STUDY ON QUANTITATIVE IDENTIFICATION MODEL OF MIXED OILS FROM SUQIAO -WENAN AREA IN JIZHONG DEPRESSION PART I:GENETIC-TYPES AND GEOCHEMICAL CHARACTERISTICS OF CRUDE OILS
冀中坳陷苏桥-文安油气田混源油定量识别模式研究(一):原油成因分类及地球化学特征

Geochemical characteristics of crude oils of Suqiao-Wenan and Chaheji area in Jizhong depression have been analyzed and studied systematically by various of geochemical techniques and methods for molecular information, the results suggest these crude oils can be fall into three groups of coal-formed oil, Paleocene Tertiary oil and mixed oil. The characteristics of coal-formed oil in Suqiao-Wenan are that saturated hydrocarbons amounts to about 80% of the bulk composition and Pristane/Phytane ratios more than 2.0, the contents of tricyclic terpanes with low carbon number(C_(19)-C_(21)) and C_(24) tetracyclic terpane are abundant, but gammacerane indices is low. In contrast, characteristics of Paleocene Tertiary oils in Chaheji area in Jizhong depression are that pristane/phytane ratio is low, contents of tricyclic terpanes with higher carbon numbers(C_(23)-C_(24)) are abundant, but the gammacerane amount is abundant. However, geochemical characteristics of mixed oils from Suqiao-Wenan area in Jizhong depression are between coal-formed oils in Suqiao-Wenan area and Paleocene Tertiary oils in Chaheji area.