Hydrocarbon detection with AVO in Block Su-75

Sedimentary difference between the eastern and western of Block Su-75 in Sulige Gasfield causes characteristic differences in seismic data, gas reservoirs position, and AVO response. It is difficult to predict reservoir using single parameter and hydrocarbon indictor attributes obtained from AVO analysis. Based on CMP gathers analysis, forward modeling of gas-reservoirs theoretical model and gas-reservoirs actual model passing through a well, the absolute amplitude value of reflections from gas reservoirs increases with the offset no matter what AVO response polarity is from the reservoir top and bottom. So AVO can be used to detect effectively the thicker gas-bearing. Our research identifies the gas bearing distribution in Block Su-75 using pseudo poisson's ratio and pseudo shear wave reflective coefficient. The result is highly consistent with the well drilling data, which provides a strong support for the future oil and gas exploitation in the area.