Hydrocarbon generation characteristics of source rocks of Kong-2 Member in Weibei Sag and its control on the distribution of oil and gas.

Small and complex petroliferous sags have gradually become one of the key areas of succession in the mature exploration areas. Taking Weibei Sag of Bohai Bay Basin as a case, the geological and geochemical characteristics of the source rocks of Kong-2 Member was analyzed, the basin simulation method was used to determine the main hydrocarbon generation area, and investigate its control on the distribution and enrichment of hydrocarbon. The results show that the abundance, type, and maturity of organic matter have a large spatial variation range, and the upper and middle sub-members of Kong-2 Member in the study area are the most important source rocks. The periods of the late deposition of the Sha-4 Member and the structural uplift are the main hydrocarbon generation periods. The Migration of hydrocarbon-generating center from subsidence center to southeast direction, resulting a large amount of hydrocarbon-generating in the slope zone, leading to the main migration and accumulation direction of hydrocarbon in the Zaohu Faulted Nose Belt. Therefore, the hydrocarbon were enriched in the southeast and poor in the central and western regions, so the next favorable exploration areas include Zaohu Faulted Nose Belt, Eastern Wacheng Step Belt, and Southern Northern Sag Belt. [ABSTRACT FROM AUTHOR]