ABSTRACT: Analysis of Physical Models Using X-Ray Tomography, with Application to Seismic Interpretation of Basin Inversion

LETOUZEY, JEAN, BERNARD COLLETTA, ROLAND VIALLY, and PASCAL BALE, Institut Francais du Petrole, Rueil-Malmaison, France, and JEAN-CLAUDE CHERMETTE, Total, Paris La Defense, France

Tectonic inversion is a major factor in the prospectivity of many hydrocarbon provinces. Such structures are widely documented from many basins around the world. From seismic sections and outcrops, these structures generally are controlled by strike-slip or dip-slip reactivation of extensional faults. During the inversion process, rocks of the hanging walls of the main pre-existing normal faults are folded and uplifted. Physical analog modeling has been used to simulate the kinematic and geometric evolution of inversion structures. Analysis of the deformed models is made using squeeze-box techniques and the x-ray computer tomography method. This nondestructive method was used to visualize the internal views of the model and the 2D or 3D structure at any stage of deformation. Fault zon s are perfectly imaged by computer tomography as dilating zones in granular material. Structure-contour maps from appropriate horizons of physical models can be digitized and used to generate synthetic seismic sections, which can provide a basis for prediction and interpretation of complex deformed areas. Numerous experiments were undertaken to investigate how the models were influenced by different parameters, the orientations and geometries of the pre-existing faults, the rates of reverse and oblique displacement, and the influence of ductile layers (salt analog). The results of these experiments have been compared with seismic images or field examples from northwest Europe, North Africa, South America, and Indonesia.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)