Shallow Water Delta Reservoir Configuration Analysis In Qk Oilfield, Bohai Bay Basin

Abstract

Summary Affected by complex contact relationships between single distributary channels and reservoir heterogeneity, the distribution of remaining oil is complex and the shallow water delta oilfield development effect becomes worse at the late stage of waterflooding development. Taking QK oilfield as an example, the reservoir configuration of shallow water delta sand body is studied by using core, well logging and production dynamic data. The classification of shallow water delta sand body configuration, interface identification and spatial structure model are established. Combined with the actual development of the oilfields, the shallow water delta sandbodies in the study area can be classified into 4 levels of reservoir configuration. The longitudinal interfaces of single distributary channel include mudstone interface of sediment origin, calcium interface of carbonate cementation origin and physical interface of erosion origin. The lateral interfaces includes three types of qualitative identification methods which are overflow sediment, lacustrine mudstone and abandoned channel deposits, and one quantitative method of thickness model. Spatially, affected by the decline of lake level, the plane shape of sand bodies changes from sheet to strip, and the connectivity of reservoirs becomes worse, which makes remaining oil mainly distribute on the top of composite channel sand bodies.