黔西地区构造变形特征及其煤层气地质意义

黔西地区处于特提斯与滨太平洋两个构造域的交接地带,多期性质不同的构造作用形成了现今错综复杂的构造变形特征。根据构造变形的差异,可划分为织金-纳雍NE向构造变形区、水城-紫云NW向构造变形区和黔西南复杂构造变形区。在野外地质的基础上,结合微观变形特征和矿物流体包裹体测试分析,认为黔西地区构造变形属于上地壳低温-中低温环境下的脆性-脆韧性变形;由于黔西地区基底构造相对稳定,成煤期后断块内部变形较弱,煤储层形成了一定程度的构造裂隙,有助于渗透率的提高,煤层气勘探开发前景良好。

Structural Deformation Features and Its CBM Geological Significance in Western Guizhou

The western Guizhou area is situated on the transition zone between the Tethys and marginal Pacific two structural domains. Multistage different natured tectonic processes formed present sinuous structural deformation features. According to structural deformation differences can divide the region into Zhijin-Nayong NE, Shuicheng-Ziyun NW and southwestern Guizhou three structural deformation areas. Based on field geological works, combined with microscopic deformation features and mineral fluid inclusions testing and analysis, considered that structural deformation in western Guizhou belongs to upper crust low, medium-low temperature environment brittle, brittle-ductile deformations. Since the basement structure in western Guizhou is relatively stable, post coal-forming age weak fault block internal deformation, certain degree of structural fissures in the coal reservoir, thus helpful to improve permeability, so, excellent CBM exploration and exploitation prospected.