The necessary and sufficient conditions of the design parameters that should be considered to build proper shale-gas reservoir simulators are investigated. The design requirements are established based on the theoretical studies of flow through extremely low permeability porous media, ion milled SEM images of the nano-geometry of shale-gas reservoir formations, laboratory petrophysical measurements, and the available production and stimulation information. This paper presents a critical discussion of the relevant aspects such as the reservoir formation structure, fluid storage and transport mechanisms, and gradual non-equilibrium motion and dynamic distribution of fluids in the pore system. Then, an overview of the capabilities of the commonly used reservoir simulation software is presented in view of the identified requirements of shale gas reservoirs. Quantitative comparisons between the alternative formulations against the conventional formulations are also presented with several examples using an in-house simulator developed in this study. Areas needing new fundamental formulations and further research for proper shale-gas reservoir modeling are delineated. This paper provides important insights and guidelines for development of adequate numerical simulators that can correctly accommodate for the proper description of the relevant phenomena, and predict gas production and water displacement in shale-gas reservoirs.

You can access this article if you purchase or spend a download.