School of Resources and Earth Sciences, China University of Mining and Technology, Xuzhou , China; 2. MOE Key Lab of Coal Bed Methane Resources and Reservoir Formation Process, Xuzhou , China

为探究煤系灰岩储层的孔隙结构，选取霍西煤田义棠矿F7断层附近太原组中K2灰岩进行了压汞测试，结合分形模型，定量化分析了孔隙结构的非均质性、分形维数与孔隙结构参数间的相互关系，并与其他储层分形特征进行了对比，讨论了水文地质条件对煤系灰岩储层分形维数的影响。结果表明：样品孔隙主要以微米中孔为主，分形维数为2.666 9~2.840 3，平均为2.760 8，介于煤层与砂岩储层之间，与页岩储层分形维数值相近；F7断层东北侧灰岩分形维数更高，非均质性更强；分形维数与基质孔隙度表现出正相关的关系，而与孔容表现出负相关的关系；对于发育导水断层的煤系灰岩区，分形维数会随着地下水的流向而增大。

In order to explore the pore size structure of the coal measures limestone reservoir, a pressurized mercury test was conducted in Limestone K2 of Taiyuan Formation near Fault F7 of Yitang Coalfield. In combination with the fractal model, a quantitative analysis was conducted on the heterogeneity of the pore size structure and the mutual relationship between the fractal dimension and the pore size structure parameters. A comparison was conducted with the fractal features of other reservoirs. A discussion was conducted on the hydrogeologic condition affected to the fractal dimension of the coal measure limestone reservoir. The results showed that the pore of the samples mainly were the micro mesoporous, the fractal dimension was between 2.666 9～2.840 3 and the average fractal dimension was 2.760 8.The pore fractal dimension was between the seam and sandstone reservoirs and was close to the fractal dimension of the shale reservoir. The limestone at the north east of Fault F7 had a higher fractal dimension and a higher heterogeneity. There was a positively related relationship between the fractal dimension and the matrix porosity and the negative related relationship between the fractal dimension and the pore volume. As for the coal measures limestone area in the developed water flow fault, the fractal dimension would be increased with the flow direction of the groundwater.