Tectonic evolution and hydrocarbon potential in northern area of the South Yellow Sea

Abstract

The northern area of the South Yellow Sea, located in the offshore region of China, resulted from the continental-continental collision orogeny during the Mesozoic and can be divided into four stages in terms of tectonic evolution: (1) pre-orogenic passive continental margin stage (Z-T2); (2) foreland basin stage corresponding with the late phase of the Sulu (苏鲁) orogeny (J3-K); (3) post-orogenic intracontinental rifted basin stage (K2 t-E); and (4) regional subsidence and coverage stage (N-Q). Based on detailed investigation and study of the intracontinental rifted basin, hydrocarbon source rocks of Late Cretaceous Taizhou (泰州) Formation distributed well in the basin, and four reservoir-cap combinations as well as numerous trap structures were found. As a result, the geological conditions would be excellent for reservoir formation in the basin, and the oil resource amount is estimated at about 20×108 t, which makes the basin a major target for hydrocarbon exploration in the South Yellow Sea.