Perturbation of Fault Network Building on a Stratigraphic Grid.

in: Proc. 26th Gocad Meeting, Nancy

Abstract

Structural uncertainty on 3-dimensional reservoir models has a significant impact on the evaluation of hydrocarbon in place and the subsequent estimation of the reserves. It is difficult to cope with such an uncertainty, and hence en effective approach to edit or update existing reservoir models is needed. Such direct editing approaches are very appealing since they remove the need for a complete and tedious updating. In this paper, we apply the theory of simple constrained deformation (Scodef) to update the geometry of a Stratigraphic Grid (SGrid) so as to account for a set of displacement vectors, which are defined on a set of geological surfaces. For instance, these vectors may be available on fault’s surfaces to stochastically perturb the fault network’s geometry. Since it is not easy to ensure that the displacement vectors are consistent, we propose using equation of continuity to constrain the updated model. The result shows that the updated stratigraphic grid honors the displacement field as much as possible while preserving consistent geometric contacts between faults/horizons. This approach was implemented as a Gocad plugin named “EasyFault” to assist reservoir engineers in updating a stratigraphic model by varying the fault network’s geometry.

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    BibTeX Reference

    @INPROCEEDINGS{P04_Zhang,
        author = { Zhang, Ling and Caumon, Guillaume },
         title = { Perturbation of Fault Network Building on a Stratigraphic Grid. },
     booktitle = { Proc. 26th Gocad Meeting, Nancy },
          year = { 2006 },
      abstract = { Structural uncertainty on 3-dimensional reservoir models has a significant impact on the evaluation of
    hydrocarbon in place and the subsequent estimation of the reserves. It is difficult to cope with such an
    uncertainty, and hence en effective approach to edit or update existing reservoir models is needed. Such
    direct editing approaches are very appealing since they remove the need for a complete and tedious
    updating. In this paper, we apply the theory of simple constrained deformation (Scodef) to update the
    geometry of a Stratigraphic Grid (SGrid) so as to account for a set of displacement vectors, which are
    defined on a set of geological surfaces. For instance, these vectors may be available on fault’s surfaces to
    stochastically perturb the fault network’s geometry. Since it is not easy to ensure that the displacement
    vectors are consistent, we propose using equation of continuity to constrain the updated model. The result
    shows that the updated stratigraphic grid honors the displacement field as much as possible while
    preserving consistent geometric contacts between faults/horizons. This approach was implemented as a
    Gocad plugin named “EasyFault” to assist reservoir engineers in updating a stratigraphic model by
    varying the fault network’s geometry. }
    }