中国南方海相烃源岩生烃动力学研究

利用Rock-Eval 6热解仪和Optkin动力学软件对中国南方海相烃源岩4种有机质类型样品进行了动力学分析,研究得出在相近演化阶段样品平均活化能是Ⅲ型>Ⅱ₂型>Ⅱ₁型>Ⅰ型,生烃能力是Ⅰ型>Ⅱ₁型>Ⅱ₂型>Ⅲ型,有效生烃期间(干酪根生烃转化率10%~90%)活化能跨度ΔE_Ⅰ<15kJ/mol,15kJ/mol<ΔE_Ⅱ1<20kJ/mol,20kJ/mol<ΔE_Ⅱ2<30kJ/mol,ΔE_Ⅲ>30kJ/mol,有效生烃温度跨度ΔT_Ⅰ≤65℃,65℃≤ΔT_Ⅱ1≤75℃,75℃≤ΔT_Ⅱ2≤85℃,ΔT_Ⅲ≥110℃.达到干酪根10%转化率的时间顺序是Ⅲ型最早,Ⅱ₂型早于Ⅱ₁型,Ⅰ型最晚.而完成90%干酪根转化率时间则是Ⅰ型早于Ⅱ₁型,Ⅱ₂型次之,Ⅲ型最晚.干酪根有机大分子结构特征和元素组成决定了其生烃活化能的频率分布特征,海相优质烃源岩具有快速生烃的特质.

KINETICS OF HYDROCARBON GENERATION OF MARINE SOURCE ROCKS IN SOUTH CHINA

With Rock-Eval 6 and Optkin kinetics software,the kinetics analysis on four types of kerogens of marine hydrocarbon source rocks in South China were carried out.The results showed that,in the similar maturity period,the hydrocarbon generation activation energy of kerogen was Ⅲ>Ⅱ₂>Ⅱ₁>Ⅰ;the ability of hydrocarbon generation was Ⅰ>Ⅱ₁>Ⅱ₂>Ⅲ;the span of generating effective hydrocarbon activation energy was ΔE_Ⅰ<15kJ/mol,15 kJ/mol<ΔE_Ⅱ1<20kJ/mol,20kJ/mol<ΔE_Ⅱ2<30 kJ/mol,ΔE_Ⅲ>30kJ/mol;the span of generating effective hydrocarbon temperature was ΔT_Ⅰ≤65℃,65℃≤ΔT_Ⅱ1≤75℃,75℃≤ΔT_Ⅱ2≤85℃,ΔT_Ⅲ≥110℃.The time of hydrocarbon generation conversion rate to reach 10% was Ⅲ<Ⅱ₂<Ⅱ₁<Ⅰ;and the type Ⅰ kerogen first reached to 90% conversion rate,and then the typeⅡ₁,type Ⅱ₂ and type Ⅲ of kerogen.The character of hydrocarbon generation activation energy distribution of kerogen was determined by their element composition and organic high molecular structure.The hydrocarbon generation speed of good marine source rocks was very fast.