Taylor E. Blood¹, George H. Hasseltine², Matthew C. Frye², Rex F. Poling²

(1) Mineral Management Service, USDOI, New Orleans, LA
(2) Mineral Management Service, New Orleans, LA

ABSTRACT: Hydrobcarbon Potential Of The Lower Miocene And Older Tertiary Deepwater Strata, Northern Gulf Of Mexico, With Special Emphasis On Shelf Plays Deeper Than 20,000 Feet Subsea Or Below Salt In The Slope

Recent discoveries in the Mississippi Fan and Perdido Fold Belts have been identified in age as being lower Miocene and older Tertiary on the basis of seismic interpretation and available paleontologic reports. Unlike other Tertiary reservoirs, the new discoveries are in strata that have been deformed after deposition. The Cenozoic Province is divided into two groups of structural styles. The first group is the syn-depositional deformation styles and includes allochthonous salt or shale and growth fault related structures. The second group is the post-depositional deformation styles and contains not only the fold belts but also other structures related to autochthonous salt movement. Allochthonous salt or shale separates the post-depositional styles group from the syn-depositional styles group. The plays and prospects in the post-depositional styles group are largely untested and maybe twice the field size of the first group.

 Sediments in this post depositional styles group were deposited in lower fans or the lowest portion of midfans that approach the areal size of the modern Mississippi fan. The geographic location and extent of potential reservoir quality sediments varied through time, and shifted seaward and to the east during the Tertiary.

 Inferences drawn from mapping in selected areas suggest that the structural densities of the post-depositional deformation structures are half that of the syn-depositional province. Structures with spill sizes of 100,000 acres are anticipated based on size distributions from mapped structures.

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