Summary
In shale gas exploration and development, gas reservoir characterization based on seismic technique forms the core of shale gas reservoir identification and evaluation, while geophysical logging is an important mean to identify and evaluate the shale gas reservoir and then provide parameters to guide completion. Compared with conventional reservoirs, it is more complicated to perform logging evaluation for shale gas reservoirs, new logging- interpretation and evaluation technique is needed for the precise evaluation of shale gas reservoirs. Therefore, a set of effective technical work flow for shale gas reservoir prediction is presented in this article. Taking Daanzhai in the eastern Sichuan Basin as an example, and starting from geologic and logging features and difficulties for evaluation, Optimum Logging Interpretation technique is adopted to calculate key parameters for the evaluation of shale gas reservoirs, establish qualitative evaluation criterion for shale gas reservoirs in this area, then find out sensitive geophysical parameters, and apply Pre-Stack Simultaneous Inversion technique to obtain reliable elastic parameter volume, finally utilize Lithofacies and Fluid Probability Analysis technique to predict the favorable development zone for shale gas reservoir, so as to lay a solid foundation for future research on brittleness and development.
