Enhancing gas field discovery by multicomponent imaging and joint inversion

Summary The dramatically lateral lithological variations due to the complex fluvial sediments result in major challenges in the characterization of the highly permeable gas sandstones among the widely distributed less permeable sandstones in the Sulige gas field, located in the Erdos basin of China. Application of the multicomponent technology in the Sulige Basin aims at enhancing the possibility to discover high productive gas reservoirs. Directly extracting Vp/Vs, Poisson’s ratio and other elastic parameters from multicomponent data provides a more accurate and straightforward way to delineate the characteristics of the sandstone gas reservoirs. However, the complicated near surface geological conditions including heterogeneity of the fluvial deposits associated with larger scale stratigraphic variability in the Sulige Basin impose serious challenges for multicomponent data processing and inversion. This paper shows a successful application of three-component seismic data in the Sulige gas field. Through the registration of the PP and PS equivalent reflection events and by building the initial velocity model, PP-PS joint inversion can provide inverted elastic parameters through both pre-stack angle gather and post-stack seismic data. It is concluded that the PP-PS joint inversion can reduce the drilling risks and effectively delineate the characteristics of the gas sand reservoir in the Sulige gas field.