贵州水城矿区煤层气地质条件与可采潜力分析

CBM Geological Condition and Exploitation Potential in Shuicheng Mining Area,Guizhou

水城矿区煤层气资源丰富,在分析矿区煤储层物性和含气性的基础上,估算了煤层气可采性参数,评价了煤层气的可采潜力。结果显示:水城矿区煤层顶、底板以及含煤地层上覆地层均为良好的区域性盖层,煤层气保存条件较好;矿区良好的煤岩、煤质特征和孔隙结构特征为煤层气的大量生成和富集奠定了基础;煤层气理论平均采收率为31.66%,可采资源量为1158×108m3,平均可采资源丰度0.98×108m3/km2,对煤层气开发较为有利;煤层的渗透性较低,可能对煤层气地面排采带来不利影响。建议矿区在煤层气地面开发工作中,注重煤储层渗透性的有效改善,并探讨矿井—地面开发结合的可行性。

CBM resource is abundant in the Shuicheng mining area.Based on mining area coal reservoir physical property and gas content analysis,have estimated and assessed CBM exploitable parameters and potential.The results have demonstrated that coal seam roof,floor and overlying coal -bearing strata in the mining area are good capping regionally,thus better CBM preserving condition.Mining area＇s good coal petrological,quality characteristics and pore structural features have laid the foundation for abundant CBM generation and enrichment.Theoretical average CBM recovery efficiency is 31.66%,recoverable resource 1 158 × 108m3,average recoverable abundance 0.98×108m3/km2,thus beneficial to CBM exploitation.Since the low CBM permeability,may bring disadvantages to CBM drainage from surface.The paper has advised that effective improvement of coal reservoir should be paid attention to CBM surface exploitation,and underground-surface combinative exploitation feasibility discussed.