基于开挖的增强型地热系统概述

doi:10.13745/j.esf.2020.1.20

摘要/Abstract

摘要：

地热能赋存于地球内部岩土体、流体和岩浆体中,是一种永久的、可再生的、储量丰富的清洁能源。地热能的开发,尤其是干热岩的开发利用,有可能成为解决人类未来能源危机的重要途径。目前采用的干热岩开采方法被称为增强型地热系统(EGS)。热储地质环境的复杂性和水力化措施对天然裂隙的依赖性,造成多数的EGS项目存在热储体积和换热面积不足、工质流量小、终端温度低,以及诱发地震风险等局限性,致使干热岩开发始终未能大规模商业化。基于开挖的增强型地热系统(EGS-E)的提出为突破传统EGS的技术弊端和规模局限提供了新思路。文章在其概念模型的基础上,从系统原理、工程构想、技术优势等方面对EGS-E进行了更详尽的阐述。EGS-E采用开挖、爆破、崩落等采矿技术,形成了独特的热储致裂系统和热能交换系统,能够大幅度降低地质环境对热储质量的限制,具备构建定制的热储空间、形成充足的换热面积,维持稳定的工质流量与温度及减少诱发地震风险等优势,为干热岩开发的商业化提供了新的解决方案。

关键词: 地热能, 干热岩, 深层地热开发, 增强型地热系统

Abstract:

Geothermal energy is a permanent, renewable, inexhaustible and clean energy stored in regosol, fluid and magmatic bodies in the Earth’s crust. Its exploitation and utilization, mainly hot dry rock (HDR), may become a meaningful way to solve the future energy crisis. The enhanced geothermal system (EGS) is the primary method used in the exploitation of HDR up till the present time. Because of the complexity of geological environment and dependency of hydraulic measures on natural fissures, most of EGS projects have many technical shortcomings, such as insufficient thermal storage volume and heat transfer area, low working fluid flow rate, low terminal temperature and induced earthquake risk, making large-scale commercialization of DHR unachievable. The prospects of the enhanced geothermal system based on excavation technology (EGS-E) inspired us to find breakthroughs overcoming the technical difficulties and limitations of EGS. In this paper, we discussed EGS-E in great detail on its operation fundamentals, engineering principles and technical advantages based on a conceptual model. By adopting mining technologies, such as excavation, blasting and caving, EGS-E can significantly overcome geological environmental restrictions on thermal storage quality to form a unique fracturing system of geothermal reservoir as well as a special thermal energy exchange system. It has the advantages of building up customized thermal storage, forming sufficient heat transfer areas, maintaining stable working fluid flow rate and temperature, and reducing earthquake risks, thus provides a brand-new scheme for the commercialization of HDR geothermal energy.

Key words: geothermal energy, hot dry rock, deep geothermal exploitation, enhanced geothermal system

中图分类号:

P314.2

亢方超, 唐春安. 基于开挖的增强型地热系统概述[J]. 地学前缘, 2020, 27(1): 185-193.

KANG Fangchao, TANG Chun’an. Overview of enhanced geothermal system (EGS) based on excavation in China[J]. Earth Science Frontiers, 2020, 27(1): 185-193.

图/表 8

图1 不同类型干热岩分布范围图(据文献[1])

Fig.1 Distribution range of different types of dry hot rock. Adapted from [1].

图2 干热岩开发“双井”EGS模型(据文献[12])

Fig.2 A conceptual two-well EGS in dry hot rock exploitation. Adapted from [12].

表1 满足发电能力的EGS相关因素限定值表[3]

Table 1 Limiting values of EGS related factors satisfying power generation capacity[3]

影响因素	限定值
流体生产率	50~100 L/s
井口流体温度	150~200 ℃
有效热交换面积	>2×10⁶ m²
热储体积	>2×10⁸ m³
流体阻力	<0.1 MPa/(kg·s^-1)
水量损失	<10%

图3 EGS-E工程模型示意图 ①—竖井;②—换热管道(其内部工质为管道工质);③—主(换热)巷;④—爆破钻孔;⑤—换热池; ⑥—岩体裂隙区(其内部工质为裂隙工质);⑦—爆破巷道;⑧—管道换热区;⑨—裂隙换热区。

Fig.3 A schematic diagram of EGS-E engineering model

图4 EGS-E致裂工程示意图

Fig.4 A schematic diagram of EGS-E fracturing engineering

图5 EGS-E致裂工程剖面切片放大图

Fig.5 Enlarged slice map of EGS-E fracturing engineering profile

图6 EGS-E热储平面切片放大图

Fig.6 Enlarged slice map of EGS-E thermal storage engineering profile

图7 EGS-E热能提取流程图

Fig.7 Flow chart of EGS-E thermal energy extraction

参考文献 55

[1]	李德威, 王焰新. 干热岩地热能研究与开发的若干重大问题[J]. 地球科学: 中国地质大学学报, 2015, 40(11):1858-1869.
[2]	KRUGER P, OTTE C E. Geothermal energy: resources, production, stimulation[M]. Palo Alto: Stanford University Press, 1973: 637-639.
[3]	RYBACH L. Geothermal energy: sustainability and the environment[J]. Geothermics, 2003, 32(4/5/6):463-470. DOI URL
[4]	BROWN D W, DUCHANE D V, HEIKEN G, et al. Mining the Earth’s heat: hot dry rock geothermal energy[M]. Heidelberg, Berlin: Springer-Verlag, 2012: 136-145.
[5]	胡剑, 苏正, 吴能友, 等. 增强型地热系统热流耦合水岩温度场分析[J]. 地球物理学进展, 2014, 29(3):1391-1398.
[6]	廖志杰, 万天丰, 张振国. 增强型地热系统:潜力大、开发难[J]. 地学前缘, 2015, 22(1):335-344.
[7]	WHETTEN J T, DENNIS B R, DREESEN D S, et al. The US Hot Dry Rock project[J]. Geothermics, 1987, 16(4):331-339. DOI URL
[8]	GOLDEMBERG J. World energy assessment: energy and the challenge of sustainability[M]. New York: United Nations Development Programme, 2000: 24-26.
[9]	王贵玲, 张薇, 梁继运, 等. 中国地热资源潜力评价[J]. 地球学报, 2017, 38(4):449-459.
[10]	FENG Y, CHEN X, XU X F. Current status and potentials of enhanced geothermal system in China: a review[J]. Renewable and Sustainable Energy Reviews, 2014, 33:214-223. DOI URL
[11]	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.
[12]	MIT. The future of geothermal energy: impact of enhanced geothermal systems (EGS) on the United States in the 21st Century[M]. Cambridge, MA: MIT Press, 2006: 9-11.
[13]	SASAKI S, KAIEDA H. Determination of stress state from focal mechanisms of microseismic events induced during hydraulic injection at Hijiori HDR site[J]. Pure and Applied Geophysics, 2002, 159:489-516. DOI URL
[14]	BERTANI R. Geothermal power generation in the world 2010-2014 update report[J]. Geothermics, 2016, 60:31-43. DOI URL
[15]	BREEDE K, DZEBISASHVILI K, LIU X, et al. A systematic review of enhanced (or engineered) geothermal systems: past, present and future[J]. Geothermal Energy, 2013, 1(1):4. DOI URL
[16]	BARIA R, BAUMGÄRTNER J, RUMMEL F, et al. HDR/HWR reservoirs: concepts, understanding and creation[J]. Geothermics, 1999, 28(4/5):533-552. DOI URL
[17]	PARKER R. The Rosemanowes HDR project 1983-1991[J]. Geothermics, 1999, 28(4/5):603-615. DOI URL
[18]	KWIATEK G, BOHNHOFF M, DRESEN G, et al. Microseismicity induced during fluid-injection: a case study from the geothermal site at Groß Schönebeck, North German Basin[J]. Acta Geophysica, 2010, 58(6):995-1020. DOI URL
[19]	CUENOT N, CHARLÉTY J, DORBATH L, et al. Faulting mechanisms and stress regime at the European HDR site of Soultz-sous-Forêts, France[J]. Geothermics, 2006, 35(5/6):561-575. DOI URL
[20]	KURIYAGAWA M, TENMA N. Development of hot dry rock technology at the Hijiori test site[J]. Geothermics, 1999, 28(4/5):627-636. DOI URL
[21]	BACHMANN C E, WIEMER S, WOESSNER J, et al. Statistical analysis of the induced Basel 2006 earthquake sequence: introducing a probability-based monitoring approach for Enhanced Geothermal Systems[J]. Geophysical Journal International, 2011, 186(2):793-807. DOI URL
[22]	KIM K H, REE J H, KIM Y, et al. Assessing whether the 2017 Mw 5.4 Pohang earthquake in South Korea was an induced event[J]. Science, 2018, 360:1007-1009. DOI URL
[23]	GRIGOLI F, CESCA S, RINALDI A P, et al. The November 2017 Mw 5.5 Pohang earthquake: a possible case of induced seismicity in South Korea[J]. Science, 2018, 360:1003-1006. DOI URL
[24]	SCHILL E, GENTER A, CUENOT N, et al. Hydraulic performance history at the Soultz EGS reservoirs from stimulation and long-term circulation tests[J]. Geothermics, 2017, 70:110-124. DOI URL
[25]	薛建球, 甘斌, 李百祥, 等. 青海共和—贵德盆地增强型地热系统 (干热岩) 地质-地球物理特征[J]. 物探与化探, 2013, 37(1):35-41.
[26]	严维德, 王焰新, 高学忠, 等. 共和盆地地热能分布特征与聚集机制分析[J]. 西北地质, 2013, 46(4):223-230.
[27]	蔺文静, 王凤元, 甘浩男, 等. 福建漳州干热岩资源选址与开发前景分析[J]. 科技导报, 2015, 33(19):28-34.
[28]	王波. 首口干热岩超深探采井在郑州开钻[J]. 能源研究与信息, 2016, 32(2):70.
[29]	张前, 吴小洁, 谢顺胜, 等. 综合物探方法在海南陵水地区干热岩资源勘查中的应用[J]. 工程地球物理学报, 2015, 12(4):477-483.
[30]	王贵玲, 蔺文静. 干热岩开发的破冰之秘[J]. 国土资源科普与文化, 2018(1):22-27.
[31]	JUNG R, . EGS: goodbye or back to the future[M/OL]//Effective and sustainable hydraulic fracturing, 2013:95-121 [2019-06-01]. https://doi.org/10.5772/56458
[32]	TOMAC I, SAUTER M. A review on challenges in the assessment of geomechanical rock performance for deep geothermal reservoir development[J]. Renewable and Sustainable Energy Reviews, 2018, 82(3):3972-3980. DOI URL
[33]	黄荣撙. 水力压裂裂缝的起裂和扩展[J]. 石油勘探与开发, 1982, 9(5):62-74.
[34]	刘建军, 冯夏庭, 裴桂红. 水力压裂三维数学模型研究[J]. 岩石力学与工程学报, 2003, 22(12):2042-2046.
[35]	张东晓, 杨婷云. 页岩气开发综述[J]. 石油学报, 2013, 34(4):792-801.
[36]	冯彦军, 康红普. 水力压裂起裂与扩展分析[J]. 岩石力学与工程学报, 2013(增刊2):3169-3179.
[37]	OLASOLO P, JUAREZ M C, MORALES M P, et al. Enhanced geothermal systems (EGS): a review[J]. Renewable and Sustainable Energy Reviews, 2016, 56:133-144. DOI URL
[38]	唐春安, 赵坚, 王思敬. 基于开挖技术的增强型地热系统:EGS-E概念模型[J]. 岩石力学与工程动态, 2018(1):49-53.
[39]	TANG M, LI H, TANG C A. Study on preliminarily estimating performance of elementary deep underground engineering structures in future large-scale heat mining projects[J]. Geofluids, 2019(4):1-10.
[40]	ZHAO J, TANG C A, WANG S J. Excavation based enhanced geothermal system (EGS-E): introduction to a new concept[J]. Geomechanics and Geophysics for Geo-Energy and Geo-Resources, 2020, 6:6. DOI URL
[41]	刘健, 刘泽功, 高魁, 等. 不同装药模式爆破载荷作用下煤层裂隙扩展特征试验研究[J]. 岩石力学与工程学报, 2016, 35(4):735-742.
[42]	严成增, 孙冠华, 郑宏, 等. 爆炸气体驱动下岩体破裂的有限元-离散元模拟[J]. 岩土力学, 2015, 36(8):2419-2425.
[43]	高金石, 杨军, 张继春. 准静态压力作用下岩体爆破成缝方向与机理的研究[J]. 爆炸与冲击, 1990, 10(1):76-84.
[44]	来兴平, 崔峰, 曹建涛, 等. 特厚煤体爆破致裂机制及分区破坏的数值模拟[J]. 煤炭学报, 2014, 39(8):1642-1649.
[45]	李连崇, 唐春安, CAI M. 自然崩落法采矿矿岩崩落过程数值模拟研究[J]. 金属矿山, 2011(12):13-17.
[46]	SANYAL S K, MORROW J W, BUTLER S J, et al. Is EGS commercially feasible?[J]. Geothermal Resources Council Transactions, 2007, 31:313-322.
[47]	TENZER H. Development of hot dry rock technology[J]. Geo-Heat Center Quarterly Bulletin, 2001, 4(22):14-18.
[48]	WARNER N R, CHRISTIE C A, JACKSON R B, et al. Impacts of shale gas wastewater disposal on water quality in western Pennsylvania[J]. Environmental Science and Technology, 2013, 47(20):11849-11857. DOI URL
[49]	MYERS T. Potential contaminant pathways from hydraulically fractured shale to aquifers[J]. Groundwater, 2012, 50(6):872-882. DOI URL
[50]	谢和平, 高峰, 鞠杨, 等. 深地煤炭资源流态化开采理论与技术构想[J]. 煤炭学报, 2017, 42(3):547-556.
[51]	DURRHEIM R J, OGASAWARA H, NAKATANI M, et al. Observational studies in South African mines to mitigate seismic risks: challenges and achievements[J]. Rock Mechanics, 2017, 3:14.
[52]	何满潮. 深部软岩工程的研究进展与挑战[J]. 煤炭学报, 2014, 39(8):1409-1417.
[53]	谢和平, 高峰, 鞠杨, 等. 深地科学领域的若干颠覆性技术构想和研究方向[J]. 工程科学与技术, 2017(1):1-8.
[54]	习近平. 为建设世界科技强国而奋斗:在全国科技创新大会、两院院士大会、中国科协第九次全国代表大会上的讲话[J]. 中国应急管理, 2016(6):4-9.
[55]	CAI M F, BROWN E T. Challenges in the mining and utilization of deep mineral resources[J]. Engineering, 2017, 3(4):432-433. DOI URL