Multiphase flow in porous rock formations is a multiscale problem due to physical processes occurring on various temporal and spatial scales. Heterogeneous petrophysical characteristics make it challenging to account for all variations, so grid coarsening and upscaling techniques are commonly used to create computationally tractable models. Lack of scale separation means that local upscaling methods are only valid for simplified setups, and nonlocal information is required to compute effective properties that accurately represent the flow patterns.
Multiscale formulations have proven to be a highly effective alternative to upscaling that incorporates subscale effects in a manner consistent with the physical models governing unresolved scale behavior. SINTEF has been such methods since the early 2000s, with a focus on handling complex grids and realistic flow physics.
Our multiscale restriction-smoothed basis (MsRSB) method is the current state-of-the-art and forms a basis of the accelerated solution engine in SLB's next-generation reservoir simulator, INTERSECT.
- Multiscale pressure solvers for stratigraphic and polytopal grids - chapter by Lie and Møyner from an open-access textbook published on Cambridge University Press. Gives a pedagogical introduction to multiscale reservoir simulation and how it is implemented in the open-source MRST software.
- Lie et al: Successful application of multiscale methods in a real reservoir simulator environment, Computational Geosciences, 2017. Discusses the research leading up to implementation of multiscale methods in SLB's INTERSECT simulator.
- Overview of multiscale methods implemented in the open-source MRST software.
- GeoScale - documents early research on multiscale reservoir simulation funded by two strategic research grants from the Research Council of Norway