韩城矿区煤岩类型对微裂隙发育的控制机理  

Mechanism of Coal Lithotypes Control on Microfissure Development in Coal Seams in Hancheng Area,Shaanxi Province

作　　者：房媛[1] 汤达祯[1] 许浩[1] 喻廷旭[1] 唐淑玲[1] 赵俊龙[1] 

机构地区：[1]中国地质大学能源学院,北京100083

出　　处：《新疆石油地质》2014年第5期526-530,共5页Xinjiang Petroleum Geology

基　　金：国家自然科学基金(41272175);大型油气田及煤层气开发国家科技重大专项(2011ZX05038-001)

摘　　要：韩城矿区煤岩类型纵向变化频繁,煤层非均质性强。裂隙多为长度大于300μm,宽度小于5μm的树枝状和正交状裂隙,微裂隙多发育在光亮煤和半亮煤中;据核磁共振T2弛豫谱分析,从光亮煤、半亮煤到半暗煤和暗淡煤,T2谱图由吸附孔、渗流孔和裂隙发育的三峰分布渐变为吸附孔、渗流孔发育的双峰分布特征,裂隙发育程度逐渐变弱,渗流孔和吸附孔之间连通性变差,吸附孔含量逐渐增加。核磁共振分析结果与X-CT扫描结果较为一致。对不同煤岩类型裂隙发育特征及煤岩显微组分分析认为,生烃潜能和扩散能力是微裂隙发育的决定因素。The production horizons in Hancheng area of Shaanxi province are characterized by longitudinally alternating coal lithotype changes and strong heterogeneity in the coal seams.The relationship between the coal lithotype and the microfissure development are analyzed by means of microscopic observation and fractal approach,combined with X-ray CT and NMR T2 spectrum analysis technologies.The results show that the microfissures are dominated by the dendritic and orthogonal types with length of over 300 μm and width of less than 5 μm,and much more developed in bright coal and semibright coal.The NMR T2 spectrum analysis indicates that from bright and semibright coal to semidull and dull coal,the trimodal pore-size distribution of adsorption pore,seepage pore and fissure is changed to bimodal distribution of adsorption pore and seepage pore.The development degree of microfissure and the connectivity between adsorption pore and seepage pore are gradually weaken,with the trend of the adsorption pore increase,showing a good consistency between the NMR T2 and the X-ray CT results.It is suggested from the microfissure development characteristics of different lithotypes and the correlations to coal macerals that hydrocarbon generation potential and its diffusion ability are the key factors of the microfissure development.

关 键 词：韩城矿区 微裂隙 核磁共振 X-CT扫描 煤岩类型 

分 类 号：TE122.2[石油与天然气工程—油气勘探]