基础理论与实验研究

不同温度条件下气体压力升降过程中瓦斯运移规律的试验研究

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  • 1. 重庆大学 煤矿灾害动力学与控制国家重点试验室,重庆 400044;2. 重庆大学 复杂煤气层瓦斯抽采国家地方联合工程试验室,重庆 400044
许江,男,1960年生,博士,教授,博士生导师,主要从事岩石力学与工程方面的教学与研究工作

收稿日期: 2014-09-10

  网络出版日期: 2018-06-09

基金资助

国家自然科学基金(No.51474040);国家自然科学基金(No.51434003);国家自然科学基金(No.51304255);重庆市基础与前沿研究计划项目(No.cstc2013jjB90001)。

Experimental study of migration laws of gas during loading-unloading process at different temperatures

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  • 1. State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; 2. State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam, Chongqing University, Chongqing 400044, China

Received date: 2014-09-10

  Online published: 2018-06-09

Supported by

This work was supported by the National Natural Science Foundation of China (51474040), the National Natural Science Foundation of China (51434003), the National Natural Science Foundation of China (51304255) and Basic and Cutting-edge Research Projects of Chongqing (cstc2013jjB90001).

摘要

利用自主研发的含瓦斯煤热-流-固耦合三轴伺服渗流装置,对不同温度条件下型煤试件在气体压力升降过程的渗流特性进行了试验研究,以模拟随采深增加引起的地温升高条件下煤的渗透特性。同时,为探讨低渗储层的滑脱效应进行了相同条件下氦气的平行试验。研究结果表明:(1)升压阶段,轴向应变增大,径向应变减小,近似呈线性变化;降压阶段,随气体压力降低,应变呈现出与升压阶段相同的变化趋势。随温度升高,应变随气体压力变化的斜率增大。(2)升压阶段,随气体压力升高,渗透率呈二次抛物线型变化,约在气体压力为3.0 MPa左右到达最小;降压阶段,随气体压力减小,渗透率先略有减小后增大,升压阶段渗透率大于降压阶段渗透率。(3)升压阶段滑脱效应引起的渗透率变化量大于降压阶段的变化量,且滑脱效应所引起的渗透率变化量随气体压力增加呈幂指数函数降低。

本文引用格式

许 江,张 敏,彭守建,李波波,武雪峰, . 不同温度条件下气体压力升降过程中瓦斯运移规律的试验研究[J]. 岩土力学, 2016 , 37(6) : 1579 -1587 . DOI: 10.16285/j.rsm.2016.06.007

Abstract

Using the self-developed triaxial servo-controlled seepage equipment for thermo-fluid-solid coupling of coal containing methane, a series of tests is conducted on coal samples during the process of gas loading-unloading at different temperatures to simulate the seepage characteristis of coal under the condition of temperature increase induced by increasing depth of mining. Meanwhile, parallel experiments on helium are also carried out to investigate the slippage effect of low permeability coal seam. The experimental results are shown as follows: (1) During the loading process, the axial strain increases and radial strain decreases linearly with the increase of gas pressure. During the unloading process, the strain of coal shows the same trend with the loading. The slope of strain varies with increasing gas pressure and temperature. (2) During the loading process, the permeability of coal shows a quadratic parabola trend with the increase of gas pressure, and it reaches the minimum at about 3.0 MPa. At the early unloading stage, the permeability of coal decreases slowly and then increases with the decrease of gas pressure. The permeability of coal during the loading process is lager than that during the unloading process. (3) Variation of permeability caused by slippage effect during loading process is greater than the amount of unloading process. What’s more, variation of permeability caused by slippage effect declines in an exponential function with the increase of gas pressure.
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