Title

SIMULATION EXPERIMENT OF BIOGENIC GAS FROM SOURCE ROCK AND BIODEGRADATION OF CRUDE OIL IN THE JIYANG DEPRESSION, THE BOHAI BAY BASIN

作者

罗霞刘华王玉林李文涛邓宇

Authors

Luo Xia Liu Hua Wang Yulin Li Wentao Deng Yu

单位

中国矿业大学, 北京, 100083 2. 中国石化胜利油田地质科学研究院, 山东, 东营, 257015 3. 农业部, 沼气科学研究所, 成都, 610041

Organization

China University of Mining & Technology, Beijing 100083, China 2. Research Institute of Geosciences, Shengli Bureau of Petroleum Administration, SINOPEC, Dongying, Shangdong 257000, China 3. The Key-open Laboratory of Anaerobic Microbiology, Ministry of Agriculture, Chengdu, Sichuan 610041, China

摘要

通过细菌检测实验,系统分析了渤海湾盆地济阳坳陷生物气源岩中细菌的赋存状况。实验表明,济阳坳陷浅层气源岩中产甲烷菌较为丰富,在2522m深处还有产甲烷菌存在,并且产甲烷菌赋存的源岩与源岩时代无相关关系,只要有适合生物气形成的环境条件,生化作用就可能发生。通过气源岩和原油在不同温度下的生物模拟实验,分析了济阳坳陷生物模拟气产率、组分及碳氢同位素特征,结果表明,无论是气源岩还是原油厌氧降解生成的生物气,都只生成甲烷和二氧化碳;45℃和65℃是生物气生成的高峰期,生物气产率分布范围为每吨TOC产气20~160m3和每吨原油产气10~15m3;生物模拟实验产物的碳同位素值随温度变化差异明显,变化范围为-80.2‰~-41.5‰;生成的二氧化碳的碳同位素值变化与甲烷碳同位素值变化规律相反;生物模拟气中氢同位素的值则比实际生物气的氢同位素值轻,模拟气中氢同位素值主要分布在-300‰~-350‰,而实际生物气的氢同位素值则分布于-240‰~-270‰。

Abstract

Detection of the bacteria in the source rocks from different types of formation,lithology and depth in the Jiyang Depression was carried out in this paper.The result shows that the methane-forming bacteria exist in mudstone and sandstone in Es3,Es1 and Ed formations with depth being from 1 297 to 2 522 meters,indicating that the existence of methane-forming bacteria depends on the survival environment of the bacteria and is independent of rock's formation and lithology.The characteristics of the biogenic gases from source rocks and biodegradation of crude oil are similar in simulation experiment.The products of simulation experiment are mathane and carbon dioxide.Temperatures at the biogenic gas generating peak are 45℃ and 65℃.The yields of biogenic gases generated by a ton of TOC and a ton of crude oil are 20-160 m3 and 10-15 m3 respectively.Carbon isotope compositions of methane which range between -80.2‰ and -41.5‰ become lighter with simulation temperature going up,while carbon isotope compositions of carbon dioxide become heavier.Hydrogen isotope compositions of biogenic gas in simulation which mainly range between -300‰ and -350‰ are lighter than those in actual formation like the Luliang Basin in Yunnan Province which mainly range between -240‰ and -270‰.

关键词：

生物气; 生物模拟实验; 济阳坳陷; 渤海湾盆地;

Keywords:

biogenic gas; biogenic gas simulation experiment; the Jiyang depression; the Bohai Bay Basin;

基金项目

DOI

https://doi.org/10.11781/sysydz200704426

渤海湾盆地济阳坳陷气源岩和原油生物模拟实验研究