Modeling Giant Structural Traps in the Perdido Fold Belt, Gulf of Mexico

Bruce D. Trudgill, Mark G. Rowan, Joseph C. Fiduk, Paul Weimer, Peter E. Gale, Bryant E. Korn, Ronald L. Phair, William T. Gafford, Geneva R. Roberts, James B. Dischinger, and Kevin Putney

The Perdido fold belt in the Alaminos Canyon OCS protraction area contains some of the largest, untested structural traps within US waters. The overall structural geometry of the fold belt is relatively simple, although individual structures show a complex array of structural styles. Previous interpretations have modeled these structures as either growth fault-bend folds or salt-cored detachment folds. Structural interpretation of high quality 2D seismic data, combined with detailed analysis of the growth strata and both 2D and 3D restorations provides the necessary control to model these structures accurately.

The 2D restorations show that the observed geometries of then folds and their growth strata are compatible with a detachment fold model. The folds developed due to gravitational gliding above, and at the basinward limit of, a thick layer of autochthonous salt. The growth strata indicate a relatively short period of folding and uplift during the late Oligocene to early Miocene.

3D restorations of an anomalous, dome-shaped structure suggest it formed due to interference between an elongate, NE-SW trending anticline and a NW-SE trending basement feature. The real test of our restorations, and the viability of the Perdido fold belt as a petroleum province remains to be tested by exploratory drilling.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California