混源油色谱指纹定量判析及其勘探意义——以高邮凹陷南部断裂带为例

高邮凹陷南部断裂带油气主要来自古近系阜二段和阜四段源岩。选择典型端元油的混合配比实验表明,按不同比例配置的混源油,其色谱指纹参数与混油比例呈线性关系。对于二元混合的混源油,利用色谱指纹判别混合比例是行之有效的方法,其关键环节是色谱指纹峰的筛选。通过配比实验创建的混源油定量判析图版,能定量判别其混合比例,从而判别不同来源油的贡献大小以及油气运移路径。通过实际图版验证,许庄油田X33井、X5-5井原油的阜四段来源油比例分别为80%和30%左右,方巷油田F4-9井、F5井的阜四段来源油比例分别在40%和10%左右。南部断裂带具备较大的混源油勘探潜力,特别是高台阶具备以阜二段来源油为主的油气成藏条件,不仅可形成阜一段油藏,还有利于白垩系泰一段成藏。

Quantification of chromatographic fingerprints of mixed crude oils and its exploration significance:A case study of the southern fault zone in Gaoyou Sag

The discovered crude oils in the southern fault zone of Gaoyou Sag are binary mixtures mainly derived from the second and fourth members of the Funing Formation. An artificial mixing experiment of two typical end-member oils in the laboratory indicates that the chromatographic fingerprint of artificially mixed oil samples changes linearly with mixing proportions, so it is an effective method to quantify mixture proportions.An important key is to screen the fingerprint peaks. The application of a quantitative identification model created using an artificial oil mixing experiment can quantify the contribution of different oil sources and its migration path way. The model shows that the contribution rate of source rocks from the fourth member of Funing Formation is 80% in well X33, 30% in well X5-5, 40% in well F4-9, and 10% in well F5. Results indicate that the model has broad exploration applications for mixed crude oils in the southern fault zone of Gaoyou Sag. Source rocks from the second member of Funing Formation contribute more oil in the higher locations of the sag. Reservoirs are found in the first member of Funing Formation and the first member of Taizhou Formation.