Patent Application
20210277722
The present disclosure is based on an application with a Chinese application number of 201810767637.1 and an application date of Jul. 13, 2018, and claims its priority. The content of the Chinese application is hereby incorporated into the present disclosure as a whole.
The present disclosure refers to a multiple ridge diamond compact for a drill bit and is related to the technical field of petroleum drilling.
Since the 1980s, diamond drill bits have been widely used in oil and gas drilling projects. Diamond bits are substantially composed of a bit body and cutting elements. There are three categories of diamond bits according to the cutting elements: PDC (polycrystalline diamond compact) bits, TSP (thermally stable polycrystalline diamond) bits and natural diamond bits. PDC bits are mainly used for drilling in soft to medium-hard formations. After continuous technological development, PDC bits have a wider application range and have good economic value. TSP bits are mainly used for drilling in medium to very hard formations. At present, deep well operations in oil and gas drilling projects are gradually increasing, and formations to be encountered are becoming more and more complex.
In the case of drilling into gravel-bearing formation or formations staggered between soft and hard and changing frequently, the impact load on the diamond compact is relatively large, and the diamond compact is prone to tooth chipping and failure, resulting in overall failure of the drill bit. Therefore, the drilling site urgently needs a diamond compact with strong impact resistance. The impact resistance of the existing diamond compact is mainly improved by changing the interface structure of the diamond layer and the cemented carbide base in the diamond compact to reduce its residual stress, or changing the material formula and processing technology. There are also PCD layers with special-shaped teeth of such as a ball head shape and a cone shape. Although the PDC with this special-shaped structure improves its impact resistance, there are phenomena such as high drilling and cutting resistance, large torque, and low drilling efficiency during use.
The technical problem to be solved by the present disclosure is to provide a multiple ridge diamond compact for a drill bit with improved drilling performance, strong impact resistance and a capability of prolonging the service life of the drill bit in view of the above-mentioned shortcomings of the prior art.
The present disclosure provides a multiple ridge diamond compact for a drill bit, comprising a cemented carbide substrate and a diamond composite layer, wherein an end surface of the diamond composite layer is provided with at least two ridges angled relative to each other, and converging ends of two adjacent ridges extend to an edge of the diamond composite layer so as to form a concave cutting edge portion at the edge.
In some embodiments, the edge of the diamond composite layer is chamfered, so that a tapered surface is formed at the edge of the diamond composite layer, and the tapered surface and the converging ends of the two adjacent ridges constitute the cutting edge portion.
In some embodiments, the ridges extend radially.
In some embodiments, there are at least three ridges, and one of the ridges is arranged along the radial direction of the diamond composite layer.
In some embodiments, the ridges constitute a polygon.
In some embodiments, there are at least two groups of ridges, each group of ridges is composed of at least two ridges angled relative to each other, and adjacent expanding ends of adjacent groups of ridges intersect in pairs within the end surface of the diamond composite layer.
In some embodiments, the groups of ridges are evenly arranged along the circumference of the diamond composite layer, and the intersection of the expanding ends of the ridges of the adjacent groups is located on the middle area of the end surface of the diamond composite layer.
In some embodiments, each ridge is formed by the intersection of two inclined surfaces, and a groove is disposed between adjacent inclined surfaces located between two adjacent ridges.
In some embodiments, the expanding ends of the ridges are higher than the converging ends.
In some embodiments, the inclined angle between the ridges and the bottom plane of the cemented carbide ranges from 0 to 20 degrees.
In some embodiments, the inclined angle is 0 degrees or 15 degrees.
In some embodiments, the inclined angle between two adjacent ridges ranges from 10 degrees to 90 degrees.
In some embodiments, the shape of the ridges is one of a line, a plane, a cambered surface, and a gradual curved surface.
In some embodiments, the ridges are parts of a conical surface and the conical ridges are tapered from the expanding end toward the converging end.
In some embodiments, the width L of the cutting edge portion ranges from 1 mm to 4 mm.
In some embodiments, the width L of the cutting edge portion is 1.5 mm or 2 mm.
In some embodiments, the radial cross section of the diamond compact is circular or elliptical.
The present disclosure further provides a drill bit comprising the above-mentioned multiple ridge diamond compact.
The present disclosure would obtain at least one of the following beneficial effects:
The plurality of ridges angled relative to each other are set as a cutting surface group to simultaneously cut a formation, the formation is first pre-crushed by means of the ridges angled relative to each other, the ridges first enter the formation from sharp surfaces (the converging ends of the ridges), a crushing pit in the direction of the ridges is further enlarged, and then the formation is further extruded and crushed by inclined surfaces on two sides of the group of ridges, such that the cutting surfaces thereof have a plowing effect, thus improving the crushing and drilling performance, reducing the drilling cutting resistance, and further increasing the ROP-rate of penetration of the diamond drill bit.
The cutting surface group composed of the ridge group and the lateral inclined surfaces also has impact resistance, which would guide the downhole cuttings to discharge, further increase the ROP of the diamond bit, and further enhance the impact resistance of the compact.
There are a plurality of cutting edge parts, and after one cutting edge part is worn, it could be rotated to another unworn cutting edge part for continued use, thereby reducing the use cost of the drill.
The present disclosure will be further described below with reference to the accompanying drawings.
As shown in
In some embodiments, the arc radius of the first ridge 104 and the second ridge 107 is 0.5 mm, and the inclined angles between the first ridge 104 and the bottom plane of the cemented carbide substrate 102 and between the second ridge 107 and the bottom plane of the cemented carbide substrate 102 are 0 degree, and the inclined angles between the first inclined surface 103 and the bottom plane of the cemented carbide substrate 102 and between the fourth inclined surface 108 and the bottom plane of the cemented carbide substrate 102 are 15 degrees. The inclined angle α between the first and second ridges 104 and 107 is 30 degrees, and the width L of the cutting edge portion between the converging ends of the first and second ridges 104 and 107 is 2 mm. The radial cross section of the multiple ridge diamond compact is circular.
In some embodiments, the shape of the ridges is one of a line, a plane, a cambered surface, and a gradual curved surface. The gradual curved surface is a part of a conical surface, and each conical ridge tapers from the expanding end toward the converging end.
In some embodiments, the diamond layer and the cemented carbide substrate are sintered under an ultra-high pressure and high temperature condition, and the bonding surface between the cemented carbide substrate and the diamond composite layer is a flat surface, a concave-convex surface or a grooved surface. Then the end surface of the diamond layer is processed into a desired shape.
As shown in
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In some embodiments, the width L of the cutting edge portions is 1.5 mm.
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In some embodiments, the angle between the ridges and the bottom plane of the cemented carbide is 15 degrees.
As shown in
The present disclosure further provides a drill bit comprising the above-mentioned multiple ridge diamond compact.
The above-combined embodiments give a detailed description of the embodiments of the present disclosure, but the present disclosure is not limited to the described embodiments. For those skilled in the art, various changes, modifications, equivalent substitutions and modifications to these embodiments without departing from the principle and essential spirit of the present disclosure still fall within the protection scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201810767637.1 | Jul 2018 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2019/095427 | 7/10/2019 | WO | 00 |
