沁水盆地北端煤层气储层特征及富集机制

煤层气的富集与储层特征密切相关,并受地质条件的制约。在详细研究煤储层特征及煤层气富集机制的基础上,对沁水盆地北端煤层气的开发前景进行了初步评价。煤岩、煤质、煤体结构及孔渗性、吸附性的观察和测试显示,该区煤层厚度大,热演化程度高,局部发育构造煤,裂隙较发育,吸附性能力强,含气量高,含气饱和度偏低,适合煤层气的开发。该区煤层气的富集主要受控于热演化史和埋藏史。在区域变质的背景上,叠加了岩浆热变质作用,生气强度大。另外,煤层的埋深、顶底板封闭性及水文地质条件都会影响煤层含气量的大小,煤层气富集是多因素有效配置的结果。 

RESERVOIR CHARACTERISTICS AND ENRICHMENT MECHANISM OF THE COAL-BED GAS IN THE NORTH OF QINSHUI BASIN

Coalbed methane(CBM)enrichment depends on the reservoir's characteristics,and it is also controlled by geologic setting.On the basis of detailed study on the reservoir's characteristics and CBM enrichment mechanism,the favorable exploitation prospect in the north of Qinshui Basin is demonstrated.The observation and test for the type,quality and structure of coal as well as the porosity,permeability and adsorbability show that the coal bed in this area is characterized by thick reservoir,high thermal evolution,local structural coal,devoloped fracture,high adsorbability,high gas content and low gas saturation.In one word,the research area fits for CBM exploitation.The CBM enrichment in the research area is controlled by thermal evolution history and burial history.Owing to magma thermal metamorphism superimposing on the regional metamorphosis,the intensity of gas generation is higher.Moreover,the burial depth,closure property of adjacent rock and hydrologic geology condition also(affect)gas content.The CBM enrichment is the result of effective multifactorial macthing.