurality of third alloy teeth 73 are arranged at intervals on the front end face and side face of the eccentric sleeve 5. The eccentric sleeve 5 is used for reaming. When reaming, it is mainly the front end face and side face of the eccentric sleeve 5 that are in direct contact with the rock formation.

[0053] Furthermore, in order to further increase the connection between the drill bit and the stabilizer 6, as one of the embodiments, the eccentric follow-up drill bit in the embodiment of the utility model also includes a first groove, a second groove and a positioning rod 8, wherein the first groove is arranged on the stabilizer 6, and the first groove extends along the radial direction of the stabilizer 6, the second groove is arranged on the connecting part 4, and the second groove is used in conjunction with the first groove. A cylindrical hole is formed between the first groove and the second groove, and the positioning rod 8 is used to be inserted into the cylindrical hole, and the positioning rod 8 is used to cooperate with the cylindrical hole gap to prevent axial rotation between the drill bit and the stabilizer 6.

[0054] Furthermore, as one specific implementation method, the cross-sectional shape of the columnar hole in the embodiment of the present invention is circular, and the first groove and the second groove are both semicircular holes.

[0055] Furthermore, as one implementation mode, at least two positioning rods 8 are provided in the embodiment of the present utility model, and the positioning rods 8 are arranged at intervals in the circumferential direction around the stabilizer 6 .

[0056] The eccentric follow-up drill bit 92 is provided with a positioning groove 91 and a positioning key 92, wherein the positioning groove 91 is provided in the circumference of the neck portion 3, and the positioning key 92 is provided on the eccentric sleeve 5, and the positioning key 92 is slidably connected with the positioning groove 91 so that the eccentric sleeve 5 has an eccentric state and a retracted state. The positioning groove 91 has a first end and a second end. When the eccentric sleeve 5 needs to be expanded, the stabilizer 6 is driven to rotate in the first direction, and there is relative rotation between the eccentric sleeve 5 and the drill bit, so that the positioning key 92 rotates to the first end of the positioning groove 91. At this time, the eccentric sleeve 5 is in an eccentric state and continues to drive the stabilizer 6 to rotate in the first direction. The eccentric sleeve 5 expands the hole as the drill bit rotates. When it is necessary to lift the drill, the stabilizer 6 is rotated in the opposite direction so that the positioning key 92 rotates to the second end of the positioning groove 91. At this time, the eccentric sleeve 5 is in a retracted state.

[0057] It should be noted that the drilling part 2 is specifically an eccentric structure. When the eccentric sleeve 5 is in an eccentric state, as seen from the projection from the guide end toward the stabilizer 6, part of the eccentric sleeve 5 is located outside the drilling part 2, and the hole is expanded through the part of the eccentric sleeve 5 that extends out; when the eccentric sleeve 5 is in a retracted state, as seen from the projection from the guide end toward the stabilizer 6, the eccentric sleeve 5 is completely located inside the drilling part 2, which facilitates lifting the drill.

[0058] In the above structure, as one embodiment, the length of the neck portion 3 in the embodiment of the present invention is greater than the length of the eccentric sleeve 5. The eccentric sleeve 5 can move axially in the neck portion 3. The neck portion 3 is provided with a first positioning surface and a second positioning surface at both ends. When drilling, the front end surface of the eccentric sleeve 5 abuts against the rock formation at the bottom of the hole, so that the rear end surface of the eccentric sleeve 5 abuts against the second positioning surface. The stabilizer 6 drives the drill bit to rotate in a first direction, thereby causing the positioning key 92 to rotate to the first end of the positioning groove 91. At this time, the eccentric sleeve 5 is in an eccentric state. When the drill is lifted, the front end surface of the eccentric sleeve 5 separates from the rock formation at the bottom of the hole. Under the action of gravity, the front end surface of the eccentric sleeve 5 abuts against the first positioning surface. The stabilizer 6 drives the drill bit to rotate in the opposite direction, thereby causing the positioning key 92 to rotate to the second end of the positioning groove 91. At this time, the eccentric sleeve 5 is in a retracted state.

[0059] In the above structure, as one embodiment, the front end of the eccentric sleeve 5 in the embodiment of the present invention is provided with an inclined surface, and the outer diameter of the eccentric sleeve 5 gradually increases in the direction away from the drilling portion 2.

[0060] Furthermore, the eccentric heel tube drill in the embodiment of the present invention is used in conjunction with a positive circulation impactor. A first air duct 61 is provided in the stabilizer 6 in the embodiment of the present invention. The first air duct 61 extends along the axial direction of the stabilizer 6. A second air duct 41 is provided in the drill bit. The two ends of the second air duct 41 are respectively connected to the first air duct 61 and the third air duct 42. The third air duct 42 is inclined and extends to the front end face of the guide part 1. An opening 11 is provided on the side of the guide part 1, and a slag discharge channel is provided on the drill bit. The opening 11 is used to connect the third air duct 42 with the slag discharge channel.

[0061] Furthermore, as one embodiment, at least two third air passages 42 are provided in the embodiment of the present invention, and the rear ends of the third air passages 42 are both connected to the second air passage 41. Preferably, three third air passages 42 are provided in the embodiment of the present invention.

[0062] Specifically, the high-pressure gas enters the third gas channel 42 from the first gas channel 61 via the second gas channel 41 and discharges the rock debris at the bottom of the hole through the opening 11 and the debris discharge channel.

[0063] Furthermore, as one of the embodiments, the slag discharge channel in the embodiment of the utility model includes a first slag discharge groove 21, a second slag discharge groove 22, a third slag discharge groove 23 and a fourth slag discharge groove 51, wherein the first slag discharge groove 21 is arranged on the front end face of the drilling portion 2, the first slag discharge groove 21 is connected with the second air duct 41 through the opening 11, the second slag discharge groove 22 is arranged in the circumference of the drilling portion 2, and the second slag discharge groove 22 is used to communicate with the first slag discharge groove 21, the second slag discharge groove 22 is arranged one-to-one with the first slag discharge groove 21, the third slag discharge groove 23 is arranged between adjacent second slag discharge grooves 22, and the fourth slag discharge groove 51 is arranged on the outer circumferential surface of the eccentric sleeve 5.

[0064] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An eccentric pipe drilling tool, characterized in that: include: A drill bit, comprising a guide portion (1), a drilling portion (2), a neck portion (3), and a connecting portion (4) connected in sequence along the axial direction of the drill bit, wherein the guide portion (1) is specifically a conical structure, and the outer diameter of the guide portion (1) gradually increases along the axial direction of the drill bit; An eccentric sleeve (5) sleeved on the outside of the neck portion (3) and rotatably connected to the neck portion (3); A rod stabilizer (6) is sleeved on the outside of the connecting portion (4) and fixedly connected to the connecting portion (4).

2. The eccentric pipe drilling tool according to claim 1, characterized in that: The tapered angle of the guide portion (1) is no greater than 30°.

3. The eccentric pipe drilling tool according to claim 1, characterized in that: The outer surface of the connecting portion (4) is provided with an external thread, the front end of the stabilizer (6) is provided with a mounting hole, the inner surface of the mounting hole is provided with an internal thread, and the connecting portion (4) and the mounting hole are connected via threads.

4. The eccentric pipe drilling tool according to claim 3, characterized in that: Also includes: First alloy teeth (71), the first alloy teeth (71) being arranged at intervals on the front end surface of the guide portion (1); second alloy teeth (72), the second alloy teeth (72) being arranged at intervals on the front end surface of the drilling portion (2); Third alloy teeth (73), the third alloy teeth (73) are arranged at intervals on the front end surface and side surface of the eccentric sleeve (5).

5. The eccentric casing drilling tool according to any one of claims 1 to 4, characterized in that: Also includes: A first groove is provided on the rod stabilizer (6), the first groove extending in a radial direction of the rod stabilizer (6); A second groove provided on the connecting portion (4) and used in conjunction with the first groove, a columnar hole being formed between the first groove and the second groove; A positioning rod (8) is arranged in the cylindrical hole and is clearance-matched with the cylindrical hole.

6. The eccentric pipe drilling tool according to claim 5, characterized in that: At least two positioning rods (8) are provided, and the positioning rods (8) are arranged at intervals in the circumferential direction around the rod stabilizer (6).

7. The eccentric casing drilling tool according to any one of claims 1 to 4, characterized in that: Also includes: A positioning groove (91) provided in the circumferential direction of the neck portion (3); A positioning key (92) is provided on the eccentric sleeve (5), and the positioning key (92) is slidably connected to the positioning groove (91), so that the eccentric sleeve (5) has an eccentric state and a retracted state. When the positioning key (92) is located at the first end of the positioning groove (91), the eccentric sleeve (5) is in the eccentric state. When the positioning key (92) is rotated to the second end of the positioning groove (91), the eccentric sleeve (5) is in the retracted state.

8. The eccentric pipe drilling tool according to claim 7, characterized in that: The length of the neck portion (3) is greater than the length of the eccentric sleeve (5), and a first positioning surface and a second positioning surface are provided at both ends of the neck portion (3). When the eccentric sleeve (5) is in an eccentric state, the rear end surface of the eccentric sleeve (5) abuts against the second positioning surface, and when the eccentric sleeve (5) is in a retracted state, the front end surface of the eccentric sleeve (5) abuts against the first positioning surface.

9. The eccentric casing drill according to any one of claims 1 to 4, characterized in that: A first air duct (61) is provided in the stabilizer (6), and the first air duct (61) extends along the axial direction of the stabilizer (6). A second air duct (41) and a third air duct (42) are provided in the drill bit, and the two ends of the second air duct (41) are respectively connected to the first air duct (61) and the third air duct (42). The third air duct (42) is inclined and extends to the front end surface of the guide part (1). The side of the guide part (1) has an opening (11). A slag discharge channel is provided on the side of the drill bit, and the opening (11) is used to connect the third air duct (42) and the slag discharge channel.

10. The eccentric pipe drilling tool according to claim 9, characterized in that: The slag discharge channel comprises: a first slag discharge groove (21) provided on the front end surface of the drilling portion (2), the first slag discharge groove (21) being in communication with the third air passage (42) through the opening (11); A second slag discharge groove (22) is provided in the circumferential direction of the drilling portion (2) and is connected to the first slag discharge groove (21), the second slag discharge groove (22) and the first slag discharge groove (21) being provided in a one-to-one correspondence, and a third slag discharge groove (23) is provided between adjacent second slag discharge grooves (22); A fourth slag discharge groove (51) is provided on the outer circumferential surface of the eccentric sleeve (5).

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