HYDROCARBON GENERATION HISTORY OF UPPER PALEOZOIC SOURCE ROCKS OF JIYANG AND LINQING DEPRESSIONS, BOHAI BAY BASIN

The TSM basin model software based on analysis of basin superposition and reformation has illustrated hydrocarbon evolution of different source rocks of Upper Paleozoic in the Bohai Bay Basin.The Upper Paleozoic source rocks in the Jiyang and Linqing Depressions have reached hydrocarbon threshold before the end of Middle Triassic and are regionally stagnated by the Indosinian movement.Differences of Meso-Cenozoic basin evolution have resulted in differences of ‘secondary hydrocarbon generation' of the Upper Paleozoic source rocks in different sags,hence influencing evaluation of hydrocarbon generation potential of the Upper Paleozoic source rocks.Studies have indicated that,the Upper Paleozoic source rocks in the Jiyang Depression have experienced 2 processes of ‘secondary hydrocarbon generation' during Yanshan and early Himalayan epoch,respectively.During the early Himalayan epoch,hydrocarbon generation amount has reached the maximum and the center of hydrocarbon generation migrates at any time.As to the Dongpu Sag,‘secondary hydrocarbon generation' starts in the early Himalayan epoch and the average hydrocarbon generation intensity is high.