海上稠油注凝胶转热水驱效果研究

Study on Effect of Hot Water Flooding of Offshore Heavy Oil After Gel Injection

为解决目前渤海稠油油藏水驱出现的含水上升快、采收率低的难题,开展了水驱转热水凝胶复合驱实验研究,以LD油田储层为研究对象,分别开展了凝胶体系的室内性能评价实验和一维、二维物理模拟实验。结果表明:该凝胶体系表现出良好的耐盐性和封堵性,在140℃条件下,凝胶封堵率在95%以上,在地层矿化度下黏度仍能保持在40000 mPa·s。一维物理并联岩心实验表明水驱注凝胶后转热水驱的采收率较水驱提高了29.75%,二维物理模拟实验表明注凝胶后波及范围明显扩大,采收率提高了5.04%,表明水驱后转凝胶-热水驱提高采收率是可行的。

In order to solve the problem of fast water cut rise and low recovery factor in water flooding of Bohai heavy oil reservoirs,the experimental study of water flooding to hot water gel composite flooding was carried out.Taking the reservoir of LD oilfield as the research object,the laboratory performance evaluation experiment and one-dimensional and two-dimensional physical simulation experiment of gel system were carried out respectively.The experimental results showed that the gel system showed good salt resistance and plugging performance.At 140℃,the plugging rate of gel was more than 95%,and the viscosity could still be maintained at 40000 mPa·s under the formation salinity.The one-dimensional physical parallel core experiment showed that the recovery factor of water drive after gel injection was increased by 29.75%compared with that of water drive.The two-dimensional physical simulation experiment showed that the swept range after gel injection was significantly expanded,and the recovery factor was increased by 5.04%,indicating that it was feasible to improve the recovery factor after water drive by switching to gel hot water drive.