摘要
Based on the biomarker characteristics analyses of the 17 oil sands and 5 crude oils, the origin of oils found in the study area was classified into four classes. Class-Ⅰ oil distributes in Pingfangwang area and Boxing subsag, being characterized by Pr/Ph>0.8, Ph/nC18<0.6, an extremely low content of gammacerane, a relatively high content of 4-methyl steranes and diasteranes and relatively high ratios of Ts/Tm and hopanes/steranes; Class-Ⅱ oil distributes in Chunhua-Lean and Chenguanzhuang structural belt, characterized by Pr/Ph<0.6, Ph/nC18>2, a high content of gammacerane, a low content of 4-methyl steranes and diasteranes and relatively low ratios of Ts/Tm and hopanes/steranes; Class-Ⅲ oil distributes in the northern gentle slope structural belt of Qingcheng, characterized by the detection of 25-norhopanes and a middle content of gammacerane; Class-Ⅳ oil distributes in Kongdian Formation of Wangjiagang area, characterized by an absolute predominant content of C29 steranes and a high content of gammacerane.
