Molecular geochemical characteristics and origin of continental oils in Yingmaili area of Tabei uplift,Tarim Basin
Although important breakthroughs have been made in continental oil and gas in Yingmaili area of Tabei Uplift,there are still disputes over the genetic type and oil source of the oil and gas.According to the molecular geochemical and isotopic parameters,the genetic type and source of crude oil are clarified through oil-source correlation study.The research results show that the crude oil in the study area is mainly divided into two types.Class Ⅰ crude oil is widely distributed in areas other than YM21 and YM46 wells.The tricyclic terpenes of class Ⅰ crude oil mostly have C21 as the main peak,the content of C24 tetracyclic terpanes is relatively high,the content of C24Tet/C26TT is between 1.0 and 2.0,and the content of diahopanes is relatively low.These features of biomarkers are similar to those of the source rocks of Huangshanjie Formation in Kuqa Depression.Class Ⅱ crude oils are distributed in YM21 and YM46 wells.The tricyclic terpenes in crude oils usually take C19 as the main peak,and the abundance of C24 tetracyclic terpenes is significantly higher than that of class Ⅰ crude oils.The C24Tet/C26TT ratio is about 3,C30 diahopanes/C30 hopanes is about 0.5.This kind of crude oil is similar to the biomarker characteristics of source rocks of the Qiakemake Formation.In addition,class Ⅰ crude oil has relatively light carbon isotope value,which is mainly distributed in the range of-29.6‰～-28.2‰.Class Ⅱ crude oil has relatively heavy carbon isotope value,and its isotope value is about-27‰.The isotope characteristics also reveal that the class Ⅰ crude oil and the class Ⅱ crude oil come from the source rocks of Huangshanjie Formation and Qiakmake Formation respectively.
biomarkeroil source correlationcarbon isotope of crude oilYingmaili areaTabei Uplift
万方数据
维普
