煤与泥岩排烃过程中甾、萜烷色层效应差异

FRACTIONATION DIFFERENCE OF STERANES AND TERPANES IN COAL AND MUDSTONE DURING HYDROCARBON EXPULSION

利用未混油或混油源岩样品（指在源岩样品中加入一定量石油）进行低温排烃模拟实验，系统研究了煤与泥岩排烃过程中甾、萜烷的色层效应。结果表明，在排烃过程中煤与泥岩甾、萜烷的色层效应存在显著差别。煤排出烃与残留烃之间的甾、萜烷分布产生了明显的变化，许多常用的甾、萜烷参数的变化已难以解释其排出烃与残留烃之间的关系，但泥岩排出烃与残留烃之间的甾、萜烷分布特征仍具有可比性。煤与泥岩表现出的明显不同的甾、萜烷色层效应提示，应用甾、萜烷等生物标志物解决煤成烃问题时必须充分考虑排烃作用的影响，并需进一步探索适用于煤成烃的方法和指标。

The simulation experiments of hydrocarbon expulsion have been conducted at low temperature (150℃) to study the fractionation of steranes and terpanes in coal and mudstone.The results show that hydrocarbon expulsion has influenced the distribution of steranes and terpanes in coal and mudstone. The geochromatography of sterane and terpane in coal is obviously different from that in mudstone during hydrocarbon expulsion. The distributions of sterane and terpane in expelled hydrocarbon of coal are different from those in residual hydrocarbon of coal and, therefore, it is difficult to explain the relationship between expelled and residual hydrocarbons of coal based on the sterane and terpane parameters. The remarkable difference in geochromatographic effects of sterane and terpane in coal and mudstone suggests that hydrocarbon expulsion should be taken into account when steranes, terpanes and other biomarkers are used to study the formation of hydrocarbon from coal. New methods and indicators are highly desirable for this study.