胡家河井田煤层气等压吸附/解吸特征研究

Study on isobaric adsorption/desorption features of coalbed methane in Hujiahe Coal Field

为了促进彬长矿区胡家河井田低煤阶煤层气开发实践,核定采收率,对4号煤层进行了样品采集、加工,完成了不同温度煤层气吸附/解吸试验,利用吸附/解吸结果绘制吸附等压线。结果表明:吸附量随着温度的升高而减小,低压阶段解吸滞后明显,高压阶段解吸过程与吸附过程可逆;CH_4吸附量与温度的关系可用二次函数表征,当温度大于临界温度(-82.6℃)时,最大吸附量沿抛物线分布;温度低于临界温度时,最大吸附量沿直线分布;最后得出CH_4吸附量的计算方法,解决了采收率核定时低阶煤含气量测试数据不准的问题。

In order to promote the practices on the low ranking coalbed methane in Hujiahe Minefield of Binchang Mining Area and to approve the mining recovery rate,the collection and processing of the coal samples from the target seam- No. 4 seam were conducted,the adsorption / desorption experiments with different temperature coal bed methane were completed and the adsorption / desorption results were applied to draw the adsorption isobar. The results showed that the absorption volume was reduced with the temperature increased. At the low pressure stage,the desorption hysteresis was obvious and at the high pressure stage,the desorption process and the absorption process could be reversible. The relationship between the CH4 absorption volume and temperature could be expressed with a quadratic function and when the temperature was higher than the critical temperature（-82.6 ℃）,the max absorption volume would be distributed along a parabola. When the temperature was lower than the critical temperature,the max absorption volume would be distributed along a straight line. Finally the calculation method obtained of the CH4 absorption volume could solve the inaccurate problem of the gas content measured data of the low ranking coal when the mining recovery rate was determined.