阳泉新景矿高煤级煤的孔隙结构分形特征

发布时间：2018-04-01 17:08

本文选题：压汞　切入点：高煤级煤　出处：《煤田地质与勘探》2017年03期

【摘要】：分形理论是宏观上定量评价储层非均质性的有效手段。以阳泉新景矿高煤级煤样品压汞数据为基础,建立分形几何模型,定量描述了孔隙结构。实验结果表明:样品孔隙以纳米孔为主,孔径、比表面积及孔容也集中分布在纳米孔段。煤样孔径65 nm以上的孔隙具有显著的分形特征,分维值分布范围为2.89~2.99,体积增量呈现阶段式的变化,孔隙结构复杂;孔径65 nm以下孔隙几乎无分形特征,比表面积增量与孔径在对数坐标中呈线性关系;基于分形特征及分子运动规律,将储层孔隙以孔径65 nm为界划分为扩散孔和渗透孔2个大类6个小类。分维值与体积孔隙中值半径、总孔隙体积呈负相关,与孔径65 nm以上的孔隙体积、比表面积呈正相关,与孔隙度无相关性。分形分维值对储层结构具有较全面的表征能力,可以作为综合指标在煤储层孔隙研究中加以应用。
[Abstract]:Fractal theory is an effective method to quantitatively evaluate reservoir heterogeneity.Based on the mercury injection data of high rank coal samples in Xinjing Coal Mine, Yangquan City, a fractal geometric model was established and the pore structure was quantitatively described.The experimental results show that the pore size, specific surface area and pore volume of the sample are mainly nano-pore, and the pore size, specific surface area and pore volume are also concentrated in the nano-pore segment.The pore size above 65 nm of coal sample has obvious fractal characteristics, the fractal dimension distribution range is 2.89 ~ 2.99, the volume increment presents the change of stage, the pore structure is complex, and the pore size below 65 nm has almost no fractal characteristic.The increment of specific surface area is linearly related to pore size in logarithmic coordinates, and based on fractal characteristics and molecular motion law, the pore size of reservoir is divided into two groups, diffusion pore and permeable pore.The fractal dimension is negatively correlated with the median radius of pore volume and the total pore volume, and is positively correlated with pore volume over 65 nm and specific surface area, but has no correlation with porosity.Fractal fractal dimension has a more comprehensive ability to characterize reservoir structure and can be used as a comprehensive index in the study of coal reservoir porosity.
【作者单位】：中国石油大学(北京)地球科学学院;中国矿业大学(徐州)资源与地球科学学院;煤层气资源与成藏过程教育部重点实验室;
【基金】：国家重点基础研究发展计划(973计划)课题(2012CB214702) 2014年山西省煤基重点科技攻关项目(MQ201402) 煤层气资源与成藏过程教育部重点实验室(中国矿业大学)开放基金资助项目(2015-007) 中国矿业大学大学生创新训练项目(201415,201517)~~
【分类号】：P618.13

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