惠民凹陷上古生界烃源岩的生烃动力学研究

以化学动力学方法定量评价烃源岩是近些年发展起来的一种新方法。本文采用金管-高压釜封闭体系研究了惠民凹陷上古生界烃源岩(碳质泥岩)生烃动力学,取得了热解产物C1和C2～C5烃类气体组分生成动力学参数,结合Kinetics生烃动力学专用软件计算,模拟了具体地质条件下的成烃规律。结果表明,生成CH4所需活化能较高,分布范围较宽;随着碳数的增加(C2～C5),所需活化能与甲烷相反。结合惠民凹陷埋藏史与受热史,烃源岩发生过二次生烃过程,模拟计算结果与实际地质背景相吻合,指出古地温演化模式对烃源岩的生烃行为有重要的影响。生烃动力学参数为计算含油气盆地烃源岩油气生成量提供了科学依据。

On the Kinetics of Hydrocarbon Generation of Late Paleozoic Source Rocks from Huimin Depression

It is a new developing method that source rock is quantitatively assessed by hydrocarbon generation kinetics. The petroleum generation pattern of the late Paleozoic source rock from the Huimin Depression has been simulated using a golden tube-high pressure stove in a closing system in this paper. The petroleum generation kinetics parameters of the degradation products for the two group compositions of C1 and C2-C5 have been deduced by a patent software Kinetics. The result shows that there is a high activation energy to generate CH4 and have a broad range of activation energy distribution. With the increase of the number of carbon(C2-C5), the activation energy contrarily decreases and have a narrowly distribution of it. Basing on the burial and geothermal history of Huimin Depression, simulated sample takes place secondary hydrocarbon generation. The result of the simulation experiments can match with the petroleum generation pattern of the source rocks in geological conditions. The mode of palaeo-geotemperature evolvement has great effect to action of generation hydrocarbon. The petroleum generation kinetics parameters provide scientific evidence to calculate the volume of gas and oil generation of source rock in oil-gas depression.