Tu Yuying, Zhang Yongli, Dong Yubin, Ma Yulin
School of Mechanics and Engineering, Liaoning Technical University, Fuxin, Liaoning 123000, China.
ACS Omega. 2023 Jul 18;8(30):27092-27101. doi: 10.1021/acsomega.3c02098. eCollection 2023 Aug 1.
Microwave radiation is an effective method for simulating the exploitation of coalbed methane (CBM). Herein, structural coal seepage is evaluated using a self-developed experiment system to explore the temperature and permeability response changes exhibited by coal samples under microwave radiation and stress loading. Microwave radiation experiments are used to conduct the numerical simulation of the microwave radiation, and the temperatures and permeability values of the coal samples under simulated and experimental conditions are compared and analyzed. The results show that the higher the microwave radiation power, the higher the temperature of coal samples within the specified time. Under the same effective stress conditions, the higher the microwave radiation power and the longer the action time, the greater the coal sample permeability. Moreover, effective stress is shown to be important for permeability. The curve change trends and numerical values of the experiment and simulation are consistent, and the accuracy of the experiment and simulation is verified in both directions. Furthermore, a numerical model of coal seams under microwave radiation is established to simulate the change law of pressure, gas seepage velocity, and free methane content of actual coal seams under microwave radiation. It is concluded that the fast heating and stable temperature resulting from microwave radiation are beneficial for the crack propagation of coal near reservoirs. The results of this study provide a new technological method for actual CBM exploitation and a new research direction for unconventional natural gas energy output.
微波辐射是模拟煤层气开采的一种有效方法。在此，利用自行研制的实验系统对构造煤渗流进行评估，以探究煤样在微波辐射和应力加载下的温度及渗透率响应变化。通过微波辐射实验对微波辐射进行数值模拟，并对模拟条件和实验条件下煤样的温度及渗透率值进行对比分析。结果表明，在规定时间内，微波辐射功率越高，煤样温度越高。在相同有效应力条件下，微波辐射功率越高、作用时间越长，煤样渗透率越大。此外，有效应力对渗透率具有重要影响。实验与模拟的曲线变化趋势及数值一致，从两个方向验证了实验与模拟的准确性。进而建立了微波辐射下煤层的数值模型，模拟实际煤层在微波辐射下压力、瓦斯渗流速度及游离瓦斯含量的变化规律。研究得出，微波辐射产生的快速加热及稳定温度有利于储层附近煤体的裂纹扩展。本研究结果为实际煤层气开采提供了一种新的技术方法，为非常规天然气能量产出提供了新的研究方向。
