Petroleum accumulation characteristics and favorable exploration area prediction in San Jorge Basin, Argentina

The San Jorge Basin is one of the most important prolific petroliferous basins in Argentina. It experienced four tectonic evolution stages and a double-layer structure was formed, which is composed of a rift system formed in the Triassic-Early Cretaceous and a depression system formed in the Early Cretaceous-Cenozoic. Based on the study of regional tectonic and depositional evolution, integrated with the latest drilling data, hydrocarbon accumulation characteristics and controlling factors were studied. The Upper Jurassic-Neocomian Group of the Lower Cretaceous and lacustrine shale in the D-129 Formation of the Lower Cretaceous are the main source rocks. The Cretaceous Chubut Group sandstone is the main reservoir. The Chubut Group lacustrine mud shale is the most important cap. Various trap types were formed due to rifting, depression and the Andean orogeny. Hydrocarbon accumulations were controlled by the distribution of mature source rocks and fault systems. The size of oil and gas pools was controlled by fluvial facies sandstones. Oil and gas distribute circularly around the basin center. The favourable exploration areas for the upper part of the Cretaceous Chubut Group sandstone, the Cretaceous D-129 Formation and the Upper Jurassic-Lower Cretaceous Neocomian Group were predicted.