Methane in subsurface: resource and hazard. Towards hybrid mathematical models and computational solutions
Presenter
April 13, 2011
Keywords:
- Coupled PDE models, multiphase multicomponent flow and transport, phase transitions, methane hydrates, coalbed methane recovery, porescale modeling, hybrid modeling
MSC:
- 82B26
Abstract
In the talk we describe two applications important for global climate
and energy studies: methane hydrates and coalbed methane. Methane
hydrates also known as "ice that burns" are present in large amounts
along continental slopes and in permafrost regions and, therefore, are
a possible source of energy and at the same time a potential
environmental hazard. Their evolution critically depends on how the
hydrate formation and dissociation affects the porescale properties.
This so far has been only modeled with ad-hoc phenomenological
approaches on top of the continuum models which account for multiple
flowing phases, energy conservation, and phase change with or without
latent heat. A similar situation arises in coalbed methane recovery
where the traditional models of multicomponent adsorption appear
inadequate to capture the dynamics of coupled porescale processes
involving matrix swelling, competitive adsorption between carbon
dioxide and methane, and adsorption hysteresis.
Both applications have had comprehensive computational realizations
based on coupled nonlinear PDE systems whose analysis has not yet been
carried out. More importantly, both call for broadening the scope of
modeling tools from traditional continuum PDE-based models to include
a variety of discrete models which help to understand processes at
porescale and to formulate constitutive relationships useful at
continuum scale. In the talk we outline challenges of traditional
continuum models, present some porescale results, and introduce some promising hybrid modeling approaches.