在准噶尔盆地侏罗系煤系烃源岩热模拟实验研究中 ,经过对原样和不同温度点热模拟残余物进行可溶有机质抽提和族组成分析、残渣干酪根处理、Ro 值测定和 TOC测定 ,并对部分样品系列进行色谱和质谱分析后发现 ,煤系烃源岩在不同热演化阶段表现出的地质地球化学特征具有相当大的差异。低演化阶段和热降解阶段天然气的形成是不同热力学条件和成气母质化学反应的结果。在低演化阶段 ,源岩镜质组反射率增长幅度并不太大 ,通常 Ro<0 .7%。原始可溶有机质和热模拟残余可溶有机质的分析结果表明 ,烃类气主要来源于原始可溶有机质的脱基团作用和大分子沥青质及干酪根边缘烃 (极性组分 )的热降解。在有机质热降解―热裂解阶段 ,烃源岩经地质埋深增温 ,热演化进程相对加快、镜质组反射率迅速递增、Ro 值从 0 .5 5 %～ 0 .70 %迅速增大到 1 .40 %～1 .70 % ,可见热动力作用足以破坏干酪根结构烃并将其降解形成油气。该阶段是干酪根经热降解大量排烃的阶段 ,其地球化学参数特征主要表现为干酪根结构烃热降解产物的特征。

With pyrolysis experiment, we extracted and analyzed the soluble organic matter  from original samples of hydrocarbon source rock of Jurassic coal measures in Zh ungeer basin and residual of different temperature, treated residual kerogen, me asured R_o and TOC, and gave chromatograph and mass spectrograph test to so me sample series. The results indicate that there is some geological and geoch emical difference of hydrocarbon source rock of coal measures at different therm al evolution stage, natural gas generated at low evolution stage and thermal deg radation stage is the result of different thermodynamic conditions and chemical  reaction of mother matter of gas generation. At low evolution stage, the vitrin ite reflectance of source rock does not increase much, usually R_o<0.7%.The analytical results of soluble organic matter of original samples and residue  in pyrolysis experiment indicate that hydrocarbon gas is mainly from releasing  of radicals of original soluble organic matter and thermal degradation of margin al hydrocarbon (polar component) of large-molecule bitumen and kerogen. At t hermal degradation-thermal cracking stage, the temperature of hydrocarbon sourc e rock increases following the increase of buried depth, and thermal evolution r elatively accelerates, the vitrinite reflectance increases from 0.55%~0.70% to 1.40%~1.70% quickly, at the same time, the thermodynamic effect is big enough  to destroy the constitutional hydrocarbon of kerogen to generate oil and gas, it is the time of kerogen to release a lot of hydrocarbon Geochemical parameter s at this stage show properties of thermal degraded constitutional hydrocarbon of kerogen.