石油实验地质2025，Vol.47Issue(4)：820-834,15.DOI:10.11781/sysydz2025040820
基于化学计量法的渤海海域庙西地区原油类型划分及油源鉴别
Crude oil type classification and source rock identification in Miaoxi area of Bohai Sea area based on stoichiometric method
摘要
Abstract
The crude oil types in the Miaoxi area of the Bohai Sea area are highly complex,and the source rocks and genetic types remain unclear.Using multivariate statistical analysis,researchers can comprehensively examine the interrelationships among multiple correlated variables,which is particularly suitable for large-scale data mining and regional oil-oil and oil-source analysis.In this study,based on the biomarker parameter index system,hierar-chical cluster analysis(HCA)and principal component analysis(PCA),common methods in multivariate statistical analysis,were applied for oil-oil and oil-source correlation of crude oil from multiple layers in the Miaoxi area.Three types of crude oil were detected.TypeⅠcrude oil are characterized by a low C23 TT/C30 H ratio with rela-tively low maturity.It may be derived from a freshwater lacustrine reducing environment with abundant input of terrigenous organic matter.This type of crude oil shows a strong correlation with the source rocks in the first and second members of the Shahejie Formation in the eastern sag of the Huanghekou Depression.TypeⅡcrude oil is at a mature stage and features lower C23TT/C30H and G/C30H ratios compared to TypeⅠ,but with slightly higher Pr/Ph,sterane/hopane,and C19 TT/C23 TT ratios.These features also indicate a freshwater lacustrine environment with terrestrial organic matter input.It is inferred that Type Ⅱ oil is mainly sourced from the third member of the Shahejie Formation,with contributions from source rocks in both the eastern sag of the Huanghekou Depression and the southern sag of the Miaoxi Depression.Type Ⅲ crude oil is at a mature stage,exhibiting a wide distribution range in multiple biomarker parameters,including ETR[(C28 TT+C29 TT)/(C28 TT+C29 TT+Ts)],G/C30H,C23TT/C21TT,Pr/Ph,C23TT/C30H C24Te/C26TT,C27/C29regular sterane,and 4-methyl sterane/C29 regular sterane.These variations reflect heterogeneity in the depositional environment of oil source rocks and organic matter types.It can be concluded that typeⅢcrude oil is mixed-source oil,likely derived from the third and fourth members of the Shahejie Formation.Alternating least squares analysis results indicated that Type Ⅲcrude oil is mainly derived from the source rocks in the fourth member of the Shahejie Formation,with a contri-bution rate of 85%to 93%,while the contribution from the third member is only 7%to 15%.关键词
主成分分析/聚类分析/油源对比/庙西地区/渤海海域Key words
principal component analysis/cluster analysis/oil and source comparison/Miaoxi area/Bohai Sea area分类
能源科技引用本文复制引用
唐友军,付天意,杨海风,王飞龙,汤国民,孙鹏..基于化学计量法的渤海海域庙西地区原油类型划分及油源鉴别[J].石油实验地质,2025,47(4):820-834,15.基金项目
国家自然科学基金项目(42202163,41972148)资助. （42202163,41972148）
