Abstract
This paper presents the construction of a high-quality, robust hybrid grid for near-wellbore modeling in the vicinity of a deviated well. The far-field region is modeled using a corner-point grid, while the near-wellbore region-referred to as the volume of interest-is remeshed using a layered unstructured grid, which consists of a combination of Voronoi and radial sub-grids. A detailed gridding and simulation workflow is outlined. The construction of the novel layered unstructured grid begins with building a base surface grid on the surface typically aligned to middle well point. The grids on the other surfaces are built through preserving the base topology but adjusting the nodes of base grid to fit the well points deviating from the base well point. A flow-based node rearrangement method is proposed to adjust the grid nodes to gain high-quality grids on each surface. The positions of new nodes are determined by ensuring equal streamlines and pressure values between nodes on the base and target surfaces, improving grid orthogonality as streamlines remain perpendicular to equipotential lines. The method’s ability to generate high-quality grids for deviated wells is demonstrated through illustrative and validation examples. Computational performance is assessed through direct comparisons across three case studies, showing that the new near-wellbore modeling model provides accurate well solutions and pressure maps with a reasonable computational cost. Additionally, the near-wellbore modeling model outperforms standard models in capturing gas flow with high compressibility, describing flow behavior in heterogeneous reservoirs, and predicting production parameters in multilayer systems.
