Solute Transport in Geo-Mechanics-Based Grown Fractures in Porous Media
A higher order implicit scheme for time-dependent advection-dispersion equations is employed to model solute transport in fractured media. This is combined with a geo-mechanics-based finite-element model to generate fracture patterns incrementally while studying their impact on mass transport at each development stage. The model produces fracture geometry as well as aperture size distributions by propagating a set of initial random flaws under a far-field stress. This quasi-static propagation assumes a linear elastic matrix, and propagates cracks governed by a sub-critical failure criterion. Fracture propagation, intersection, and closure are handled geometrically. A series of simulations is carried out to investigate the effect of heterogeneity on a geomechanically generated porous fractured rock mass, as opposed to stochastically generated datasets, on macro-scale dispersion. The computational results suggest that aperture size distributions play a significant role in modelling solute transport in fractured media. Results indicate the anomalous behaviour of mass transport in heterogeneous porous media.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009