An impregnated diamond drill bit for inhibiting core cake formation

Abstract

The present invention belongs to the field of rock mass engineering technology, and discloses an inner cone impregnated diamond drill bit for inhibiting core cake formation, comprising: a drill bit steel body and a drill bit matrix; the drill bit matrix comprises: a plurality of cutting teeth fixed on the drill bit steel body along the circumferential direction; a drainage gap is provided between adjacent cutting teeth; an inclined surface is provided between the inner side surface and the top surface of the cutting tooth, and the inclined surface is radially inclined from the top of the cutting tooth toward the inside. The drill bit provided by the present invention can fully control the core cake formation during drilling.

Description

Technical Field

[0001] The invention relates to the technical field of rock mass engineering, in particular to an inner cone impregnated diamond drill bit for inhibiting core cake formation. Background Art

[0002] Due to the great burial depth and high ground stress of deep rock projects, the core often becomes pancake-shaped when drilling with a diamond drill bit through core drilling, which causes great difficulties in ground stress measurement and often leads to inaccurate ground stress test results or even failure of successful testing. Summary of the invention

[0003] The invention provides an inner cone impregnated diamond drill bit for inhibiting core pancake formation, which solves the technical problem in the prior art that the core pancakes when the diamond drill bit for core drilling is used.

[0004] In order to solve the above technical problems, the present invention provides an inner cone impregnated diamond drill bit for inhibiting core cake formation, comprising: a drill bit steel body and a drill bit matrix;

[0005] The drill bit matrix comprises: a plurality of cutting teeth fixed on the drill bit steel body along the circumferential direction;

[0006] A drainage gap is provided between adjacent cutting teeth;

[0007] An inclined surface is provided between the inner side surface and the top end surface of the cutting tooth, and the inclined surface is inclined radially inward from the top end of the cutting tooth.

[0008] Furthermore, the number of the cutting teeth is 14.

[0009] Furthermore, the inclination angle of the inclined surface is 30 degrees.

[0010] Furthermore, the top end surface of the cutting tooth is a convex arc surface.

[0011] Furthermore, the width of the drainage gap is 4 mm.

[0012] Furthermore, a boss is provided on the drill bit steel body, and the drill bit matrix is ​​fixed on the boss.

[0013] Furthermore, the drill bit matrix is ​​formed on the boss by an impregnation process.

[0014] Furthermore, the drill bit steel body is a hollow structure.

[0015] Furthermore, the boss is located at the upper end of the drill bit steel body.

[0016] Furthermore, the drill bit steel body is provided with threads.

[0017] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0018] The inner cone impregnated diamond drill bit for inhibiting core cake formation provided in the embodiment of the present application adopts an inner cone lip impregnated diamond drill bit. Specifically, the cutting teeth of the drill bit matrix are set to an inner inclined surface to increase the contact area between the teeth and the rock, which can ensure that the stress value generated inside the rock mass during drilling is relatively small, and it is not easy to cause the core surface to crack due to stress concentration, thereby reducing the occurrence of cake formation. At the same time, by optimizing other parameters of the diamond drill bit, the drilling efficiency of the diamond drill bit is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0020] Figure 1 Top view of an inner cone impregnated diamond drill bit to suppress core cake formation;

[0021] Figure 2 A schematic cross-sectional view of the cutting teeth of an inner cone impregnated diamond drill bit for suppressing core cake formation;

[0022] Figure 3 A schematic diagram of the structure of the drill bit steel body of an inner cone impregnated diamond drill bit for suppressing core cake formation;

[0023] Description of the accompanying drawings: 1-drill bit steel body, 11-external boss, 12-inner boss, 2-drill bit matrix, 21-cutting tooth, 22-drainage gap, 3-thread. DETAILED DESCRIPTION

[0024] The embodiment of the present application solves the technical problem in the prior art that the core becomes pancake-shaped when drilling with a diamond drill bit for core drilling by providing an inner cone impregnated diamond drill bit that inhibits the pancake-shaped core.

[0025] In order to better understand the above-mentioned technical scheme, the above-mentioned technical scheme will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical scheme of the present application, rather than limitations on the technical scheme of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0026] In the prior art, the lip shape of diamond drill bits for core drilling is generally flat-bottomed and stepped, but the flat-bottomed diamond drill bits and stepped diamond drill bits generate relatively large stress inside the rock, and there is stress concentration at the lip surface, which is easy to damage the core during drilling, and cracks are easy to occur at the core, providing conditions for core cake. The design of the special-shaped lip surface structure provided in this embodiment is to design the lip surface shape of the diamond drill bit according to different use requirements and working formations, so as to replace the traditional lip surface shape.

[0027] See also Figure 1 , Figure 2 and Figure 3 An inner cone impregnated diamond drill bit for inhibiting core cake formation comprises: a drill bit steel body 1 and a drill bit matrix 2; the drill bit matrix 2 comprises: a plurality of cutting teeth 21 circumferentially fixed on the drill bit steel body 1; drainage gaps 22 are provided between adjacent cutting teeth 21.

[0028] It is worth noting that an inclined surface is provided between the inner side surface and the top surface of the cutting tooth 21, and the inclined surface is radially inclined inward from the top of the cutting tooth 21, thereby forming a special-shaped lip surface structure, thereby increasing the contact area between the tooth and the rock, and ensuring that the stress value generated inside the rock mass during drilling is relatively small, and it is not easy to cause core cracking caused by stress concentration on the surface of the core, thereby reducing the occurrence of cake phenomenon.

[0029] In this embodiment, the number of the cutting teeth 21 is 14, the inclination angle of the inclined surface is 30 degrees, the top end surface of the cutting teeth 21 is a convex arc surface, and the width of the drainage gap 22 is 4 mm.

[0030] Furthermore, a boss is provided on the drill bit steel body 1, and the drill bit carcass 2 is fixed on the boss; the drill bit carcass 2 is formed on the boss by an impregnation process; the drill bit steel body is a hollow structure, and the boss is located at the upper end of the drill bit steel body 1, and is divided into an inner boss 12 and an outer boss 11.

[0031] In order to facilitate the connection with the connecting rod, a thread 3 is provided on the drill bit steel body 1 .

[0032] In this embodiment, compared with an ordinary rectangular lip or other conical lip surfaces, the stress at the core of the drill bit with an inner conical lip surface is smaller during drilling, which can avoid cracks at the core and thus form core pancakes. The conical lip surface increases the penetration rate, can reduce the torque fluctuation of the drill bit, improves the drilling efficiency, and reduces energy consumption.

[0033] The basic component of the diamond drill bit matrix is ​​still tungsten carbide, which has the advantages of high hardness, strong wear resistance and little thermal damage to diamond, but it is easy to oxidize. Iron-based powder can be added to the matrix formula to reduce the sintering temperature and maintain the original strength of diamond. The rich iron-based resources can enhance the matrix strength and increase the life of the drill bit.

[0034] The graphite mold material of the hot pressing process is made of high-purity graphite material and artificial dense graphite. It has high compressive strength, will not deform, will not stick, is easy to process, and can be used multiple times.

[0035] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0036] The inner cone impregnated diamond drill bit for inhibiting core cake formation provided in the embodiment of the present application adopts an inner cone lip impregnated diamond drill bit. Specifically, the cutting teeth of the drill bit matrix are set to an inner inclined surface to increase the contact area between the teeth and the rock, which can ensure that the stress value generated inside the rock mass during drilling is relatively small, and it is not easy to cause the core surface to crack due to stress concentration, thereby reducing the occurrence of cake formation. At the same time, by optimizing other parameters of the diamond drill bit, the drilling efficiency of the diamond drill bit is improved.

[0037] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. An inner cone impregnated diamond drill bit for inhibiting core cake formation, characterized in that: include: Drill bit steel body and drill bit matrix; The drill bit matrix comprises: a plurality of cutting teeth fixed on the drill bit steel body along the circumferential direction; A drainage gap is provided between adjacent cutting teeth; An inclined surface is provided between the inner side surface and the top surface of the cutting tooth, and the inclined surface is inclined radially inward from the top of the cutting tooth, and the inclined angle of the inclined surface is 30 degrees, so as to increase the contact area between the cutting tooth and the rock, limit the stress value generated inside the rock mass during drilling, and prevent the core from cracking due to stress concentration on the surface of the core, thereby reducing the occurrence of cake phenomenon; The top end surface of the cutting tooth is a convex arc surface; The drill bit steel body is a hollow structure.

2. The inner cone impregnated diamond drill bit for inhibiting core cake formation according to claim 1, characterized in that: The number of the cutting teeth is 14.

3. The inner cone impregnated diamond drill bit for inhibiting core cake formation according to claim 1, characterized in that: The width of the drainage gap is 4 mm.

4. The inner cone impregnated diamond drill bit for inhibiting core cake formation according to claim 1, characterized in that: The drill bit steel body is provided with a boss, and the drill bit matrix is ​​fixed on the boss.

5. The inner cone impregnated diamond drill bit for suppressing core cake formation as claimed in claim 4, characterized in that: The drill bit matrix is ​​formed on the boss by an impregnation process.

6. The inner cone impregnated diamond drill bit for inhibiting core cake formation as claimed in claim 5, characterized in that: The boss is located at the upper end of the drill bit steel body.

7. The inner cone impregnated diamond drill bit for suppressing core cake formation according to claim 1, characterized in that: The drill bit steel body is provided with threads.

Images