Building PEBI grids conforming to 3D geological features using Centroidal Voronoi Tesselations.

in: Proc. 31st Gocad Meeting, Nancy

Abstract

For numerical reservoir flow simulation, grids that are conformal to the geological features are needed in order to reduce the homogenization error (in particular between horizons) and to retrieve the major flow features (such as faults). In this paper, Voronoi Tessellations are obtained by an optimization method. The minimized function is modified from the classical Centroidal Voronoi function in order to make cells conformable to the geological features. The geological features are considered as inner surfaces, dividing the reservoir into closed subdomains. Two ways are investigated: in the first way, the barycenter of the cell is modified if the cell overlaps a feature such that the feature has a repulsive effect on the seeds; in the second way, an objective function reflecting the contribution of the parts of the cell on each side of the feature is computed and added to the original centroidal function term. These methodologies are applied successfully to 3D synthetic reservoirs with internal features such as horizons, faults, partly cutting faults and pinch-outs.

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BibTeX Reference

@INPROCEEDINGS{MerlandGM2011,
    author = { Merland, Romain and Levy, Bruno and Caumon, Guillaume },
     title = { Building PEBI grids conforming to 3D geological features using Centroidal Voronoi Tesselations. },
 booktitle = { Proc. 31st Gocad Meeting, Nancy },
      year = { 2011 },
  abstract = { For numerical reservoir flow simulation, grids that are conformal to the geological features are needed in order to reduce the homogenization error (in particular between horizons) and to retrieve the major flow features (such as faults). In this paper, Voronoi Tessellations are obtained by an optimization method. The minimized function is modified from the classical Centroidal Voronoi function in order to make cells conformable to the geological features. The geological features are considered as inner surfaces, dividing the reservoir into closed subdomains. Two ways are investigated: in the first way, the barycenter of the cell is modified if the cell overlaps a feature such that the feature has a repulsive effect on the seeds; in the second way, an objective function reflecting the contribution of the parts of the cell on each side of the feature is computed and added to the original centroidal function term. These methodologies are applied successfully to 3D synthetic reservoirs with internal features such as horizons, faults, partly cutting faults and pinch-outs. }
}