3-D Reversible
Approach for
Gibergues, Natacha, Muriel Thibaut, Institut Francais du Petrole, Rueil-Malmaison Cedex, France
The 3D coupled backward
and forward deformation of basin models
can be treated with a mechanical or a kinematic approach. Because of the
difficulty met with the mechanical approach we adopted a kinematic approach
which is supposed to be sufficiently representative of the natural processes.
The model proposed here considers two mechanisms of deformation:
the vertical shear and the flexural slip. For both, we ensure the preservation
of the thickness of the layers, and of area of the neutral surface. The
methodology is 3D, reversible and simple to implement.
The model was first validated in 2.5D on a cylindrical basin,
then on a 3D model with a lateral variation for the strike of the ramp from 10°
to 25°, and, finally, on a model with a curb ramp. Different mechanisms of
deformation may be applied to each layer of the basin and layers are
independent one by one. For different increments of displacement (500m to 2km),
the models present a shape with a coherent geometry.
The great
simplicity of the hypothesis allows a easy handling of more complex models.