萨尔图油田河流相储集层高含水后期剩余油分布规律研究

萨尔图油田葡Ｉ组河流相储集层非均匀性复杂，在高含水后期仍有相当数量的剩余油。沉积微相的特征与组合是决定砂体非均质性质的主要因素，也是产生大量剩余油的根本原因。高弯曲河道剩余油分布与侧积体变化一致，呈侧积层和废弃河道遮挡的环形条带状。最外缘的废弃河道和点坝下游处剩余油富集；与注水砂体连通不好的点坝存在较多的剩余油；低弯曲河道与顺直河道水淹沿主流快速推进，河道边部形成继续分布的剩余油富集区。

REMAINING OIL, DISTRIBUTION AT HIGH WATER-CUT STAGE IN RIVER FACIES RESERVOIR OF SAERTU OIL FIELD

The river facies reservoir in PI Formation of Saertu oil field is very heterogeneous. There are still significant amount of oil remained in it even at the late high water-cut production stage. The feature and combination of micro-facies deposits are the main factors determining the heterogeneity of sand bodies, and the fundamental reason causing large amount of oil remaining in situ. The distribution pattern of remaining oil in highly meandered stream deposits is consistent with the distribution variation of the lateral accretion bodies, and takes a ring-like zone created by the lateral accretion layer and the abandoned channel. The remaining oil is normally enriched in the outer most abandoned channel and the lower part of point bar,especially the point bar badly connected with water-flooded sand bodies. The fast water break through along the main flow streamlines of the lowly meandered channel and the straight channel resulted in a discontinuous remaining oil enrichment region in the edge of the river.