(295a) Modeling Adsorption and Transport Processes in Kerogen

A better elucidation of adsorption and transport processes in chemically heterogeneous and complex geomaterials such as kerogen can play a significant role in an improved understanding of phenomena such as retention of hydrocarbons and small fluid molecules (e.g., CO₂) in kerogen and their expulsion from it. In the present investigation, a Grand Canonical Monte Carlo/Molecular Dynamics simulation approach is used to model adsorption and transport of pure CH₄ and CO₂ in a type II oil window kerogen, and subsequently to determine the adsorption and transport properties of CH₄ and CO₂ at various reservoir conditions. The CO₂ exhibits relatively higher adsorption in type II oil window kerogen than CH₄ at given reservoir temperature and pressure. Further, the adsorption capacity of both CO₂ and CH₄ decreases with an increase in reservoir temperature. Finally, the transport of CH₄ and CO₂ molecules within kerogen matrix is highly influenced by the fluid-surface interaction and availability of the transport pathways within the kerogen matrix.