Expulsion of petroleum from type III kerogen source rocks in gaseous solution: modelling of solubility fractionation
Expulsion of petroleum from type III kerogen source rocks in gaseous solution: modelling of solubility fractionation
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DOI：
10.1144/gsl.sp.1991.059.01.03
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
D. Leythaeuser;H. S. Poelchau
中科院分区：
文献类型：
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作者：
D. Leythaeuser;H. S. Poelchau
从含干酪根的III型烃源岩中排出的正构烷烃混合物的组成在中等成熟度水平上显示出强烈的根据分子链长度的分馏迹象。这种效应归因于气体溶液中的排出过程。分馏程度随初次运移的压力和温度条件而变化。本文用Price等（1983）的实验数据建立的油的气相溶液的分馏方程，模拟了C15+-正构烷烃的分馏效应。对于已知的组合物驱逐的正构烷烃，我们的模拟模型允许估计的压力和温度条件下，在主迁移。对于超压的III型干酪根烃源岩来说，气态溶液中的石油排出是一种特别有效的运移机制。文中给出了两个地质实例，证明了这种烃源岩气态溶液中石油排出的组分效应。所观察到的正构烷烃分布驱逐可以密切匹配的模拟分布，这是计算的P-T条件估计重建的埋藏历史的两个案例的历史。
Abstract The composition of n-alkane mixtures expelled from type III kerogen-bearing source rocks at moderate maturity levels shows strong signs of fractionation according to molecular chain length. This effect is attributed to the process of expulsion in gaseous solution. The degree of fractionation varies with the pressure and temperature conditions of primary migration. Fractionation effects for C15+-n-alkanes have been simulated with the help of equations developed from experimental data of Price et al. (1983) for gaseous solution of oil. For known compositions of expelled n-alkanes our simulation model allows the estimation of pressure and temperature conditions during primary migration. Expulsion of petroleum in gaseous solution is a particularly effective migration mechanism for overpressured type III kerogen-bearing source rocks. Two geological case histories are presented which demonstrate the compositional effects of petroleum expulsion in gaseous solution from such source beds. The observed n-alkane distributions expelled can be closely matched by simulated distributions, which were calculated for P-T conditions estimated from reconstructions of the burial histories of both case histories.