原油裂解成气动力学研究进展

The Advancement of Kinetic Study on Crude Oil-cracking Gas

对于高温古油藏来说,原油裂解气是形成天然气藏的重要气源。原油裂解成气关系到天然气生成和原油消耗,因而客观评价这一过程对油气勘探有着重要意义。生烃动力学和热模拟实验是原油裂解成气动力学研究的基础。本文总结了原油裂解热模拟实验、原油裂解成气过程及判识指标,讨论了原油裂解成气动力学模型及碳同位素动力学,分析了原油裂解成气动力学研究的地质应用。指出现有的原油裂解成气判识指标难以确定有些天然气是属于原油裂解气还是干酪根裂解气,尤其是高—过成熟阶段生成的天然气;碳同位素动力学已逐渐成为当今国内外油气地球化学研究的前沿,而对原油裂解成气过程中的碳同位素分馏效应研究不够,其预测模型尚不完善。

As a high temperature paleo-oil reservoir, crude-oil-cracking gas is an important source for natural gas pool. The process of crude oil cracking to gas closely relates to the generation of natural gas and the consumption of crude oil, therefore an objective evaluation of this process has great significance to the exploration activities for oil and gas. Hydrocarbon generation kinetics and thermal simulation experiments are the basis of the kinetic study of crude-oil-cracking gas. This paper summarized the thermal simulation experiments of crude-oil-cracking and the processes of crude oil cracking to gas as well as their indicators. This paper also discussed the kinetic models of crude oil cracking to gas and the kinetics of carbon stable isotope, analyzed the geological applications of the kinetics of crude oil cracking to gas. This paper concluded that the current identification index of crude oil cracking to gas is inefficient in distinguishing the oil-cracking source or the kerogen-cracking source for some natural gases, especially for those generated in highly and over mature stages. Although the kinetic study of carbon stable isotope had become an international forefront research field of oil-gas geochemistry, this paper proposed that the current researches of the effects of carbon stable isotope in the process of crude oil cracking to gas are not enough and the prediction models are not well established.