Damage Evolution and Post-peak Gas Permeability of Raw Coal Under Loading and Unloading Conditions
| Autor: | Chin Jian Leo, Dong-ming Zhang, Dan Feng, Guangzhi Yin, D. S. Liyanapathirana, Xian-meng Zhang |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Hydrogeology
Petroleum engineering Coalbed methane business.industry General Chemical Engineering technology industry and agriculture Coal mining 02 engineering and technology Permeation 010502 geochemistry & geophysics Overburden pressure complex mixtures 01 natural sciences Catalysis respiratory tract diseases Permeability (earth sciences) 020401 chemical engineering otorhinolaryngologic diseases Geotechnical engineering Coal 0204 chemical engineering business Geology 0105 earth and related environmental sciences Resource recovery |
| Zdroj: | Transport in Porous Media. 117:465-480 |
| ISSN: | 1573-1634 0169-3913 |
| DOI: | 10.1007/s11242-017-0842-z |
| Popis: | Coalbed methane, a naturally occurring gas in coal, is regarded as a relatively clean-burning and eco-friendly resource. During mining, coalbed methane may be leaked to the environment, leading to potential coal mine catastrophes such as coal and gas outbursts, and gas explosions. In the interest of mine stability, and to enhance resource recovery and utilisation, it is fundamentally important to understand the permeability characteristics of coal, in particular its post-peak permeability behaviour. In this paper, an in-house developed tri-axial apparatus with the ability to investigate coupled thermal–hydrological–mechanical behaviour under servo-controlled seepage has been used to carry out a series of gas permeation experiments in coal samples. The coal samples were subjected to tri-axial tests, including the simulation of coal extraction by unloading the confining pressure applied on the test specimens. The deformation and permeability characteristics of raw coal during these tests were recorded. The volume changes of the coal samples during the tests were observed to occur in three stages: Stage 1: contraction, Stage 2: little or no volume change, and Stage 3: dilation. Corresponding to the volume changes, the gas seepage can also be divided into three stages: seepage decrease, steady seepage, and accelerated seepage. Based on the observed behaviour of coal samples during the tri-axial permeation tests, an analytical model to simulate damage evolution and its effect on the permeability of coal containing gas is proposed in this paper. It may be used to study the evolution of permeability with stress changes, and to provide insights into coal and gas outbursts in practice. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink