华北地区石炭-二叠系煤层气富集区水文地质特征

HYDROGEOLOGIC FEATURES OF CARBONIFEROUS-PERMIAN COAL BED GAS ENRICHED AREAS IN NORTH CHINA

作者将华北地区煤层气勘探领域的水文地质环境划分为供水、强交替、弱交替、滞缓、停滞及泄水区带６种类型。认为大城地区为承压条件不显著的弱交替－滞缓水文地质环境，晋城地区为开启性弱交替水文地质环境，柳林地区为承压条件好的滞缓水文地质环境。通过对美国圣胡安、黑勇士盆地煤层气富集区、水文地质条件分析，提出距供水区较近，陡水势面背景下的平缓部位、重碳酸纳水型较高矿化度区、古水文地质继承性好的地区有利于煤层气富集。并选出吴堡河谷、三呼庄北、石楼西侧及固县东侧４个有利勘探区块。

Abstract The hydrogeologic environment of coal bed gas fields in North China is divided by the authors into six types: contribution, strong alternation, weak alternation, detention, stagnation and drainage zone. It is considered that the hydrogeologic environment of Dacheng area is a weak alternation detention zone with not obvious confined conditions, that of Jincheng area is an open and weak alternation zone, and that of Liulin area is a detention zone with good confined conditions. By analyzing on the hydrogeologic conditions of coal bed gas enriched areas in the San Juan Basin and the Black Brave Basin of the United States, it is suggested that the areas nearby contribution zones, the gentle areas with sharp water potential surface, the areas with higher degree of NaHCO 3/H 2O type mineralization and the areas with good inherited palaeohydrogeologic conditions are favorable for the enrichment of coal bed gases. The Guanbao River Valley, the northerm part of Sanhuzhuang, the western side of Shilou and the eastern side of Guxian County are elected preliminary as four favorable exploration blocks.