砂岩结构与渗透性尺度转换关联研究

Water brusting from thick sandstone aquifers in north China type coalfields has enormous influence on the safety production in coal mines. Now the breadth and precision of sandstone hydraulic parameters can’t adapt to the requirement of water yield prediction and seepage property evaluation, then the results can’t accord with the fact. Sandstone samples of different depths in the boreholes collected vertically from typical sandstone water-bearing rock group in Kaiping coalfield, their microscopic structures and characteristics of pores distribution will be studied using SEM and CT scanning technology, permeability macro-parameters in field and structural micro-parameters in test should be established, and percolation models be built, the threshold be obtained with analysis, and so, various factors on seepage and the influence of nonlinear seepage will be quantification. The correlation vertical models of permeability macro-parameters with grain structure and microscopic pores features will be established at each point of the plane by Geo-statistics; Combination of section vertical models in different points, using scale conversion and fractal method, the arrangement spatial random function models about macro parameters and microscopic features can be established. The models reliablity should be revised and validated by the model fitting with the field tests information, then the permeability macro parameters at each spatial points for space be acquired by the model solution.

华北型煤田煤层顶板赋存厚层砂岩含水层，其涌（突）水对煤矿安全生产影响极大。目前获取砂岩水力参数的广度和精度均不能适应水量预测、富水性评价的要求，导致结果与实际相去甚远。选择开平煤田典型完整砂岩含水岩组，在钻孔中垂向上采集不同深度的砂岩样本，应用SEM和CT扫描技术，研究其微观砂岩颗粒及孔隙空间分布特征，采用分形几何相、逾渗理论的研究方法，建立渗透性参数与砂岩结构参数的微观关联函数关系，构建逾渗模型，分析逾渗规律，获取逾渗阀值，量化各种因素对渗流启动及非线性渗流的影响。应用地质统计方法，建立各平面点上砂岩渗透性中尺度参数与砂岩颗粒结构、孔隙等微观特性关联的垂向模型；组合剖面上不同深度的垂向模型，采用尺度转换及分形方法，建立砂岩渗透性大尺度参数与砂岩颗粒结构、孔隙等微观特性关联的层次空间随机函数模型，利用已有信息通过模型拟合，验证模型可靠程度，校正模型，获得空间各点对应的渗透性参数。

本项目研究了砂岩结构与渗透性尺度转换关联关系。采集华北煤田典型完整砂岩含水岩横向和垂向上的砂岩样本进行实验研究。开展了铸体薄片、孔渗测试、BET吸附、高压压汞等室内实验研究，获得砂岩样品的成分和组分、孔隙度和渗透率、孔隙结构、孔隙粒径分布等参数。在此基础上，应用SEM和CT扫描技术，研究其微观砂岩颗粒及孔隙空间分布特征，借助分形理论，利用分形方法计算周长、面积等参数，预测砂岩样品的孔隙度和渗透率，并与实测结果进行对比，进而探讨其关联性，建立了砂岩渗透性与结构的函数关系。实际矿井涌水量预测案例表明，砂岩结构与渗透率微观关系，以及升尺度转换关系，不仅可行，而且具有一定精度，说明砂岩微观结构规律及尺度转换代替方法或者辅助野外抽水试验具有可行性。.共发表论文34篇，其中SCI检索论文10篇。出版专著1本，专利6项，软著2项，获奖7项。