THERMAL EVOLUTION DEGREE AND ITS HYDROCARBON GEOLOGICAL IMPLICATIONS OF THE MAIN STRATA SERIES IN THE SOUTHERN NORTH CHINA CRATON

The southern North China Craton is one of the area in China experienced decades of exploration while no industrial reservoir has been found.To objectively evaluate the thermal status and its evolution processes is one of the key in this area.Based on more than 600 suits of Ro data and other geothermometer data,the thermal evolution characteristics and its hydrocarbon geological implications of the Paleogene,Mesozoic and Upper Paleozoic are discussed in this paper.The values of Ro from the Paleogene System are higher in the north and lower in the south.Most of the organic matter in Zhoukou Depression is immature and low mature,in contrast with the mature status in Jiyuan and Zhongmou Sags of Kaifeng Depression.Thermal evolution degree of the Mesozoic is higher than the one of the Paleogene in general.The Lower Cretaceous in Tanzhuang-Shenqiu Sags and the Trassic in Jiyuan sag are now in the peak liquid hydrocarbon-generating stage.The thermal evolution degree of the Upper Paleozoic shows strong heterogeneity in space,ranging from immature to overmature,and decreased from north to south.Taikang Uplift and adjacent northern Luyi Sag are inferred to well prospective area for normal nature gas or coal bed methane exploration.Some areas such as the mid-south part of Niqiuji Sag,the east part of Tanzhuang-Shenqiu Sags and the south of Xiangcheng Sag in Zhoukou Depression have the potential of secondary hydrocarbon generation.