实验室条件下厌氧降解原油及次生气体地球化学特征

THE GEOCHEMICAL CHARACTERS OF CRUDE OILS AND SECONDARY GAS AFTER ANAEROBIC BIODEGRADATION IN LABORATORY

段传丽 陈践发 郭建军 师生宝 李程善 聂国振

Duan Chuanli Chen Jianfa Guo Jianjun Shi Shengbao Li Chengshan Nie Guozhen

长江大学, 地球化学系, 湖北, 荆州, 434023 2. 中国石油大学, 资源与信息工程学院, 北京, 102249

Department of Geochemistry, Yangtze University, Jingzhou, Hubei 434023 China

选取胜利油田2个油样(一个遭受明显改造,另一个没有遭受明显改造),实验室条件下对2个油样进行厌氧降解,定期抽取微生物作用后的油样,对降解后的原油及厌氧降解原油产生的天然气进行多种实验分析,探讨原油的变化以及厌氧降解气的地球化学特征。结果表明:原油在厌氧降解过程中,族组分发生变化;原油被微生物厌氧降解产生二氧化碳,部分二氧化碳被还原成甲烷;次生气中甲烷碳同位素主要分布在-43.4‰左右,二氧化碳碳同位素主要为-11.8‰左右,表明厌氧降解气是有机成因的。而随着降解时间的增加,甲烷碳同位素变轻,二氧化碳碳同位素变重。

Two oils(one suffered obviously transformation,the other did not) from the Shengli oilfield were selected for anaerobic biodegradation in laboratory.The oils with microbiological degradation were regularly extracted and analyzed.It showed that the oil group composition was changed during anaerobic degradation,and CO2 was produced and part of them was reduced to CH4.The value of carbon isotope of the secondary CH4 was mainly distributed in about -43.4‰,δ13C of CO2 was mainly in -11.8‰.With the degraded time increasing,δ13C of CH4 was become lighter and δ13C of CO2 become heavier.

国家"十五"科技攻关项目(2003BA613A-08-1)

https://doi.org/10.11781/sysydz200803297