AAPG Bulletin, V. 83 (1999), No. 4 (April 1999), P. 578-612.

The Perdido Fold Belt, Northwestern Deep Gulf of Mexico, Part 2: Seismic Stratigraphy and Petroleum Systems¹

Joseph C. Fiduk,² Paul Weimer,² Bruce D. Trudgill,² Mark G. Rowan,² Peter E. Gale,³ Ronald L. Phair,⁴ Bryant E. Korn,⁴ Geneva R. Roberts,⁵ William T. Gafford,⁵ Roger S. Lowe,⁶ and Tomas A. Queffelec⁶
 

©Copyright 1999.  The American Association of Petroleum Geologists.  All Rights Reserved
 

¹Manuscript received January 21, 1998; revised manuscript received August 27, 1998; final acceptance October 3, 1998.
²Energy and Minerals Applied Research Center, Department of Geological Sciences, Campus Box 399, University of Colorado, Boulder, Colorado 80309-0399; e-mail: carl@emarc.colorado.edu
³Shell Deep Water Business Unit, P.O. Box 61993, New Orleans, Louisiana 70160. Present address: British-Borneo Exploration, Inc., 1201 Louisiana, Suite 3500, Houston, Texas 77002.
⁴Texaco Exploration and Production Inc., P.O. Box 60252, New Orleans, Louisiana 70160.
⁵Amoco Production Company., P.O. Box 3092, Houston, Texas 77253.
⁶Mobil Exploration & Producing U.S. Inc., 1250 Poydras, New Orleans, Louisiana 70113.

We would first like to thank our AAPG reviewers A. W. Bally, J. Feng, and elected editor N. F. Hurley for their helpful comments that improved the manuscript. We thank Shell Offshore Inc., Texaco Exploration and Production Inc., Amoco Production Company, and Mobil Exploration & Producing U.S. Inc. for their financial support and permission to publish the results of this research. Additional seismic data were supplied by Western Geophysical and Richard Buffler at the University of Texas Institute for Geophysics. We are grateful to Alan Herring at EDCON Inc. for allowing us to view and incorporate regional gravity data into our interpretations. We extend our thanks to Terry Blair for his help finding references in the Mexican geologic literature. We also thank Cogniseis Development Inc. (now Paradigm Geophysical), Landmark Graphics Corporation, and Badleys for software support. Special thanks are extended to Barry McBride, Nancy Hunter, and Platte River Associates, Inc., for their help in running the BasinMod^® program. Finally, we thank David Knapp for his endless supply of help in the EMARC lab. 
 

ABSTRACT

Analysis of 12,000 km of two-dimensional multifold seismic data shows a thick succession of Mesozoic and Cenozoic deep-water strata in the Perdido fold belt, northwestern deep Gulf of Mexico. These strata differ in seismic facies, areal distribution, and reservoir/petroleum potential. Mesozoic strata are interpreted as dominantly fine-grained carbonates and show minor thickness changes. Cenozoic strata are largely mud-dominated siliciclastic turbidite deposits and vary considerably in thickness across the fold belt. These changes reflect the shifting position of Cenozoic marginal-marine depocenters.

Mesozoic reservoir potential consists of fractured Upper Jurassic and Cretaceous deep-water carbonates. Cenozoic reservoir potential consists of siliciclastic deep-water turbidites. Portions of the Paleocene to lower Eocene strata are sand-prone and are the downdip equivalents of the lower and upper Wilcox shallow-marine depocenters. These strata are all incorporated within the folds. Lower to middle Oligocene strata coincide with the main growth phase of the fold belt. Potentially sand-prone middle Oligocene to lower Miocene strata are the downdip equivalents of the Vicksburg (early Oligocene), Frio (Oligocene), and Oakville (early Miocene) shallow-water depocenters. These strata form potential stratigraphic traps against the folds.

Mesozoic source potential was modeled assuming Oxfordian, Tithonian, Barremian, and Turonian source beds. One-dimensional thermal maturation modeling showed these sources reached peak oil generation between 51 and 39 Ma, 39 and 8 Ma, 32 and 2 Ma, and 26 and 8 Ma, respectively. Cenozoic source potential was modeled using an Eocene source. Modeling showed this source reached only early oil generation in the basinward half of the fold belt. Thermal maturation was reached by source beds at different times in different locations due to changes in burial depth, amount of structural uplift, and underlying thickness of autochthonous salt. All of these factors indicate that seal and reservoir carry significant risk, but that the potential exists for large petroleum accumulations.