全二维气相色谱技术在石油地球化学中的应用进展

Advances in the application of comprehensive two-dimensional gas chromatography in petroleum geochemistry

石油是一种多组分的复杂有机混合物,在形成、运移过程中较易受到各种物理、化学和生物作用的改造,其中含量极低的化合物或特殊化合物用常规一维气相色谱难以检测确定。因全二维气相色谱技术具有超高的分辨率和灵敏度、较大的峰容量及准确的定性和定量检测结果,可对复杂混合物进行分离与鉴定,从而解决了石油复杂成分的精确定量分析难题。研究结果表明:①全二维气相色谱分别与硫化学发光检测器、电子俘获检测器、氢火焰离子化检测器以及飞行时间质谱仪联用后,在原油馏分烃类组成分析及杂原子化合物分析检测方面的适用范围大、应用效果非常显著;②该技术可用于解析稠油的不可分离混合物成分(UCM)、评价原油裂解程度和判识超深层液态原油保存极限深度、定量评价硫酸盐热化学还原反应(TSR)蚀变强度以及识别原油中痕量分子化合物并进行结构鉴定;③该技术在石油地球化学科学问题研究中发挥了独特优势,今后将在页岩油气勘探以及深层-超深层液态原油运移、成藏保存和次生改造研究中发挥重要作用。

Petroleum,a complex multi-component organic mixture,is susceptible to various physical,chemical,and biological transformations during its formation and migration.Consequently,it is difficult to identify compounds of extremely low concentrations or special compounds in petroleum using conventional one-dimensional gas chromatography(1DGC).In contrast,comprehensive two-dimensional gas chromatography(GC×GC),enjoying ultra-high resolution and sensitivity,high peak capacity,and accurate qualitative and quantitative detection results,allows for the separation and identification of complex mixtures,thus meeting the challenge of performing accurate,quantitative analyses of complex petroleum components.Key findings of this study include:(1)Coupled with various detectors such as a sulfur chemiluminescence detector(SCD),electron capture detector(ECD),flame ionization detector(FID),or a time-offlight mass spectrometer(TOFMS),the GC×GC exhibits wide application and notable efficiency in analyzing and detecting the hydrocarbon compositions and heteroatomic compounds of crude oil fractions;(2)GC×GC can be employed to analyze unresolved complex mixtures(UCMs)in heavy oil,assess the cracking degree of crude oil,determine the preservation threshold of ultra-deep liquid hydrocarbon,quantitatively assess the intensity of thermochemical sulfate reduction(TSR),and identify potential trace molecular compounds in crude oil and their structures;(3)GC×GC,which has exhibited unique advantages in the field of petroleum geochemistry,is expected to play a significant role in shale oil and gas exploration and research on the migration,accumulation,preservation,and modification of liquid crude oil in deep to ultra-deep reservoirs.