罗681井高密度钻井液技术

罗681井是罗家鼻状构造带罗68断块的一口评价井，完钻井深3860m．该区块地质构造复杂，施工过程中先后钻遇沙三断层、盐膏层、高压油气层、地下水层及沙四段等多套压力体系，经常出现井壁坍塌、井漏和井喷等复杂情况，施工难度和风险系数都比较大．通过使用聚合物防塌钻井液体系和聚磺防塌钻井液体系，配合相应的泥浆工艺和工程技术措施，预防了复杂情况的发生，施工中井壁稳定，井下安全，井径规则，满足了施工要求，也为本区块其它井的施工提供了详实的工艺参数．

High Density Drilling Fluid Technology in Luo 681 Well

Luo 681 well is an appraisal well, and is located in Luo Jiabi tectonic zone. The total depth is 3,860 m. The geologic structure is so complex that faulted formation, salt bed, elevated pressure hydrocarbon reservoir, water layer and sha forth section were drilled. So wellbore instability, lost circulation and blowout fre- quently occurred. The field operation was very difficult. After polymer anti-caving drilling fulid and sulphonated polymer ＆ anti-caving drilling fluid were applied, complex circumstance was avoided by corresponding mud tech- niques and onsite technology. The borehole wall was stable and downhole was safe during the course of drilling. The borehole gauge was regular and consistent, which meet the requirement of field operation. At last, the suc- cess of exploration was helpful to explore the oilfield further.