韦二煤矿煤储层物性特征及煤层气资源前景

Physical property characteristics of coal reservoir and prospect of CBM resources in Weier Coal Mine

依据韦州矿区煤炭勘探煤层资料、煤层气参数井获取的储层资料,通过对煤层气开发地质信息的有效提取,对韦二煤矿煤储层物性进行深入分析、研究,对煤层气资源量进行了计算,并采用数模方法预测了煤层气抽采率,确定了地面煤层气抽采相对有利区。研究认为:区内煤层含气性整体偏低,煤层甲烷含量在0.20~11.73 m^3/t,气含量高值区仅出现在部分煤层、局部区域。多期次构造运动致使裂隙发育复杂化,硬度变小,煤体结构多为碎粒—糜棱结构,渗透率降低。主要可采煤层煤层气资源量为5.55×10^8 m^3,资源丰度为1.51×10^8 m^3/km^2,属中等丰度、小型煤层气藏。各煤层煤层气采收率较低,约为15%,可采潜力较差。资源量在煤层分布上相对集中,12、14、15煤层气含量4 m^3/t以上重叠区域为煤层气地面抽采相对有利区块。

Based on the coal seam data of coal exploration in Weizhou Mining Area and the reservoir data obtained from CBM parameter wells,the physical properties of coal reservoir in Weier Coal Mine were deeply analyzed and studied through the effective extraction of geological information of CBM development.The CBM resource quantity was calculated,and CBM extraction rate was predicted by using mathematical model method,and relatively favorable area for surface CBM extraction was determined.The results showed that gas bearing capacity of coal seams in the area is generally low,and the methane content in coal seams ranged from 0.20 to 11.73 m^3/t,and the areas with high gas content only appear in some coal seams and local areas.The multi-stage tectonic movement made the fracture development complicated,the hardness becomes smaller,the coal structure was mostly broken grain mylonite structure,and the permeability was reduced.The main recoverable coalbed methane resource was 5.55×10^8 m^3,and the resource abundance was 1.51×10^8 m^3/km^2,which belonged to medium abundance and small scale coalbed methane reservoir.The recovery rate of CBM in each coal seam was low,about 15%,and the recoverable potential was poor.The resources were relatively concentrated in the coal seam distribution,and the overlapped areas of 12,14 and 15 coalbed methane content above 4 m^3/t were relatively favorable areas for CBM surface extraction.