煤成烃的成因与评价

Origin and appraisal of coal derived gas and oil

据荧光显微镜和共聚焦激光显微镜对煤中壳质组、微壳质体的定量观测和煤与煤岩组分的13CNMR分析测定,以及煤岩显微组分的热演化生烃模拟实验结果,讨论了煤的富氢组分与煤的大分子结构中甲基、α亚甲基,次甲基含量对煤成液态烃和气态烃的控制作用,并提出了针对低演化烟煤阶段煤成气与油的评价指标。由于我国多数含煤盆地是以富含镜质组和惰质组的腐殖煤为主,因此决定了含煤盆地的油气勘探方向主要是煤成天然气。只有少数含煤盆地的含煤岩系中,广泛存在壳质组和微壳质组含量较高的煤分层,才具有煤成油的实际勘探前景,如吐哈盆地等。

The exinites and microexinites in coals quantitatively analyzed under fluorescent and con-focal laser microscopes, the 13^C NMR was performed on the compositions of the coals and the coal-bearing formations, and simulating experiments of maceral thermal evolution were carried out. According to the results, the control of the contents of methyl,a methylene and methine in hydrogen-rich ingredients and macromolecular structures of the coals on both the liquid and gaseous coal derived hydrocarbons were discussed, and the evaluation criteria for the gas and oil derived from bituminous coals at low thermal evolution stage were proposed. The majority of the coal-bearing basins in China are predominated by humolites rich in vitrinites and inertinites, which indicates that coal derived gas should be the exploration target in coal-bearing basins. Only a few coal-bearing basins with widely distributed coal layers rich in exinites and micrioexinites, such as the Turpan-Hami Basin, may be prospects for coal derived oil.