增强型地热系统:潜力大、开发难

The enhanced geothermal system(EGS):Huge capacity and difficult exploitation

文中讨论了为什么要开发干热岩地热资源？什么是干热岩系统和增强型地热系统？中国干热岩系统的潜力,如何发展中国的EGS以及我们可供考虑的建议。随着常规能源的不断消耗,可再生能源日益受到人类的青睐。在可再生能源中,地热能的容量最大,地热发电提供的是基本负荷,但是由于诸多因素,开发滞后。尤其是对潜力大、开发难的增强型地热系统,中国更是从研究到开发,都刚刚起步。如果地热发电的规模要超过风能及太阳能等其他新能源,不能仅靠水热型地热系统的开发利用,而必须重视和利用干热岩资源,大力研发增强型地热系统。中国干热岩系统的潜势如何呢？中国科学院地质地球物理研究所利用921个大地热流数据编制了《中国大陆地区新版热流图》以及3~10km深处不同深度温度分布图,计算了不同深度干热岩地热资源量,总数为2.09×107 EJ;其中主要分布在青藏高原,占全国总资源量的五分之一。作者们认为,干热岩资源的开发和增强型地热系统的建立是一个系统工程,地热资源的开发是一项风险投资,亚经济型的EGS风险更甚。国家必须统一安排和投资。工程项目必须学习国外的经验和吸取开发的教训。要选择关键地区进行试验和研究。作者们建议可考虑选择羊八井地热田的北部作为试验地区。

This paper includes five parts：Why should exploit Hot Dry Rock（HDR）geothermal resources？What is Hot Dry Rock system and Enhanced Geothermal System（EGS）？How much is the potential of HDR system in China？How are we to develop EGS in China？and the last one is our recommendations.With the conventional energy sources continually consumed,the renewable energy sources is increasingly favored by people.In renewable energies,the geothermal energy is with huge capacity and the geothermal power generation can provide the basic load,but its development has lagged behind wind and solar energies due to many factors.In particular,the research and development of Enhanced Geothermal System with huge capacity and difficult of exploitaition are just beginning in China.If geothermal electric energy production must surpass wind and solar energy,the development and utilization of geothermal energy can not only rely on the hydrothermal systems,but must pay attention to the utilization of HDR and to the research and development of EGS.How much is the potential of HDR system in China？Based on 921 heat flow data,the heat flow map and deep temperature map（at 3-10km）of Chinese Mainland has been prepared by the Institute of Geology and Geophysics of Chinese Academy of Sciences.They calculated subsurface temperature and HDR resources at different depth of about 2.09×10^7 EJ.Among them,the Qinghai-Tibet Plateau occupied one fifth of the total of resources.The authors argue that the exploitation of HDR and establishment of EGS is a systematic project.The geothermal development is a risk investment and the sub-economic EGS has a greater risk.The state should make unified arrangement and investment.The project must learn from foreign experience and lessons of exploitation.A key area has been selected for testing and research.The authors thought that the northern part of Yangbajain Geothermal Field in Tibet is a better choice to be a test area.