关于煤层气资源量估算中可采边界的探讨

以往煤层气勘探资源量计算过程中,在有些低煤阶煤矿区存在含气量很高,但甲烷含量不足80％的情况,按原标准仍然处于风化带内,而这些区域则正在进行商业开发,但却不能估算煤层气资源量.本文通过对煤层气风化带的划定标准及各类区域煤层气含气特征的分析,以及从资源量计算的实际需要出发,提出仍然用煤层气含量和甲烷浓度两项指标确定低煤阶...

Discussions on Recoverable Boundary during Estimations of Coalbed Methane Resources

During the previous processes of the coalbed methane(CBM) resources calculations, in some low-rank coal mining area, the gas content of coal reservoir is very high while the methane concentration is less than 80%. According to the original standard, those low-rank coals are still in the weathering zone, leading to that the CBM resources of those low-rank coals cannot be calculated, though the business development of those low-rank coal mining area is already in progress. A solution to solve this contradiction is presented in this paper according the actual requirement for the CBM resources calculations, by means of analyzing the definition criteria of the methane weathering zone and the gas bearing characters of coals deposited in different kinds of regions. In this solution, indexes of gas content and methane concentration are still applied to define the recoverable boundary while the influences of methane weathering region are not considered. The solution presented in this paper can provide new insights for the CBM resources calculations and can also be applied for the CBM resources calculations of high-rank coals.