H. Scott Sumner¹, John H. Shinol²

(1) Spirit Energy Deepwater Exploration, Unocal Corporation, Sugar Land, TX
(2) Unocal Corporation, Sugar Land, TX

ABSTRACT: Structural Analysis of the Northwest Gulf of Mexico Deepwater Foldbelts

The Foldbelt play on the lower slope/abyssal plain of the deepwater Northwest Gulf of Mexico is an evolving trend with significant hydrocarbon potential. In order to help understand the prospectivity along the trend, which extends from the Mississippi Fan Foldbelt in Eastern Atwater Valley underneath the Sigsbee Salt Canopy to the Perdido Foldbelt in Alaminos Canyon, various techniques of structural analysis were performed. The results of the analysis were carefully integrated with related regional features and events throughout the basin as well as previous work (e.g. 2D palinspastic restorations) within the foldbelts to insure consistency and validate conclusions. The analysis relied heavily on grid manipulation of a series of regional structure maps at key horizons and included map view shortening, map view structural curvature, trend surface analysis, and paleo-structure/fetch interpretations.

At a regional scale the structural analysis demonstrated a clear linkage along salt-based decollements between downdip contractional deformation in the foldbelts and updip coeval extension associated with major Tertiary deltaic depocenters. Within the foldbelts the results of the analysis were used to help develop kinematically sound models that aid in the prediction of trap styles, trap locations, ages of deformation, magnitude and distribution of shortening, faulting and fracturing patterns, and hydrocarbon charge/fetch.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado