Development of Flow and Transport Model for Dual Domain Fractured Formation

Development of flow and contaminant transport models for three-dimensional (3D) discrete fracturenetworks (DFNs) is critical to characterize flow and transport in fractured rocks. The fractures in a rock arerelatively permeable compared with the rock matrix. Because of the complex fracture geometry andconnectivity, generations of fracture unstructured mesh and simulations of flow and transport in 3D DNFbecome challenging tasks, to simulate the flow and solute interaction between fracture and matrix is verydifficult. In the past study, the domain of simulation was restricted to 1D or 2D, and the flow andadvection-dispersion transport was also limited in the DFNs. To satisfy the requirements of practicallarge-scale problems, the developed flow and transport models for fractured rocks need to be able to handlethe complex interactions of fractures and rock matrices and provide upscaled parameters for large-scalesimulation scenarios. The objectives of this study are to use numerical methods to develop, test, andimplement flow and transport models in fractured rocks This research integrates interdisciplinary studies thatinclude: (1) generations of 3D discrete fracture networks based on fracture geometry properties from fieldmeasurements, (2) developments of DFN mesh generation by using the Delaunay triangulation algorithm anda boundary recovery technique, (3) developments of automatic mesh exporting modules for other publicdomain models such as TOUGH series models and HYDROGEOCHEM model and for the developed flowand transport model in this study, (4) calculations of equivalent hydraulic conductivity for the large-scaledfractured rocks based on the developed models. The models and results are expected to provide useful andefficient tools for water resource management, geological storage of CO2 and waste nuclide fuels, geothermalenergy developments, and tunnel excavations and other fractured rock relevant engineering applications.