Refined Description Of The Sub-layer Reservoir And Analysis Of Remaining Oil

The Eastern Block(including the first and the second transition zone of Eastern Block) is located in the east of Daqing Sazhong oilfield. The mining section of Eastern Block is SA II 1 ~ 15+16, the new wells started production in June 2013 by the way of water flooding. Now the block Is in the extra-high water cut period, resulting in invalid water cycle is serious and low economy benefit. In order to further enhance oil recovery, on the basis of the mine-field tests of ASP flooding and the succeeding of industrial demonstration area, in order to improve the development effect of tertiary oil recovery, we decide to product by the way of ASP flooding with strong alkali in the Eastern Block. In order to better carry out the follow-up ASP flooding production, this article refined descript the reservoir of this block after water flooding, and by the use of logging data and numerical simulation method to analyses the distribution characteristics and laws of the residual oil after water flooding. The analysis shows that, the residual oil distribution is scattered after water flooding, in the plane,the residual oil is divided into the injection-production system is imperfect, non-producing type, inter-well remaining, fault block type, channel side retained; longitudinal(1) interlayer remaining oil enrich in the layer which is thin, poor properties, serious heterogeneity(2) remaining oil in layer mainly enrich in the upper reservoir and the side of channel sand body, water flooding have a good effect on the reverse rhythm reservoir, such as estuary and crevasse splay, the remaining oil enrich in the part of poor properties.From the above analysis, it is shown that the sub-layer reservoir of the Eastern Block are all water-flooded, the thickness ratio of medium and higher water-flooded layers is above 90%, the water-cut was 96.9% when new wells were put into production, the water-cut is 96.5% in current. The remaining oil distribute separately, in the plane, it mainly distributed in the overbank sand of channel edge, the thin-poor layers of inter-channel and the injection-production system imperfect area; in vertical, it enrich in the top of thick positive rhythm reservoir. Study on refine description of reservoir and remaining oil distribution provides a theoretical basis for the subsequent ASP flooding production, be better for the implement of ASP flooding, and enhance oil recovery.