颗石藻生烃的热模拟实验研究──Ⅰ．烃的产率、性质及烯烃、烷烃的特征

XPERIMENTAL STUDY ON SIMULATING HYDROCARBONGENERATION OF COCCOLITHOPHORIDAES BY HEATING──Ⅰ.Generation Rate and Property of Hydrocarbons,Characteristic of Alkanes and Alkenes

对同一种属但生长在不同环境中的两种颗石藻进行了加热模拟实验，探讨其成烃机理。实验发现，颗石藻含有丰富的石油烃类，加热生成的正构烷烃及类异成二烯烷烃分布与含颗石藻烃源岩相似。对颗石藻生烃的热演化规律研究表明，氯仿沥青大量产生及烃类组成发生较大变化的实验温度区间为２００～３００℃，此阶段产物相当于镜质体反射率Ｒ０为０．３５～０．５５的含颗石藻烃的源岩，为低成熟原油生成阶段。本文还研究了颗石藻热模拟产物中植烯类化合物和Ｃ＿（２０－）、Ｃ＿（２２－）类胡萝卜烷等类异成二烯烃随温度的变化，并检测出一种推测为Ｃ＿（２２－）二甲基－烷基环己烷的化合物。

Heating experiments to simulate hydrocarbon generation have been made for two kinds of Coccolithophoridaes which belong to the same species but live in different water-temperature environments, and the mechanism of hydrocarbon generation of Coccolithophorldaes has been discussed. It shows that there are many kinds of crude-oil hydrocarbons in Coccolithophoridaes,and the distribution of n-alkanes and isoprenoid alkanes generated by heating is similar to that of oil-source rocks containing Coccolithophoridaes. Experiments on temperature dependence of the generation of Coccolithophoridaes indicate that the generation of a large quantity of chloroform and the essential change in hydrocarbon composition take place at 200-300℃. The product of this stage corresponds to the oil-source rocks containing Coccolithophoridaes with an R, range of 0. 35～0. 55%, as is in the case of low-maturity crude oil. This study also discusses the isoprenoid in the products of heating experiments on Coccolithophoridaes, such as phytenes and C20-, C22- Carotane. A compound considered as C22-Dimethyl-Cyclahexane has been discovered in the experiments.