NEW EXPLORATION PROGRESS AND HYDROCARBON POTENTIAL OF THE MESO-PALEOZOIC SYSTEMS IN THE SOUTH YELLOW SEA

The main targets of oil and gas exploration in the South Yellow Sea Basin have shifted from the Cenozoic to the Meso-Paleozoic in 2005. In this paper, we presented an integration of data of regional geology, geophysics, geochemistry, and drilling data collected, and a discussion on the new progress of stratigraphic sequences, sedimentary facies, depositional systems, residual basin characteristics and petroleum geological conditions and other aspects of the Mesozoic and the Paleozoic in recent years in the South Yellow Sea Basin. The Meso-Paleozoic residual deposits can be divided into three structural layers:the lower (the Sinian-Ordovician), the middle (the Silurian) and the upper (the Devonian-Triassic). Basins in Mesozoic and Paleozoic were marine-oriented and characterized by carbonate platform-slope-basin depositional systems, carbonate ramp-basin depositional system and transitional deltaic systems. The Meso-Paleozoic systems have four sets of source rocks in lower Cambrian, Upper Ordovician-lower Silurian, lower Permian and upper Permian respectively, of which the source rocks in the Qixia Formation, Longtan Formation and Dalong Formation of Permian are the most favorable. The main Mesozoic-Paleozoic reservoirs are carbonate rocks, followed by clastic rocks. Comprehensive analysis reveals that the most favorable exploration area of the Mesozoic and Paleozoic hydrocarbon in the South Yellow Sea Basin is in the Central uplift area.