Material Source and Manufacturing Process
- PDC composite sheet for oil and gas: it is a composite material made by sintering diamond micropowder and cemented carbide substrate under ultra-high pressure and high temperature conditions15.
- Natural diamond composite sheet: natural diamond is the main raw material, and natural diamond is compounded with other materials (e.g. cemented carbide, etc.) through a special process, and the acquisition of natural diamond depends on natural mining.
Structural Characteristics
- PDC composite sheet for oil and gas: usually consists of a thin polycrystalline diamond layer in the upper part and a cemented carbide backing layer in the lower part. The thickness of the polycrystalline diamond layer is generally controlled at about 0.5-1 mm, but now it has also been developed to 2-4 mm.
- Natural Diamond Composite Slices: The structure is also a composite of natural diamond layer and backing layer, but the crystal structure of natural diamond is formed naturally, and when combined with the backing layer, the characteristics of the bonding interface are different from those of PDC, and the thickness of the natural diamond layer and other indexes are subject to the limitations of natural diamond raw materials.
Performance
- Hardness and abrasion resistance: The hardness of PDC composite sheet is generally HV7500-9000, while natural diamond is the highest hardness substance in nature, and its hardness is higher than that of PDC composite sheet. In terms of wear resistance, PDC's wear resistance is generally 60-80 times that of Cemented Carbide, and the wear resistance of natural diamond composite tablets is theoretically higher.
- Impact resistance: PDC composite tablets have better impact resistance due to the support of the cemented carbide backing and can withstand certain drilling impacts. Although natural diamond has high hardness, natural diamond crystals have defects such as disintegration surfaces, which are relatively easier to rupture along the disintegration surfaces when subjected to impacts, and the impact toughness is relatively poor.
- Thermal stability: When PDC composite piece is around 350℃, the wear speed will be accelerated significantly, and the strength will be invalidated around 700℃. The thermal stability of natural diamond composite sheet is relatively good, but graphitization and other phenomena will occur at high temperature, affecting its performance.
Cost and Market Price
- PDC Composite Slices for Oil and Gas: Produced by synthetic method, the production efficiency is relatively high and the cost is relatively low, which is widely used in the field of oil and gas drilling, and the market price is relatively more affordable to meet the demand of large-scale drilling.
- Natural Diamond Composite Slices: Due to the scarcity of natural diamond and high mining cost, natural diamond composite slices are costly and expensive in the market, and are relatively less used in oil and gas drilling, and usually only used in some special drilling scenarios with very high performance requirements and sufficient budget.
Application Scenarios
- PDC Oil & Gas Composite Blades: Suitable for drilling in soft to medium-hard formations, such as shale, sandstone, etc. It can effectively improve drilling efficiency and reduce costs by utilizing its advantages of high cutting efficiency and good impact resistance.
- Natural diamond composite blades: more suitable for drilling very hard formations, such as granite, etc. They have unique advantages in some high-end drilling projects where drilling precision and efficiency are highly required and economic cost is not a major consideration.
