基于泉(井)水特性的准噶尔盆地东南缘煤矿硫化氢成因研究

摘要

The enrichment abnormal of hydrogen sulfide (H2S) in the coal-bearing stratum of the southeastmargin of Junggar basin,occurred many casualties.The characteristics of chemical and microbial activity of groundwater can sensitively reflect the change of information in the crust.Based on the characteristics of spring (well) water in the study regions,this paper discussed the origin of hydrogen sulfide in coal mines,which is of great significance to identify the source,occurrence and control of hydrogen sulfide gas in coal bearing strata and the exploitation of coalbed methane and hydrocarbon.The gas composition in coal bed mainly are N2 and CH4,components H2S,CO2 and heavy hydrocarbon,the highest content of H2S in the gas is 2.11％.The chemistry type of stratigraphic water along flow direction changed from HCO3-Ca-Na and HCO3-SO4-Na-Ca into HCO3-SO4-Cl-Na-K.The salinity,hardness and pH value of water gradually become high,which is saltwater of alkalescence.The spring (well)water outcropping in the coal bearing strata,which rich in CH4,N2,CO2,H2S,H2 and some heavy hydrocarbons,et al.The content of methane and water temperature in the spring of No.4 have been downward trend,while the content of H2S,CO2 and SO42-remained stable upward trend.The δ13C values of carbon in water generally from-1.81％ to-1.12％,has the characteristics of little.The number of sulfate reducing bacteria (SRB) up to 3 500 (A/g sample) detected in mine groundwater,which direct the SRB breed intense.About 4.35％ clone have relation with the anaerobic oxidation of methane in the No.10 spring,in addition,SRB within the anaerobic sulfur environment from habitat in the deep strata (coal bearing strata)in water also was detected.The conclusions indicate that the water body is in anaerobic condition,the propagation of microorganisms in the spring water is closely related to the sulfur compounds.Both above have the characteristic of BSR.While the coal forming environment and coal and rock burned are not enrichment of large-scale H2S.So that,the formation of H2S is in a close connection with the BSR in the later stage.%位于准噶尔盆地东南缘地带的矿区含煤地层硫化氢富集异常,发生过多起伤亡事故.地下水体的化学特性、微生物活动特征能灵敏地反映地壳内部信息变化,基于区域泉(井)水特性,探讨煤矿硫化氢成因,对查明煤岩层硫化氢气体的来源、赋存和防治,以及煤层气、油气等开采具有重要意义.煤矿瓦斯气体组分以CH4,N2为主,伴有CO2,H2S和重烃等;区域地层水沿径流方向水化学类型由HCO3-Ca-Na和HCO3-SO4-Na-Ca演变成HCO3-SO4-Cl-Na-K,矿化度、硬度及pH逐渐变高,为弱碱性咸水;含煤地层出露泉水富含CH4,N2,CO2,H2S,H2和重烃气体;4号泉CH4含量和水温一直呈下降趋势,而H2S,CO2及SO42-含量则保持平稳上升趋势;水体中CO2的δ13 C值较轻,普遍在-1.81％ ～-1.12％间.矿井地下水水体检测到的硫酸盐还原菌(SRB)数量最高达3 500个/g,表明SRB繁衍活动激烈;10号泉4.35％的克隆子与CH4厌氧氧化相关,还检测到一些来自栖息于地层深部(含煤岩层)水体中与厌氧含硫环境中的SRB,表明水体处于厌氧状态,泉水中微生物的繁衍生息与含硫化合物密切相关.上述均具有发生硫酸盐生物还原(BSR)作用的特征,而区域成煤环境及煤岩层火烧都不具备大规模H2S富集条件,由此可知,目前区域硫化氢的形成与后期的BSR作用有密切联系.