The Early Cretaceous structural features and its influence on hydrocarbon accumulation in the southern Hurenbuqi depression, Erlian Basin

The Hurenbuqi Sag, located on the Bayinbaolige uplift in the northern Erlian Basin, is a secondary depression rich in oil. In order to study the influence on hydrocarbon accumulation of the Early Cretaceous structures in the southern Hurenbuqi Sag, the geological, drilling and geophysical data has been analyzed carefully to reveal the Early Cretaceous extensional structural characteristics, differential structural deformation characteristics, tectonic evolution process, and the hydrocarbon accumulation process. The study revealed that, extensional tectonic system is the mainly composition of Early Cretaceous structure, it has controlled the three main tectonic subsidence stages, early initial tectonic subsidence, middle rapid tectonic subsidence and late slow tectonic subsidence, of the southern Hurenbuqi Sag. During the tectonic evolution, the Early Cretaceous deformation obviously controlled the development of the source rocks and hydrocarbon accumulation. This study is of great significance for analyzing the enrichment regulations of hydrocarbon and guiding the next oil and gas exploration.