Effect of Aperture Distribution on NetworkFracture Permeability Using EMT Approach

For many engineering rock works, permeability of fracture network is calculated byanalytical and numerical methods. Analytical methods usually apply for simple andregular joint set systems and for complicate networks only numerical methods areapplicable. Numerical simulations demand a large computing resources and its verytime consuming particularly when we have a large model size with denselypopulated of fractures. The Effective Medium Theory approach is an alternativemethod for numerical modeling. We developed the new code based on the EMTapproach for calculating permeability and Representative Elementary Volume(REV) of fractured rocks. Using Monte Carlo simulation techniques, stochastic DFNmodels were generated with a large number of realizations with the same fracturedensity but different fracture aperture distributions. The Universal Distinct ElementCode (UDEC) is also facilitated for numerical simulation analysis. The results showthat EMT method gives overestimated values of permeability compared with thenumerical method. The REV size for EMT models is smaller than numerical modelsfor all of models.

Keywords:

Aperture distribution , Permeability , Correlation , Representativeelementary volume (REV) , Monte Carlo , Effective Medium Theory