江汉盆地樊参1井二元脂肪酸的色谱质谱特征及地球化学意义初探

GC-MS Characteristics and Geochemical Significance of Diatomic Fatty Acids from well Fancan-1 in Jianghan Basin

通过对江汉盆地潜江凹陷樊参１井不同层位暗色泥岩的分析发现，二元脂肪酸在荆河镇组、潜江组普遍存在，其碳数分布范围为Ｃ９～Ｃ２３，主峰碳数多为Ｃ１５或Ｃ１６。与一元脂肪酸的特征不同，二元脂肪酸不具偶碳优势特征，而且在垂向上也没有变化。进一步分析得知：二元脂肪酸的前身物是植物碎屑，其成烃机理为二元脂肪酸在强还原环境下加氢醇化脱水形成相同碳数的一元脂肪酸，然后一元脂肪酸再进一步转化为正烷烃。

Based on the GC-MS analysis of black mudstones from well Fancan-1 in Jianghan basin, it has been observed that there are diatomic fatty acids in the Jinghezhen and Qianjiang Formations, and that the carbon number of the acids ranges from C￣9 to C￣23 and the dominant carbon number is C￣15 or C￣16. Different from monatomic fatty acids, the diatomic fatty acids do not show the even carbon preference, and their carbon number and dominant carbon number is not related to burial depth. Combined with geological setting analysis, the precursor of diatomic fatty acids is phytoclasts,the mechanism of hydrocarbon generation is that the diatomic fatty acids form monatomic fatty acids in very reduction environment, then transform alkanes.