Novel concave ridge-shaped cutting element capable of easily removing cobalt

Abstract

The utility model discloses a novel concave ridge type cutting element easy to remove cobalt, which comprises a hard alloy matrix and a diamond composite layer, at least one convex ridge extending from the radial edge to the center of a cylinder is arranged on the end face of the diamond composite layer, and a cutting edge is formed at the highest position of the convex ridge; the thinnest part of the diamond composite layer is a plane, an inclined plane or a curved surface, and the thickness of the thinnest part of the diamond composite layer is greater than or equal to 0.8 mm. The diamond compact has the advantages that aggressiveness is high, deep cobalt removal is easier, a stratum is cut through the concave ridge-shaped face, the cutting face has a high ploughing function, the crushing drilling performance of the compact is improved, drilling cutting resistance is reduced, and then the mechanical drilling speed of a diamond drill bit is increased.

Description

Technical Field

[0001] The utility model relates to the field of diamond composite sheets, and more specifically, to a novel inner concave ridge cutting element which is easy to remove cobalt. Background Art

[0002] Since the 1980s, diamond drill bits have been widely used in oil and gas drilling projects. Diamond drill bits are mainly composed of a drill body and a cutting element. Diamond drill bits are divided into three categories according to the cutting element: PDC (polycrystalline diamond) drill bits, TSP (thermally stable polycrystalline diamond) drill bits and natural diamond drill bits. PDC drill bits are mainly used for drilling in soft to medium-hard formations. After continuous technological progress, the application range of PDC drill bits is becoming wider and wider, and they have good economic value. TSP drill bits are mainly used for drilling in medium-hard to extremely hard formations. At present, deep well operations in oil and gas drilling projects are gradually increasing, and the formations encountered are becoming more and more complex.

[0003] When drilling dense mudstone, it is difficult for the diamond composite sheet to penetrate into the formation to form effective cutting. After passing through the dense layer, the formation is interlaced with soft and hard layers, and the changes are relatively frequent. The impact load on the composite sheet is large, and the diamond composite sheet is prone to tooth collapse and failure, which leads to the overall failure of the drill bit. Therefore, the drilling site is in urgent need of a diamond composite sheet with strong impact resistance and strong formation penetration ability. The impact resistance of existing diamond composite sheets is mainly improved by changing the interface structure between the diamond layer and the cemented carbide base in the diamond composite sheet to reduce its residual stress, or by changing the material formula and processing technology. There are also PCD layers with special-shaped teeth such as ball head and cone. Although this special-shaped PDC structure improves its impact resistance, there are problems such as large drilling and cutting resistance, large drill bit torque, and low drilling efficiency during use. Patent CN109681125A provides a diamond composite sheet with concave convex ridge teeth. Although it has good ability to press into the formation and has high cutting efficiency, the thickness of the diamond layer on both sides of the convex ridge is relatively small, which is not conducive to the composite sheet using deep cobalt removal treatment process to improve the wear resistance of the composite sheet. Utility Model Content

[0004] The utility model aims to provide a novel inner concave ridge cutting element which is easy to remove cobalt, has strong aggressiveness and is easier to deeply remove cobalt.

[0005] The technical solution adopted by the utility model to solve this technical problem is: a new type of easy-to-remove cobalt inner concave ridge cutting element, including a cemented carbide substrate and a diamond composite layer, the end surface of the diamond composite layer has at least one convex ridge extending from the radial edge to the center of the cylinder, and the highest point of the convex ridge forms a cutting edge;

[0006] The thinnest part of the diamond composite layer is a plane, an inclined surface or a curved surface, and the thickness of the thinnest part of the diamond composite layer is greater than or equal to 0.8 mm.

[0007] Preferably, the end face of the diamond composite layer has at least one ridge which is concave from the radial edge toward the center of the cylinder.

[0008] Preferably, the diamond composite layer has a thickness of 0.8 mm to 1.5 mm at its thinnest point.

[0009] Preferably, the plurality of ridges are arranged at a certain angle, which is between 0° and 180°. The angles between the cutting edges formed by the plurality of ridges and the bottom surface of the cemented carbide can be the same or different.

[0010] Preferably, the number of cutting edges is 1 to 10.

[0011] Preferably, the ridge is in the shape of a line, a plane, an arc surface or a gradually changing curved surface.

[0012] Preferably, the convex ridge forms a certain angle with the bottom plane of the cemented carbide, and the angle is between 1° and 20°.

[0013] Preferably, the ridge width is between 0 and 4 mm, excluding 0 mm and including 4 mm.

[0014] Preferably, both sides of the ridge are planes, inclined surfaces, curved surfaces or a combination of planes and curved surfaces.

[0015] Preferably, the radial cross-section of the diamond composite layer is circular or elliptical.

[0016] Preferably, the bonding surface between the cemented carbide substrate and the diamond composite layer is in the shape of a plane, a concave-convex surface or a grooved surface, an annular grooved surface, or the like.

[0017] Preferably, the center of the diamond composite layer cylinder can be naturally transitioned from an inner concave to a convex ridge, or can be connected and transitioned between a platform and a convex ridge.

[0018] The utility model at least has the following beneficial effects:

[0019] 1) The concave ridge surface is used to cut the stratum, and the cutting surface has a strong plowing effect, which improves the crushing and drilling performance of the composite piece, reduces the drilling and cutting resistance, and thus improves the mechanical drilling speed of the diamond drill bit.

[0020] 2) There is a plane, inclined plane or curved surface on both sides of the concave ridge surface in the diamond layer so that the thinnest thickness of its edge is greater than a certain size. Since the thickness of the thinnest diamond layer exceeds the safety value of the deep decobalting process, it can be subjected to a deeper decobalting treatment to prevent the cemented carbide substrate from being corroded during the decobalting treatment. It can adopt a deep decobalting process, thereby obtaining better wear resistance.

[0021] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a three-dimensional diagram of the first embodiment.

[0023] Figure 2 It is a top view of the first embodiment.

[0024] Figure 3 It is a rear view of the first embodiment.

[0025] Figure 4 It is a side view of the first embodiment.

[0026] Figure 5 It is a three-dimensional diagram of the second embodiment.

[0027] Figure 6 It is a top view of the second embodiment.

[0028] Figure 7 It is a rear view of the second embodiment.

[0029] Figure 8 It is a side view of the second embodiment.

[0030] Fig. 9 It is a three-dimensional diagram of embodiment 3.

[0031] Fig.10 It is a stereogram of the fourth embodiment.

[0032] Fig.11 It is a three-dimensional diagram of embodiment 5. DETAILED DESCRIPTION

[0033] The present invention is described in detail and completely in conjunction with the embodiments below. A person skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the embodiments, it should be noted that the technical solutions and technical features provided in each part of the present invention, including the following description, can be combined with each other without conflict.

[0034] In addition, the embodiments of the present invention involved in the following description are generally only a part of the embodiments of the present invention, rather than all of the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0035] The present invention is further described in detail below in conjunction with the embodiments and implementations, and the specific implementation process is as follows:

[0036] Example 1 Figures 1 to 4 As shown, it includes a diamond composite layer 101 and a cemented carbide substrate 102. The end face of the diamond composite layer has a ridge 103. The ridge 103 and the side bevels 104 and 105 on both sides, the two side planes 108 and 109, and the transition surfaces 106 and 107 between the two side bevels and the two side planes constitute the surface of the diamond composite layer. In this embodiment, the ridge is an arc surface with a curvature radius of 4mm, a cutting edge width L of 2.1mm, and an angle α between the ridge 103 and the bottom plane 102 is 5 degrees. The angle between the two side bevels 104 and 105 and the bottom plane 102 is 15 degrees. The angle between the two side planes 108 and 109 and the bottom plane of the cemented carbide is 5 degrees. The arc radius of the transition surface 106 and 107 is 6mm. The radial cross-section of the diamond composite sheet is circular with a diameter of 15.8mm. The thinnest thickness of the diamond layer relative to the cemented carbide substrate is 1mm. The edge of the diamond composite layer is provided with a chamfer 110, which is an oblique chamfer.

[0037] Example 2 Figures 5 to 8 As shown, it includes a diamond composite layer 101 and a cemented carbide substrate 102. The end face of the diamond composite layer has two ridges 203 and 204. Each ridge extends from the edge of the composite layer and intersects at the center of the end face. The two ridges are evenly distributed along the circumference, that is, the central angle between two adjacent gradient arc ridges is 180°. One side of the end face is composed of a curved ridge 203 and the inclined surfaces 205 and 206 on both sides, the two side planes 209 and 213 and the transition surfaces 211 and 212. The ridge 203 and the two side inclined surfaces form a cutting edge. The other side of the end face is composed of a ridge 204 and the side inclined surfaces 207 and 208 on both sides, the two side planes 209 and 213 and the transition surfaces 214 and 215. The ridge 204 and the two side inclined surfaces form another cutting edge. In this embodiment, the two concave arc ridges are arc surfaces with a curvature radius of 4mm, a cutting edge width of 2.1mm, an angle α between the ridge 203 and the bottom plane 202 of 5 degrees, an angle β between the ridge 204 and the bottom plane 202 of 5 degrees, and an angle of 15 degrees between the inclined surfaces on both sides and the bottom plane 102, and the planes on both sides are parallel to the bottom plane 202, and the radius of the transition arc surface between the inclined surfaces on both sides and the planes is 6mm. The thinnest wall thickness of the diamond layer is 1mm. The radial cross-section of the diamond composite sheet is circular with a diameter of 15.8mm. The edge of the diamond composite layer is chamfered, and the chamfer can be an oblique chamfer.

[0038] Example 3 Fig. 9As shown, the end face of the diamond composite layer has three inner concave convex ridges 303, 304, 305, each inner concave arc surface convex ridge extends from the edge of the composite layer and intersects at the center of the end face, and the inner concave arc surface convex ridges are uniformly distributed along the circumference, that is, the central angle between two adjacent convex ridges is equal to 120°. The other structures are the same as those in the second embodiment.

[0039] Embodiment 4 Fig.10 As shown, the difference between it and the third embodiment is that the inner concave arc ridges 403, 404, and 405 are gradual arc surfaces, and the arc curvature radius thereof linearly transitions from the radial edge 1mm to the central curvature radius 3mm. The three ridges have the same angle with the bottom plane, which is 5 degrees. The inclined surfaces on both sides of the ridges are transitioned to the plane using an arc surface, and the arc curvature radius is 6mm.

[0040] Example 5 Fig.11 As shown, the difference between it and the first embodiment is that the planes 508 and 509 on both sides of the ridge are parallel to the bottom plane of the cemented carbide, and the thinnest thickness of the diamond composite layer is 1 mm.

[0041] Although the implementation scheme of the utility model has been disclosed as above, it is not limited to the applications listed in the specification and implementation scheme. It can be fully applied to various fields suitable for the utility model. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the utility model is not limited to the specific details and the embodiments shown and described herein.

Claims

1. A new type of easily cobalt-removable concave ridge cutting element, comprising a cemented carbide substrate and a diamond composite layer, characterized in that: The end surface of the diamond composite layer has at least one ridge extending from the radial edge to the center of the cylinder, and the highest point of the ridge forms a cutting edge; The thinnest part of the diamond composite layer is a plane, an inclined surface or a curved surface, and the thickness of the thinnest part of the diamond composite layer is greater than or equal to 0.8 mm.

2. The novel easy-to-remove-cobalt concave ridge cutting element according to claim 1, characterized in that: The end surface of the diamond composite layer has at least one convex ridge which is concave from the radial edge to the center of the cylinder.

3. The novel easy-to-remove-cobalt concave ridge cutting element according to claim 1 or 2, characterized in that: The thinnest thickness of the diamond composite layer is 0.8mm to 1.5mm.

4. The novel easy-to-remove-cobalt concave ridge cutting element according to claim 2, characterized in that: The plurality of ridges are arranged at a certain angle, and the angle is between 0° and 180°.

5. The novel easy-to-remove-cobalt concave ridge cutting element according to claim 2, characterized in that: The number of cutting edges is 1 to 10.

6. The novel easy-to-remove-cobalt concave ridge cutting element according to claim 1 or 2, characterized in that: The convex ridge is in the shape of a line, a plane, an arc surface or a gradually changing curved surface.

7. The novel easy-to-remove-cobalt concave ridge cutting element according to claim 1 or 2, characterized in that: The convex ridge forms a certain angle with the bottom plane of the cemented carbide, and the angle is between 1° and 20°.

8. The novel easy-to-remove-cobalt concave ridge cutting element according to claim 1 or 2, characterized in that: The ridge width is between 0 and 4 mm.

9. The novel easy-to-remove-cobalt concave ridge cutting element according to claim 1 or 2, characterized in that: The two sides of the ridge are planes, inclined surfaces, curved surfaces or a combination of planes and curved surfaces.

10. The novel easy-to-remove-cobalt concave ridge cutting element according to claim 1 or 2, characterized in that: The radial cross section of the diamond composite layer is circular or elliptical.

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