高校地质学报2017，Vol.23Issue(3)：499-510,12.DOI:10.16108/j.issn1006-7493.2017004
鄂尔多斯盆地紫金山地区煤孔隙分形规律及其主控地质因素分析
The Fractal Regularity of Coal Porosity and Its Controlling Geological Factors in Zijinshan Area
摘要
Abstract
Through the pore structure test of gas-fat coal from Zijinshan area in Eastern Ordos Basin,the main geological factors are analyzed and coalbed methane potential information implied by fractal dimension is suggested on the basis of describing the development characteristics and fractal law of the main coal seam.The results show that the porosity of coal is low in Zijinshan area.The pore structure is mainly composed of micropores,macropores and transition pores take the second places,and mesopores are the least.Microporous had the most contribution rate to pore volume and specific surface area,reflecting that the main coal seam is beneficial to adsorbent CBM.There are three types of coal pores in the study area based on the analysis of mercury injection curve,combined with mercury injection parameters analyzing.No.8 +9# has more open holes,and its pore throat distribution is relatively concentrated and relatively large,and hence it is more conducive to coalbed methane seepage than No.4 + 5#.The boundary of coal sample adsorption pore and seepage pore is determined as 100 nm in the study area based on the fractal analysis of mercury injection data.The fractal dimension of pore is greatly influenced by the degree of metamorphism,No.4 +5# is mainly formed by deep metamorphism,No.8 +9# is subjected to relatively strong regional magmatic thermal metamorphism.Deep metamorphism is beneficial to the increase of coal adsorption capacity.The regional magmatie metamorphism can effectively improve the structure of coal,enhance the connectivity of the pores and improve the desorption,diffusion and seepage capacity of coal seam.In addition,the fractal dimension is also influenced by the ash yield and coal macerals.Combined with the analysis of gas-bearing parameters,No.8 + 9# has a higher degree of recovery than No.4 + 5# coal when resources are similar.关键词
紫金山地区/气-肥煤/孔隙结构/分形特征Key words
Zijinshan area/gas-fat coal/pore structure/fractal feature分类
天文与地球科学引用本文复制引用
王博洋,秦勇,申建,汪岗,孙泽飞..鄂尔多斯盆地紫金山地区煤孔隙分形规律及其主控地质因素分析[J].高校地质学报,2017,23(3):499-510,12.基金项目
国家科技重大专项(2016ZX05041-001) （2016ZX05041-001）
国家自然科学基金重点项目(41530314) （41530314）
