Method of detailed reservoir description in secondary development of old oilfield.

The heterogeneity of the thick reservoir is the key point in the detailed reservoir description at the stage of the secondary development. Taking the Yangsanmu Oilfield, the pilot test area of Dagang petroliferous province, as an example, the thick reservoir is subdivided based on the fine strata correlation and the study on sedimentary microfacies. The interlayer of the thick reservoir is identified, its 3D model is built and the thick reservoir is divided into relatively independent flow units acording to the architecture analysis. Then the remaining oil distribution is studied using the data of water flooded zones interpretation and oil saturation monitoring. They may serve as the geological foundation for the secondary development plan design.