含瓦斯煤层注热温度场的数值模拟

Numerical simulation of temperature field on coalbed of gas with heat injection

为验证煤层气注热开采的合理性,在实验室进行了考虑温度条件下煤层气的解吸渗流实验,实验结果表明,煤体在升温情况下煤层气解吸渗流量增加,注热开采煤层气具有合理性。根据实验结论,建立了含瓦斯煤层注热传热过程的数学模型,利用ANSYS软件进行了含瓦斯煤层注热温度场的数值模拟。数值模拟结果表明,注蒸汽后煤层的温度梯度改变,热量在井筒径向具有一定的热扩散位移。在热扩散范围内,煤层气更容易发生脱附解吸,有利于煤层气的产出。

For validating rationality of heat injection in mining coal-bed gas, the experiment of desorption and seepage in non isothermal condition is done in laboratory. The results of experiment shows that the coal-bed gas increases under the condition of adding temperature and it＇s rational to heat injection in mining coal-bed gas. According to the experimental conclusions, the mathematic model of transferring heat process of coal-bed is given. ANSYS software is used to simulate the temperature field of coal-bed under the condition of horizontal well. The result of numerical simulation shows that the temperature gradient of coal-bed is changed after heat injection, and a displacement of thermal diffusion exists in radial direction of well. The produce of coal-bed gas increases and the desorption phenomenon is easier in the range of heat diffusion.