Qualification and validity of a smeared fractures modeling approach for flow and transport in fractured media

International audienceModeling flow and transport in a natural fractured medium is a difficult issue due among others to the large contrasts in the medium, its geometrical complexity as well as the strong level of uncertainties for all parameters leading to stochastic modeling. We present here a contribution to the smeared fracture approach answering the above requisites. It is a continuous representation of the fractured block for a regular discretiza-tion mesh, the presence of the fracture network being accounted for by a heterogeneous field of the parameters. Different realization can be easily considered within a Monte Carlo framework addressing geometrical uncertainties while working on coarse mesh allows for reduction of the computer costs. A smeared fracture method is developed, adapted to flow and transport for a Mixed and Hybrid Finite Element numerical scheme. This approach, developed so far for 2D problems, is evaluated on test cases involving comparisons with simulation performed on the same geometry, but modeled explicitly. Results show that major transport features are captured by smeared fracture model and allow for a good quantitative restitution of the transfers. This makes this approach an interesting compromise between precision and versality associated to low computer costs in the perspective of Monte Carlo simulations. The limits of the approach for large cinetical contrasts throughout the domain will be further studied in the future