Poroelasticity of Methane-Loaded Mature and Immature Kerogen from Molecular Simulations

Autor: Amaël Obliger, Nicolas Capit, Pierre-Louis Valdenaire, Roland J.-M. Pellenq, Franz J. Ulm, Jean-Marc Leyssale
Přispěvatelé: Massachusetts Institute of Technology (MIT), Aix Marseille Université (AMU), Multiscale Material Science for Energy and Environment (MSE 2), Department of Civil and Environmental Engineering [Cambridge] (CEE), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Composites Thermostructuraux (LCTS), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Snecma-SAFRAN group-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Langmuir
Langmuir, American Chemical Society, 2018, 34 (45), pp.13766-13780. ⟨10.1021/acs.langmuir.8b02534⟩
Langmuir, 2018, 34 (45), pp.13766-13780. ⟨10.1021/acs.langmuir.8b02534⟩
ISSN: 0743-7463
1520-5827
Popis: International audience; While hydrocarbon expulsion from kerogen is certainly the key step in shale oil/gas recovery, the poromechanical couplings governing this desorption process, taking place under a significant pressure gradient, are still poorly understood. Especially, most molecular simulation investigations of hydrocarbon adsorption and transport in kerogen have so far been performed under the rigid matrix approximation, implying that the pore space is independent of pressure, temperature, and fluid loading, or in other words, neglecting poromechanics. Here, using two hydrogenated porous carbon models as proxies for immature and overmature kerogen, that is, highly aliphatic hydrogen-rich vs highly aromatic hydrogen-poor models, we perform an extensive molecular-dynamics-based investigation of the evolution of the poroelastic properties of those matrices with respect to temperature, external pressure, and methane loading as a prototype alkane molecule. The rigid matrix approximation is shown to hold reasonably well for overmature kerogen even though accounting for flexibility has allowed us to observe the well-known small volume contraction at low fluid loading and temperature. Our results demonstrate that immature kerogen is highly deformable. Within the ranges of conditions considered in this work, its density can double and its accessible porosity (to a methane molecule) can increase from 0 to ∼30%. We also show that these deformations are significantly nonaffine (i.e., nonhomogeneous), especially upon fluid adsorption or desorption.
Databáze: OpenAIRE