深层稠油油藏高干度蒸汽驱物理模拟实验

Physical simulation experiment of high quality steam flooding in deep heavy oil reservoir

赵燕 杨艳霞 吴光焕

中国石油大学（华东）胜利学院，山东 东营 257000 中国石化胜利油田分公司勘探开发研究院，山东 东营 257015

College of Shengli, China University of Petroleum, Dongying 257000, China Research Institute of Exploration and Development, Shengli Oilfield Company, SINOPEC, Dongying 257015, China

胜利油田稠油资源丰富，大部分稠油油藏埋藏深、边底水活跃，油藏压力难以降低到5 MPa，矿场实施的常规蒸汽驱井底注汽干度为30%左右，提高采收率幅度不明显。为改善该类稠油油藏蒸汽驱开发效果，基于高干度注汽技术的发展，以孤岛油田中二北Ng5稠油油藏为原型，开展7 MPa压力条件下二维纵向蒸汽驱物理模拟实验，监测分析注汽干度分别为10%，30%，50%的蒸汽驱过程中蒸汽腔的形成和发育状况，研究注汽干度对深层稠油油藏蒸汽驱开发指标的影响规律。实验结果表明：注汽干度对深层稠油蒸汽驱开采效果影响明显，提高注汽干度，地下蒸汽腔形成时间缩短，蒸汽腔扩展距离变大，蒸汽驱结束时间变长，最终采收率明显提高；7 MPa油藏压力条件下，蒸汽驱的蒸汽干度至少应大于50％。井底注汽干度由30%提高到50%可增加胜利油田深层稠油油藏蒸汽驱有效动用储量1.32×108 t。

It is difficult to reduce pressure of most heavy oil reservoirs to 5 MPa in Shengli Oilfield, owing to the deep burial and edge-bottom water. The increased recovery efficiency range of steam flooding is low in the case of the downhole steam dryness of 30%. To enhance development efficiency of steam flooding, a physical simulation study of steam flooding at 7 MPa was performed by taking the heavy oil reservoir in Ng5 layer of Gudao District as a model. Based on the technology of high quality steam, the evolution of steam chamber during steam flooding has been monitored and analyzed with 10%, 30% and 50% steam dryness, and the influence law on steam flooding of stream dryness has been studied. Laboratory experimental data show that the formation time of steam chamber shortens, the steam chamber extends bigger, the flooding time increases, and oil recovery ratio is enhanced significantly with increasing steam quality. Therefore stream dryness should be greater than 50% at pressure of 7 MPa. It is one of the effective ways to improve the performance of steam flooding in deep heavy oil reservoirs by increasing steam quality, which may increase reserves 1.32×108 t suitable for steam flooding by increasing stream dryness from 30% to 50%.

10.6056/dkyqt201802029