Modeling of Transport Phenomena and Multicomponent Sorption for Shale Gas and Coalbed Methane in an Unstructured Grid Simulator

Abstract

AbstractShale gas and coal bed methane (CBM) assets have become increasingly important over the last decade, and are expected to become major energy sources for the future generations. However, there are unanswered fundamental physics and transport questions for each of these resources. Various physics-based approaches have been proposed and implemented to understand and simulate the flow mechanisms. However, the connectivity of organic and mineral matter is not fully understood and thus the exact transport mechanism in shale gas is still uncertain. This in turn can significantly limit the quality of resource potential and production forecast estimates.This work addresses the challenges for shale gas and CBM simulations and presents a coupled sorption-transport model for both assets, along with its implementation in an unstructured grid compositional simulator. The models presented have been designed to capture key physics while still being straightforward to apply. A model for handling multicomponent isotherms based on pure component data is described. Existing experimental data were fit with the model and the results are discussed. A general transport mechanism workflow, which can be applied to both shale gas and CBM, is proposed. Results and findings are provided for the overall proposed scheme from gas desorption in the organic matter to the different transport mechanism in the matrix and the fractures.