Fracking drill bit. Polycrystalline diamond drill bit used in the drilling of wells for natural gas. This one is being used for fracking. Fracking or hydraulic fracturing is a drilling technique used to extract gas from shale deposits. A mixture of sand, chemicals and water is pumped under high pressure from the surface to underground horizontal wells. The pressure forms fissures (fractures) in the shale. The sand keeps the fissures open, allowing gas to flow into the well and rise to the surface. The main drilling is of the wells prior to the hydraulic fracturing process. Photographed in Arkansas, USA.