State-of-the-art in modeling of unconventional gas recovery

This paper provides a survey of fourteen recently developed numerical simulators used for modeling production from unconventional gas reservoirs. These simulators are evaluated with respect to key features, including: (1) the ability to model complex geological situations (single vs. dual-porosity, coal/sand sequences, coal/shale sequences, faulting, etc.), (2) the ability to model different governing flow mechanisms, (3) the ability to model different exploitation schemes (unstimulated vertical drainage wells, hydraulically stimulated vertical drainage wells, horizontal drainage wells, etc.), and (4) the numerical capabilities of the models (numerical formulations, ability to run on a personal computer vs. a main frame computer, etc.). From this survey, five 'modules' are identified as being essential to the numerical prediction of gas production from unconventional reservoirs.