油气二次运移地球化学常用参数变化规律的新认识——石油二次运移模拟实验的启示和思考

Understanding on the geochemical parameters used for secondary oil migration:Revelation from simulation experiment of secondary oil migration

为了利用地球化学参数的变化规律正确判断油气二次运移方向,运用自行设计的实验装置进行了油气运移模拟实验,对收集的样品族组分、饱和烃色谱-质谱、芳烃色谱-质谱、烷基酚类化合物及中性氮化合物进行了分析。结果表明,原油在通过输导层的运移过程中,具有和色谱(色层)过程同样的效应,在地层中运移的组分(除饱和烃族组分外)含量都不是单调地降低或者升高,而是有一个富集的过程。将化合物相对浓度曲线和化合物比值曲线合成一张图,则可根据化合物相对浓度和比值的关系正确判断运移的方向:二者一致升高的方向或者一致降低的方向就是油气运移的方向;如果二者不一致,那么降低的一方的变化方向就应是油气运移的方向。

To judge the direction of petroleum secondary migration by using geochemical parameters, the simulation experiment of secondary oil migration was performed in self-designed apparatus. The family composition, saturated hydrocarbons, aromatic hydrocarbons, and alkyl phenol and neutral nitrogen compounds in the simulation samples were analyzed using GC-MS. The results demonstrate that crude oils have the same phenomena as the chromatography process while passing through carrier beds. In the experiment, except for the light fraction which is mainly used for solvent, all other compound contents do not simply increase or decrease, instead they have an enriching process. The migration direction can be judged by combining the concentration curve of the compounds and their ratio curve into one drawing. If both the curves change in one direction （increase or decrease）, the direction is the migration direction. If they have different directions, then the decrease direction is the migration direction of crude oils.