矿物对原油裂解影响的实验研究

Experimental study on effects of minerals on oil cracking

在限定体系下(密封金管),对原油、原油+蒙脱石和原油+方解石进行了裂解产气模拟实验。结果表明,原油+蒙脱石裂解的甲烷和总气态烃(C1-C5)产率在大多数实验温度点与纯原油裂解基本相同,只有在高温度点才相对偏高,反映了蒙脱石对原油裂解的催化效应。原油+方解石裂解的甲烷和总气态烃的产率则在大多数实验温度点比纯原油裂解相对偏低,并且在高温度点明显偏低,表明方解石对原油裂解具有抑制作用。纯原油和原油+方解石裂解气态烃产物中异构烷烃和烯烃的相对含量基本相同,而原油+蒙脱石裂解气态烃产物中异构烷烃和烯烃的含量则明显偏高。依据2℃/h和20℃/h两个升温速率甲烷和总气态烃产率,应用美国Lawrence Livermore国家实验室开发的Kinetics软件模拟了纯原油、原油+蒙脱石和原油+方解石裂解生成甲烷和总气态烃的动力学参数,推算了在地质条件下原油裂解主要阶段的温度范围。

Oil cracking experiments were conducted in absence of minerals, i.e., montmorillonite and calcite. in a confined system （gold capsules） in the presence and ompared with the result of the experiment for oil alone, .the amounts of methane and total hydrocarbon gases （C1 -C5） are generally similar in most experimental temperature ranges, but relatively high in the high experimental temperatures in the experiment for oil plus montmorillonite, demonstrating the catalytic effect of montmorillonite on oil cracking. However, they are relatively low in most experimental temperature ranges, and substantially low in the high experimental temperatures in the experiment for oil plus calcite, indicating the inhibitive effect of calcite on oil cracking. The relative concentrations of iso-alkanes and gaseous olefins are similar between the experiments for oil alone and oil plus calcite, but they are substantially higher in the experiment for oil plus montrriorillonite than the other two experiments. Based on the data of oil cracking at the heating rates of 2℃/h and 20℃/h, kinetic parameters for the generation of methane and total gaseous hydrocarbons were modeled using the KINETICS software developed by LLNL, USA. The results were used to estimate the temperatures of the main stage of oil cracking under geological condition.