Petroleum geology and resources of northeastern Mexico

Abstract

Petroleum deposits (primarily gas) in northeastern Mexico occur in two main basins: the Mesozoic Sabinas basin and the Tertiary Burgos basin. About 90 gas fields are present in the Burgos basin. Production is from Eocene and Oligocene nearshore marine and deltaic sandstone reservoirs. Most of the fields are small to medium in size on faulted anticlinal or domal structures, some of which may be related to deep-seated salt intrusion. Cumulative production from these fields is about 4 tcf gas and 100 million bbl condensate and oil. Since 1975, about 10 gas discoveries, some with large initial production rates, have been discovered in Jurassic sandstone and Cretaceous carbonate reservoirs in the Sabinas basin and adjacent platform areas. Sedimentary cover of Jurassic and Cretaceous rocks in the Sabinas and adjacent Parras basins ranges from about 1550 m (5000 ft) to 9000 m (30,000 ft) thick. The Sabinas basin contains many elongate northwest- or west-trending asymmetric and overturned Laramide anticlines, most of which have not been drilled. Some of these structures may be related to movement of Jurassic salt or gypsum. The thick Cretaceous clastic section in the Parras basin is tightly folded and faulted. The potential for undiscovered petroleum in the Burgos more » basin is probably low because of previous exploration intensity at shallow to intermediate depths and lack of adequate reservoirs in the deeper beds. Success ratio in the Sabinas basin has been relatively high, and the potential for additional gas reserves may be good. The thick, folded and thrust-faulted Upper Cretaceous continental and marine clastic section in the Parras basin is unexplored but should have good potential for both biogenic and thermal gas accumulations. « less