Juan Antonio Cuevas¹, Benjamin Marquez¹, Juan Rogelio Roman¹, Jaime Patiño¹, Daniel Velez¹, Mario Aranda¹

(1) Pemex Exploracion y Produccion, Villahermosa, Tabasco, Mexico

ABSTRACT: Petroleum Systems of the Southwestern Gulf of Mexico

Reserves of 648 mmboe at the southwestern Gulf of Mexico (SGM) were discovered through 65 wildcats in Mesozoic reservoirs allocated in 16 fields. Documentation of Petroleum Systems (PS) based on recently acquired 2D, 3D seismic data, and seafloor cores is currently in progress.

SGM is a Neogene unstable continental margin, which presents a variety of PS related to three N-S structural provinces associated with gravity W-E driven tectonic setting, which are: 1) Quetzalcoatl Extensional Fault-Belt (QEFB); 2) Matamoros Structural Salt-Complex (MSSC); and 3) Mexican Ridges Contractional Fold-Belt (MRCFB).

The western province of the QEFB, along the continental platform, presents growth Tertiary rollovers detached in lower Neogene levels. Potential plays could be charged by source-rocks (SR) of two PS. Biomarkers from oils indicate that (SR) of the Jurassic and Cretaceous oil-reservoirs, at the QEFB foot-wall, are marine carbonates and shales of Upper Jurassic (UPJ) and Tertiary ages respectively.

The eastern domain of the MRCFB, at deep waters of the SGM, includes potential plays of Pliocene and Miocene turbidite deposits allocated in elongated anticlines in the Tertiary and Upper Mesozoic piles. Two hypothetical PS are evidenced by biomarkers and indicate the dominant presence of (UPJ) shally carbonate and rarely Tertiary siliciclastic (SR). The central MSSC, restricted to the northern part, includes a variety of potential plays of Pliocene and Miocene turbidites in hallokinesis-structures and hypothetical PS charge, similar to those present at Texas Gulf Coast. The three structural provinces are highly prospective for gas and light-oil trapped in Neogene reservoirs.

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