煤炭地下气化高温井筒温度场研究

Study on Temperature Field of High Temperature Wellbore of Underground Coal Gasification

基于井筒与地层的传热情况,根据能量守恒及井筒传热原理,考虑物性参数随温度和压力变化,建立了生产井井筒的温度场预测模型,形成了求解算法和数学仿真模型,研究了温度场的影响因素。结果表明:产出气各物性沿井深分布差异较大,在分析时有必要耦合考虑;随着日产量和井底温度增加,井筒各段的温度均上升,其中日产量在30×10^(4) m^(3)/d时,井口的产出气温度最高(686℃),井底温度在1000℃时,井口温度为588℃;井底压力对温度场影响很小,在工程应用中可忽略不计;随着井深增加,井口温度下降。

Based on the heat transfer between the wellbore and the formation and the principle of the energy conservation and the heat transfer in the wellbore,considering the varying physical properties with temperature and pressure,the prediction model of the wellbore temperature field is established along with the algorithm and the mathematical simulation model.The influencing factors of the temperature field are then explored via the devised model.The results show that the physical properties of the output gas vary significantly along the depth of the mine,and it is necessary to consider the coupling effect in the analysis;with the increasing daily production and the rising temperature at the bottom of the mine,the temperature at each segment of the wellbore rises.When the daily production reaches 30×10^(4) m^(3)/d,the output temperature is the highest corresponding to 686℃.When the temperature at the bottom of the mine is 1000℃,the output temperature is 588℃;the pressure at the bottom of the mine has little influence on the temperature field,which can be ignored in the engineering applications;with the increasing depth of the mine,the output temperature decreases.