Another trend in the development of polycrystalline diamond petroleum composite drill bits is to study new types of high-performance polycrystalline diamond petroleum composite cutting teeth. The first is also to improve the wear resistance, mechanical properties, process performance, and cutting performance of the cutting element (polycrystalline diamond compact) itself. For many years, the diamond thickness of the polycrystalline diamond petroleum composite cutting teeth was limited to 0.6 mm (0.025 inch), because the researchers established the relationship between the cutting tooth residual stress and the diamond thickness. During the pressing process, residual stresses are generated in the cutting teeth of the polycrystalline diamond petroleum composite sheet, and the size thereof increases as the thickness of the diamond layer increases. These stresses cause the diamond layer to crack, exfoliate, and delaminate, thereby lowering the polycrystalline diamond. The life of the cutting teeth of the petroleum composite and the efficiency of the drill. For this reason, polycrystalline diamond compacts show the following trends.
1. Improve the self-performance of the composite sheet In order to improve the performance of the composite sheet, one is to improve the performance and life index (to improve the wear ratio, surface roughness, impact resistance), and the second is to improve the process performance index (to improve thermal stability). Under this guiding ideology, many high abrasion ratio, high heat resistance, high impact resistance composite sheets, polishing sheets, mirror sheets and the like have appeared.
2. Changing the structure of the composite sheet The structure of the composite sheet was changed to improve the adhesion of the diamond layer and the cemented carbide substrate, the impact resistance, the cutting performance at work, and the adaptability to the formation. Under this kind of guiding ideology, many new structural composite sheets emerged. One is a thickened composite sheet, such as a diamond layer edge-thickened type, an overall thickened type, and a cemented carbide substrate-thickened type; one type is a non-planar interface type. Structural composite sheet, such as radiation slot teeth, ring groove teeth, claw-shaped (rectangular, trapezoidal, corrugated) teeth. The non-planar interface technology can reduce the stress gradient of the cutting teeth of the polycrystalline diamond petroleum composite sheet and make the damage stress away from the diamond edge. This technique allows the thickness of the diamond layer of the cutting tooth to be increased without generating the aforementioned stress relationship.
3. The shape of the improved composite sheet is improved on the appearance of the composite sheet, and special composite sheets such as wedge-shaped teeth, rectangular teeth, ball-toothed teeth, and the like are developed. There are also pregnancies (inlaid with natural diamonds, single crystals, polycrystals in cemented carbide bases) and mosaic cutters.
The development of polycrystalline diamond petroleum composite drill bit is the deep research of polycrystalline diamond oil composite bit design theory, the development of special design analysis software, the development of solid simulation, working state simulation technology to make the design level up; second is to strengthen Bit bit theory and manufacturing process technology research work. Due to incomplete research methods and insufficient research work, the bit industry in China is mostly in the stage of simple imitation and simple play. Polycrystalline diamond petroleum composite drill bit is an edge technology involving many disciplines such as geology, drilling, superhard materials, powder metallurgy, machinery and welding. Therefore, the manufacturing plant should carry out research and manufacture of superhard materials and research institutes. The extensive cooperation of drilling geology departments has broken the monopoly of foreign countries and established a set of scientific polycrystalline diamond petroleum composite drill bit design and manufacturing system. This is important for improving the level and market competitiveness of domestic polycrystalline diamond petroleum composite drill bit. Practical significance and obvious economic benefits