裂隙储层非均质性对干热岩热提取的影响研究  

Effect of Fractured Reservoir Heterogeneity on Heat Extraction of Hot Dry Rocks

作　　者：王贵阳 王怡冉 刘阳 夏庆威 Wang Guiyang;Wang Yiran;Liu Yang;Xia Qingwei(School of Mechanics and Optoelectronic Physics,Anhui University of Science and Technology,Huainan Anhui 232001)

机构地区：[1]安徽理工大学力学与光电物理学院,安徽淮南232001

出　　处：《中外能源》2024年第11期35-43,共9页Sino-Global Energy

基　　金：2023年安徽省大学生创新创业训练计划项目“CO_(2)脉冲注入下的干热岩储层渗流特性研究”(编号:S202310361186)。

摘　　要：热提取是影响干热岩开发的关键问题,裂隙储层激发后的非均质性对热提取影响显著。为此,通过数值模拟研究了不同裂隙数量、渗透率各向同性与各向异性、不同地温梯度对干热岩热提取的影响规律。模拟结果表明:裂隙数量的差异会影响热提取介质在裂隙中的流动速度和压力,进而影响热提取率。裂隙数量从50增加至100时,测点处的最低温度由284K增加到288K,温度降低量减少4K;裂隙数量从100增加至200时,测点处的最低温度由288K增加到290K,温度降低量减少2K。储层渗透率的各向异性对热提取影响明显,在裂隙数相同条件下,渗透率各向异性比渗透率各向同性早到达温度的稳定值。在裂缝数分别为50、100、200时,各向异性的模型储层温度比渗透率各向同性的模型分别早10年、9年、7年到达温度的稳定值。在一定的地温梯度范围内,较高的地温梯度有利于热提取。在相同的裂缝数量和热提取时间下,储层地温梯度越大,测点处温度变化速率越高。Heat extraction is a key issue affecting the development of hot dry rock,and the heterogeneity of fractured reservoirs after stimulation significantly affects it.Therefore,the effect of different numbers of fractures,isotropy and anisotropy of permeability,and various geothermal gradients on thermal extraction from hot dry rocks were studied by numerical simulation.The simulation results show that the difference in the number of fractures will affect the flow rate and pressure of the heat extraction medium in the fractures,and then affect the heat extraction rate.When the number of fractures increases from 50 to 100,the minimum temperature at the measuring point rises from 284K to 288K,and the temperature decreases drops by 4K.When the number of fractures increases from 100 to 200,the minimum temperature at the measuring point rises from 288K to 290K,and the temperature decreases drops by 2K.The anisotropy of reservoir permeability has a significant impact on heat extraction.Under the same number of fractures,the permeability anisotropy reaches a stable temperature earlier than the permeability isotropy.When there are 50,100,and 200 fractures respectively,the temperature of the anisotropic reservoirs reaches a stable value 10,9,and 7 years earlier than that of the isotropic one.The higher geothermal gradient is conducive to heat extraction in certain ranges of geothermal gradient.Under the same number of fractures and heat extraction time,the greater the geothermal gradient of the reservoirs,the higher the temperature change rate at the measuring point.

关 键 词：干热岩 热提取 非均质性 裂隙数量 渗透率 地温梯度 

分 类 号：P314[天文地球—固体地球物理学]