干热岩钻井液技术新进展

热岩钻井液遇到的2个主要关键问题是抗高温和堵漏能力。分析了干热岩钻井施工的地质特点和钻井液技术难点，调研了干热岩钻井液体系及现场应用情况，总结了适合不同地层条件的国内外干热岩钻井液新技术，以及现阶段存在的问题，展望了未来的发展方向。目前干热岩钻井液仍是以聚磺钻井液为主的水基体系，已研究出抗高温泡沫钻井液、充气钻井液、液氮流体等，他们在现场的应用效果明显；具有地层伤害小、抗温抗盐、地层适应性强、环境友好等特点的体系是干热岩钻井液未来的发展方向。 

Progress on Drilling Fluid Technology for Hot Dry Rock Drilling

Two key issues encountered in hot dry rock drilling are high temperature and lost circulation. This paper introduces the analyses made on the geological characteristics of hot dry rock and the drilling fluid technology required for drilling the hot dry rock, and surveying performed on drilling fluid system for hot dry rock drilling and the field applications of the drilling fluids. New technologies for hot dry rock drilling found both in China and abroad suitable for different formation conditions are summarized. Problems found of the hot dry rock drilling fluid are also presented with the prospecting for the development of the technology. Presently, polymer sulfonate water base drilling fluid is mainly used for hot dry rock drilling, however, some other drilling fluids, such as high temperature foam mud, aerated drilling fluid, liquefied nitrogen fluid etc. are also prospective fluids for hot dry rock drilling. These new hot dry rock drilling fluids have been successfully applied in field operation with good results; they impose low formation damage, and are high temperature and salt resistant. Other advantages include good adaptability to different formation conditions and performance in environment protection, all of which represent the future of the development of the hot dry drilling fluid technology.