本文關(guān)鍵詞： 煤層氣 碳同位素 沁水盆地 成因 微生物氣　出處：《煤炭學(xué)報(bào)》2016年06期 　論文類型：期刊論文

【摘要】：為了研究沁水盆地北部寺家莊太原組煤層甲烷(CH_4)及二氧化碳(CO_2)的成因,對(duì)11口煤層氣井排采氣進(jìn)行了化學(xué)組分和同位素測(cè)試,探討了煤層CH_4及CO2的成因及聯(lián)系。結(jié)果表明:沁水盆地北部煤層CH_4平均體積分?jǐn)?shù)為98.6%,CO_2為0.25%,N_2為1.07%;煤層CH_4碳同位素值介于-33.2‰~-40.8‰,平均值為-37.1‰,以煤熱裂解成因?yàn)橹?含有微生物CO_2還原成因CH_4,屬于混合成因煤層氣。沁北煤層CH_4碳同位素分餾起主導(dǎo)作用的是解吸-擴(kuò)散-運(yùn)移作用,儲(chǔ)層淺部壓力小,含輕碳同位素的CH_4優(yōu)先解吸,經(jīng)擴(kuò)散運(yùn)移至上部地層進(jìn)而逸散到大氣中。煤層CO_2的δ~(13)C值為-15.9‰~+0.05‰,平均值為-8.6‰,為煤熱演化初期或最近一次煤層抬升再沉降后煤中有機(jī)質(zhì)熱裂解產(chǎn)生,碳同位素較重的地方受地下水或微生物CO_2還原作用影響。煤層CO_2碳同位素隨煤層埋藏變淺而變重,淺部煤層微生物CO_2還原作用強(qiáng),使CO_2碳同位素變重。
[Abstract]:In order to study the origin of methane CHD _ 4 and CO _ 2) in the coal seam of Sijiazhuang Taiyuan formation in northern Qinshui Basin, the chemical composition and isotopic composition of 11 coal-bed methane wells were tested. The origin and relation of CH_4 and CO2 in coal seam are discussed. The results show that the average volume fraction of CH_4 in coal seam in the north Qinshui basin is 98.6%, the average volume fraction of CH_4 is 0.25%, the carbon isotope value of CH_4 in coal seam is between -33.2 鈥，

本文編號(hào)：1555163