Study On The Sedimentary Characteristics And Reservoir Prediction Of Beach-bar Of Es4 In Dongying Sag

The beach-bar is main exploration target in the shelving of nonmarine downfaulted basin. Traditionally, the depositional system of clasolite beach-bar is thought localizing in slope of lake-basin and palaeohigh underwater. Dongying sag is a typifier of half basin in China east. By exploration practice, it is found out that the distribution of beach-bar of Es4 is not only controlled under nosing structure, and it is disagreement with traditional idea. Hence it is very important the study of forming and distribution of beach-bar. Being aimed at difficulties of beach-bar of Es4 in Dongying sag, the comprehensive research is done by present sedimentology, high definition sequence stratigraphy and geophysical technology. The sedimentary characteristics and identification mark and distribution of beach-bar in Dongying sag are clearly and definitely. On base of the geologic model, the relationship of geologic framework and seismic response is built up by forward modeling. The comprehensive predict method of beach-bar is built up and practiced in exploration, and the good effect is acquired.Using the data of drilling core, seismic and logging, the sediment features and origin mechanisms of beach bar sand-body. in Dongying sag are researched systemically, the writer thinks that there are one third sequence and three system fields, the beach bar sand-body mainly forms in low order fields of third system fields. The beach bar sand-body is classified into beach dam sands and bank sands. Palaeogeomorphology, Palaeosource, Palaeohydropower and Palaeobasal-level controls forming and distribution of beach bar sand-body. Palaeogeomorphology controls the distribution and Palaeosource controls the development level and Palaeohydropower controls facies belt distribution and Palaeobasal-level controls overriding styles.A case study of E2s4 in Dongying depression, it is put forward that the comprehensive prediction method of geology- geophysics based on the genesis features of beach bar sand-body. Firstly, by researching stratigraphic sequence the distribution areas of beach bar sand-body are known; secondly, analyzing response characters of geology-seism, effective reservoir prediction methods and seismic attribution parameters are chosen; finally, favorite facies belts are understood by multi-attribution analyzing of target stratum and the beach bar sand-body is described by linking well and seism. Using of this method, well effects are gained in predicting beach bar sand-body of E2s4 of Dongying depression. It indicates that the comprehensive uses of geology analyzing and geophysics skills is effective to predict and descript the reservoirs of beach bar sand-body.