有机显微组分生烃参数的加和性及其应用

Additivity of hydrocarbon-generation kinetic parameters for organic macerals and its application

从化学动力学角度考察了几种显微组分的热解实验数据,求得的显微组分活化能的分布及平均值能很好地解释显微组分的生烃特征。鉴于显微组分的生烃参数具有一定的加和性,提出一种数学配比的方法:正演过程由显微组分合成混合样品的生烃动力学参数,反演过程由混合样品求取显微组分的生烃动力学参数。实际计算结果证实,正演过程是可行的,说明地球化学工作者可以人工合成能代表一个地层、一个区块整体特征的代表性参数用于生烃史、生烃量等定量计算,从而提高计算的精度;反演的尝试未能取得成功,可能是因为忽略实验数据的误差及无机矿物对生烃过程的复杂影响从而导致迭代算法失败,无法得到合理的计算结果,由此指出无机矿物对生烃的影响值得作深入的定量研究。

The pyrolysis data of several macerals are studied in terms of chemical kinetics and the distribution and the mean of activation energy for these macerals can well explain their hydrocarbon generation characteristics. According to the additivity property of these kinetic parameters, a new method of allocation is suggested. It consists of two parts： in forward process, obtaining the kinetic parameters of mixture samples from the pyrolysis data of macerals, and in inverse process calculating the kinetic parameters of macerals from mixtures. The calculating results show that the forward process is feasible, suggesting that the ＂representative parameters＂ of the geochemical characteristics of certain formation or area can be artificially synthesized and used to improve the precision of the quantitatively modeling of hydrocarbon-generation in geologic history. The reverse process, however, is unsuccessful, owing probably to the negligence of errors of the pyrolysis data and/or the effect of inorganic minerals on hydrocarbon-generation which result in the failure of the iterative calculations.