煤层群条件下的煤层气成藏特征  

Coalbed methane (CBM) reservoir-forming character under conditions of coal seam groups

作　　者：杨兆彪[1] 秦勇[1] 高弟[1] 王斌[2] 

机构地区：[1]中国矿业大学资源与地球科学学院,江苏徐州221116 [2]胜利石油管理局井下作业公司试气2队,山东东营257077

出　　处：《煤田地质与勘探》2011年第5期22-26,共5页Coal Geology & Exploration

基　　金：国家自然科学基金项目(40730422);江苏省科研创新计划项目(CX09B_117Z)

摘　　要：基于对我国煤层群发育特征的分析,在概述前人多煤层条件下煤层气成藏特征研究成果的基础上,发现煤层群成藏特征主要表现在垂向上存在"多层统一煤层气系统"或"多层叠置含气系统",陆相河流–三角洲–湖泊相的煤层群一般为"多层统一煤层气系统",海陆过渡相的三角洲–潮坪–泻湖相煤层群一般为"多层叠置含气系统"。进一步解剖比德–三塘盆地实测钻孔资料显示,层序组合是煤层群独立含气系统发育的关键。依据该区抽水钻孔资料分析亦证明,至少存在4套独立含气系统。泻湖潮坪相发育的煤组存在超压的可能,但储层能势分布不均匀。另外,煤层群内部各煤层之间由于"烃浓度封闭效应"及煤层本身的低渗透性对流体流动存在"叠加封闭"作用,使煤层群储层存在"超压"可能性增大。这些结论深化了对煤层群成藏特征的认识。Based on development character of Chinese coal seam groups,research fruits of predecessors about CBM reservoir-forming character under conditions of coal seam groups were summarized.CBM reservoir-forming character of coal seam groups mainly exhibited ＂multiple united CBM system＂ or ＂multiple superposed CBM system＂,coal seam groups of land river-delta-lake environments commonly showed ＂multiple united CBM system＂,but coal seam groups of sea-land transition delta-tideflat-lagoon environments showed ＂multiple superposed CBM system＂.Results of further anatomizing borehole measuring data of Bide-Santang basin showed that strata sequence combination is a key factor of multi-coal-seam independent gas system.In accordance with water pumping borehole data,there are more than four independent gas systems,and overpressure may exists in coal-group developed in lagoon and tidal facies,but reservoir energy is uneven.Because of ＂obturating effect of hydrocarbon concentration＂ between each coal seam and effect of ＂superposed obturation of low penetrability of coal seam on liquid flowing,the possibility that overpressure exists in coal seam group increases.These findings deepen the understanding on reservoir-forming characteristics of multi coal seams.

关 键 词：煤层群 含气系统 叠加封闭 超压 层序 成藏特征 

分 类 号：P618.13[天文地球—矿床学]