生物降解原油地球化学研究新进展

THE ADVANCES IN THE GEOCHEMISTRY OF THE BIODEGRADED OIL

生物降解作用是原油的一种重要的蚀变作用,对原油的物性和经济价值有着负面的影响。全球石油大多遭受过生物降解。生物降解作用对常见生物标志物的影响得以较好的描述,综述了近年来高分子量正构烷烃、三环萜烷、25 降藿烷生物降解的新进展。目前对生物降解作用的细节、发生机理尚不十分清楚,讨论了原油喜氧和厌氧降解机制,认为厌氧作用可能起主导作用,降解速率很慢。温度是控制生物降解作用的重要因素,储层温度大于80℃不会发生生物降解作用。生物降解原油多为混源油,介绍了研究生物降解原油的多期成藏方法。沥青质不易生物降解,其热解产物及钌离子催化氧化产物在生物降解原油对比、油源对比中具有重要的作用;最后指出了今后的发展方向。

The biodegradation of crude oil in the reservoir is an important alteration process and has undesirable impact on the oil physical property and economic value. Most of the world oil has been biodegraded. The effects of biodegradation on the ordinary biomarkers have been well known. Some advances in the biodegradation of the uneasily biodegraded biomarkers in recent years, such as high-molecular-weight alkanes, tricyclic terpanes and 25-norhorpane, were reviewed. At present, the details and mechanism taking place during the biodegradation are still obscure. Both aerobic and anaerobic biodegradation mechanisms were discussed. It is proposed anaerobic biodegradation may be dominating and the biodegradation rate is very slow. The temperature was thought to be the main factor controlling the biodegradation. The biodegradation would cease at the reservoir temperature over 80℃. In most case, the biodegraded oils are mixing oils. The methods describing multiple hydrocarbon filling history of the biodegraded oil were introduced. Asphaltene of the biodegraded oil is unsusceptibility to biodegradation and its pyrolysate and Ruthenium-ion-catalyzed-oxidation production has important role in the oil-oil correlation and oil-source correlation for the biodegraded oil. Finally the trend of research on the biodegradation was proposed.