Multi-Stage Basin Development and Hydrocarbon Accumulations: A Review of the Sichuan Basin at Eastern Margin of the Tibetan Plateau

Abstract

Sichuan Basin is one of the uppermost petroliferous basins in China. It experienced three evolutionary phases which were marine carbonate platform (Ediacaran to Late Triassic), Indosinian-Yanshanian orogeny foreland basin (Late Triassic to Late Cretaceous) and uplift and tectonic modification (Late Cretaceous to Quaternary). The present-day tectonics of the Sichuan Basin and its periphery are characterized by three basic elements which are topography, basement type and surface structure, and two settings (plate margin and interior). Therefore, be subdivided into five units which have different structure and tectonic history. The basin contains five different sets of source rocks with thickness up to 2 500 m. These source rocks were well preserved due to the presence of Middel–Lower Triassic evaporites (>∼200 m) and thick terrestrial sediments filling in the Indosinian-Yanshanian foreland basin (>3 000 m). The uplift and erosion since Late Cretaceous has significant influence on cross-strata migration and accumulation of oil and gas. The multi-phase evolution of the basin and its superimposed tectonic elements, good petroleum geologic conditions and diverse petroleum systems reveal its bright exploration prospects.

Keywords

multi-stage basin / hydrocarbon accumulation / Sichuan Basin / eastern margin of the Tibetan Plateau

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