The exploration and development of the Xihu Sag in the East China Sea Basin are mainly concentrated in the Eocene Pinghu Formation and the Oligocene Huagang Formation.With the increasingly severe situation of hydrocarbon exploration,it is urgent to deepen and expand the exploration direction to the Lower Eocene Baoshi Formation.Based on the sedimentary environment and paleontological characteristics of the Baoshi Formation and utilizing the existing data,a comprehensive evaluation of the abundance,type,maturity,and carbon isotopes of the organic matter in the hydrocarbon source rocks of the Baoshi Formation is carried out to explore the distribution and exploration potentials of the high-quality hydrocarbon source rocks of the Baoshi Formation in the study area.The study indicates that the Baoshi Formation in the YZ-1 well area is a restricted marine sedimentary environment.The organic matter abundance of the hydrocarbon source rocks in the Baoshi Formation is medium.The maceral of organic matter is mainly vitrinite and inertinite,which is mainly humic type(type III).Carbon isotope analysis of the group components shows that mixed sources in terms of parent material type characterize the hydrocarbon source rocks of the Baoshi Formation.The organic matter maturity of the existing source rock samples in the upper part of the Baoshi Formation is relatively low,generally lower than 0.8%,and it is presumed that the maturity of the lower part is higher.Comprehensive analysis shows that there may be high-quality hydrocarbon source rocks of the Baoshi Formation in the three deep depression areas in the north-central part of the Xihu Sag,which can be used as an idea for the next step of oil and gas exploration.
sedimentary environmentabundance of organic mattermixed sourcecharacteristics of source rocksBaoshi Formation
NETL
NSTL
万方数据
