Stratigraphy, Structure, and Hydrocarbon Potential of the Northern Bolivia Sub-Andean Thrust Belt (Beni Basin)

Abstract

Abstract Despite the presence of Late Devonian world-class source rock and several noncommercial discoveries, the northern Bolivian Beni Basin and its associated fold-and-thrust belt is one of the most underexplored sub-Andean basins in South America. To address the petroleum potential of the region, we carried out an integrated study of the tectono-stratigraphic settings of the northern Bolivian sub-Andes. We provide two balanced cross-sections, five stratigraphic correlations, and nine distribution maps of key Paleozoic to Cenozoic stratigraphic units. The revised distribution maps show that the Devonian and Carboniferous–Permian source-rocks are present over most of the sub-Andean fold-and-thrust belt (SAZ), whereas the Silurian and Late Cretaceous source rocks are limited to the southern or northern segments of the SAZ. On the other hand, potential Jurassic, Late Cretaceous, and Late Paleogene to Neogene sandstone reservoirs show global widespread distribution. Tentative sequential restorations of the structural cross-sections are provided and suggest a main Miocene shortening period followed by a Pliocene-Pleistocene period of vertical uplift of the whole SAZ. Based on both the stratigraphic and structural review of the study area, the potential plays of the northern Bolivian sub-Andes are discussed. The main exploration risks are related to the timing and presence of the interpreted structures in depth.