Regional geologic and tectonic setting of the Maracaibo supergiant basin, western Venezuela

Abstract

This special issue contains eight topical studies on the structure, stratigraphy, and petroleum system of the Maracaibo Basin, a supergiant basin in western Venezuela. Most of the work reported in this special issue is the product of thesis-related research by master's and doctoral-level students at the Jackson School of Geosciences of the University of Texas at Austin during a collaborative relationship with the Venezuelan national oil company, Petrleos de Venezuela, S. A., that was initiated in the late 1980s. This introductory article presents a regional overview of the tectonic setting and geology of the Maracaibo Basin. With a cumulative oil production of more than 30 billion bbl, since the first production well was drilled in 1914 and estimated ultimate oil reserves of more than 44 billion bbl, the Maracaibo Basin is the most prolific hydrocarbon basin in the Western Hemisphere. Unlike the more extensive Gulf of Mexico giant hydrocarbon provinces, the relatively small size (50,000 km2; 19,305 mi2), relative simplicity in its structure and stratigraphy, and wealth of surface and subsurface data make the Maracaibo Basin an attractive target for basinwide synthesis. The objective of this article is to present a regional compilation of two-dimensional (2-D) and three-dimensional (3-D) seismic data, wells, and outcrop data at a basinwide scale to reveal the basin's 3-D structure and stratigraphy. Moreover, we show regional tectonic reconstructions, regional geologic maps, and basin subsidence history to better constrain four major tectonic events that affected the basin and that are critical for understanding the timing and distribution of major unconformities and clastic wedges, the distribution of the reservoir rocks, the reactivation of older fault trends, and the timing of maturation for underlying source rocks. Many of these topics are discussed in greater detail in the other eight articles in this special issue.