Abstract
Flow, mass and energy transport processes in natural reservoirs are controlled to a large degree by the presence of geological heterogeneities including structures such as fractures and fault zones embedded in a spatially varying three-dimensional (3D) porous matrix of the reservoir. Despite recent advances, currently, state-of-the-art models rely on a number of simplifications partly related to our inability to represent heterogeneities as observed in the field into dynamic model realizations. In this respect, an adequate geometric representation of the discrete system is a basic requirement. In this study, we show how fundamental concept from computational geometry can be assembled and used to bridge the gap between geological and dynamic forward models. The result is an automated, open source software solution (MeshIt) to generate quality 3D meshes suitable for the study of flow and transport processes in faulted and fractured reservoirs. The software enables us to integrate into a 3D volumetric representation dip** structures, comprising fault zones and fractures as well as inclined well paths. This permits us to correctly simulate interactions between discrete flow paths along these interacting components and the 3D flow within the reservoir matrix. The crucial factor that makes the approach applicable to real case reservoirs is that all algorithms are local and scalable parallel and have computing times increasing approximately linearly with data volumes. We test the performance and the robustness of the software against three different scenarios of increasing complexity and further discuss current limitations and range of applicability of the software. Although all examples describe geothermal applications, it is worth mentioning that the approach is equally valid for other applications in geoscience from oil and gas industry to carbon capture and sequestration issues.
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Acknowledgments
This work has been performed in the framework of the GeoEn-phase 2 project and funded by the Federal Ministry of Education and research [BMBF, Grant 03G0767A]. A special thank goes to Dr. Si Hang from the WIAS Institute in Berlin for sharing his expertise in the field of mesh generation. The authors would like to acknowledge Prof. Guillaume Caumon whose comments as a reviewer provide valuable to improve not only the quality and scientific merit of the manuscript, but also help finding novel solutions to some aspects of the meshing software.
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Cacace, M., Blöcher, G. MeshIt—a software for three dimensional volumetric meshing of complex faulted reservoirs. Environ Earth Sci 74, 5191–5209 (2015). https://doi.org/10.1007/s12665-015-4537-x
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DOI: https://doi.org/10.1007/s12665-015-4537-x