Forward Modeling of {3D} Geological Structures With Rigid Elements Method

Gautier Laurent and Guillaume Caumon and Mark Jessell. ( 2012 )
in: Proc. 32nd Gocad Meeting

Abstract

Most current approaches to structural modeling rely on the geometrical compatibility with seismic and well data. Among them, certain thorough studies also assess the kinematical and mechanical consistency, but this is generally performed in an a posteriori quality control step, for example using restoration. Such post-process also provides critical insights on the basin or reservoir history and on the deformation field, but it requires significant modeling efforts and computing time. This paper presents a forward modeling approach aiming at introducing first-order kinematical and mechanical consistency at the early stage of the structural modeling process. In this type of application, several tectonic scenarios have to be rapidly tested, which calls for tools being simple, efficient and robust enough to be interactive or used in an automated process. On the other hand, the full deformation path is generally poorly constrained. This brings to light that interactiveness may be more important than physical accuracy. To meet these requirements, we suggest that a simplified mechanical deformable model should be used to generate kinematically plausible structures and assess first-order deformations. In this paper, a rigid element deformable model is used. It consists in discretizing the space with rigid polyhedrons that are linked together by a non-linear energy similar to elastic mechanical energy. Boundary conditions are set on certain elements in order to honor typical subsurface data. The optimal deformation is obtained by minimizing the total energy and the displacement field is finally transferred to the geological objects embedded into the rigid elements. The forward modeling approach produces 3D structural models by successively applying the effects of tectonic events on an assumed initial geometry until the observations of the current structures are honored. The underlying tectonic history of resulting models is thus explicitly controlled by the interpreter and can be used to study structural uncertainties.

Download / Links

BibTeX Reference

@inproceedings{RUNKJRM16,
 abstract = { Most current approaches to structural modeling rely on the geometrical compatibility with seismic and well data. Among them, certain thorough studies also assess the kinematical and mechanical consistency, but this is generally performed in an a posteriori quality control step, for example using restoration. Such post-process also provides critical insights on the basin or reservoir history and on the deformation field, but it requires significant modeling efforts and computing time.
This paper presents a forward modeling approach aiming at introducing first-order kinematical and mechanical consistency at the early stage of the structural modeling process. In this type of application, several tectonic scenarios have to be rapidly tested, which calls for tools being simple, efficient and robust enough to be interactive or used in an automated process. On the other hand, the full deformation path is generally poorly constrained. This brings to light that interactiveness may be more important than physical accuracy. To meet these requirements, we suggest that a simplified mechanical deformable model should be used to generate kinematically plausible structures and assess first-order deformations. In this paper, a rigid element deformable model is used. It consists in discretizing the space with rigid polyhedrons that are linked together by a non-linear energy similar to elastic mechanical energy. Boundary conditions are set on certain elements in order to honor typical subsurface data. The optimal deformation is obtained by minimizing the total energy and the displacement field is finally transferred to the geological objects embedded into the rigid elements.
The forward modeling approach produces 3D structural models by successively applying the effects of tectonic events on an assumed initial geometry until the observations of the current structures are honored. The underlying tectonic history of resulting models is thus explicitly controlled by the interpreter and can be used to study structural uncertainties. },
 author = { Laurent, Gautier AND Caumon, Guillaume AND Jessell, Mark },
 booktitle = { Proc. 32nd Gocad Meeting },
 title = { Forward Modeling of {3D} Geological Structures With Rigid Elements Method },
 year = { 2012 }
}