Simulating Mineral Weathering in 3D Fractured Media

Abstract:

Recent advances in coupled fracture network and reactive transport codes have provided the tools to investigate many long-standing questions in the Earth sciences. One such question is “why is there a discrepancy between lab and field-based mineral dissolution rates?”. A potential answer is the range of reaction rates caused by heterogeneous flow paths in fractured media. In this study, we investigate several methods to set up three-dimensional fractured media simulations to test hypotheses related to mineral weathering. These simulations are run using dfnWorks, a high-fidelity discrete fracture generating software, coupled with PFLOTRAN, a multi-component reactive transport code. Several conceptual models of fractured media with varying fracture density are considered. These are used to determine the effect of boundary conditions and initial conditions on mineral dissolution rates in the presence of secondary minerals.