Some key technical issues in modelling of gas transport process in shales: a review

Abstract

As a result of small pore sizes and property heterogeneities at different scales, flow processes and the related physical mechanisms in shales can be dramatically different from those in conventional gas reservoirs. To accurately capture the “unconventional” flow and transport in shales requires reevaluation of dominant physics controlling flow in shales, as well as innovative hardware technologies to estimate critical material and flow properties. To do so, we need to quantify the current knowledge and identify technology gaps especially as related to the modeling fluid flow in shale gas reservoirs. While fluid flow in shale includes many important aspects, this paper focuses on fluid flow in complex heterogeneous shale matrix. It discusses the recent progress in the areas of multi-scale fluid flow, fracturing fluid imbibition, and stress-dependent shale matrix properties. Future research topics in the related areas are also suggested based on the identified technology gaps.