Overview of Ultra-Deep Well High-Temperature Drilling Fluid Technology and Discussion of Its Research Direction

In the future,the continental scientific drilling depth of China will reach 12000m ~ 13000m,and temperature of the well bottom will exceed 350 ℃.The drilling fluid will face a super-high-temperature high-pressure fluid environment,and the drilling technology will face a severe challenge.This paper focuses on presentation about the applications of drilling fluid to typical ultra-deep wells and high-temperature geothermal boreholes in China and elsewhere in the world.It is proposed that the main technical difficulty of the high temperature drilling fluid is the controlling of rheology,filtration and lubrication,and that research direction of drilling fluid technology is temperature drilling fluid agent and systems for the ultra-high temperature above 250 ℃ as well as the high-temperature drilling fluid testing equipment and ground cycle cooling system.