Rock drilling tools manufacturer ProDrill: PDC (Poly-crystalline diamond compact/composite) drill bits are an effective rotary drilling tool for drilling into homogeneous sedimentary rock formations such as shale, sandstone, dolomite, limestone etc. These drill bits use the shearing scraping or shaving action when encountering the rock formation.
PDC drill bits, or fixed cutters, come in either matrix or steel body. Matrix body fixed cutters are made from tungsten carbide material. This provides improved wear resistance and erosion. Additionally, they are typically more heavy set as far as cutter count. In applications of high fluid volume or high sand, matrix body bits offer longer life and multiple bit runs.
PDC drill bit with 3 wings concave type, steel body, 98mm
Steel body fixed cutters are made from a high alloy steel. These bits can sometimes be repaired and may be good for multiple runs, depending on the application. Because steel is better able to withstand high impact, steel body bits are often designed with higher blade stand-off and cutter exposure, thus increasing ROP.
Cost is a major factor in drilling a well. Tungsten carbide is more expensive than steel and matrix bodies contain more PDC Cutters making matrix more expensive. Although fixed cutters differ in design aspects from roller cone bits, they share much in common. Both have pins that conform to API standards and both are manufactured to specific plus or minus tolerances. Both fixed cutters and roller cone bits are dull graded the same way.