3-D
Lepage, François1, Thomas
Laverne1, Frantz Maerten1, David Desmarest1,
Emmanuel Quetelard1, Michael Palomas1, Laurent Maerten1
(1) IGEOSS,
For many years structural geologists have
been using computer tools to construct balanced 2D and 3D structural models.
The tools available to restore geological structures are based on a variety of
geometric techniques, which aim at reproducing natural deformation, constrained
by assumptions such as preservation of area or volume, minimization of
deformation, minimization of changes in segment length. While the challenge of
restoring structural models could be attributed to inadequate data, hardware,
and software in the past, the challenge today is to integrate a complete
mechanics into the methodology. Indeed, it is established that rock deformation
is a physical process that involves parameters such as the initial geometry,
the distribution of mass, rock properties, and the constitutive laws that
govern the deformation. Therefore, we propose the next generation tool that
allows elastically-based 3-D volume restoration. The method, when realistically
well constrained, honors the fundamental physical laws that govern deformation,
that are (i) conservation of mass, (ii) conservation of momentum and (iii)
conservation of energy. Mechanically-based decompaction as been implemented
based on both the heterogeneous rock properties assigned to the model and the compaction
rule chosen. This innovation permits fault slip during decompaction and does
not unrealistically deform the model. We describe the complete workflow from
interpreted horizons and faults, to 3-D model building, to model setup, to
volume restoration. We offer examples to illustrate the applications in the oil
and gas industry for the characterization of structurally complex reservoirs.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California