弱碱三元驱后剩余油定量分析

三元驱后地层中仍存在大量剩余油,明确剩余油类型及数量对进一步提高采收率具有重要意义。利用电子计算机断层扫描(computed tomograph,CT)及图像分析软件定量分析了水驱后、弱碱三元驱后不同渗透率岩心中各种类型的微观剩余油。结果表明:水驱后剩余油主要类型为簇状、柱状、盲端状;弱碱三元驱对水驱后各类剩余油均有不同程度的驱替作用,对簇状剩余油驱替效果最好;盲端状剩余油饱和度在三元驱后有小幅度升高。弱碱三元驱后剩余油形态与水驱后一致,簇状剩余油占比最高,需要进一步动用该类剩余油以提高采收率;

Quantitative Analysis of Remaining Oil after Weak Base ASP Flooding

There is still a lot of remaining oil after ASP flooding. It is important to clarify the type and quantity of remaining oil for further enhancing oil recovery. Various types of micro remaining oil after water flooding and weak base ASP flooding were quantitatively analyzed by CT scanning and image analysis software. The results shows that the main types of remaining oil after water flooding are cluster, columnar and blind end; weak base ASP flooding can displace all kinds of remaining oil after water flooding to different extent, and it has the best displacement effect on cluster remaining oil; the blind end oil increases slightly after weak base ASP flooding; the forms of remaining oil after weak base ASP flooding is the same as that after water flooding, and the cluster residual oil accounts for the highest proportion; this kind of oil needs to be further extracted to enhance oil recovery.