耐高温环保型冲洗液体系在西藏甲玛3000 m科学深钻中的应用研究

Application research of high temperature resistant and environment-friendly drilling fluid system in 3000m scientific deep drilling in Jiama， Tibet

摘要:

西藏甲玛铜多金属矿床3000 m科学深钻是青藏高原固体矿产调查领域首个3000 m深钻，终孔孔深3003.33 m，终孔孔径98 mm，创造了青藏高原小口径固体矿产勘查领域最新的孔深纪录。项目位于西藏甲玛海拔5200 m高山深切割区，自然气候恶劣，项目施工环保要求严格，深部地层温度高，地层复杂，主要表现在水敏性强、破碎严重和地应力高，施工难度极大。针对环保及地层问题，通过对粘土、环保降滤失剂、环保增粘剂、环保抑制剂等处理剂进行实验对比，采用正交实验的极差分析法得到了各项指标所对应的水平的影响大小和优化水平取值，确定了冲洗液的优化配方范围，成功研发了一套耐高温环保型冲洗液体系。现场应用取得了良好的效果。

Abstract:

The 3000m deep scientific borehole for the Tibet polymetallic deposit is the first 3000m deep scientific borehole in the field of the investigation of solid mineral resources in the Qinghai-Tibet Plateau， and it has created the latest hole depth record in the field of small-diameter solid mineral exploration in the Qinghai-Tibet Plateau. The project is located in the high mountain and deep cut area at 5200m above the sea level in Jiama， Tibet， with harsh natural climate， strict environmental protection requirements for the drilling project， high temperature in the deep strata， and complicated strata characterized mainly by strong water sensitivity， serious breakage and high in-situ stress which leads to extremely drilling difficulty. In view of the environmental protection and the stratum problem， through the experimental comparison of clay， the environmental protection fluid loss reducer， the environmental protection tackifier， the environmental protection inhibitor and so on， the treatment agents with the best performance were optimized； by using the method of range analysis of orthogonal experiment， the influence of each index corresponding to the level and the value of the optimum level were obtained， the range of the optimum formula of drilling fluid was determined； and a high temperature resistant and environment-friendly drilling fluid system has been successfully developed with good field application effects.