天然气生成动力学模拟及其地质应用

天然气形成、运移和聚集的定量化研究是当前国际上研究的热点。文章介绍了天然气生成动力学模拟借助热解实验数据，获得油气生成动力学参数的方法。结合具体盆地演化史，能定量地预测盆地天然气组分和碳同位素组成，恢复天然气的成藏史，最近的发展则以生烃动力学模拟实验和色谱同位素比值质谱（GC-IRMS）的结合作为标志。黄金管限定体系是目前开展封闭体系下天然气生成实验较理想的实验设备，该体系下正十八烷的裂解动力学研究表明：地质条件下饱和烃很难直接裂解生气，在原油族组分中生气潜力小于沥青质、非烃，甚至芳烃化合物。

KINETIC SIMULATION OF NATURAL GAS GENERATION AND ITS GEOLOGICAL APPLICATION

Quantitative study of generation, migration and accumulation of natural gas is the current hot spot of research in the world. In combination with pyrolysis experimental data, kinetic simulation of gas generation can be used to achieve the kinetic parameters of hydrocarbon generation; while in combination with the specific basin evolution history, it can be used to quantitatively predict the gas compositions and carbon isotope components and to restore gas reservoiring history. Its recent development is marked by the integration of kinetic simulation experiment of hydrocarbon generation with gas chromatography- isotope ratio mass spectrometry (GC-IRMS). The gold tube confining-system is a relatively ideal apparatus for gas generation experiment in a closed system. Kinetic experiment of n-octadecane pyrolysis in this system shows that it is very difficult to directly crack the saturated hydrocarbons into gas under in-situ conditions and the gas generation potentials of saturated hydrocarbons are smaller than that of asphaltenes, nonhydrocarbons and even aromatic compounds in the group compositions of crude oil.