| Abstract |
Air DTH underbalance drilling technique has high efficiency in hard rock. The application of this technology in geothermal wells can not only greatly improve the rate of penetration, but also protect the reservoir, maximize the productivity of geothermal wells, increase the benefits of geothermal project exploitation, and promote the rapid development of geothermal industry. However, there are still many bottleneck technologies to be broken through in the application and popularization of DTH. After nearly 10 years of continuous research and innovation by the cooperating teams, China's air DTH drilling technology and application has achieved a series of achievements that attract worldwide attention, i.e. economic drilling depth, the highest drilling rate, single bit life, high pressure pneumatic DTH hammmer, large tonnage drill for air DTH hammer. The cost of the whole series of supporting equipment greatly reduced. This paper will comprehensively introduce the research, development and application of air DTH drilling technology and equipment in China's geothermal industry, as well as the research and development goals of key technologies and major equipment in the next step, and advocate large-scale promotion of air DTH drilling technology in the geothermal industry. |