Poly-crystalline Diamond Drill Bit Development

The development of directional drilling in the coal industry has been enhanced by access to Poly-Crystalline Diamond (PCD) bit technology. This technology has been developed in the oil industry with ongoing improvements driven by the need for improved drilling rates, more robustness for longer life and ability to penetrate a wider range of strata types. Although the underground drilling applications require smaller bit diameters, the technology has been applied with modifications to create suitable smaller bits. This paper describes PCD and bit design technology and identifies a range of drill bits now available and their applications in the underground in-seam directional drilling industry.