Abstract: A strain of microbacterium sp.3-28 was screened to biodegrade the asphaltene fraction of crude oil in Bohai Oilfield and Karamay Oilfield.The effects of microbe degradation on the components and composition among the saturated hydrocarbons,aromatic hydrocarbons,resins and asphaltene fractions in oils were analyzed.The results showed that the physiochemical characteristics of crude oil changed obviously under the effect of microbacterium sp.3-28.The viscosity of oils in Suizhong 36-1 and Karamay oilfields decreased by 24.9% and 32.4% respectively,and the freezing points decreased by 5.2℃ and 7.7℃ respectively.The saturated hydrocarbons and aromatic hydrocarbons increased by 8.0% and 21.4% respectively,and the asphaltene fraction decreased by 37.5% and 58.7% respectively.The fraction ratio of short chain to long chain of the saturated hydrocarbon got higher after biodegradation of oil.The quality of the thickened oil was greatly improved.

Key words: microbial enhanced oil recovery, thickened oil exploitation, Microbacterium sp. 3-28, biodegradation, physicochemical characteristics of thickened oil, laboratory research

摘要： 从原油及含油污水中分离并培育出一株能有效地降解稠油中重质组分的菌株3-28,其生理生化特征和分子鉴定结果表明,该菌株属于微杆菌属(Microbacterium)。用该菌株对渤海和新疆等油田的稠油进行了微生物降解实验,分析了细菌降解对原油粘度等物理特征的改变及其对饱和烃、芳烃以及胶质、沥青质各组分在原油中相对含量和内部组成的影响。结果表明,该菌株降解作用使原油性质发生了明显变化:渤海绥中36-1油田的原油粘度降低24.9%,凝固点降低5.2℃;克拉玛依油田的原油粘度降低32.4%,凝固点降低7.7℃;绥中36-1油田的原油中饱和组分和芳烃组分含量增加8.0%,克拉玛依油田的原油增加21.4%;沥青质含量分别降低了37.5%和58.7%。原油组成也发生了一定的变化,原油饱和烃轻、重组分比值增加,改善了原油的理化特征。

关键词: 微生物采油技术, 稠油开采, 微杆菌3-28, 生物降解, 稠油理化特征, 实验研究