Abstract

The last stratigraphic and structural assessments of the Ene Basin (Peru, Block 108) defined a prospective petroleum system. Over the past 50 years, this basin has been studied by a number of oil companies and scientists. Surface geology and ∼750 km (∼460 mi) of 2-D seismic sections have provided most of the information, since no exploratory well has been drilled to date. The presence of well-known source and reservoir rocks, several hydrocarbon manifestations at the surface, and large anticlines define two main plays, currently making the Ene Basin the frontier basin with greatest exploration potential in Peru. The Ene Basin is part of the Peruvian sub-Andean system developed ∼300 km (185 mi) east from the Pacific trench, cratonward of the Eastern Andes. As shown by their common stratigraphy, the evolution of this intermontane basin was related to the southern Ucayali and Camisea Basins until they were separated by the uplift of the Otishi and Shira basement blocks during the Andean orogeny. The Ene Basin is divided into two main structural domains based on their different mechanical stratigraphy that imprinted contrasting structural styles: (1) the northwestern domain displays marked stratigraphic similarities with the northerly Pachitea Sub-Basin, being characterized by a thick Mesozoic succession, salt domes, and a deformation style related to the inversion of the southeastern rim of the Triassic–Jurassic Pucará extensional basin; (2) the southeastern domain is affected by thin-skinned structural deformation and exhibits a similar stratigraphy than the easterly Ucayali Basin, characterized by thin to absent pre-Cretaceous Mesozoic units and variable Cretaceous–Paleozoic unconformable relationships. Contrasting structural styles and the uneven distribution of shortening are related to differing degrees of interaction between the two main structural domains and the surrounding basement blocks.