Local updating of meshed 2D geomodels for seismic simulation

in: 2020 RING Meeting, ASGA

Abstract

As the first step of a project to locally update three-dimensional geological models", we propose a method to robustly introduce boundaries in a triangulated geomodel. this allows the integration of new data, simulation results, or geometry perturbation to reflect subsurface uncertainties. The 2D geological model is locally updated, meaning that only a given region is modified and that the rest of the model remains identical. The area that can be modified is either specified as an input parameter or defined automatically. The input data is a triangulated surface storing the geological structure and physical properties. We focus on the insertion of a boundary implicitly defined by an iso-value of a scalar field. The output is an updated mesh, which contains the new boundary. Distinctly from current model modification, we operate on the mesh and aim at keeping this mesh valid throughout the modifications. The cost of recomputing physical properties over the updated mesh, which depends on the model size and grid resolution, is minimal since mesh modifications are local. To assess the impact of the model updates," we consider elastic wave propagation simulated with a Discontinuous Galerkin method. Results on a fluid contact in a reservoir show a consistent behavior and clear the path for more complex model updates and for considering these updates in solving subsurface inverse problems.

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BibTeX Reference

@INPROCEEDINGS{LEGENTIL_RM2020,
    author = { Legentil, Capucine and Pellerin, Jeanne and Cupillard, Paul and Caumon, Guillaume },
     title = { Local updating of meshed 2D geomodels for seismic simulation },
 booktitle = { 2020 RING Meeting },
      year = { 2020 },
 publisher = { ASGA },
  abstract = { As the first step of a project to locally update three-dimensional geological models", we propose a method to robustly introduce boundaries in a triangulated geomodel. this allows the integration of new data, simulation results, or geometry perturbation to reflect subsurface uncertainties. The 2D geological model is locally updated, meaning that only a given region is modified and that the rest of the model remains identical. The area that can be modified is either specified as an input parameter or defined automatically. The input data is a triangulated surface storing the geological structure and physical properties. We focus on the insertion of a boundary implicitly defined by an iso-value of a scalar field. The output is an updated mesh, which contains the new boundary. Distinctly from current model modification, we operate on the mesh and aim at keeping this mesh valid throughout the modifications. The cost of recomputing physical properties over the updated mesh, which depends on the model size and grid resolution, is minimal since mesh modifications are local. To assess the impact of the model updates," we consider elastic wave propagation simulated with a Discontinuous Galerkin method. Results on a fluid contact in a reservoir show a consistent behavior and clear the path for more complex model updates and for considering these updates in solving subsurface inverse problems. }
}