胜利浅海地区低渗透油层保护技术研究与应用

针对胜利浅海地区埕岛东部斜坡带东营组低渗透油层,从储层及流体特征分析入手,通过实验分析评价了研究区内储层敏感性,总结了低渗透储层在钻井过程中潜在损害因素,在此基础上优化了钻井完井液体系,研制了优质无污染海水钻井液体系。结合该钻井液体系与目前使用的其它钻井液体系进行基本性能对比情况、抗污染性能评价以及动态滤失效果分析,该钻井液体系油层保护效果较好,岩心渗透率恢复率超过90%。现场推广应用19口井,有6口井进行过测试,其中表皮系数均小于零的完善井5口,轻微损害井1口,测试井的完善率达83.3%,表明应用该钻井液体系取得了良好的保护油层效果。

Study and Application of Low-permeability Reservoir Protection Techniques in Shengli Shallow Sea Area

Study has been conducted on reservoir characteristics and fluid property in low-permeability reservoir of Dongying formation in the eastern slope area of Chengdao oil-field in Shengli shallow sea area. Through laboratory study on reservoir sensitivity, the reservoir damage mechanism and damage degree were understood. On the basis of the study results, drilling fluid and completion fluid were optimized. In addition, high quality sea water drilling fluid has been developed. Through basic characteristic comparison with other drilling fluid systems, evaluation on the anti-pollution property and analysis of dynamic filtration results, it is indicated that this kind of drilling fluid system has good result in oil reservoir protection, with 90% core permeability retrieving. This kind of drilling fluid system has been applied in 19 wells, and testing has been conducted in 6 wells. Among these six wells, the performance of five wells has been improved, with skin factor less than zero. One well was slightly damaged. The improvement efficiency of these six tested wells is 83.3%, which indicated that kind of drilling fluid system has good result in oil reservoir protection.