我国瘦煤储层物性特征分析

摘要

The lean coal resources are abundant in China. Total resources above depth 2 000 m have 1 227.86×108 tons, and mainly dis⁃tributed in Shanxi, Guizhou, Henan, Shaanxi and Sichuan provinces. To assess lean coal physical features, analyzed, measured and col⁃lected lean coal samples maceral, proximate analysis, ultimate analysis, aperture structure, porosity and isothermal adsorption tested da⁃ta from 49 different area. The result has shown that lean coal maceral is mainly vitrinite, then inertinite, almost no exinite. Along with increasing of coalification degree, Mad and Vdaf gradually decreasing, Cdaf, Ndaf contents gradually increasing, Hdaf, Odaf contents gradually decreasing, H/C and O/C atomic ratios gradually decreasing. Transitional pores and micropores are rather developed, macropores the second, mesopores poor developed. Micropore content and porosity present slowly increasing trend along with increasing of coalification degree;the Longmuir volume is the same, while Longmuir pressure and equilibrium water content present slowly decreasing trend.%我国瘦煤资源丰富，埋深2000 m以浅的瘦煤资源总量为1227.86×108 t，主要分布在山西、贵州、河南、陕西、四川等地。为评价我国瘦煤储层物性特征，分析了49个不同地区瘦煤煤样的显微煤岩组分、工业分析、元素分析、孔径结构、孔隙度、等温吸附实验数据，结果表明：我国瘦煤煤岩显微组分以镜质组为主，惰质组次之，几乎不含壳质组；随煤化程度的增加，Mad和Vdaf逐渐减少，Cdaf、Ndaf含量逐渐增大，Hdaf、Odaf含量逐渐减少，H/C原子比和O/C原子比逐渐减小；过渡孔、微孔较为发育，大孔次之，中孔发育较差；微孔含量和孔隙度均随煤化程度的增加呈现缓慢增加的趋势；朗格缪尔体积随煤化程度的增加呈现缓慢升高的趋势，朗格缪尔压力及平衡水含量随煤化程度的增加呈现缓慢下降趋势。