沁水盆地樊庄北部构造特征与煤层气富集

樊庄区块位于沁水盆地南部,地层自下向上依次有本溪组、太原组、山西组、下石盒子组、上石盒子组和石千峰组,其中太原组15号煤和山西组3号煤是区内可采煤层,也是煤层气开发的目的地层。本文通过樊庄北部三维地震解释成果,利用导向滤波、相干属性等手段,对区内断层、褶皱、微构造、陷落柱精细刻画,对煤层构造、埋深、厚度、含气性有了更全面的认识,揭示了区内发育多期褶皱断层复合叠加带,陷落柱聚集和带状分布特征,地下水由西南片向东北片不断运移,影响了不同流经区域的产气量,综合以上分析,认为构造是樊庄北部煤层气富集的主要影响因素。

Structural Characteristics and CBM Enrichment in North Fanzhuang of Qinshui Basin

The Fanzhuang Block is located in south of Qinshui Basin, and the formations in this area from below are Benxi Formation, Taiyuan Formation, Shanxi Formation, Xiashihezi Formation, Shangshihezi Formation and Shiqianfeng Formation. The No. 15 Coal Seam of Taiyuan Formation and No.3 Coal Seam of Shanxi Formation are the recoverable coal seams within the area, which is also the targeted seams of CBM development. According the results of 3-D seismic interpretation, the paper makes use of steerable filter and coherence attribute to meticulous depict the faults, folds, micro structure and collapse columns in the area, and to achieve a comprehensive knowledge about the structure, burial depth, thickness and gas content of the coal seams. It also proposes the characteristics of the area, including development of the composite and superimposed zone of multiple folds and faults, accumulation of collapse columns, zonal distribution, and continuous migration of underground water from southwest to northeast, which brings influence on the gas production of different regions flowing through. Based on the analysis, it come to a conclusion that the structure is the major influencing factor on CBM enrichment in North Fanzhuang.