利用测井资料评价煤层顶底板的裂缝发育程度

Evaluation of fracture development degree in coal seam roof and floor based on logging data

针对常规测井难以有效评价煤层顶底板裂缝发育程度的问题,对鄂东气田东缘韩城矿区50块煤层顶底板砂泥岩样品进行岩石力学特性实验研究。在静态力学参数刻度测井资料计算的动态岩石力学参数的基础上,对煤层顶底板的完整性系数、破裂系数、稳定性系数进行了计算,进而对研究区煤层顶底板裂缝发育程度进行评价。结果表明:所述方法能够有效地预测煤层顶底板的裂缝发育程度;研究区煤层顶底板裂缝较为发育。煤层含气量分析化验和排采结果显示,在裂缝发育的井区含气性和排采出气量较低,表明煤层顶底板的封闭性较差。

It is difficult to effectively evaluate the fracture development degree in coal seam roof and floor according to conventional logging data. For solving this problem,the mechanical properties of 50 rock samples of the coal seam roof and floor from Hancheng Mining in the eastern edge of Ordos Basin are studied in laboratory. The dynamic rock mechanics parameters are calculated based on the logging data scaled by static rock mechanics parameters. Based on this,the integrity coefficient,the rupture coefficient and the stability coefficient of the oal seam roof and floor are calculated,and the fracture development degree in the coal seam roof and floor is evaluated. It is shown that the fractures are developed in the coal seam roof and floor,and the fracture development degree evaluation method is effective. The coalbed gas content analysis result and coalbed gas recovery result show that the gas content and the gas production in developed fracture area are low,which indicates that the sealing of coal seam roof and floor is poor.