Reservoir Description Using Hybrid Seismic Inversion: A 3D Case Study From Maria Ines Oeste Field, Argentina

In this paper, we apply hybrid seismic inversion on a three-dimensional (3D) seismic data set from María Inés Oeste, an oil and gas field in Argentina. The María Inés sandstones are Paleocene in age, the traps are mainly structural, and the reservoir is about 50 m thick, containing either oil or gas. These oil/gas-bearing sands usually cause anomalously high amplitude brightspots on the stacked seismic data. These brightspots were generally used as hydrocarbon indicators for this area. Drilling through these bright-spots has resulted in pay, as well as many dry wells. Hybrid seismic inversion, a combination of prestack waveform inversion and poststack inversions of some amplitude-variation-with-offset (AVO) attributes, allowed us to demonstrate that the Poisson's ratio, obtained from this hybrid inversion was effective in fluid discrimination and provided successful drilling locations. We also demonstrate that the Poisson's ratio contrast; obtainable from a standard AVO is not as effective in fluid discrimination as the one from hybrid inversion.