Application of prestack reservoir characterization technology for multicomponent seismic in low permeability and tight sandstone gas reservoirs

摘要

The Sulige gas field in China belongs to a low-porosity and low-permeability, tight sandstone gas reservoir. There is a large overlap in the acoustic impedance of the gas-bearing sandstone and the surrounding rocks, with no unified interface of gas bearing layers and water bearing layers, restricting the gas productivity construction. Therefore, it is a multi- solution problem to characterize gas reservoir by the conventional P-wave seismic and it is difficult to identify fluids. This paper selects sensitive elastic parameters of fluid characteristics based on detailed petrophysical property analysis. We present a new approach that attempts to match the PP and P-SV data, and acquires much higher precision and stable seismic elastic parameters that can truly indicate physical property and gas potential of a reservoir by using the prestack joint inversion of PP and P-SV data rather than using PP data alone. The quantitative interpretation of the seismic elastic multiparameter cross-plots technique reduces the ambiguity of fluid identification by using the PP data or one elastic parameter alone. For the Sulige gas field, the successful wells ratio has been increased by more than 10% by using the prestack reservoir characterization technology for multicomponent seismic compared with using P-wave seismic alone.