Abstract: Fouriertransformation infro-red microspectroscopy Micro-FTIR technique was used to investigate the chemical compositions and structures of cutinite,vitrinite and fusinite from Jurassic coals in Tarim basin at different temperatures. The results show that the chemical structure of cutinite is mainly composed of long aliphatic-side chain with minor amounts of aromatic compounds. Vitrinite is mostly composed of aromatic compounds, in addition to large amount of short aliphatic-side chain compounds. Whereas fusinite are dominant by aromatic structure. The study indicates that cutinite is one of the best oil source-rocks, with the higher hydrocarbon-generation potential; vitrinite is one of better gas source-rocks, and has medium hydrocarbon-generating potential; fusinite has little hydrocarbon-generating potential. In addition, the components of aliphatic structures of cutinite, vitrinite and fusinite decrease, the aromatics are enriched and condensation of aromatic structure increases with increasing the temperature, and along with the rise of temperatures, the intensity of aliphatic structure and heteroatomic compounds decrease obviously, however the aromatic structure changes a little.

Key words: Tarim basin, Micro-FTIR, macerals, chemical structure, thermal simulation

摘要： 应用显微红外光谱技术，对塔里木盆地侏罗纪煤中有代表性的3种组分角质体、镜质体、丝质体在不同热模拟温度下的结构组成变化特征进行了研究，结果表明：角质体结构组成中含有较丰富的长链脂族结构，而芳香结构和含氧官能团的含量则相对较少；与此相反，丝质体结构组成中芳香烃占绝对优势，而脂族结构含量则很少；镜质体结构组成介于角质体和丝质体之间，含有较多的短链脂族结构和芳香结构。据此推断，角质体具有高的生烃潜力，是一种倾油组分；镜质体生烃潜力中等，是一种倾气组分，但也可以生成一定数量的液态烃；丝质体生烃潜力很小，对煤成烃的贡献微不足道。另外，随热模拟温度的升高，3种组分中的脂族结构和含氧官能团都呈现明显的由强到弱的变化，而芳香结构比较稳定，在整个生烃热演化过程中则呈现芳环缩合度增加芳烃相对富集的趋势。由此说明，煤生烃过程主要是一种脂族结构和含氧基团不断脱落、芳香结构不断缩聚的过程。

关键词: 塔里木盆地, 显微傅里叶红外光谱, 显微组分, 化学结构组成, 热模拟