Tectonic evolution and hydrocarbon accumulation model for marine strata in Jianghan Basin

After the forming of an entire metamorphosed basement during the Late Proterozoic,Jianghan Basin experienced four tectonic cycles:Caledonian,Hercian-Early Indosinian,Late Indosinian-Early Yanshanian and Late Yanshanian-Himalayian.Because these cycles,3 kinds of basin models formed which were the open-sea basin of platform type before the Indosinian,the foreland lake basin during Indosinian and the intracontinental fault-depression salt lake since Yanshanian.The control and destructive effect of the four tectonic cycles on the hydrocarbon accumulation are analyzed.According to the time of hydrocarbon generation and whether hydrocarbon break through original closed system from the first accumulation to finally reservoir forming,the hydrocarbon accumulation for marine strata in Jianghan Basin is divided into primary,secondary and regenerated accumulation models,and the favorable prospect areas are analyzed.