Coal Reservoir Laboratory of National CBM Engineering Center, China University of Geosciences ( Beiing) China
United Coalbed Methane Co. , Ltd.

为总结鄂尔多斯盆地东缘构造变形对煤层气的控制作用,结合不同区块构造演化、构造类型、含气量和岩石力学性质,分析了影响煤层气开发的关键因素。结果表明:研究区煤系在三叠纪达最大埋深,在研究区中南部的大地热流有明显上升,较煤变质程度较热流平稳下降的北部高;缓倾斜、单斜、背斜、向斜、推覆构造、逆断层和挤压型层滑等7种有利的阻气构造发育,以缓倾斜和单斜广泛发育且最为有利;受地应力影响,同一井位上下煤层的气体富集程度有较大差异;煤层顶板有泥岩、砂岩和灰岩等,灰岩也具有良好的封存效果。在分析不同顶底板组合和构造结合的基础上,提出了"砂通煤""水包气"的构造控气模式,并划分了有利的储气构造位置。

In order to conclude the structural control effect on coalbed methane in East Margin of Ordos Basin, the key elements control coalbed mathane develop ment were analyzed based on tectonic evolution, structural types, gas content and rock mechanic of coal bearing strata in different blocks. Results showed that the coal strata in the study area were subsided into the deepest depth in Triassic, and the heat flow in the south and middle area increased obviously, which resulted in a higher coal rank than the north under a steadily declined heat flow condition; seven types structure favorable for gas accumulation were developed, e. g. gently incline, monocl ine, anticline ( syncline)，nappe tectonics, reverse fault and extruded layer slip, of which the gently incline and monocline developedwere developed largely and the mo st favorable; under the influence of in-situ stresses, the two sets coal seams of the same well showed magnificent difference in gas accumulation; the coal roof develop ed mudstone, sandstone and limestone, with different effects on methane preservation, of which the limestone showed good sealing effect. Based on the analysis of diff erent coal roof combination and structural patterns, the " co-produced sandstone reservoiring" and " water confining gas reservoring" were proposed, and the prolific str uctural area were also plotted.

国家自然科学基金资助项目(41272175)；国家科技重大专项资助项目(2011ZX05062-01,2011ZX05034-01)；国土资源部公益性行业科研专项资助项目(201311015)；