增强型地热系统采热性能影响因素分析

Analysis of Influencing Factors on Heat Extraction Performance of Enhanced Geothermal System

为了综合分析增强型地热系统各参数对系统采热性能的影响,以及参数相互之间的影响规律,以云南腾冲热海热田为地质背景,利用正交设计思想通过数值模拟方法对井间距、注入流量、注入温度、储层渗透率等因素的变化进行了分析。结果表明:注入流量是影响系统采热性能的关键因素,并对注入温度、井间距的确定有显著影响;注入流量越大,系统稳定采热时间和运行寿命越短,且注入流量较小的变化(提高0.06m^3/s)会对系统采热温度产生较大的影响(降低47℃);增加注入温度可以提高系统的采热温度和运行寿命,但注入温度升高30℃、运行50a后采热温度只提高10℃,效果有限;井间距、渗透率、开采压力对系统采热性能的影响相近,且远小于注入流量。

The Rehai geothermal field was taken as the geological background,the influence of well spacing,injection flow rate and temperature,and reservoir permeability on the heat extraction performance of the enhanced geothermal system were analyzed by using the orthogonal design method,and also the mutual influence between these factors.The results show that the injection flow rate is the key factor affecting the heat extraction performance and has a significant impact on the determination of injection temperature and well spacing.The larger the injection flow rate is,the shorter the stable heat extraction time and operating life are.The smaller the change of injection flow rate(increase 0.06m^3/s)is,the greater the impact will be on the heat extraction temperature(decrease 47℃);Increasing the injection temperature can improve the heat extraction temperature and operating life;however,the effect is limited.When the injection temperature is increased by 30℃,the heat recovery temperature is only increased by 10℃after 50a.The effects of well spacing,permeability,and production pressure on the heat extraction performance are similar and much smaller than the injection flow rate.