A Rigid Element Method for Building Structural Reservoir Models

Gautier Laurent and Guillaume Caumon and Mark Jessell and Jean-Jacques Royer. ( 2012 )
in: 13th European Conference on the Mathematics of Oil Recovery (ECMOR)

Abstract

Most current approaches for building structural reservoir models focus on geometrical aspects and consistency with seismic and well data, the difficult part being to handle complex faulted structures. Very few approaches account for the validity of a 3D geological model regarding structural compatibility. It may be done using restoration to check the kinematic and/or mechanical model consistency. This is generally performed in an a posteriori quality control step which also provides critical insights on the basin / reservoir history and on the deformation field, but requires significant modeling efforts and computing time. This paper presents a more pragmatic approach by introducing a first-order kinematic and mechanical consistency at the early stages of the structural modeling process. Because the full deformation path is generally poorly constrained, we suggest using simplified approaches to generate kinematic plausible structures and assess first-order deformations. In this type of application, the need for simplicity, efficiency and robustness is more important than physical accuracy because the modeling system must be interactive. To meet these objectives, a mechanical deformable model taken from computer graphics, has been adapted to geological problems. It consists in discretizing the space with rigid polyhedrons that are linked together by a non-linear energy, similar to the elastic mechanical energy. The optimal deformation is then obtained by minimizing the total energy with appropriate boundary conditions to honor typical subsurface data. Last, the displacement field is finally transferred to the geological objects embedded into the rigid elements. With this approach, a 3D structural model can be obtained by starting with an assumed initial geometry, and by successively modeling the tectonic events that have lead to the current structures. The underlying tectonic history of resulting models is thus explicitly controlled by the interpreter and can be used to study structural uncertainties.

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    BibTeX Reference

    @INPROCEEDINGS{Laurent2012ECMOR,
        author = { Laurent, Gautier and Caumon, Guillaume and Jessell, Mark and Royer, Jean-Jacques },
         title = { A Rigid Element Method for Building Structural Reservoir Models },
         month = { September },
     booktitle = { 13th European Conference on the Mathematics of Oil Recovery (ECMOR) },
          year = { 2012 },
       address = { Biarritz, France },
      abstract = { Most current approaches for building structural reservoir models focus on geometrical aspects and consistency with seismic and well data, the difficult part being to handle complex faulted structures. Very few approaches account for the validity of a 3D geological model regarding structural compatibility. It may be done using restoration to check the kinematic and/or mechanical model consistency. This is generally performed in an a posteriori quality control step which also provides critical insights on the basin / reservoir history and on the deformation field, but requires significant modeling efforts and computing time.
    This paper presents a more pragmatic approach by introducing a first-order kinematic and mechanical consistency at the early stages of the structural modeling process. Because the full deformation path is generally poorly constrained, we suggest using simplified approaches to generate kinematic plausible structures and assess first-order deformations. In this type of application, the need for simplicity, efficiency and robustness is more important than physical accuracy because the modeling system must be interactive. To meet these objectives, a mechanical deformable model taken from computer graphics, has been adapted to geological problems. It consists in discretizing the space with rigid polyhedrons that are linked together by a non-linear energy, similar to the elastic mechanical energy. The optimal deformation is then obtained by minimizing the total energy with appropriate boundary conditions to honor typical subsurface data. Last, the displacement field is finally transferred to the geological objects embedded into the rigid elements.
    With this approach, a 3D structural model can be obtained by starting with an assumed initial geometry, and by successively modeling the tectonic events that have lead to the current structures. The underlying tectonic history of resulting models is thus explicitly controlled by the interpreter and can be used to study structural uncertainties. }
    }