Abstract:

Oil reservoir in the Qijiawu area of the Huanghua Depression is dolomitic limestone in the lower Shayi Member of Shahejie Formation of Eogene.The crude oil of the Qijiawu area is characterized by high density, high paraffin, high content of sulfide and high content in asphalt. The crude oil shows distinct geochemical characteristics that are high normal paraffin hydrocarbons with distinct parity preponderance, isoprenoid alkanes with phytane preponderance and gonane components with evident C₂₇ααα sterane preponderance. The mud shale in Shayi Member has developed more gammaceranealkane and undeveloped tricyclic terpane. These characteristics indicate the crude oil of the Qijiawu area belongs to immaturity or lower maturity crude oil. According to the results of crossing the parameters（gammacerane-alkane/C₃₀ hopane and C₂₉ nor-hopane/C₃₀ hopane，gammacerane-alkane/C₃₀ hopane and Pr/Ph）of the crude oil with the parameters of mud shale in lower Shayi Member, we draw a conclusion that the mud shale of lower Shayi Member of Shahejie Formation is the oil source rock in the project area.

Key words: Huanghua Depression, geochemical characteristics, oil-source correlation