Abstract: Implications of 3D Structural Restoration in Complex Deformation Zone: Example of an Albian Rafted Structure in the Congo Basin

Calassou, S. and X. Legrand - Elf; D. Rouby - Geosciences Rennes, France; D. Janodet - Elf Congo; J. M. Flament and H. Lecanu - Elf

The understanding of the 3D motion associated with an extensional deformation is a key of the 3D structural and geometrical coherency. The example results from the break-up (Albo-Cenomanian and Tertiary) of the Lower Albian carbonate platform. We used 3D restoration to establish paleogeographic maps taking into account the relative position of wells intersections with horizons at deposition time.

To do this, the 3D displacement is defined with two methods of structural restoration, between current and Upper and Lower Albian state.

The first restoration was performed on a cylindrical part of the 3D model, with several 2D sections (Geosec). Projections of wells on sections were unfolded and unfaulted. For each step of restoration, 3D structural models were rebuilt from sections.

The second restoration was performed on the whole 3D model. We unfolded and unfaulted the 3D surface of the Lower Albian (CXlla).

We discuss the results of these two methods, the 3D displacement of wells intersections and the implications of these 3D displacements on the realization of paleogeographic maps.

AAPG Search and Discovery Article #90933©1998 ABGP/AAPG International Conference and Exhibition, Rio de Janeiro, Brazil