Flexible definition of horizons and boundary conditions in 3D mechanics-based restoration: Application to mechanically-based interpolation and fault displacement uncertainty

in: Proc. 34th Gocad Meeting, Nancy, ASGA

Abstract

Structural restoration is a technique to recover the geometry of geological structures in the past and thus validate the consistency of a geological model. In 3D mechanics-based restoration, elastic behavior combined with Dirichlet boundary conditions allows to retro-deform structures. The boundary conditions are currently set on mesh elements which constitute the volume to restore. This leads to several practical challenges to generate the mesh and setting the boundary conditions, which hamper widespread applications of 3D restoration. For instance, associating two points on two fault blocks is only possible in classical restoration if these points are mesh vertices. This paper presents a method to define horizons and boundary conditions independently to the mesh. Any point inside the volume to restore can be used to apply a boundary condition, leading to a higher flexibility in restoration. Moreover, mesh constraints during mesh volume generation are greatly reduced. The proposed method is applied on two applications. Firstly, we propose a workflow using the restoration on hard data only (horizon picking) to build the stratigraphic model. Secondly we test several fault block slips and use the restoration results to select the most probable models. From 200 restored models, the ten ``best" models are selected according to a criterion based on dilatation.

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BibTeX Reference

@INPROCEEDINGS{,
    author = { Chauvin, Benjamin P. and Caumon, Guillaume },
     title = { Flexible definition of horizons and boundary conditions in 3D mechanics-based restoration: Application to mechanically-based interpolation and fault displacement uncertainty },
 booktitle = { Proc. 34th Gocad Meeting, Nancy },
      year = { 2014 },
 publisher = { ASGA },
  abstract = { Structural restoration is a technique to recover the geometry of geological structures in the past and thus validate the consistency of a geological model. In 3D mechanics-based restoration, elastic behavior combined with Dirichlet boundary conditions allows to retro-deform structures. The boundary conditions are currently set on mesh elements which constitute the volume to restore. This leads to several practical challenges to generate the mesh and setting the boundary conditions, which hamper widespread applications of 3D restoration. For instance, associating two points on two fault blocks is only possible in classical restoration if these points are mesh vertices. This paper presents a method to define horizons and boundary conditions independently to the mesh. Any point inside the volume to restore can be used to apply a boundary condition, leading to a higher flexibility in restoration. Moreover, mesh constraints during mesh volume generation are greatly reduced. The proposed method is applied on two applications. Firstly, we propose a workflow using the restoration on hard data only (horizon picking) to build the stratigraphic model. Secondly we test several fault block slips and use the restoration results to select the most probable models. From 200 restored models, the ten ``best" models are selected according to a criterion based on dilatation. }
}