Preserving Geological Information during Real-Time Editing of Faults in Tetrahedral Models

in: Proc. IAMG 2006

Abstract

Modelling underground physical processes with finite elements or finite differences methods requires volume meshes of the subsurface. Tetrahedral grids offer much greater geometric accuracy than Cartesian or curvilinear grids because cell sizes and shapes can adapt to complex geological features. In tetrahedral grids, faults can be modelled as topological discontinuities. Accounting for new information on fault geometry through a complete rebuild of the model is time-consuming. Instead, we present a tool which makes small geometric modifications to faults in tetrahedral models. Fault editing is performed without computing a new tessellation for the whole model, and in real-time so that feedback is immediate. If these modifications occur close to a fault contact, consistent fault contact geometry is maintained: the secondary fault moves along the main fault without going through it, and the overall shape of the main fault does not change. When the edited model contains geological properties, the rock properties attached to the points in the model are updated in order to maintain the spatial continuity of the property in each fault block and according to fault throw, and to maintain the conditioning to well or seismic data in the edited domain.

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BibTeX Reference

@INPROCEEDINGS{Tertois06IAMG,
    author = { Tertois, Anne-Laure },
     title = { Preserving Geological Information during Real-Time Editing of Faults in Tetrahedral Models },
 booktitle = { Proc. IAMG 2006 },
      year = { 2006 },
  abstract = { Modelling underground physical processes with finite elements or finite differences methods requires volume meshes of the subsurface. Tetrahedral grids offer much greater geometric accuracy than Cartesian or curvilinear grids because cell sizes and shapes can adapt to complex geological features. In tetrahedral grids, faults can be modelled as topological discontinuities. Accounting for new information on fault geometry through a complete rebuild of the model is time-consuming. Instead, we present a tool which makes small geometric modifications to faults in tetrahedral models. Fault editing is performed without computing a new tessellation for the whole model, and in real-time so that feedback is immediate. If these modifications occur close to a fault contact, consistent fault contact geometry is maintained: the secondary fault moves along the main fault without going through it, and the overall shape of the main fault does not change. When the edited model contains geological properties, the rock properties attached to the points in the model are updated in order to maintain the spatial continuity of the property in each fault block and according to fault throw, and to maintain the conditioning to well or seismic data in the edited domain. }
}