Abstract
The paper presents methods for generation of unstructured adaptive 3D PEBI grids, allowing for effective multiphase filtration modelling of reservoirs with multiple structural and technology features (faults of complex geometry, horizontal wells and wells with hydraulic fractures). We developed the algorithm of local grid rearrangement due to newly opened/shut wells and hydraulic fracturing, reducing simulation time. For problems, requiring accurate flow simulation in vicinity of structural features, an automatic local grid refinement was implemented.
On grids under consideration, three-phase filtration problem is solved numerically, accounting for gravitational, viscous and capillary forces and phase transition of hydrocarbon components. For the discretization of governing equations, two-point approximation is used as well as mimetic finite difference approximation customized for problems being solved. Distinctive feature of the proposed numerical method is direct flow computation in hydraulic fractures.
