中文摘要：

采用自行开发的增强型地热系统（EGS）地下热流动过程三维动态模拟软件,模拟不同地质条件下EGS的长期运行过程,分析热储周围岩体的热补偿对产热温度以及热储内岩石、流体温度演化的影响.该数值模型视热储为等效多孔介质,采用两个能量方程分别描述流体和岩石的温度场,深入探究岩石与循环流体之间的换热过程.研究发现,热储周围岩体的热补偿作用与热储内流场形态强烈相关,且并不总是提高EGS的生产温度.在深度方向上有较大的优势流动的热储中,热补偿作用在EGS运行早期甚至会降低采出流体的温度.随着EGS的运行,热储温度持续降低,热补偿将对热能开采的影响将逐渐转向正面,对生产流体温度的提高效果增强.

英文摘要：

With a self-developed numerical model, we simulate long-time operation processes of an imaginary doublet enhanced geothermal system （EGS） with different geological conditions and analyze effects of thermal compensation on evolution of production temperature and fluid and rock temperature in the heat reservoir. The model treats heat reservoir as an equivalent porous media while considers thermal non-equilibrium between rock matrix and fluid. It uses two energy equations to describe temperature field of rock and circulating fluid, respectively, enabling thorough investigations on local heat exchange processes of rock and fluid. It reveals that influence of thermal compensation from rocks encircling heat reservoir is strongly correlated with flow pattern in the reservoir, and it does not always have positive effect on EGS production temperature. If there appears an obvious preferential flow in depth direction of the reservoir, thermal compensation can even lower production temperature during early period of EGS operation. With advance of EGS operation, rock temperature in reservoir decreases and thermal compensation gradually brings a pronounced positive effect on production temperature.