中国西北地区两种镜质组结构及生烃特征

Chemical Structure and Hydrocarbon Generation Character of Vitrinites in Northwest China Area

应用热解-色谱/质谱及核磁共振(NMR)研究了中国西北地区两种镜质组的化学结构。研究表明SGM基质镜质体结构中亚甲基碳所占比例较大,热解产物中正构烷烃/烯烃对所占比例较高,而MYG均质镜质体脂肪碳部分甲氧基、甲基碳所占比例较大,热解产物中以酚类、烷基苯为主。两种镜质组不同的结构决定了其不同的生烃特征。SGM基质镜质体除了生成气态烃外,还可以生成一定数量的液态烃,而MYG均质镜质体则主要以生成气态烃为主。

Chemical structure of the desmocollinite and the telocollinite in NW China area have been studied using flash pyrolysis-gas chromatography/mass spectra and solid state CP/MAS NMR spectra. Studies show that methylene carbons are in large proportion in SGM democollinite, and alkane/alkene doublets are in large proportion in pyrolysate of SGM desmocollinite. In contrast, methyl carbon and carboxyl carbon are in large proportion in MYG telocollinite and alkylphenols, alkylbenzenes are the main components in pyrolysates of MYG. The differences in chemical structure of the two vitrinites indicate the different hydrocarbon generation abilities. SGM have the ability to generate liquid hydrocarbons beside gas hydrocarbon generation, but MYG vitrinite is mostly the gas-prone.