Gas migration model based on overburden strata fracture evolution law in three dimensional mine-induced stress conditions

3rd International Conference on Energy Materials and Environment Engineering

能源学;生态环境科学

Li, Xing^1,2 ; Yin, Guangzhi^1,2

State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing

400030, China^1

College of Resources and Environmental Sciences, Chongqing University, Chongqing

400030, China^2

关键词: Comsol multiphysics;    Fracture distributions;    Fracture feature;    Gas concentration;    Guiding significances;    Overlying strata;    Similarity simulation;    Simultaneous extractions;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/61/1/012005/pdf
DOI  :  10.1088/1755-1315/61/1/012005

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

Based on the fracture features obtained from similarity simulation excavation experiment in 3D mine-induced stress condition, the gas migration model in gob area was set up, and numerical simulation using COMSOL Multiphysics software on gas migration law was studied. The research results show that: Gas pressure variety gradient and flow velocity are obviously influenced by fracture distribution shape. Gas concentration distribution presents the rounded rectangle shape in the lower strata, while in higher strata it tends to be a "O shape" morphology which is similar to the fracture form in strata above the gob. Besides, the pressure relief gas mainly accumulates in the working face fracture field, especially in the higher overlying strata. In the compaction field, gas concentration distribution form presents a "saddle" shape morphology in the vertical section, and gas concentration in boundary fracture zone is higher than in the compaction zone. It is remarkable that gas concentration in start-up fractured zone is also relatively high, and with the advance of working face, its gas enrichment degree decreases. The results of the research have an important guiding significance for coal and gas simultaneous extraction.