Integrated Rock-Breaking Methods in Well Drilling

This paper introduces integrated rock-breaking methods,such as frictional heat-mechanical,microwave-mechanical,and laser-gas rock-breaking,which are more efficient compared to conventional rock breaking methods.Due to technical bottlenecks of each method,they are not ready for industrial application,so mechanical rock-breaking is still the principle method at present.Based on the research on the present development of thermal properties of rock,air drilling equipment and heat-resistant materials,the author considered thermal-mechanical rock-breaking method would be the most promising approach.In this method,fuel could be provided through dual-wall drill pipe and swivel,and high-temperature bit could be produced from heat-resistant material.High temperature can vitrify the borehole wall in deep and super deep well drilling,and protect reservoirs.