宁夏汝箕沟矿区煤层气地质学特征

根据煤田勘探、煤矿开采阶段的资料,结合室内外观测测试,探讨了二号煤的煤层气地质学特征: a. 汝箕沟矿区二号煤厚度巨大、连续性强、含气量高,为煤层气开发奠定了物质基础; b. 煤阶高,但基质孔隙、割理、外生裂隙发育,储层渗透性好; c. 区域上异常高压的分布范围可能比较广泛,且吸附等温线反映出利于降压排采的特征。这些都充分说明该区煤层气的勘探开发可与沁水盆地相媲美,且在煤厚、渗透性、异常压力、吸附等方面优于沁水盆地。

Coalbed gas geological characteristics of No.2 coal in Rujigou district, Ningxia

According to the data collected from different stages of coal exploration, coal mining, field investigation and laboratory measurements, the reservoir characteristics of No.2 coal are emphasized in this paper. The results show: a. No.2 coal seam is thick, laterally extensive, and high gas content, and that is the foundation for coalbed methane development; b. Although the coal rank is high, the matrix pores, cleats, and fractures are well-developed, therefore, the reservoir permeability is high; c. Perhaps the abnormal high reservoir pressure distributes regionally, as well as the adsorption isotherm showed that the coalbed gas can be quickly developed during depressurizing process. The conditions of coalbed gas ara more favorable for development in the Rujigou district than that in the Qinshui basin with the correlations of coal thickness, permeability, abnormal high pressure, and adsorption.