Fast flow computation methods on unstructured tetrahedral meshes for rapid reservoir modelling

• Published in: Computational geosciences 2020-04, Vol.24 (2), p.641-661
• Main Authors: Zhang, Zhao, Geiger, Sebastian, Rood, Margaret, Jacquemyn, Carl, Jackson, Matthew, Hampson, Gary, De Carvalho, Felipe Moura, Silva, Clarissa Coda Marques Machado, Silva, Julio Daniel Machado, Sousa, Mario Costa
• Format: Article
• Language: English
• Subjects: Algorithms; Computation; Computational fluid dynamics; Earth and Environmental Science; Earth Sciences; Finite element method; Flight tests; Fluids; Geology; Geotechnical Engineering & Applied Earth Sciences; Hydrogeology; Lake dynamics; Mathematical Modeling and Industrial Mathematics; Mathematical models; Mesh generation; Modelling; Original Paper; Prototypes; Reservoirs; Soil Science & Conservation; Test wells; Testing; Three dimensional flow; Three dimensional models; Tracers; Two dimensional models; Uncertainty; Unstructured grids (mathematics); Workflow
• ISSN: 1420-0597; 1573-1499
• DOI: 10.1007/s10596-019-09851-6

Subsurface reservoir models have a high degree of uncertainty regarding reservoir geometry and structure. A range of conceptual models should therefore be generated to explore how fluids-in-place, reservoir dynamics, and development decisions are affected by such uncertainty. The rapid reservoir modelling (RRM) workflow has been developed to prototype reservoir models across scales and test their dynamic behaviour. RRM complements existing workflows in that conceptual models can be prototyped, explored, compared, and ranked rapidly prior to detailed reservoir modelling. Reservoir geology is sketched in 2D with geological operators and translated in real-time into geologically correct 3D models. Flow diagnostics provide quantitative information for these reservoir model prototypes about their static and dynamic behaviours. A tracing algorithm is reviewed and implemented to compute time-of-flight and tracer concentrations efficiently on unstructured grids. Numerical well testing (NWT) is adopted in RRM to further interrogate the reservoir model. A new edge-based fast marching method is developed and implemented to solve the diffusive time-of-flight for approximating pressure transients efficiently on unstructured tetrahedral meshes. We demonstrate that an implementation of the workflow consisting of integrated sketch-based interface modelling, unstructured mesh generation, flow diagnostics, and numerical well testing is possible.