砂岩微观孔隙分形特征与宏观渗透性能的相关性

发布时间：2018-11-05 15:24

【摘要】：为探索砂岩孔隙微观特征与宏观渗透性能的相关性,针对酸刺沟煤矿3个钻孔不同深度9个砂岩样本的SEM图像(放大1 000倍)进行统计分析,SEM图像中孔隙"周长-面积"具有较好的分形特征,分形维数值取1~1.3.之后,借鉴宏观砂岩孔隙中水体渗流的不等径毛束管模型,建立了基于微观孔隙分形特征的渗流不等径毛束管理论模型,推导了微观尺度下渗透系数和渗透率的计算理论模型,计算了各样本的渗透率和渗透系数,取值范围分别在0.002~0.09 m D和1.2~24.4 m/s.为验证理论模型的计算结果,对相同岩芯样本的渗透率进行了中尺度下的实测,实测值取值范围0.34~0.59 m D.最后经相关分析,建立了微观尺度和中尺度下渗透率的相关关系式,相关系数为0.7.可以得出结论,所建立砂岩孔隙微观尺度下渗透率计算的理论公式有一定的合理性,其与中尺度的渗透率存在一定的相关性.
[Abstract]:In order to explore the correlation between microcosmic characteristics of sandstone pores and macroscopic permeability, the SEM images of 9 sandstone samples with different depths in 3 boreholes in Suozhigou coal mine were analyzed statistically. The "circumference and area" of pores in SEM images have good fractal characteristics, and the fractal dimension values are taken as 1 ~ 1. 3. Then, using the model of unequal diameter capillary tube for reference, a theoretical model of percolation with unequal diameter capillary tube based on fractal characteristics of micro-pore is established, and the theoretical model of permeability coefficient and permeability is derived at microscopic scale. The permeability and permeability coefficient of each sample are calculated in the range of 0.002 ~ 0.09 mm D and 1.2 ~ 24.4 m / s, respectively. In order to verify the calculated results of the theoretical model, the permeability of the same core samples was measured at mesoscale, and the measured values ranged from 0.34 to 0.59mD. Finally, by correlation analysis, the correlation between microscale and mesoscale permeability is established, the correlation coefficient is 0.7. It can be concluded that the theoretical formula for calculating the permeability of sandstone pores on micro scale is reasonable and has a certain correlation with mesoscale permeability.
【作者单位】：中国矿业大学(北京)资源与安全工程学院;华北科技学院安全工程学院;
【基金】：国家自然科学基金(41072188) 新世纪优秀人才支持计划(NCET-11-0838) “十二五”国家科技支撑计划(2012BAK04B04)
【分类号】：P641.4

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