1. School of Mechanical Engineering,Liaoning Technical University,Fuxin　 123000,China; 2. School of Mechanics and Engineering,Liaoning Technical University,Fuxin　 123000,China

为得到低渗透储层煤层气注蒸汽开采过程煤层气运移产量规律,在实验室试制了蒸汽加热三轴解吸渗透试验装置,并进行了不同饱和蒸汽压力条件下煤样吸附甲烷运移产量测定试验。试验结果表明,在一定的围、轴压下,甲烷运移产量随解吸时间呈现Langmuir变化趋势;在不同的注蒸汽压力条件下,甲烷运移产量随饱和蒸汽压力的增加而增大、增幅减小,煤体温度随蒸汽注入压力不同呈现指数增长形式,在一定时间内由于换热效率降低使煤体达到注热饱和,继续注热无明显效果;煤体注蒸汽后,由于应力急剧增加造成短时期内无甲烷运移产出,随应力的降低和游离甲烷增加,甲烷运移速率呈现指数型增长趋势,甲烷运移最终产量增加,甲烷运移产量较未注热最高可增产46.3%。试验结果可为煤层气注蒸汽开采工艺方案及产量预测提供参考。

In order to obtain the migration yield law of coal-bed methane (CBM) in a low permeability coal reservoir in the process of steam injection exploitation,an experiment set of desorption and seepage under the conditions of triax- ial stress and steam was designed and the experiment about methane migration yield features in coal at different satu- rated steam pressures was conducted. The results show that the migration yield of methane exhibits the Langmuir trend with a desorption time at a certain confining and axial pressure;with the increase of saturated steam pressure,the mi- gration yield increases,but its growth rate decreases gradually. The temperature of coal sample shows an exponential growth trend at different saturated steam pressures. A thermal saturation phenomenon is subsequently induced by re- ducing the heat exchange efficiency in a specified time and then the effect of heat injection is not obvious. There is no methane migration yield due to the sharp increase of stress in a short time after the steam injected in the coal sample. Then the migration velocity of methane increases exponentially with the stress decrease and free methane increase and migration yield increases finally. The maximum migration yield of methane in this experiment is 46. 3% higher than that without steam injection. The experimental results will provide a reference for the technical plan and yield predic- tion of CBM exploitation with steam injection.

LI Weikang,YANG Xinle,ZHANG Yongli,et al. Experimental study on migration yield law of coal-bed methane under the condition of sat- urated steam[J]. Journal of China Coal Society,2018,43(5):1343-1349.