Fully integrated reservoir flow, geomechanics and seismic modeling: a tool for better reservoir characterization and geomechanical prediction using 4D seismic

The effects of geomechanics on seismic arrival changes have been observed in both numerical calculations and time‐lapse (4D) seismic field monitoring of reservoirs undergoing depletion. For strongly stress‐sensitive formations, reservoir characterization requires the integration of seismic surveillance and geomechanics analysis. In this paper we present a parallel iteratively coupled geomechanics and reservoir flow model to account for the complex interactions between fluid‐flow and solid mechanics, and the interactions between the reservoir and its bounding formations. The model is shown to possess several advantages: pore volume changes may be obtained both inside and outside the reservoir; every component that contributes to the detected time‐shifts may be accurately quantified; and pressure‐ and saturation‐dependent fluid properties, stress‐sensitive rock mechanical properties, as well as the nonlinear flow and solid behavior are integrated together in a consistent way. Thus, the presented method can serve as a better forward modeling tool for weak reservoir 4D seismic analysis to reduce the uncertainty in reservoir characterization and some geomechanical predictions, e.g. surface subsidence and sand production.