Analysis and characterization of sandstone reservoir architecture in middle and late stages of offshore oilfield development

In the middle and late stages of oilfield development, analysis of internal architecture and characterization of sandstone reservoirs in a sandy sequence are significant to reservoir research. Under the circumstance of less well data, the effective way for offshore oilfield to carry out reservoir architecture research is to follow the principle of “well-seismic integration” “under the guidance of seismic survey” , established on the seismic response model to the internal structure characteristics of reservoirs. In order to effectively carry out reservoir research, it is required to make clear the vertical division of sequences using the shape of logging curves, sand body thickness and vertical elevation difference, and lateral recognition of boundaries for composite sand bodies, which are defined with structure sensitive seismic attributes. Combined with the data from development stage, we proposed in this paper a set of reservoir structure characterization and genetic characterization methods. Firstly, sedimentary models are constructed by revealing the types of sediments and controlling mechanism of sand body distribution; Secondly, internal structure of the reservoir is predicted by comparing and optimizing sensitive seismic attributes; Thirdly, well seismic data is transformed into reasonable parameters with clear geological meanings; Finally, geological maps are compiled by integration of multiple factors.