Colloidal Gas Aphron (CGA) Drilling Fluid: A Drilling Technique to Protect EGS Geothermal Reservior

Abstract

Hot dry rock (HDR) has a high-temperature reservoir and huge resources and is considered to be clean and renewable energy that can undertake the new energy revolution. There are many technical bottlenecks in the industrial development of HDR by using the enhanced geothermal system (EGS) technology. By analyzing EGS cases and drilling fluid technology, this paper proposes that colloidal gas aphron (CGA) drilling fluid can effectively solve the serious leakage problem in low-pressure blocks, and has a geothermal reservoir protection effect. This paper summarizes the research progress of high-temperature resistant CGA drilling fluid in the past 10 years, as well as the application status in the engineering site. The applicability of CGA drilling fluid in EGS was comprehensively analyzed and discussed, and the future research direction of CGA drilling technology was proposed.