基于X-CT技术的沁水盆地南部煤储层精细描述

Fine description of coal reservoir in southern Qinshui Basin based on X-CT technology

基于X射线层析扫描(X-CT)技术,通过表征不同煤岩类型煤储层的孔-裂隙和矿物的发育特征,分析煤岩组构,建立煤岩体可视化与三维重构,对沁水盆地南部3号和15号煤层储层特征行了精细描述。结果表明:扫描CT数在不同煤岩类型的样品中呈现较大差异,孔裂隙及矿物发育呈现出较好的规律性;切片平均CT孔隙度及矿物含量均与切片平均CT数有良好相关性。对比这2个煤层的X-CT试验结果,发现3号煤层平均CT数小于15号煤层,说明3号煤层中无机组分含量较低,孔裂隙较为发育,而15号煤层中存在相对多的无机矿物质;3号煤层CT数的极差、标准差和变异系数均大于15号煤层,说明3号煤层的层内非均质性较15号煤层强。

Based on the X-CT technology, with the characterization on the development features of the pore cracks and mineral in the dif- ferent lithotype coal reservoir, the coal fabric was analyzed, the coal and rock mass visualization and 3D reconstruction were established and a fine description was conducted on No. 3 seam and No. 15 seam in southern Qinshui Basin. The results showed that in the different lithotype samples, the CT number would be different and the development of the pore cracks and mineral would have a good law. The average CT porosity and the mineral content of the slices would have a good correlation to the average CT number of the slices. In correlation with the X-CT experiment results of the two seams, the average CT number of No. 3 seam would be less than No. 15 seam. Therefore the inorganic component content of No. 3 seam was low and the pore cracks were well developed. And there were relatively high inorganic minerals existed in No. 15 seam. The CT number of No. 3 seam was very poor and the standard deviation and the variation coefficient would all be higher than No. 15 seam. The above showed that the inhomogeneity in No. 3 seam was higher than No. 15 seam.