【摘要】：為進一步厘清沁水盆地高階煤煤層氣富集機理,綜合運用地球化學分析測試技術(shù),系統(tǒng)刻畫了沁水盆地南部煤層含氣量和煤層氣分子組成特征,初步探討了其影響因素。研究結(jié)果顯示沁水盆地南部各區(qū)塊煤層含氣量呈南高北低分布趨勢。煤層含氣量與煤化程度具有顯著正相關(guān)性,這可能與煤層內(nèi)有機孔隙發(fā)育關(guān)系密切;與煤層厚度,尤其薄煤層厚度(≤2m)具顯著正相關(guān)性,當煤層厚度大于2m時這種相關(guān)性反而不甚明顯,表明研究區(qū)煤層氣賦存狀態(tài)以吸附態(tài)為主,薄煤層中氣體飽和度相對較低;含氣量與煤層埋深和上覆地層剝蝕量之間在南部區(qū)塊沒有顯著相關(guān)性,在北部區(qū)塊呈現(xiàn)出弱相關(guān)性,表明煤層氣主要以吸附態(tài)存在,北部區(qū)塊保存狀況可能相對較好。研究區(qū)煤層氣屬于典型干氣,南部區(qū)塊煤層氣甲烷含量和穩(wěn)定碳同位素值均較北部區(qū)塊高,非烴氣體含量則相對較低。煤化作用程度是控制煤層氣分子組成和煤層甲烷穩(wěn)定碳同位素組成的重要因素。煤層氣吸附-解吸-擴散-運移散失可導致煤層氣富含CO_2,甲烷穩(wěn)定碳同位素值偏重。次生生物氣的生成對部分煤層甲烷穩(wěn)定碳同位素組成影響顯著。該研究對于尋找沁水盆地煤層氣"甜點"區(qū)具有重要意義。
[Abstract]:In order to further clarify the enrichment mechanism of high order coal bed methane in Qinshui Basin, the gas content and molecular composition of coal seam in the southern part of Qinshui Basin are systematically described by using geochemical analysis and test techniques, and the influencing factors are discussed. The results show that the gas content of coal seam in the south Qinshui basin is high and low in north and south. There is a significant positive correlation between coal bed gas content and coalification degree, which may be closely related to the development of organic pores in coal seam. There is a significant positive correlation with the thickness of coal seam, especially the thickness of thin coal seam (鈮，

本文編號：2403985