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{,
        author = { Tertois, Anne-Laure and Mallet, Jean-Laurent },
         title = { Preserving geological information during real-time editing of faults in tetrahedral models },
         month = { "sep" },
     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. }
    }