阅读说明：本技术 聚晶金刚石复合片和pdc钻头 (Polycrystalline diamond compact and PDC drill bit ) 是由 童力峰 于 2020-05-14 设计创作，主要内容包括：一种聚晶金刚石复合片和PDC钻头,聚晶金刚石复合片包括：硬质合金基座和金刚石层,金刚石层的一侧与硬质合金基座的第一侧连接,金刚石层的远离硬质合金基座的一侧表面突出地形成有十字形的切削突起,每个切削突起的宽度由金刚石层的中心向外边缘处逐渐变小,相邻两个切削突起之间形成相对于金刚石层的径向平面倾斜的切削面,切削面由金刚石层的中心向外边缘处逐渐倾斜。本发明采用以分布在PDC钻头上的四象限人造聚晶金刚石齿,因而很容易吃入地层,破岩效率高,有效地提供机械钻速和减少钻头泥包,在钻头收到侧向力的作用下能获得更好的破岩效果,稳定的定向工具面的特点,有更好的研磨性和抗冲击性。(A polycrystalline diamond compact and a PDC drill bit, the polycrystalline diamond compact comprising: the cutting tool comprises a hard alloy base and a diamond layer, wherein one side of the diamond layer is connected with the first side of the hard alloy base, cross-shaped cutting protrusions are convexly formed on the surface of one side, far away from the hard alloy base, of the diamond layer, the width of each cutting protrusion is gradually reduced from the center of the diamond layer to the outer edge, a cutting surface inclined relative to the radial plane of the diamond layer is formed between every two adjacent cutting protrusions, and the cutting surface is gradually inclined from the center of the diamond layer to the outer edge. The invention adopts the four-quadrant artificial polycrystalline diamond teeth distributed on the PDC drill bit, thereby being easy to eat into the stratum, having high rock breaking efficiency, effectively providing the mechanical drilling speed and reducing the drill bit mud bag, being capable of obtaining better rock breaking effect under the action of lateral force received by the drill bit, having the characteristics of stable directional tool surface and better grindability and impact resistance.)

1. A polycrystalline diamond compact, comprising: carbide base (1) and diamond layer (2), one side of diamond layer (2) with the first side of carbide base (1) is connected, keeping away from of diamond layer (2) one side surface of carbide base (1) is formed with crisscross cutting protrudingly (3), every the width of cutting protrudingly (3) by the center of diamond layer (2) is to outer edge taper, adjacent two form between cutting protrudingly (3) for cutting face (4) of the radial plane slope of diamond layer (2), cutting face (4) by the center of diamond layer (2) is to outer edge taper.

2. A polycrystalline diamond compact according to claim 1, characterised in that the axial sides of the cutting projections (3) are inclined surfaces (5).

3. A polycrystalline diamond compact according to claim 1, wherein the cutting face (4) is angled at 5 ° to the radial plane.

4. A polycrystalline diamond compact according to claim 1, characterised in that the cutting protrusion (3) is formed with a first chamfer (6) at its peripheral edge at the outer edge of the diamond layer (2), and/or a second chamfer (7) at its radial edge of the cutting protrusion (3), and/or a third chamfer (8) at its peripheral edge of the cutting face (4).

5. A polycrystalline diamond compact according to claim 4, wherein the first chamfer (6) is a circular arc chamfer having a radius of 0.5mm, the second chamfer (7) is a 0.5x45 ° chamfer and the third chamfer (8) is a 0.8x40 ° chamfer.

6. A polycrystalline diamond compact according to claim 2, characterised in that the angle between the left and right inclined surfaces (5) of the cutting protrusion (3) is 34.15 ° and/or the width of the cutting protrusion (3) tapers at an angle of 20 ° from the centre to the outer edge of the diamond layer (2).

7. A polycrystalline diamond compact according to claim 2, characterised in that a cruciform locating step (9) is protrudingly formed on the surface of the cemented carbide substrate (1) on the side remote from the diamond layer (2).

8. A polycrystalline diamond compact according to claim 7, characterised in that the positioning step (9) is 1mm thick and/or the diamond layer (2) is 3.6mm thick.

9. A PDC bit comprising the polycrystalline diamond compact (10) of any one of claims 1 to 8, a plurality of the polycrystalline diamond compact (10) being disposed on blades (11) of the PDC bit.

10. The PDC drill bit of claim 9, wherein the blades (11) are provided with tooth cavities (12), positioning grooves (13) matched with the positioning steps (9) at the bottom of the polycrystalline diamond compact (10) are formed at the bottoms of the tooth cavities (12), and the polycrystalline diamond compact (10) is welded in the tooth cavities (12).

Technical Field

The invention belongs to the technical field of manufacturing of PDC geological drill bits, and particularly relates to a polycrystalline diamond compact and a PDC drill bit.

Background

The conventional PDC drill bit (polycrystalline diamond compact bit) uses the conventional cylindrical design of teeth, the thickness of a diamond layer is 2.0mm, and a hard alloy substrate, the cutting surface of the diamond layer is planar, and the circumferential profile has specific chamfering requirements. The cutting teeth are cutting edges of the PDC drill bit for rock breaking, and the using effect of the PDC drill bit is determined by the performance of the cutting teeth. The good cutting tooth performance can improve the mechanical drilling speed and footage of the PDC drill bit, shorten the well construction period and reduce the comprehensive drilling cost.

Disclosure of Invention

The invention provides a polycrystalline diamond compact and a PDC drill bit, and aims to solve at least one technical problem.

To solve the above problems, as one aspect of the present invention, there is provided a polycrystalline diamond compact including: the cutting tool comprises a hard alloy base and a diamond layer, wherein one side of the diamond layer is connected with the first side of the hard alloy base, cross-shaped cutting protrusions are convexly formed on the surface of one side, far away from the hard alloy base, of the diamond layer, the width of each cutting protrusion is gradually reduced from the center of the diamond layer to the outer edge, a cutting surface inclined relative to the radial plane of the diamond layer is formed between every two adjacent cutting protrusions, and the cutting surface is gradually inclined from the center of the diamond layer to the outer edge.

Preferably, both side axial side surfaces of the cutting protrusion are inclined surfaces.

Preferably, the cutting face is angled at 5 ° to the radial plane.

Preferably, a first chamfer is formed at a peripheral edge of the cutting protrusion at the outer edge of the diamond layer, and/or a second chamfer is formed at a radial edge of the cutting protrusion, and/or a third chamfer is provided at a circumferential edge of the cutting face.

Preferably, the first chamfer is a circular arc chamfer with a radius of 0.5mm, the second chamfer is a 0.5x45 ° chamfer, and the third chamfer is a 0.8x40 ° chamfer.

Preferably, an angle between the right and left inclined surfaces of the cutting protrusion is 34.15 °, and/or a width of the cutting protrusion is gradually reduced from a center to an outer edge of the diamond layer at an angle of 20 °.

Preferably, a cross-shaped positioning step is protrudingly formed on one side surface of the cemented carbide base, which is far away from the diamond layer.

Preferably, the positioning step has a thickness of 1mm, and/or the diamond layer has a thickness of 3.6 mm.

The invention also provides a PDC drill bit which comprises the polycrystalline diamond compact, wherein a plurality of polycrystalline diamond compacts are arranged on the blades of the PDC drill bit.

Preferably, a tooth cavity is formed in the blade, a positioning groove matched with the positioning step at the bottom of the polycrystalline diamond compact is formed in the bottom of the tooth cavity, and the polycrystalline diamond compact is welded in the tooth cavity.

The invention adopts the four-quadrant artificial polycrystalline diamond teeth distributed on the PDC drill bit, so the drill bit is easy to eat into the stratum, the rock breaking efficiency is high, particularly, the granite stratum has better rock breaking effect, the mechanical drilling speed is effectively improved, and the drill bit mud bag is reduced. In the use of directional well, the structure of the artificial polycrystalline diamond tooth of four-quadrant can obtain better broken rock effect, the characteristics of stable directional tool face especially under the effect that the drill bit received the lateral force, and the special structural design of diamond star tooth makes has better abrasiveness and impact resistance, has improved PDC drill bit's life, has fine mechanical footage.

Drawings

FIG. 1 schematically illustrates a perspective view of the present invention;

FIG. 2 schematically illustrates a front view of the present invention;

FIG. 3 schematically illustrates a C-C cross-sectional view of FIG. 2;

FIG. 4 schematically illustrates a side view of the present invention;

FIG. 5 schematically illustrates a rear view of the present invention;

FIG. 6 schematically illustrates a perspective view of a drill bit of the present invention;

FIG. 7 schematically shows an enlarged view of section A of FIG. 6;

fig. 8 schematically shows an enlarged view of a portion B of fig. 6.

Reference numbers in the figures: 1. a cemented carbide base; 2. a diamond layer; 3. cutting the protrusion; 4. cutting the surface; 5. an inclined surface; 6. a first chamfer; 7. a second chamfer; 8. a third chamfer; 9. positioning a step; 10. a polycrystalline diamond compact; 11. a blade; 12. tooth points; 13. positioning a groove; 14. the tooth tip is acute.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways as defined and covered by the claims.

As one aspect of the present invention, there is provided a polycrystalline diamond compact, in particular, a PDC bit diamond tooth for oil and gas development and drilling, comprising: the cutting tool comprises a hard alloy base 1 and a diamond layer 2, wherein one side of the diamond layer 2 is connected with the first side of the hard alloy base 1, and a cutting protrusion 3 with a cross-shaped star-shaped structure is convexly formed on the surface of one side, far away from the hard alloy base 1, of the diamond layer 2.

Wherein the width of each cutting protrusion 3 is gradually reduced from the center of the diamond layer 2 to the outer edge, a cutting surface 4 inclined relative to the radial plane of the diamond layer 2 is formed between two adjacent cutting protrusions 3, and the cutting surface 4 is gradually inclined from the center of the diamond layer 2 to the outer edge.

In the technical scheme, the cross-shaped cutting protrusions 3 are divided into four cutting surfaces 4, which are similar to four quadrants, wherein the four quadrants refer to diamond tooth surfaces in four equal areas, so that a four-quadrant artificial polycrystalline diamond compact is formed.

The invention adopts the four-quadrant artificial polycrystalline diamond teeth distributed on the PDC drill bit, so the drill bit is easy to eat into the stratum, the rock breaking efficiency is high, particularly, the granite stratum has better rock breaking effect, the mechanical drilling speed is effectively improved, and the drill bit mud bag is reduced. In the use of directional well, the structure of the artificial polycrystalline diamond tooth of four-quadrant can obtain better broken rock effect, the characteristics of stable directional tool face especially under the effect that the drill bit received the lateral force, and the special structural design of diamond star tooth makes has better abrasiveness and impact resistance, has improved PDC drill bit's life, has fine mechanical footage. The four-quadrant artificial polycrystalline diamond can be used for multiple times by rotating the point surface position of one of the four equal area surfaces of the diamond.

In order to verify the technical effect of the invention, the structure of the four-quadrant artificial polycrystalline diamond compact is subjected to mechanical analysis by adopting special mechanical analysis SimSOLid software, load analysis of the acting force received by the star-shaped teeth is tested under the conditions that the PDC drill bit receives the torque and the bit pressure in the drilling process, the acting force torque is 40KN.M, and the bit pressure is 20 tons, the stress load yield force of the star-shaped structure is designed to reach 4.700e +008N/M ^2 by calculating the diamond layer of the star-shaped teeth, then the position of the star-shaped teeth which uses the sharp point of the diamond layer firstly is calculated according to the characteristic that each blade of the drill bit penetrates into the stratum by the design of the PDC drill bit, the directionality of the star-shaped teeth which are distributed in each tooth cave of the drill bit is calculated by software, so that the mechanical structure cut from the point of the four-quadrant artificial polycrystalline diamond compact is distributed at the radial position of, and calculating and simulating the actual condition that the PDC drill bit is axially rotated, and grinding after the sharp point of the rock stratum is fractured through the action of the bit pressure and the torque.

In addition, still carried out the experiment of scraping the cutting granite layer in the laboratory to the acute angle portion of the artificial polycrystalline diamond compact of four-quadrant, through Remington sensor etc. to the artificial polycrystalline diamond compact of four-quadrant and improve 2.75 times than traditional single-quadrant limit tooth (pure flat tooth) cooling effect, can produce 900 high heat in the twinkling of an eye of shearing the rock stratum, improve heat sensitivity and thermal stability greatly, prevent that the diamond material from passivating and producing the bakelite electricity.

Preferably, both side axial sides of the cutting protrusion 3 are inclined surfaces 5. Preferably, the cutting face 4 is angled at 5 ° to the radial plane. Preferably, the angle between the right and left inclined surfaces 5 of the cutting protrusion 3 is 34.15 °, and/or the width of the cutting protrusion 3 is gradually reduced from the center of the diamond layer 2 to the outer edge thereof by an angle of 20 °.

Preferably, a first chamfer 6 is formed at the peripheral edge of the cutting protrusion 3 at the outer edge of the diamond layer 2, and/or a second chamfer 7 is formed at the radial edge of the cutting protrusion 3, and/or a third chamfer 8 is provided at the peripheral edge of the cutting face 4. Preferably, the first chamfer 6 is a circular arc chamfer with a radius of 0.5mm, the second chamfer 7 is a chamfer of 0.5x45 °, and the third chamfer 8 is a chamfer of 0.8x40 °.

Preferably, a cross-shaped positioning step 9 is protrudingly formed on the surface of the cemented carbide base 1 on the side away from the diamond layer 2. Preferably, the positioning step 9 has a thickness of 1mm, and/or the diamond layer 2 has a thickness of 3.6 mm.

The invention also provides a PDC drill bit which comprises the polycrystalline diamond compact 10, wherein a plurality of polycrystalline diamond compacts 10 are arranged on the blades 11 of the PDC drill bit.

Preferably, a tooth cavity 12 is formed in the blade 11, a positioning groove 13 used for being matched with the positioning step 9 at the bottom of the polycrystalline diamond compact 10 is formed at the bottom of the tooth cavity 12, and the polycrystalline diamond compact 10 is welded in the tooth cavity 12.

In different embodiments, the invention provides four-quadrant artificial polycrystalline diamond teeth with the outer diameters of phi 13.0mm, phi 16.0mm and phi 19.0mm respectively, the four-quadrant artificial polycrystalline diamond teeth comprise diamond layers with the thickness of 3.6mm and hard alloy substrate bases, the four-quadrant artificial polycrystalline diamond teeth are combined through heat treatment at high temperature of 2000 ℃ and high pressure (200MPA), a special positioning jig is needed to control the structure, the sharp-angle positioning step of the four-quadrant artificial polycrystalline diamond teeth is 1.0mm and the structure, and the main cutting point of the sharp-angle protruding in a four-corner star shape is symmetrical in position.

The main chip bottom layer of the diamond layer is similar to a quadrangle star shape, and four cutting points (namely, sharp tooth tips 14) with different shapes and four cutting surfaces 4 with plough-shaped structures are formed. The four-corner star-shaped tip on the surface of the diamond adopts a special design R angle, and the precision requirement of R0.5 mm is met, so that the design requirement improves the load stress of a sharp angle to 3.000e +008N/M ^ 2; the design of a chamfer angle of 0.5x45 degrees is adopted for the profile edge of the tooth surface of the four-quadrant artificial polycrystalline diamond. Four locations are formed at the surface locations of the diamond layer for the PDC bit cutting faces. A positioning groove for positioning a step surface corresponding to a tooth hole of a drill bit is designed at the bottom of a star-shaped tooth hard alloy base, so that four-quadrant artificial polycrystalline diamond composite sheet teeth are accurately positioned in each tooth hole of the drill bit through mechanical calculation of a PDC drill bit body, diamond sharp angles of the four-quadrant artificial polycrystalline diamond composite sheet teeth are longer on blades of the drill bit to form a regular distribution on the blades of the drill bit, sharp scraping points are formed on main cutting surfaces of the blades of the PDC drill bit, 20-degree extending reverse sharp angles are formed after the blades of the PDC drill bit are immersed into a rock stratum through the sharp angles, the motion mechanics of the four-quadrant artificial polycrystalline diamond composite sheet teeth distributed in the PDC drill bit and shearing action tracks acting on the rock stratum are calculated by solid works hydrodynamics software aiming at different rock strata, the rock stratum can be more effectively crushed, and the depth of the immersed into the rock stratum is large, the drilling machine speed of the drill bit is effectively increased, the formed structure with the point band surface plays a good rock stratum crushing effect (particularly granite stratum) aiming at a hard stratum, and then the toughness of the four-quadrant artificial polycrystalline diamond compact is increased with the point band surface, so that slurry has good fluidity at the bottom of the PDC drill bit. A cooling analysis chart of the four-quadrant artificial polycrystalline diamond tooth of the PDC drill bit under the same slurry discharge capacity, density and hydraulic parameters is analyzed by combining with solid works hydromechanics software, and the impact strength of the star-shaped tooth is improved by 30% compared with that of a conventional flat tooth by combining the concave-convex surface of the tooth surface of the diamond layer with the curved surface structure of a four-corner star shape. Thereby the life of four-quadrant artificial polycrystalline diamond tooth has been prolonged for four-quadrant artificial polycrystalline diamond tooth's drill bit footage is efficient.

Furthermore, a sharp corner point drives a plough-shaped cutter to cut the surface 4, a plough surface of 5 degrees is designed on the cutting surface 4, the formed plough-shaped cutting surface of 5 degrees plays a role in cutting the granite rock layer at the sharp edge angle when the rock layer is broken, and the depth of the cut into the granite rock layer is 2.35 mm/s under the action of the rotating speed of 80RPM when the torque is 40 KN.M. In the profile design of the cutting surface of the plow-shaped knife, the chamfer angle of the cutting surface of the plow-shaped knife is designed to be a chamfer angle of 0.8x40 degrees, the cutting surface of the plow-shaped knife is effectively utilized to reduce shearing stress when breaking granite rock stratum, the heat effect and the cooling efficiency of the cutting surface of the plow-shaped knife are improved, and therefore the service life of the whole four-quadrant artificial polycrystalline diamond tooth is prolonged.

The design has the constant head tank in the tooth cave bottom of the body wing of PDC drill bit, when connecing the artificial polycrystalline diamond tooth of four-quadrant with brazing, need carry out fixed-position welding with the artificial polycrystalline diamond tooth point acute angle location step of four-quadrant, the hydrodynamics and the mechanical mechanics analysis that design according to the drill bit combine on the wing of every PDC drill bit, let the artificial polycrystalline diamond tooth point acute angle of four-quadrant of drill bit wing face arrange and form regular distribution on the wing, let the cutting theory that lets the artificial polycrystalline diamond tooth of four-quadrant of drill bit wing cutting face drive the design of face with the point, let every wing of PDC drill bit also form the effect of scraping the cutting stratum with the multiple spot multiaspect.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.