氢抑制条件下的有机质热演化动力学模型r——以三塘湖盆地芦草沟组为例

摘要

Organic matters of the source rocks in the Lucaogou Formation of the Malang Sag,Santanghu Basin are rich in hydrogen components,which suppresses the thermal evolution of organic matters.To simulate thermal evolution of organic matters,a new kinetic model of organic thermal evolution under the condition of hydrogen suppression was established in-tegrating time,temperature,and hydrogen retardation based on Sweeny and Burham Easy % Ro time and temperature con-trolling kinetic model.In the new kinetic model,activity energies are adjusted by hydrogen index.The results show that hydrogen suppression contributes to 0.2% of Ro value in the Lucaogou Formation.Hydrogen suppression also resulted in delays of both initial generation of hydrocarbons and peak generation of hydrocarbons.This new established model is widely applicable to thermal histories for different kerogen types with higher accuracy.%三塘湖盆地马朗凹陷芦草沟组烃源岩含有较多的富氢组分,有机质的热演化受到氢抑制.为了模拟氢抑制背景下的有机质热演化史,在经典的Sweeny和Burham Easy%Ro时-温双控化学动力学模型基础上,本文考虑氢抑制对有机质热演化的影响,根据氢指数调节反应活化能,建立了描述有机质热演化的时-温-氢抑制多控化学动力学模型.研究结果表明,芦草沟组氢抑制对Ro的贡献值为0.2%左右;由于氢抑制的影响,芦草沟组烃源岩进入生烃门限和开始大量生烃的时间均被延迟.文中新建立的化学动力学模型可以应用于各种类型干酪根的有机质热演化史模拟,其精度更高、应用范围更广.