基于局部热非平衡的含裂缝网络干热岩采热性能模拟
|
摘要
采用压裂技术在干热岩中构造裂缝网络,工作流体在裂缝内的循环携热使干热岩中高温资源得到有效提取。为真实模拟岩体与流体间能量传递,基于局部热非平衡理论,将储层视为由基质岩体与离散裂缝组成的双重介质模型,建立温度-渗流-应力全耦合模拟采热过程中流体流动、热量传递、岩体变形的相互作用,进而对不同注采井网和模型参数下采热性能进行研究。结果表明:干热岩资源开采过程的模拟有必要采用温度-渗流-应力耦合,裂缝分布的非均匀性对采热性能有影响;注采井网的合理布局有利于地热能大规模动用与高效开发;基岩热膨胀系数影响温差引起的热应力作用从而影响采热性能;合理选择注采压差有利于开发,压差过大将缩短开发寿命,注入温度越高采热速率越高。
Heat carrying fluids can be injected and circulated in fractured networks formed in hot dry rocks for effective heat mining. In order to simulate the heat transfer process between the rock mass and the working fluid realistically,a local thermal non-equilibrium model was adopted,considering the reservoir as a dual-medium model composed of matrix rock and discrete fractures. The interactions of the fluid flow,heat transfer and rock mechanics during the heat mining process was simulated via a full thermo-hydro-mechanical( THM) coupling model,and the heat mining performance with different inject-product well patterns and operation parameters was investigated. The simulation results show that the adoption of the THM coupling model is necessary and adequate for the simulation of the heat resource mining process,and the heterogeneous distribution of the fractures has an significant influence on the performance of heat mining. Reasonable layout of the injection-production well patterns is conducive to the large-scale utilization and efficient exploitation of the geothermal energy. The thermal expansion coefficient of the rock matrix can affect the thermal stress induced by temperature difference,thus affecting the heat mining performance. Rational selection of injection-production pressure difference is beneficial heat extraction,but an excessive pressure difference can shorten the duration of the process.
Heat carrying fluids can be injected and circulated in fractured networks formed in hot dry rocks for effective heat mining. In order to simulate the heat transfer process between the rock mass and the working fluid realistically,a local thermal non-equilibrium model was adopted,considering the reservoir as a dual-medium model composed of matrix rock and discrete fractures. The interactions of the fluid flow,heat transfer and rock mechanics during the heat mining process was simulated via a full thermo-hydro-mechanical( THM) coupling model,and the heat mining performance with different inject-product well patterns and operation parameters was investigated. The simulation results show that the adoption of the THM coupling model is necessary and adequate for the simulation of the heat resource mining process,and the heterogeneous distribution of the fractures has an significant influence on the performance of heat mining. Reasonable layout of the injection-production well patterns is conducive to the large-scale utilization and efficient exploitation of the geothermal energy. The thermal expansion coefficient of the rock matrix can affect the thermal stress induced by temperature difference,thus affecting the heat mining performance. Rational selection of injection-production pressure difference is beneficial heat extraction,but an excessive pressure difference can shorten the duration of the process.
引文
[1] JULIO G,CRAIG H,MARK W,et al. The northwest geysers EGS demonstration project, California-part 1:characterization and reservoir response to injection[J].Geothermics,2016,63:97-119.
[2] JONNY R,PIERRE J,DOBSON P F,et al. The northwest geysers EGS demonstration project,California-part2:modeling and interpretation[J]. Geothermic,2016,63:120-138.
[3] TOMAC I,GUTIERREZ M. Micro-mechanics of hydrothermo-mechanical fracture propagation in granite[R].ARMA 14-7148,2014.
[4]郭亮亮.增强型地热系统水力压裂和储层损伤演化的试验及模型研究[D].长春:吉林大学,2016.GUO Liangliang. Test and model research of hydraulic fracturing and reservoir damage evolution in enhanced geothermal system[D].Changchun:Jilin University,2016.
[5] ZHAO Yangsheng,FENG Zijun,FENG Zengchao,et al.THM(thermo-hydro-mechanical)coupled mathematical model of fractured media and numerical simulation of a3D enhanced geothermal system at 573 K and buried depth 6 000-7 000 m[J]. Energy,2015,82:193-205.
[6] HANNES H,SIMON W,TAYFUN B,et al. Potential for enhanced geothermal systems in Alberta,Canada[J].Energy,2014,69:578-591.
[7] GUO Bin,FU Pengcheng,HAO Yue,et al. Thermal drawdown-induced flow channeling in a single fracture in EGS[J].Geothermics,2016,61:46-62.
[8] PANDEY S N,CHAUDHURI A,KELKAR S. A coupled thermo-hydro-mechanical modeling of fracture aperture alteration and reservoir deformation during heat extraction from a geothermal reservoir[J]. Geothermics,2017,65:17-31.
[9]孙致学,徐轶,吕抒桓,等.增强型地热系统热流固耦合及数值模拟[J].中国石油大学学报(自然科学版),2016,40(6):109-117.SUN Zhixue,XU Yi,LU Shuhuan,et al. A thermohydro-mechanical coupling model for numerical simulationof enhanced geothermal systems[J]. Journal of China University of Petroleum(Edition of Natural Science),2016,40(6):109-117.
[10] SUN Zhixue,ZHANG Xu,XU Yi,et al. Numerical simulation of the heat extraction in EGS with thermalhydraulic-mechanical coupling method based on discrete fractures model[J]. Energy,2017,120:20-33.
[11]骆雄飞.局部非热平衡条件下多孔介质通道中对流换热的研究[D].武汉:华中科技大学,2014.LUO Xiongfei. Research of forced convection in a channel filled with porous media using local thermal non-equilibrium model[D]. Wuhan:Huazhong University of Science and Technology,2014.
[12] ZHU W C,WEI J,ZHAO J,et al. 2D numerical simulation on excavation damaged zone induced by dynamic stress redistribution[J]. Tunnelling and Underground Space Technology,2014,43:315-326.
[13]陈必光,宋二祥,程晓辉.二维裂隙岩体渗流传热的离散裂隙网络模型数值计算方法[J].岩石力学与工程学报,2014,33(1):43-51.CHEN Biguang,SONG Erxiang,CHENG Xiaohui. A numerical method for discrete fracture network model for flow and heat transfer in two-dimensional fractured rocks[J]. Chinese Journal of Rock Mechanics and Engineering,2014,33(1):43-51.
[14]白冰.岩土颗粒介质非等温一维热固结特性研究[J].工程力学,2005,22(5):186-191.BAI Bing. One-dimensional thermal consolidation characteristics of geotechnical media under non-isothermal condition[J]. Engineering Mechanics,2005,22(5):186-191.
[15] QU Zhanqing,ZHANG Wei,GUO Tiankui. Influence of different fracture morphology on heat mining performance of enhanced geothermal systems based on COMSOL[J].International Journal of Hydrogen Energy,2017,42:18263-18278.
[16] ZENG Yuchao,SU Zheng,WU Nengyou. Numerical simulation of heat production potential from hot dry rock by water circulating through a novel single vertical fracture at desert peak geothermal field[J]. Energy,2013,56:92-107.
[17]任韶然,崔国栋,李德祥,等.注超临界CO2开采高温废弃气藏地热机制与采热能力分析[J].中国石油大学学报(自然科学版),2016,40(2):91-98.REN Shaoran,CUI Guodong,LI Dexiang,et al. Development of geothermal energy from depleted high temperature gas reservoir via supercritical CO2injection[J].Journal of China University of Petroleum(Edition of Natural Science),2016,40(2):91-98.
[2] JONNY R,PIERRE J,DOBSON P F,et al. The northwest geysers EGS demonstration project,California-part2:modeling and interpretation[J]. Geothermic,2016,63:120-138.
[3] TOMAC I,GUTIERREZ M. Micro-mechanics of hydrothermo-mechanical fracture propagation in granite[R].ARMA 14-7148,2014.
[4]郭亮亮.增强型地热系统水力压裂和储层损伤演化的试验及模型研究[D].长春:吉林大学,2016.GUO Liangliang. Test and model research of hydraulic fracturing and reservoir damage evolution in enhanced geothermal system[D].Changchun:Jilin University,2016.
[5] ZHAO Yangsheng,FENG Zijun,FENG Zengchao,et al.THM(thermo-hydro-mechanical)coupled mathematical model of fractured media and numerical simulation of a3D enhanced geothermal system at 573 K and buried depth 6 000-7 000 m[J]. Energy,2015,82:193-205.
[6] HANNES H,SIMON W,TAYFUN B,et al. Potential for enhanced geothermal systems in Alberta,Canada[J].Energy,2014,69:578-591.
[7] GUO Bin,FU Pengcheng,HAO Yue,et al. Thermal drawdown-induced flow channeling in a single fracture in EGS[J].Geothermics,2016,61:46-62.
[8] PANDEY S N,CHAUDHURI A,KELKAR S. A coupled thermo-hydro-mechanical modeling of fracture aperture alteration and reservoir deformation during heat extraction from a geothermal reservoir[J]. Geothermics,2017,65:17-31.
[9]孙致学,徐轶,吕抒桓,等.增强型地热系统热流固耦合及数值模拟[J].中国石油大学学报(自然科学版),2016,40(6):109-117.SUN Zhixue,XU Yi,LU Shuhuan,et al. A thermohydro-mechanical coupling model for numerical simulationof enhanced geothermal systems[J]. Journal of China University of Petroleum(Edition of Natural Science),2016,40(6):109-117.
[10] SUN Zhixue,ZHANG Xu,XU Yi,et al. Numerical simulation of the heat extraction in EGS with thermalhydraulic-mechanical coupling method based on discrete fractures model[J]. Energy,2017,120:20-33.
[11]骆雄飞.局部非热平衡条件下多孔介质通道中对流换热的研究[D].武汉:华中科技大学,2014.LUO Xiongfei. Research of forced convection in a channel filled with porous media using local thermal non-equilibrium model[D]. Wuhan:Huazhong University of Science and Technology,2014.
[12] ZHU W C,WEI J,ZHAO J,et al. 2D numerical simulation on excavation damaged zone induced by dynamic stress redistribution[J]. Tunnelling and Underground Space Technology,2014,43:315-326.
[13]陈必光,宋二祥,程晓辉.二维裂隙岩体渗流传热的离散裂隙网络模型数值计算方法[J].岩石力学与工程学报,2014,33(1):43-51.CHEN Biguang,SONG Erxiang,CHENG Xiaohui. A numerical method for discrete fracture network model for flow and heat transfer in two-dimensional fractured rocks[J]. Chinese Journal of Rock Mechanics and Engineering,2014,33(1):43-51.
[14]白冰.岩土颗粒介质非等温一维热固结特性研究[J].工程力学,2005,22(5):186-191.BAI Bing. One-dimensional thermal consolidation characteristics of geotechnical media under non-isothermal condition[J]. Engineering Mechanics,2005,22(5):186-191.
[15] QU Zhanqing,ZHANG Wei,GUO Tiankui. Influence of different fracture morphology on heat mining performance of enhanced geothermal systems based on COMSOL[J].International Journal of Hydrogen Energy,2017,42:18263-18278.
[16] ZENG Yuchao,SU Zheng,WU Nengyou. Numerical simulation of heat production potential from hot dry rock by water circulating through a novel single vertical fracture at desert peak geothermal field[J]. Energy,2013,56:92-107.
[17]任韶然,崔国栋,李德祥,等.注超临界CO2开采高温废弃气藏地热机制与采热能力分析[J].中国石油大学学报(自然科学版),2016,40(2):91-98.REN Shaoran,CUI Guodong,LI Dexiang,et al. Development of geothermal energy from depleted high temperature gas reservoir via supercritical CO2injection[J].Journal of China University of Petroleum(Edition of Natural Science),2016,40(2):91-98.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |