Abstract: Oil-based drilling fluid is widely used in high-temperature and high-pressure deep wells, high angle directional wells, horizontal wells with large displacement and ultra-strong water sensitive formations. It can effectively reduce downhole troubles and protect reservoirs. High temperature resistant and high density oil-based drilling fluid system is developed with independent intellectual property rights. The key treating agents include organic clay, primary/auxiliary emulsifiers, fluid loss additive and nano-blocking agent. Three oil-based drilling fluids are developed by using different kinds of base oil – diesel oil, white oil and GTL. The maximum density of oil-based drilling fluids can reach 2.6g/cm3 and resists temperature of 200°C, with an emulsion-breaking voltage surpassing 1000V. They can replace their foreign counterparts thanks to their good rheological property and settlement stability. This oil-based drilling fluid system is used for deep wells in Tarim and shale gas areas of Fuling, Changning and Huangjinba, showing a strong debris-carrying and blocking capacity. With the drilling rate obviously improved, the drilling period is shortened for 15 to 20 days on average.

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摘要： 油基钻井液广泛用于高温高压深井、大斜度定向井、大位移水平井和超强水敏等各种复杂地层,能有效减少井下复杂情况发生,保护储层。抗高温高密度油基钻井液体系DR-OBM具有自主知识产权,核心处理剂包括有机土、主（辅）乳化剂、降滤失剂和纳米封堵剂,研发了包括3类不同基础油（柴油、白油和气制油）的油基钻井液。油基钻井液最高密度可达2.6g/cm³,抗温达200℃,破乳电压大于1000V,具有良好的流变性和沉降稳定性,替代了进口产品。在塔里木深井和涪陵、长宁、黄金坝等页岩气地区现场应用,油基钻井液体系稳定,携岩和封堵能力强,井径规则,起下钻和下套管顺利,钻速明显提高,钻井周期平均缩短15~20d。

关键词: 油基钻井液, 高温高密度深井, 乳化剂, 降滤失剂, 纳米封堵剂