Using TOUGH2 numerical simulation to analyse the geothermal formation in Guide basin, China
Abstract: The Guide sedimentary basin is located in the northeastern part of Qinghai-Xizang Plateau,which is rich in geothermal resources. However,exploitation of the geothermal resources has so far been limited,because of limited understanding of the resources quantity and storage gained from scientific researches. In this study,using a typical cross section across the basin and taking into account its geothermal and geological conditions,a new water-heat coupled model was built and associated modelling was done by the software TOUGH2. During modelling process,the accuracy and applicability of the model was confirmed through the calibration of relevant parameters for modelling the heat and water transport and the formation of geothermal reservoir across the basin,with particular focus on the Neogene geothermal field. Results show that the groundwater that flows from the basin margins to the center is heated by the Neogene and Paleogene sedimentary rocks with high geothermal gradients. Since the east-west extending fault F1 is conductive,it acts as preferential flow paths which on one hand provide additional and rapid flows to the thermal reservoir; and on the other hand,cool down the thermal water to a certain extent due to the infiltration of shallower water sources in the vicinity of the fault. Furthermore,the estimated geothermal resources quantity is close to that of previous studies. In comparison with the Paleogene rock formations,the Neogene geothermal reservoir shows a better nature in terms of water content,aquifer permeability and resources exploitability,although the resource quantity of the Paleogene reservoir is considerable.
- Guide basin /
- TOUGH2 /
- Two-dimensional modelling /
- Numerical simulation /
- Geothermal resource evaluation
Table 1. Geothermal reservoir of Neogene in geothermal field
Borehole No. Hole depth (m) Elevation (m) Lithology of heat reservoir Hydraulic head (m) Draw-down (m) Flow (m3/d) Water tempera-ture (℃) Salinity (g/L) ZK2 266.88 2 222.96 Medium sand, coarse sand and gravel +23.0 22.99 603.245 18.5 0.423 ZK4 272.50 2 224.98 Medium sand, coarse sand and gravel +20.33 18.13 554.342 21.5 0.568 7 ZK13 293.38 2 212.93 Medium sand, coarse sand and sandy gravel +24.75 18.90 1 074.211 25.5 0.413 3 ZK3 385.63 2 231.15 Medium sand, coarse sand and gravel +8.52 7.71 27.862 34.6 0.646 RK2 404.41 2 212.12 Medium sand and coarse sand +20.8 19.39 1 219.795 26.5 0.495 6 ZK15 470.41 2 226.94 Medium sand, coarse sand and sandy gravel +9.13 8.15 145.843 22.5 0.464 2 RK1 603.95 2 207.48 Moderate coarse sandstone +32.85 15.53 1 221.35 28.0 0.528 2 R2 1 709.5 2 206.00 Medium sandstone and medium fine sandstone +11.07 28.1 1 288.22 36.5 0.527 R3 2 701.2 2 213.00 Medium sandstone and medium fine sand +12.4 43.08 968.46 41.0 0.638
Table 2. Main parameter table
Material name No. of samples Density (kg/m3) Porosity Permeability Thermal conductivity (W/(m·c)) Specific heat capacity(J·kg·C) (X) (m2) (Y) (m2) (Z)(m2) Aquifuge (GSC) 2 2 490.0 0.18 1.0E-16 1.0E-16 1.0E-16 1.85 1 112.45 Neogene aquifer (XHS) 5 2 380.0 0.131 2.26E-12 2.256E-12 2.256E-12 1.72 920.17 Paleogene aquifer (GHS) 3 2 463.0 0.127 7.0E-15 7.0E-15 7.0E-15 1.76 924.35 Neogene fault (XDL) 2 2 380.0 0.131 5.0E-12 1.0E-16 1.0E-16 1.72 920.17 Paleogene fault (GDL) 1 2 463.0 0.127 14.0E-15 14.0E-15 14.0E-15 1.76 924.35 Thermal insulation boundary (GRBJ) 2 490 0.108 1.0E-16 1.0E-16 1.0E-16 0 1 112.45
Alberto J, Javier R, Carlos V, et al. 2012. The thermal state and strength of the lithosphere in the Spanish Central System and Tajo basin from crustal heat production and thermal isostasy. Journal of Geodynamics, 58: 29-37. Doi: 10.1016/j.jog.2012.01.005. Ben N, Andrea F, Niels B. 2008. Heat flow and lithospheric thermal regime in the Northeast German basin. Tectonophysics, 460: 215-229. Doi: 10.1016/j.tecto.2008.08.022. Chen HJ. 2014. Qinghai Province Guide basin characteristics of geothermal geology and geothermal resource evaluation. M.S thesis. Beijing: China University of Geosciences (Beijing). FANG Bin, ZHOU Xun, LIANG Si-hai. 2009. Characteristics and utilization of the Zhacang hot springs in Guide County, Qinghai. Geo-science, 23(1): 57-63. doi: 10.23917/forgeo.v23i1.4999 GAO Liang, LIANG Juan-e. 2013. Numerical simulation of thermal reservoir of Guantao Formation in Wuqing region based on TOUGH 2.0. China Water Transport, 13(11): 141-142, 145. Doi: CNKI:SUN:ZSUX.0.2013-11-060. General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China. 2011. Geologic exploration standard of geothermal resources (GBT11615-2010). LANG Xu-juan, LIU Feng, LIU Zhi-ming, et al. 2013. Terrestrial heat flow in Guide basin, Qinghai. Geological Science and Technology Information, 3: 227-232. Doi: CNKI:SUN: DZKQ.0.2016-03-031. LANG Xu-juan. 2016. The thermal structure and geothermal genesis mechanism in Guide basin. Ph.D thesis. Beijing: Chinese Academy of Geological Science. LEI Hong-wu, JIN Guang-rong, LI Jia-qi, et al. 2014. Coupled thermal-hydrodynamic processes for geothermal energy exploitation in enhanced geothermal system at Songliao basin, China. Journal of Jilin Unviersity: Earth Science Edition, 44(5): 1633-1646. Doi: 10.13278/j.cnki. jjuese.201405207. LIAO Juan, MA Teng, CHEN Liu-zhu, et al. 2013. Hydrochemistry of high-arsenic thermal groundwater of low-temperature in the Guide basin in Qinghai, China. Hydrogeology and Engineering Geology, 40(4):121-126. Doi: CNKI:SUN:SWDG.0.2013-04-024. LI Le-le. 2016. Research on the preservative research on the preservative law and genetic model of geothermal resources in Guide basin, Qinghai Province. M.S. thesis. Nanchang: East China University of Technology. Li XW, Mo XX, Yu XH, et al. 2013. Petrology and geochemistry of the early Mesozoic pyroxene andesites in the Maixiu Area, West Qinling. China: Products of subduction or syn-col-lision? Lithos, 172-173: 158-174. http://dx.doi.org/10.1016/j.lithos.2013.04.010. doi: 10.1016/j.lithos.2013.04.010 LI Zhao-hong. 2016. LNAPLs leakage and migra-tion feature assessment in one watersealed cavern based on water curtain and air tight-ness theory. M.S. thesis. Beijing: China Uni-versity of Geosciences (Beijing). LIN Wu-le, HU Xiang-yun, CHEN Yu-feng, et al. 2017. Geothermal research in Guide basin. Annual Meeting of Chinese Geoscience Union 2017. LIU Feng, LANG Xu-juan, LU Chuan, et al. 2017. Thermophysical parameters and lithospheric thermal structure in Guide basin, northeast Qinghai–Tibet Plateau. Environmental Earth Sciences, 76: 199. DOI:10.1007/s 12665-017-6503-2. LIU Xue-yan. 2010. Numerical analysis of coupling between heat transfer and seepage in fracture rock near field of nuclear waste repository. M.S. thesis. Beijing: Beijing Jiaotong University. Liu YS, Gao S, Jin SY, et al. 2001. Geochemistry of lower crustal xenoliths from Neogene Hannuoba basalt, North China craton: Impli-cations for petrogenesis and lower crustal composition. Geochimica et Cosmochimica Acta, 65(15): 2589-2604. DOI: 10.1016/S0016-7037(01)00609-3 Michael JOS, Karsten P, Marcelo JL. 2001. State of the art of geothermal reservoir simulation. Geothermics, 30(04): 395-429. Doi: 10.1016/S0375-6505(01)00005-0. Oliver S, Heather A, Sheldon L, et al. 2013. Hydrothermal models of the Perth metropolitan area, Western Australia: Implications for geothermal energy. Hydrogeology Journal, 21:605-621. DOI: 10.1007/s10040-012-0945-0. Pollack HN, Hurter SJ, Johnson JR. 1993. Heat flow from the earth's interior: Analysis of the global data set. Reviews of Geophysics, 31:267-280. Doi: 10.1029/93RG01249. Pruess K, Coldenburg, Gmoridis. 1999. TOUGH2 user's guide. USA: Lawrence Berkeley National Laboratory: 1-210. SONG Chun-hui, FANG Xiao-min, GAO Jun-ping, et al. 2001. Tectonic uplift and sedimentary evolution of the Guide basin in the northeast margin of Tibetan Plateau in Cenozoic Era. Acta Sedimentologica Sinica, 19(4):493-500. Doi: 10.3969/j.issn.1000-0550.2001.04.003. WANG Gui-ling, ZHANG Wei, MA Feng, et al. 2018. Overview on hydrothermal and hot dry rock researches in China, China Geology, 1: 273-285. doi: 10.31035/cg2018021. WANG Gui-ling, LIU Zhi-ming, LIU Qing-xuan, et al. 2002. Modeling of geothermal reinjection in Xi'an geothermal field, West China. Acta Geoscientica Sinica, 2: 183-188. DOI: 10.3321/j.issn:1006-3021.2002.02.016 WANG Yang, ZHANG Ke-ni. 2011. Fracture simulation method of enhanced geothermal system (EGS). Annual Meeting of Chinese Geoscience Union. XUE Yu-qun, XIE Chun-hong. 1980. A review of numerical methods application in hydro-geology. Hydrogeology and Engineering Geology, 1: 40-45. DOI: CNKI: SUN: SWDG.0.1980-01-012. YUE Gao-fan, DENG Xiao-fei, XING Lin-xiao, et al. 2015. Numerical simulation of hot dry rock exploitation using enhanced geothermal systems in Gonghe basin. Science & Technology Review, 33(19): 62-67. Doi: 10.3981/j.issn.1000-7857.2015.19.010. ZHANG Yuan-dong, WEI Jia-hua, WANG Guang-qian. 2006. Impact of regional groundwater flow on geological temperature field with energy abstraction from the aquifer. Journal of Tsinghua University (Science and Te-chnology), 9: 1518-1521. DOI: 10.3321/j.is-sn:1000-0054.2006.09.007. ZHENG Yan. 2009. Numerical simulation study on geological storage of carbon dioxide in Jiangling Sag, Jianghan Basin. M.S. thesis. Wuhan: China University of Geosciences (Wuhan).