准南阜康区块煤层后生生物成因H_(2)S的发现与成因机制  

Discovery and generation mechanisms of epigenetic biogenic H_(2)S from coal seams in the Fukang block,southern Junggar Basin,China

作　　者：闫佩佩 苏现波[1,2,3,4] 邹成龙 赵伟仲 汪露飞 伏海蛟 YAN Peipei;SU Xianbo;ZOU Chenglong;ZHAO Weizhong;WANG Lufei;FU Haijiao(Institute of Resources&Environment,Henan Polytechnic University,Jiaozuo 454003,China;Unconventional Gas Research Institute,Henan Polytechnic University,Jiaozuo 454003,China;School of Energy Resources,China University of Geosciences(Wuhan),Wuhan 430074,China;Collaborative Innovation Center of Coalbed Methane and Shale Gas for Central Plains Economic Region,Jiaozuo 454003,China;Xinjiang Cleanseed New Energy Co.Ltd.,Fukang 831500,China)

机构地区：[1]河南理工大学资源环境学院,河南焦作454003 [2]河南理工大学非常规天然气研究院,河南焦作454003 [3]中国地质大学(武汉)资源学院,湖北武汉430074 [4]中原经济区煤层(页岩)气协同创新中心,河南焦作454003 [5]新疆科林斯德新能源有限公司,新疆阜康831500

出　　处：《煤田地质与勘探》2023年第10期52-61,共10页Coal Geology & Exploration

基　　金：国家自然科学基金重点项目(42230804);国家自然科学基金面上项目(42072193)。

摘　　要：随着排采的进行准南东段阜康区块煤层气井产出的煤层气中H_(2)S浓度呈现逐渐增加的趋势,对安全生产构成严重威胁。基于煤层气勘探开发资料,结合实验室厌氧发酵实验,对该区块排采阶段煤层H_(2)S的异常原因进行初步探讨。煤层气勘探阶段含气量测试结果表明,煤层气原始气体中H_(2)S含量低,最高仅为2.152×10^(−6);排采初期并未出现H_(2)S浓度异常现象,但随着排采的进行,部分井出现异常,如13号井在排采7 a后H_(2)S含量异常增加,高达700×10^(−6)。灰色关联分析表明,H_(2)S的浓度与煤层气井的产水量和水质密切相关,当地下水的补给带来充足的营养物质供给菌群代谢时,就会促进H_(2)S的产出。由该区煤和排采水作为发酵基液构建的厌氧发酵系统表明,H_(2)S的产量与发酵液中SO_(4)^(2−)含量成反比、与HCO_(3)^(−)含量成正比;CH4的产气高峰滞后于H_(2)S,且累计生成量显著低于H_(2)S,而由该区的煤与蒸馏水作为发酵基液构建的厌氧发酵系统则以产CH4为主,仅生成微量的H_(2)S,说明H_(2)S是硫酸盐还原菌以CH4为电子供体还原SO_(4)^(2−)生成的;发酵液中小分子有机酸含量的不断减少说明硫酸盐还原菌同样利用了有机酸为电子供体还原SO_(4)^(2−)生成H_(2)S。因此,现场生产资料和实验室厌氧发酵结果表明该区H_(2)S是由煤层水中的SO_(4)^(2−)被硫酸盐还原菌还原生成。这种排采阶段生成的生物气与以往人们认为的原生和次生生物气都不相同,将其称为后生生物气,其中的H_(2)S称为后生生物H_(2)S。排采过程中后生生物气的生成进一步说明人工干预下的煤层气生物工程实施的可行性。In the Fukang block located in the eastern part of the southern Junggar Basin,coalbed methane(CBM)from CBM wells exhibits a gradually increasing H_(2)S concentration in the process of CBM production via water drainage,severely threatening production safety.Based on the CBM exploration and extraction data,as well as the anaerobic fermentation experiments,this study preliminarily investigated the causes of abnormal H_(2)S concentrations during the CBM production in the Fukang block.As indicated by the gas content test in the CBM exploration stage,the original CBM showed a low H_(2)S concentration of only up to 2.152×10^(−6).Abnormal H_(2)S concentrations did not occur at the beginning of CBM production.However,some wells exhibited abnormal H_(2)S concentrations as CBM production proceeded.For example,the No.13 CBM well showed an abnormal increase in H_(2)S concentration after seven years of gas production,with the H_(2)S concentration reaching 700×10^(−6).The grey relational analysis reveals that the H_(2)S concentration is closely related to the yield and quality of water in CBM wells.H_(2)S generation can be promoted under a sufficient supply of nutrients from groundwater for microbial metabolism.As shown by the anaerobic fermentation system constructed with the coal and water produced from the Fukang block as the anaerobic broth,the H_(2)S production was inversely and positively proportional to the SO_(4)^(2−)and HCO_(3)^(−)contents in the fermentation broth,respectively.In this system,CH4 showed a lagging gas production peak and significantly lower cumulative gas production compared to H_(2)S.However,the anaerobic fermentation system constructed with coal from the block and distilled water as the fermentation broth primarily produced CH4,with only a small amount of H_(2)S.These findings indicate that H_(2)S was generated from the reduction of SO_(4)^(2−)by sulfate-reducing bacteria(SRB)using CH4 as electron donors.The gradually decreasing content of low-molecularweight organic acids in the fermentat

关 键 词：准南阜康区块 煤层气井水 硫酸盐还原 SO_(4)^(2−) 后生生物成因H_(2)S 

分 类 号：P618.11[天文地球—矿床学]