三轴应力下超临界水对寺河矿无烟煤渗流与变形特性的影响规律研究

Influence of supercritical water on seepage and deformation characteristics of Sihe Mine anthracite under triaxial stress

为了探索煤层在原位超临界水环境下改性的渗流和变形特性,将煤炭超临界水处理技术和原位改性采矿技术相结合,以?25 mm×50 mm寺河矿无烟煤为样本,在三轴应力条件下开展了超临界水环境下的渗流及变形特性研究。研究结果表明,在365、400、435℃的亚临界和超临界水注水条件下,无烟煤的渗透率分别比原煤下降了56.75%、96.93%和94.99%,整体渗透率的变化趋势为先快速降低再略微升高;实验初期无烟煤的渗流通道会逐渐闭合,持续注热一段时间后,渗流现象会再次恢复,恢复时间约43.5、24.54、19.81 h;渗流恢复同时伴随剧烈的轴向压缩变形,试验温度越高,最终轴向压缩应变越大,约为0.06、0.11、0.16。

In order to explore the seepage and deformation characteristics of coal seams modified in in-situ supercritical water environment, we combined coal supercritical water treatment technology and in-situ modified mining technology to study the percolation and deformation characteristics of anthracite coal of ?25 mm×50 mm in the Sihe Mine under triaxial stress supercritical water environment. The results show that under the subcritical and supercritical water injection conditions of 365 ℃, 400 ℃ and 435 ℃, the permeability of anthracite coal decreases by 56.75%, 96.93% and 94.99%, respectively;Compared with the original coal, and the overall permeability changes in the trend of rapid decrease and then slightly increase;The percolation channels of anthracite coal in the early stage of the experiment will gradually close, and after a period of continuous heat injection, the percolation phenomenon will recover, and the recovery time is about 43.5, 24.54 and 19.81 h;the recovery is accompanied by a sharp axial compression deformation, and the higher the test temperature is, the larger the axial compression deformation is, about 0.06, 0.11 and 0.16.