Difficulties in drilling through harder rock formations, particularly as they become fractured, limit the energy resources that can be economically developed. This project will develop a method in which high pressure waterjets are added to polycrystalline diamond inserts in a specially designed bit, attached to a hammer drill. The bit will be designed so that high fluid pressure is generated within it, by the action of the main driving hammer. The addition of the jets to the cutting action of the bit inserts will reduce the overall force required to advance the tool. At the same time, the rate of penetration will be increased. Because lower forces are required for penetration, more accurate steering through harder, more fractured ground is allowed. Phase I will establish the merits of this drilling combination and parameters for optimization. The component parts to assemble a drilling bit, based upon the combination, will be designed. Phase II tests will further optimize the operating parameters in various rock formations, and will include laboratory and field tests. Anticipated Results/Potential Commercial Applications as described by the awardee: A characterized, effective tool should significantly reduce the costs of drilling wells through harder and more highly fractured rock. Well safely may be enhanced as well by encouraging the use of mud drilling in potentially dangerous wells
