钻、完井过程油层保护技术的研究与应用

Study and application of oil layer protection technique in the process of drilling and completing wells

大庆油田开发对象逐渐转向二、三次加密井的薄差油层，由于该类油层泥质含量高、油层物性差，因此注重钻完井全过程的油层保护工作就显得格外重要。以薄差油层天然岩心为实验载体，开展了储层敏感性评价、高聚物钻井液与A级固井水泥储层伤害程度评价及伤害原因分析、钻井液屏蔽暂堵剂的优化与评价、射孔完井液清洗剂防膨剂的优选评价以及油层复合保护技术开发等室内实验：在室内实验的基础上，以杏八～十二区过渡带二次加密井为试验区，开展了钻井液屏蔽暂堵剂、洗井液临界密度固井、射孔完井液、热泡沫气举、油层复合保护剂等钻完井全过程油层保护技术现场试验，生产和测试结果均见到了较好的效果。

The development target of Daqing Oilfield gradually turns to thin and worse layers of second and tertiary infilling well. Because high shale contents and worse oil layer property are in this type layer, so it is very important to pay attention to oil layer protection work in the process of drilling and completing wells. Taking natural cores in thin and worse layers as a example, several laboratory experiments are developed, including reservoir sensitivity evaluation, reservoir damage degree evaluation and reasons analysis of high - polymer drill fluid and cement with A grade, optimization and evaluation of drill fluid shielded diversion agent, optimization and evaluation of perforated completion fluid, flushing agent and anti-swelling agent and reservoir composite protection technique development. Based on lab tests, transition belts in Xing 8 ～ 12 areas act as test field, and several oil layer protection technique field tests in the process of drilling and completion well are developed, which includes drill fluid shielded diversion agent, flushing fluid critical density cement, perforation completion fluid, thermal foam airlift and reservoir composite preservative agent. At last, production and test results all show better effectiveness.