增强型地热系统热开采过程的数值模拟研究
收稿日期: 2013-05-20
修回日期: 2013-09-13
网络出版日期: 2013-10-31
基金资助
国家高技术发展863计划项目（2012AA052802）；中国科学院“百人计划”项目
A Numerical Study to Heat Mining Process of Enhanced Geothermal Systems
Received date: 2013-05-20
Revised date: 2013-09-13
Online published: 2013-10-31
增强型地热系统（EGS）是指采用人工方法在地下3 ~ 10 km内的干热岩体中形成储层、通过灌输采热流体以开采出干热岩中热能用于地面发电的地热利用系统，是一种极富潜力的可再生清洁能源利用技术。循环流体在地下热储中的流动与换热对EGS的采热性能有重要影响。本文首先对EGS数值模型进行了综合评述，然后基于一套自主开发的三维瞬态数值模型模拟了不同渗流条件下EGS地下热储内的热流过程。通过对模拟结果的分析，揭示了均匀压裂的人工热储中流体短路的形成机理，并通过对比双井和三井系统中流场和局部地热开采率分布，结合当前钻井工艺和裂隙激发技术水平，探讨了抑制流体短路、优化EGS采热性能的可能方案。
陈继良 , 蒋方明 . 增强型地热系统热开采过程的数值模拟研究[J]. 新能源进展, 2013 , 1(2) : 187 -195 . DOI: 10.3969/j.issn.2095-560X.2013.02.011
Enhanced geothermal system aiming to mine heat from hot dry rocks (HDR) locating within subsurface 3 ~ 10 km depths represents a promising renewable energy utilization technology. It normally needs to create an artificial heat reservoir in HDR by a certain rock-fracturing technology such as hydraulic stimulation and then to circulate heat transmission fluids through the heat reservoir to extract heat for earth-surface power-generation utilization. The flow and heat transport process in the subsurface reservoir has significant influence on the heat extraction performance of EGS. A detailed review on EGS numerical models is given first, and then a self-developed 3D transient model focusing on the subsurface thermo-fluidic process in EGS during heat extraction is briefly introduced. With this model, long-term operation processes of EGSs are simulated. Analyzing the simulation results reveals the formation mechanisms of “short circuit” flow in homogeneously fractured reservoir. We then perform a comparison study on the heat extraction performance of doublet and triplet EGSs. Comparing the seepage flow field and heat extraction ratio distribution for EGSs of different borehole layout, in combination of the state-of-the-art of borehole drilling and reservoir stimulation technologies, we further propose some possible strategies to restraining “short circuit” flow and improving the heat extraction performance of EGS.
Key words： EGS; HDR; geothermal energy; numerical model
[1] Tester J W, Anderson B J, Batchelor A S, et al. The future of geothermal energy[R]. Massachusetts Institute of Technology, 2006.
[2] Bertani R. Geothermal power generation in the world 2005-2010 update report[J]. Geothermics, 2012, 41: 1-29.
[3] 许天福, 张彦军, 曾昭发等. 增强型地热系统（干热岩）开发技术进展[J]. 科技导报, 2012, 30(32): 42-45.
[4] 汪集旸, 胡圣标, 庞忠和等. 中国大陆干热岩地热资源潜力评估[J]. 科技导报, 2012, 30(32): 25-31.
[5] Li K. Comparison of geothermal with solar and wind power generation systems[C]//Proceedings, 38th Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, USA, February 11-13. 2013. STR-198.
[6] Gérard A, Genter A, Kohl T, et al. The deep EGS (Enhanced Geothermal System) project at Soultz-sous-Forêts (Alsace, France)[J]. Geothermics, 2006, 35(5-6): 473-484.
[7] Tenma N, Yamaguchi T, Zyvoloski G. The Hijiori hot dry rock test site, Japan. Evaluation and optimization of heat extraction from a two-layered reservoir[J]. Geothermics, 2008, 37(1): 19-52.
[8] Ismail B I. New Developments in Renewable Energy- Chapter 13: ORC-Based Geothermal Power Generation and CO2-Based EGS for Combined Green Power Generation and CO2 Sequestration[M]. InTech, 2013: 303-328.
[9] 王晓星, 吴能友, 张可霓, 等. 增强型地热系统开发过程中的多场耦合问题[J]. 水文地质工程地质. 2012, 39(2): 126-130.
[10] Taron J, Elsworth D. Thermal-hydrologic-mechanical- chemical processes in the evolution of engineered geothermal reservoirs[J]. International Journal of Rock Mechanics and Mining Sciences, 2009, 46(5): 855-864.
[11] O'Sullivan M J, Pruess K, Lippmann M J. State of the art of geothermal reservoir simulation[J]. Geothermics, 2001, 30(4): 395-429.
[12] Sahimi M. Flow and transport in porous media and fractured rock[M]. Wiley-VCH, 2012.
[13] McClure M. W. Fracture stimulation in enhanced geothermal systems[D]. Stanford University, 2009.
[14] Bataillé A, Genthon P, Rabinowicz M, et al. Modeling the coupling between free and forced convection in a vertical permeable slot: Implications for the heat production of an Enhanced Geothermal System[J]. Geothermics, 2006, 35(5-6): 654-82.
[15] He L, Jin Z. A local thermal non-equilibrium poroelastic theory for fluid saturated porous media[J]. Journal of Thermal Stress, 2010, 33(8): 799-813.
[16] Pruess K. The TOUGH codes−A family of simulation tools for multiphase flow and transport processes in permeable media. Vadose Zone Journal[J]. 2004, 3(3): 738-746.
[17] Xu T, Spycher N, Sonnenthal E, et al. TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions[J]. Computers & Geosciences, 2011, 37(6): 763-774.
[18] Kalinina E, McKenna S A, Hadgu T, et al. Analysis of the effects of heterogeneity on heat extraction in an EGS represented with the continuum fracture model[C] //Proceedings: 37th Workshop on Geothermal Reservoir Engineering. Stanford University, Stanford, California, USA, January 30-February 1, 2012: 436-445.
[19] Jiang F M, Luo L, Chen J L. A novel three-dimensional transient model for subsurface heat exchange in enhanced geothermal systems[J]. International Communications in Heat and Mass Transfer, 2013, 41: 57-62.
[20] Butler S J, Sanyal S K, Robtson A. A numerical simulation study of the performance of enhanced geothermal systems[C]//Proceedings, 29th Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, USA, January 26-28, 2004: SGP-TR-175.
[21] Rybach L, Mongillo M. Geothermal sustainability-a review with identified research needs[J]. GRC Transactions, 2006, 30: 1083-1090.
[22] Foss M M. Testimony on “Tapping America’S Unconventional Oil Resources for Job Creation and Affordable Domestic Energy: Technology and Policy Pathways”[R]. Bureau of Economic Geology/Center for Energy Economics, 2012.
[23] Richard O. Optimal well design for enhanced stimulation fluids recovery and flowback treatment in the Marcellus Shale gas development using integrated technologies[J]. Hydrology: Current Research, 2012.
[24] Mukherjee H, Economides M. A parametric comparison of horizontal and vertical well performance[J]. SPE Formation Evaluation, 1991, 6(2): 209-216.
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