塔里木盆地北缘库拜煤田陡倾斜煤储层纳米孔隙特征及其地质控制

近年来新疆塔里木盆地北缘库拜煤田陡倾斜煤储层成为我国煤层气勘探开发新热点，部分煤层气井相继取得高产。本次采集了库拜煤田陡倾斜储层不同深度及煤体结构共61块煤样，通过煤岩组分与成熟度、低温液氮吸附、等温吸附等实验，分析了陡倾斜煤储层纳米孔隙结构特征及其地质控制。结果表明：受控于南天山山前冲断带内部不同部位剪切及挤压强度的非均质性，库拜煤田陡倾斜储层纳米孔隙体积随深度增加先增大后减小；随煤体破坏程度的增大，煤岩纳米孔隙体积相应增加且其孔隙结构复杂程度趋于复杂；陡倾斜储层倒转位置煤体变形相对增强，构造煤发育程度较高，煤岩纳米孔隙体积以及比表面积相应增大，甲烷吸附能力强、含气性较好。研究成果对陡倾斜储层煤层气勘探和开发具有重要指导意义。

Nano-pore characteristics and their geological control of the steeply inclined coal reservoir in the Cubey coalfield,the northern Tarim Basin

In recent years, the steeply inclined coal reservoir in Cubey coalfield, northern margin of Tarim Basin, Xinjiang, has become a new hot spot for CBM exploration and development in China, and some CBM wells have achieved high production. In this paper, 61 coal samples were collected from different depths and coal structure of steeply inclined coal reservoirs in Cubey coalfield. Through the experiments of coal rock composition and maturity, low temperature liquid nitrogen adsorption and isothermal adsorption, the characteristics of nano-pore structure and geological control of steeply inclined coal reservoirs were analyzed. The results shows that:Controlled by the heterogeneity of shear and compression strength in different parts of the piedmont thrust belt in South Tianshan, the nano-pore volume of steeply inclined reservoir in Cubey coalfield increases first and then decreases with the increase of depth; With the increase of coal failure degree, the nano-pore volume of coal rock increases and the complexity of pore structure tends to be complex; The deformation of coal body at the inversion position of steeply inclined reservoir is relatively enhanced, and the development degree of tectonic coal is relatively high. The nano-pore volume and specific surface area of coal rock increase accordingly, and the methane adsorption ability is strong and the gas content is good. Results of this work can provide instructions on CBM exploration and development of the steep inclined coal reservoir.