中文摘要：

增强型地热系统（EGS）是开发深层高温地热能的有效途径.本文在垂直单裂隙模型（SVFM）的基础上构建了平行多裂隙模型（MPFM）,验证了其可靠性及优越性,创新地提出了换热单元体（HTU）的概念,将对整体热储层的研究集中于采热基本单元上,并利用此模型对EGS采热过程中裂隙流体及热储层温度场的演化进行模拟.基于介质分类,将采热的影响因素分为流体和岩体.本文针对岩体热储层分别设计多组案例,分析了岩体HTU尺寸及储层初始温度对釆热的影响.结果表明,HTU的厚度与流体产出温度呈负相关,但与热储层的热采率呈正效应;HTU的长度与采出温度和热储寿命呈正相关;热储层的初始温度也与流体采出温度呈正相关,对热储寿命影响不大.因此,热储层激发越充分,对流换热越充分,采热效率越高.注采策略应与热储层的激发情况相配合,才能取得较好的热开采效果.

英文摘要：

Enhanced geothermal system（ EGS） is an effective way to explore deep geothermal energy. Based on the knowledge of simple vertical fracture model（ SVFM）, multi-parallel fracture model（ MPFM） is built up and validated. It can basically simulate the evolution of reservoir and fluid temperature field during the heat extraction process,and does not have the limitations on the rock size. In this paper,a concept of heat transfer unit（ HTU） has been put forward,which focuses the study of whole heat reservoir on a basic heat extraction unit. By the differences of medium, the affecting factors of heat extraction can be divided into fluid and rock. Several comparison cases,which mainly focus on the scale of HTU and the initial reservoir temperature,have been established to study the influence of the rock on the process of heat mining. The results suggest that the thickness of HTU has a negative effect on the fluid outlet temperature,but has a positive effect on the whole heat extraction rate; the length of HTU has a positive correlation with the outlet temperature and the lifetime of reservoir; the initial reservoir temperature is also of positive effect to the heat production temperature,but it has a negligible effect on the lifetime of the reservoir. In conclusion, better heat reservoir stimulation will improve the heat extraction efficiency. Since the heat extraction efficiency is controlled by both fluid and rock,in order to get better result,the injection-production strategy should be matched with the reservoir stimulation result.