Fine Reservoir Description Of Block Wen25 In Wenliu Oilfield

Considering the geological characteristics and development status of block Wen25 in Wenliu oilfield, guided by the theory of petroleum geology, sedimentology, reservoir geology and development geology, adopting the technical means of fine description, such as high-resolution sequence stratigraphy, reservoir evaluation and reservoir 3D modeling, using computer technology, to do some research about fine reservoir description of block Wen25 in Wenliu oilfield.Based on the research of the logging and cores, applying the principles and methods of high-resolution sequence stratigraphy ,we divided the lower submember Es2 into 8 sand groups, 41 sub layers, and 1 sand group of upper submember Es3 into 5 sub layers, total of 46 sub layers, then built the high-resolution sequence stratigraphic framework of research area. Using the data of geology, logging and production performance, by fine geologic correlation, recognized and composed faults once more to make them meet the subsurface geological conditions. Finally we built the fine structural model.Based on the previous research, the analysis of core observation, sediment deposition background and sediment features, we judge that the provenance of lower submember Es2 came from northeast of this area , the facies of this area is terminal fans, which developed middle subfacies and distal subfacies, the main microfacies are distributary channel, proximal overbank, distal overbank and mudflat. The provenance of upper submember Es3 came from west and northwest of this area, the facies is shallow water delta front sediment. The main microfacies are distributary channel, channel margin, sand sheet and interdistributary. We draw the sandstone thickness maps and microfacies maps of all sub layers, and then built the sediment model of this area.The rock types of this area are mainly feldspar-quartz sandstone and feldspar sandstone, including less debris-feldspar sandstone. The degree of sorting is medium, textural maturity is higher. By observing cast sections and scanning electront microscopy, we recognized the diagenetic processes of compaction, cementation, dissolution and metasomasis. The diagenetic evolution is between middle diagenetic stage B and late diagenetic stage. The main type of pore throat structure is medium pores and fine throats, carbonate cement may have an impact to microscopic heterogeneity of sandstone. The in-layer heterogeneity is strong, interlayer heterogeneity is relatively weak. Plane heterogeneity is greatly influenced by the planar distribution of sedimentary facies. In a comprehensive study of various macro- heterogeneous and micro-heterogeneous reservoir parameters on the basis of the reservoir quality, the reservoir quality was divided into three types.Adopting stochastic modeling method, the 3D reservoir structure models are built up. With microfacies studies, we built microfacies models of all sub layers. Utilizing the facies-controlled simulation method, the attribute parameter model is built up.