不同类型有机质生物产甲烷模拟实验研究

RESEARCH ON BIOGENIC GAS GENERATION SIMULATION EXPERIMENTS ON DIFFERENT TYPES OF ORGANIC MATTER

张英 王晓波 李谨 李剑

Zhang Ying Wang Xiaobo Li Jin Li Jian

北京大学, 石油与天然气研究中心, 北京, 100871 2. 中国石油勘探开发研究院, 廊坊分院, 河北, 廊坊, 065007 3. 中国石油天然气成藏与开发重点实验室, 河北, 廊坊, 065007

Institute of Oil & Gas, Peking University, Beijing 100871, China 2. Langfang Branch, Petro China Research Institute of Petroleum Exploration and Development, Langfang, Hebei 065007, China 3. Key Laboratory of Gas Reservoir and Development, Petro China, Langfang, Hebei 065007, China

为研究不同类型有机质的生物产甲烷能力和特征,选择了代表藻类、水生草本植物、陆生草本植物和泥炭的6个样品进行生物模拟实验研究。实验气体产物的分析结果揭示:不同类型有机质生物产甲烷潜力差异大,藻类和泥炭的产气能力相差可达百倍,藻类等优质有机质对生物气生成和成藏的贡献值得关注;不同类型的有机质生物转化率相差巨大,进行生物气源岩评价时应予以考虑;生物甲烷的碳同位素值受生成过程中碳同位素分馏效应和母质碳同位素的双重控制,分布范围较宽,生物二氧化碳的碳同位素明显偏重。建议鉴别气藏中天然气的成因时,应结合甲烷碳同位素、二氧化碳碳同位素和天然气组分等数据进行多参数综合判识。

In order to study the biogenic methane generating abilities and characteristics of different type of organic matter,six samples of four types of organic matter are selected to take biogenic gas generation simulation experiments.The analyzing result of gas products shows that the differences of biogenic methane product potential among different organic matters are great.Gas generating potential difference between algae and peat is a hundred times.The distribution of high qualifies organic matter such as algae in the biogenic gas source rock and its contribution in gas reservoir formation should be paid more attentions.The biogenic transformation rates of different organic matters are distinguished greatly,so it is worth paying some attentions when evaluating biogenic gas source rock.In addition,the carbon isotope ratio of biogenic methane is doubly controlled by the isotopic fraction effect and the carbon isotope ratio of mother material,and the distribution range is large.The isotope value of biogenic carbon dioxide is obviously heavy.It is suggested many parameters such as methane carbon isotope,carbon isotope of carbon dioxide and gas composition should be comprehend together when identifying the origin of gas reservoir.

中国石油基金项目(2008A-0608)

https://doi.org/10.11781/sysydz200906633