Rock Physics Template for Brittleness Interpretation and Its Application in Gas Shale/clay Prediction

In order to accurately predict the high brittleness gas shale/clay using seismic data, this article proposed a rock physics template based on an organic-rich rock physics model and two new RBIs (short for relative brittleness index) which presented by us formerly. The template establishes a connection of the mineral composition, porosity, elastic properties, pore structure and RBI. Moreover, it also can efficiently interpret the brittle variation trend of sand, sandy mudstone, and mudstone. Through the analysis of logging data based on the template, we can easily obtain the characteristic of sand, sandy-mudstone, non-gas shale, and gas shale. On the basis of these analyses, spatial distribution scale of high quality gas-contained brittle shale can be precisely predicted by utilizing pre-stacked seismic AVO inversion results, and the predicted results are in well agreement with the logging data.