摘要
为了探讨含H2S煤层沉积环境特征,以彬长矿区小庄矿延安组4^#煤层为研究对象,借助X⁃射线衍射仪、液晶库伦定硫仪、X⁃射线荧光光谱仪、等离子体质谱分析仪、稳定同位素质谱仪等实验仪器,从煤层显微组分、矿物组分、煤体孔隙及吸附特征、古盐度、沉积环境氧化还原性、水动力学表征指数、同位素特征及煤层热演化史等方面,对该区域煤层沉积环境特征进行了研究,并明确了煤层H2S的成因类型。研究结果表明:①研究区地质构造简单,井田中心带的南玉子向斜对H2S的富集有一定影响,且煤层顶底板岩性以泥岩为主,透气透水性差,对H2S富集起到封堵作用;②4^#煤层富含有机质(植物化石)、碳酸盐矿物,地层古盐度Sr/Ba值较小(<0.5),沉积环境表征(U/Th值、Cu/Zn值以及还原性指数K)为厌氧—弱还原性,以上条件为该区域煤层H2S的生成提供了原料和环境基础;③煤层黄铁矿δ^34S值(-9‰^-0.6‰)偏负、甲烷δ^13C1值偏低(<-55‰),煤层热演化温度(96~113°C)低于120°C,综合得到研究区成因类型以生物硫酸盐还原成因(BSR)为主。
In order to study the sedimentary environment characteristics of H2S-bearing coal seam,taking 4^# coal seam of Yan’an Formation in Xiaozhuang mine,Bingchang mining area as a research object. With the help of Xray diffractometer,liquid crystal coulomb sulfur analyzer,X-ray fluorescence spectrometer,plasma mass spectrometry,stable isotope mass spetrometer and other experimental instruments,the sedimentary environment characteristics of the study area were studied,and the genesis type of H2S was defined,in the aspect of the coal maceral,mineral composition,salinity,oxidation reduction and water dynamic characterization of index,the sedimentary environment isotope and thermal evolution history of coal seam. The research results show that:(1)the geological structure of the study area is simple,and the Nanyuzi syncline in the central belt of the wellfield has a certain impact on the enrichment of H2S. In addition,the lithology of the top and bottom of the reservoir is dominated by mudstone with poor permeability and water permeability,which plays a plugging role in the enrichment of H2S.(2)No.4 coal seam is rich in organic matter(plant fossils)and carbonate minerals. The paleosalinity index Sr/Ba value of the strata is small(<0.5).(3)The δ^34S value of coal pyrite is negative(from-9‰ to-0.6‰),while the methane δ^13C1 value is negative(<-55‰),the thermal evolution of coal seam temperature(96 ℃ to 113 ℃)below 120 ℃,therefore,the study area is dominated by biological sulfate reduction(BSR).
作者
张静非
赵继展
陈冬冬
李树刚
林海飞
ZHANG Jing-fei;ZHAO Ji-zhan;CHEN Dong-dong;LI Shu-gang;LIN Hai-fei(Xi’an Research Institute of China Coal Technology and Engineering Group Corporation,Xi’an 710077,China;School of Safety Engineering,Xi’an University of Science and Technology,Xi’an 710054,China)
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2020年第1期100-109,共10页
Natural Gas Geoscience
基金
国家自然科学基金科学仪器基础研究专项（编号：51327007）
国家自然科学基金（编号：51504189
51674192）
中煤科工集团西安研究院有限公司科技创新基金资助项目（编号：2017XAYZD06
2018XAYZD10
2018XAYMS08）联合资助~~
关键词
含H2S煤层
沉积环境
成因类型
富集
生物硫酸盐还原作用
H2S-bearing ccoal seam
Sedimentary environment
Genesis type
Enrichment
Biological sulfate reduction
