摘要
Gaoqing-Pingfangwang buried hill belt is the most favorable buried hill belt in Dongying Depression.The reservoir type and the oil source are very complex in the study area.Based on the geochemical characteristics analyses of crude oil,the origins of the oils found in the study area are classified into three classes.ClassⅠoil is characterized by low ratio of Pr/Ph and high content of gammacerane,which shows that the oil may come from the upper section of the 4th member of Shahejie Formation.Class Ⅱ oil has a high ratio of Pr/Ph and low content of gammacerane,which shows that the oil may come from the lower section of the 3rd member of Shahejie Formation.Class Ⅲ oil has the mixed characteristics of ClassⅠand ClassⅡ.It is found out that the oils of Pingfangwang,Pingnan and Xiaoying Oilfields mainly source from the lower section of the 3rd member of Shahejie Formation.The oil sources of Gaoqing Oilfield are complex,in which the oils of Tertiary reservoir mainly come from the lower section of the 3rd member of Shahejie Formation and the oils of Mesozoic reservoir mainly source from the upper section of the 4th member of Shahejie Formation,locally having the mixed oil source characteristics.