高、低煤阶煤层气藏地质特征及控气作用差异性研究  

Differences of Coalbed Methane Geological Characteristics and Gas-Controlling Function between Low Rank Coal and High Rank Coal

作　　者：王勃[1] 巢海燕[1] 郑贵强[1] 李景明[1] 郭志斌[2] 王红岩[1] 刘洪林[1] 李贵中[1] 

机构地区：[1]中国石油勘探开发研究院廊坊分院,河北廊坊065007 [2]陕西省煤田地质局物探测量队,西安710005

出　　处：《地质学报》2008年第10期1396-1401,共6页Acta Geologica Sinica

基　　金：国家重点基础规划“973”项目“煤层气成藏机制及经济开采基础研究”(编号2002CB211705)资助成果

摘　　要：高、低煤阶煤层气地质特征及控气作用差异性是研究煤层气富集成藏的重要组成部分,是煤层气勘探开发理论研究过程中重要的基础性研究领域之一。本文以中国沁水、阜新盆地和美国粉河盆地等典型的含气盆地为例,探讨了高、低煤阶煤层气的储层物性差异,分析了构造控气和水文地质控气作用的差异性。研究表明,高煤阶气藏含气量高,CH4百分含量高,δ13C1值大于-38.75‰,储层渗透率变化小,储层改造难,构造热事件对煤层气的生成、富集贡献大,持续的水动力使气藏遭到破坏,且破坏幅度大,现今地下水格局对气藏的形成具有一定的影响;低煤阶气藏含气量低,CH4百分含量低,δ13C1值大于-49.11‰,储层渗透率变化大,储层易改造,煤热演化史及煤阶影响着煤层气的生成、富集,在煤层气生成过程中活跃的水动力是甲烷生成的主要的水文地质条件之一,但持续的水动力使气藏遭到破坏,且破坏幅度小,而合适的地层水矿化度则是低煤阶煤层气生成的重要条件,地下水格局对气藏的调整和改造起到决定性的影响。The differences of Coalbed Methane （CBM） geological characteristics and gas-controlling function between low rank coal and high rank coal, which is an important portion of the CBM reservoir research and the CBM development and exploration theory research. Based on some CBM basins, such as Qinshui, Fuxin and Power River Basin in America, physical property differences of reservoirs between high and low coal ranks were discussed, gas-controlling differences between structure and hydrologic geology were analyzed. The reservoirs with the high rank coal have high gas content, with 13δC1 value over 〈-38.75‰, poor permeability. Reservoir reformation is difficult. Tectonic thermal event contributes mainly to CBM generation and enriching. Everlasting hydrodynamic force would destroy CBM reservoir seriously. The reservoirs with the low rank coal have low gas content, with 13δC1 value 〈-49.11‰, good permeability. Reservoir reformation is comparatively easy. CBM generation and enriching are influenced by coal thermal evolution history and coal rank. During the CBM generating process, stirring hydrodynamic force is taken as the main geological agent, but everlasting hydrodynamic force would destroy CBM reservoir slightly, and proper formation water salinity is an important factor of low rank CBM generating.

关 键 词：煤阶 煤层气藏 储层物性 

分 类 号：P618.11[天文地球—矿床学] P618.510.2[天文地球—地质学]