Ru County is rich in hot dry rock geothermal resources with a 98℃ hot spring distributed. However, research on the resources is scarce. This study evaluated the hot dry rock geothermal resource in Ru County on the basis of borehole temperature measurement and terrestrial heat flow survey. The results show that the average geothermal gradient was 18.7℃/100 m with a max of 35.2℃/100 m and the heat flow changed between 60 and 170 MW/m2. Heat came from the deep magma in the geothermal field. The geothermal reservoir was composed of dense fractures produced by sub-faults in the upper part of F1 fault and F3 fault. The cover of the geothermal reservoir contained exposed granite on the east side of the Reshui River and Sinian slate on the west side. According to our model, the temperature was 260℃ on the lower site and 255℃ on the upper site. The stratum thickness is about 3500-4000 m above the geothermal reservoir. In Ru County, the geothermal reservoir has a shallow burial depth and a high temperature belonging to a suitable destination area of hot dry rock development.
[1] 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[M]. 科技导报, 2012, 30(32): 25-31. Wang Jiyang, Hu Shengbiao, Pang Zhonghe, et al. Estimate of geothermal resources potential for hot dry rock in the continental area of China[M]. Science & Technology Review, 2012, 30(32): 25-31.
[2] 黄少鹏. 中国地热能源开发的机遇与挑战[J]. 中国能源, 2014, 36(9): 4-8. Huang Shaopeng. Opportunity and challenges of geothermal development in China[J]. Energy of China, 2014, 36(9): 4-8.
[3] 蔺文静, 刘志明, 王婉丽, 等. 中国地热资源及其潜力评估[J]. 中国地 质, 2013, 40(1): 312-321. Lin Wenjing, Liu Zhiming, Wang Wanli, et al. The assessment of geothermal resources potential of China[J]. Geology of China, 2013, 40 (1): 312-321.
[4] 蔺文静, 刘志明, 马峰, 等. 我国陆区干热岩资源潜力估算[J]. 地球学 报, 2012, 33(5): 807-811. Lin Wenjing, Liu Zhiming, Ma feng, et al. An estimation of HDR resources in China's mainland[J]. Acta Geoscientica Sinica, 2012, 33 (5): 807-811.
[5] Goff F, Decker E R. Candidate sites for future hot dry rock development in the United States[J]. Journal of Volcanology and Geothermal Research, 1983, 15(1-3): 187-221.
[6] Whetten J T, Dennis B R, Dreesen D S, et al. The US hot dry rock project[J]. Geothermics, 1987, 16(4): 331-339.
[7] Lim J S, Bejan A, Kim J H. Thermodynamics of energy extraction from fractured hot dry rock[J]. International Journal of Heat and Fluid Flow, 1992, 13(1): 71-77.
[8] Zaigham N A, Nayyar Z A. Renewable hot dry rock geothermal energy source and its potential in Pakistan[J]. Renewable and Sustainable Energy Reviews, 2010, 14(3): 1124-1129.
[9] Brown D W, Duchane D V. Scientific progress on the Fenton Hill HDR project since 1983[J]. Geothermics, 1999, 28(4-5):591-601.
[10] Richards H G, Parker R H, Green A S, et al. The performance and characteristics of the experimental hot dry rock geothermal reservoir at Rosemanowes, Cornwall (1985-1988)[J]. Geothermics, 1994, 23(2): 73-109.
[11] Parker R. The Rosemanowes HDR Project 1983-1991[J]. Geothermics, 1999, 28(4/5): 603-615.
[12] Kuriyagawa M, Tenma N. Development of hot dry rock technology at the Hijiori test site[J]. Geothermics, 1999, 28(4-5): 627-636.
[13] Yanagisawa N, Matsunaga I, Sugita H, et al. Temperature-dependent scale precipitation in the Hijiori Hot Dry Rock system, Japan[J]. Geothermics, 2008, 37(1): 1-18.
[14] Wallroth T, Eliasson T, Sundquist U. Hot dry rock research experiments at Fj llbacka, Sweden[J]. Geothermics, 1999, 28(4-5): 617-625.
[15] Zeng Y C, Su Z, Wu N Y. Numerical simulation of heat production potential from hot dry rock by water circulating through two horizontal wells at Desert Peak geothermal field[J]. Energy, 2013, 56(7): 92-107.
[16] Chen J, Jiang F. Designing multi-well layout for enhanced geothermal system to better exploit hot dry rock geothermal energy[J]. Renewable Energy, 2015, 74(2): 37-48.
[17] Zhao Y, Feng Z, Xi B, et al. Deformation and instability failure of borehole at high temperature and high pressure in hot sry rock exploitation[J]. Renewable Energy, 2015, 77(2): 159-165.
[18] 许天福, 张延军, 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. Xu Tianfu, Zhang Yanjun, Zeng Zhaofa, et al. Technology progress in an enhanced geothermal system (hot dry rock) [J]. Science & Technology Review, 2012, 30(32): 42-45.
[19] 王贵玲, 马峰, 蔺文静, 等. 干热岩资源开发工程储层激发研究进展[J]. 科技导报, 2015, 33(11): 103-107. Wang Guiling, Ma Feng, Lin Wenjing, et al. Reservoir stimulation in hot dry rock resource development[J]. Science & Technology Review, 2015, 33(11): 103-107.
[20] 马峰, 孙红丽, 蔺文静,等. 中国EGS示范工程靶区选址与指标矩阵 评价[J]. 科技导报, 2015, 33(8): 41-47. Ma Feng, Sun Hongli, Lin Wenjing, et al. Target site selection and index matrix evaluation of EGS trial project in China[J]. Science & Technology Review, 2015, 33(8): 41-47.
[21] 陈墨香, 汪集旸, 邓孝. 中国地热资源: 形成特点和潜力评估[M]. 北 京: 科学出版社, 1994. Chen Moxiang, Wang Jiyang, Deng Xiao. Geothermal energy in China: Formation characteristics and potential assessment[M]. Beijing: Science Press, 1994.
