LG地区超深井钻井液技术

通过分析LG地区的地质特点和钻井工程措施要求，针对超深井钻井液所面临的难题和挑战，建立和应用“三强”聚合物钻井液、“三低”防塌钻井液、欠平衡钻井液和抗高温弱凝胶防卡钻井液技术，较好地解决了长井段大尺寸井眼的安全快速钻井、气体钻井后替入钻井液的井壁稳定和井眼通畅、长段红层泥页岩井段防塌、欠平衡钻井和长裸眼小井眼的超深井高温防卡等技术难题。形成了LG地区的特色钻井液技术，有力地保障了该地区的安全快速钻井。

Drilling fluid technology for the ultra-deep wells in the LG area

Based on the analysis of geologic features and drilling engineering requirements of the LG area, in view of the difficulties and challenges faced by ultra-deep drilling fluid technology, several drilling fluid systems were developed and tested on fields, including the technologies of the "three strongs - strong inhibition, sealing and anti-sloughing properties" polymer drilling fluid, the "three lows - low loss circulation, low wetting angle, and low activity" anti-sloughing drilling fluid, the under-balanced drilling fluid, and the low-gel, high-temperature and sticking-free drilling fluid. These systems have been successfully used to realize the fast safe drilling of long and large-sized holes, to ensure wellbore stability and smooth tool running after gas drilling is turned to mud drilling, to prevent sloughing at long shale section, to ensure successful underbalanced drilling, and to prevent sticking in long slim open hole of high-temperature and ultra-deep wells. They have formed the unique drilling fluid technology for the LG area, being an important guarantee for fast safe drilling at this area.