温度对褐煤渗透特性影响的试验研究

采用太原理工大学采矿工艺研究所研制的煤(岩)MDS200三轴渗透试验机,在不同应力、不同温度条件下,对内蒙乌盟矿区褐煤进行热渗透试验研究。研究结果表明:随着煤层埋藏深度的增加,即体积应力的增加,褐煤渗透率总体上是呈下降趋势;在温度和体积应力不变的情况下,褐煤随着孔隙压力的增大,渗透率呈先下降,再增大的趋势,其临界点为2MPa左右;在体积应力和孔隙压力不变的情况下,随着温度的升高(100℃以内),褐煤的渗透率呈先下降,再急剧增大,再减小的趋势,渗透率的极低点温度为50℃左右,极高点温度80℃左右;当温度小于50℃时,随着孔隙压力的增大,渗透率呈下降趋势,当温度高于50℃时,随着孔隙压力的增大,渗透率呈上升趋势。

EXPERIMENTAL STUDY OF EFFECT OF TEMPERATURE ON PERMEABILITY CHARACTERISTICS OF LIGNITE

By adopting the triaxial permeability test system MDS200，which was made by Institute of Mining Technology of Taiyuan University of Technology，some experimental researches are conducted on the permeability of lignite collected in Inner Mongolia Autonomons Region，China，under the condition of different volumetric stresses and different temperatures. The results indicate that，with the increase in coal burial depth，in other words，with the increase in volumetric stress，the permeability of lignite tends to decrease as a whole；under the condition of unchanged temperature and volumetric-stress，with the increase in pore pressure，the permeability of lignite has a tendency towards declining at first and then rising again. The critical point of the pore pressure is about 2 MPa. Under the condition of unchanged volumetric stress and pore pressure，with the increase in temperature(within 100 ℃)，the permeability of lignite decreases at first，then rises and decreases at last. During this process，the lowest temperature is 50 ℃，while the highest temperature is 80 ℃. When the temperature is below 50 ℃，with the increase in pore pressure，the permeability has a downtrend；when the temperature is above 50 ℃，the permeability has a uptrend.