采用液氮冷冻冲击粉碎-密闭加热脱附-氦气吹扫-冷阱捕集-气相色谱在线分析装置(专利申请号2007101194606)对粒径达2cm左右的烃源岩样品进行轻烃在线分析。因样品粒径大,大大减少了样品在粉碎前、后轻馏分的损失,较好地保留了烃源岩分散有机质中轻馏分的原始面貌。所获色谱图中,由C5至C13大约可得203个化合物的色谱峰;在C6-C8分段中,通常较难分离的谱峰分离对(2-甲基己烷与2,3-二甲基戊烷)可得到低于半峰宽的较满意分离,尚可见3-乙基戊烷呈肩峰出现。重复性实验证明该方法重复性较好。以准噶尔盆地烃源岩样品为例,对该分析方法在油源对比研究中的应用作了初步探索,结果表明此方法有可能为油气勘探中油源的识别和残留烃量的计算等提供一个新的研究工具。图3表6参19
By the online analysis system of liquid nitrogen freezing--impact crushing--closed thermal desorption--helium purging--cold trap capturing--gas chromatogram (Patent Application No. 2007101194606), the online analysis is made for the source rock samples of about 2 cm grain size. Due to the large grain size of the samples, the light fraction loss of the samples before and after crushing is greatly reduced. As a result, the original status of light fractions of organic matter in the source rock is maintained well. In the acquired chromatogram, about 203 peaks from C5-C12 have been got, pair peaks of 2-methylhexane and 2,3-dimethylpentane could be separated to lower than half of the peak width, and 3 ethylpentane could also be seen as a shoulder peak. The repeatability of the measurement is good. With the source rock samples from Junggar Basin as an example, this analysis method is applied in oil-source correlation. This method may provide a new research tool for identifying the oil sources and calculating the remaining hydrocarbon volume in oil-gas exploration.