页岩油储层环保型高性能水基钻井液体系研究及应用

Research and application of environmentally friendly high-performance water-based drilling fluid system for shale oil reservoirs

为了满足页岩油储层钻井对钻井液环保性能的要求,以环保型页岩抑制剂HBY-S和环保型复合润滑剂HBR-L为主要处理剂,并结合其他环保型处理剂,研制出了一种适合页岩油储层钻井的环保型高性能水基钻井液体系。室内对钻井液体系的耐温性能、抗污染性能和环保性能进行了评价,结果表明:体系具有良好的耐温性能,经过160℃老化后钻井液体系的高温高压滤失量为9.6mL,岩屑滚动回收率可以达到90.6%,润滑系数为0.089;体系具有较强的抗污染能力,钻井液中加入10%NaCl、1.0%CaCl_(2)或者15%岩屑粉时流变性能和滤失性能均比较稳定;体系的环保性能优良,钻井液的EC_(50)值为85000(无毒),BOD_(5)/COD值为26.5%(易降解),重金属含量均低于行业标准值。环保型高性能水基钻井液在某页岩油区块水平井钻井过程中进行了成功应用,其中DG-1井钻井期间未出现井下复杂事故,现场钻井液性能稳定,环保性能达标,实现了安全高效钻井的目标,在页岩油水平井钻井中具有良好的推广应用前景。

In order to meet the environmental performance requirements of drilling fluid for shale oil reservoir drilling,an environmentally friendly high performance water-based drilling fluid system suitable for shale oil reservoir drilling was developed using environmentally friendly shale inhibitor HBY-S and environmentally friendly composite lubricant HBR-L as the main treatment agents,combined with other environmentally friendly treatment agents.The indoor evaluation of the temperature resistance,pollution resistance,and environmental performance of the drilling fluid system showed that the system had good temperature resistance.After aging at 160 ℃,the high-temperature and high-pressure filtration loss of the drilling fluid system was 9.6mL,the rock debris rolling recovery rate could reach 90.6%,and the lubrication coefficient was 0.089;The system has strong antifouling property,and the rheological and filtration properties are relatively stable when 10%NaCl,1.0%CaCl_(2) or 15%rock debris powder is added to the drilling fluid;The system has excellent environmental performance,with an EC_(50) value of 85000(non-toxic) and a BOD_(5)/COD value of26.5%(easily degradable) for drilling fluid.The heavy metal content is lower than the industry standard value.The environmentally friendly high-performance water-based drilling fluid has been successfully applied in the drilling process of a shale oil block horizontal well.During the drilling process of DG-1 well,there were no complex downhole accidents,and the on-site drilling fluid performance was stable,meeting the environmental performance standards,achieving the goal of safe and efficient drilling.It has good prospects for promotion and application in shale oil horizontal well drilling.