Estimation of reservoir temperature using silica and cationic solutes geothermometers:a case study in the Tengchong geothermal area  

作　　者：Xiaobo Zhang Qinghai Guo Jiexiang Li Mingliang Liu Yanxin Wang Yijun Yang 

机构地区：[1]School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences

出　　处：《Chinese Journal Of Geochemistry》2015年第2期233-240,共8页中国地球化学学报

基　　金：supported by the National Natural Science Foundation of China(No.41120124003);the Ministry of Education of China(111 Project,No.B08030);the Research fund of Bureau of Science and Technology of Qinghai Province(No.2013-G-Q08A);the Fundamental Research Fund for National Universities,China University of Geosciences(Wuhan) (Nos.CUG120505 and CUG120113)

摘　　要：Reservoir temperature estimation is vitally important for assessing the exploitation potential of a geothermal field.In this study,the concentrations of major chemical constituents in geothermal water sampled from boiling and hot springs in the Tengchong hydrothermal area were measured,and quartz and cationic solutes geothermometers were used to calculate subsurface temperatures.Log(Q/K) diagrams and Na-K-Mg triangular diagrams were applied to evaluating the equilibrium status of geothermal water samples with regard to reservoir minerals,and results were used to select suitable geothermometers.The results show that samples RH01,RH03,RH04,RH05,and LL16 were in or very close to full equilibrium with the selected minerals,and therefore a NaK geothermometer is appropriate.A K/Mg geothermometer,however,is applicable to LP08 and PZH18 whose chemical compositions adjusted to the shallow reservoir temperatures during their re-equilibrium processes.In contrast,cationic solute geothermometers are unsuitable for SQ20 and RH07,which are categorized as immature water in the Na-K-Mg diagram;a quartz geothermometer was adopted to evaluate the corresponding subsurface temperatures of these samples.According to the reservoir temperature estimation made in this study,there is at least one high-temperature reservoir below Rehai with a possible temperature range of 210-270 ℃.Reservoir temperature estimation is vitally important for assessing the exploitation potential of a geothermal field.In this study,the concentrations of major chemical constituents in geothermal water sampled from boiling and hot springs in the Tengchong hydrothermal area were measured,and quartz and cationic solutes geothermometers were used to calculate subsurface temperatures.Log（Q/K） diagrams and Na-K-Mg triangular diagrams were applied to evaluating the equilibrium status of geothermal water samples with regard to reservoir minerals,and results were used to select suitable geothermometers.The results show that samples RH01,RH03,RH04,RH05,and LL16 were in or very close to full equilibrium with the selected minerals,and therefore a NaK geothermometer is appropriate.A K/Mg geothermometer,however,is applicable to LP08 and PZH18 whose chemical compositions adjusted to the shallow reservoir temperatures during their re-equilibrium processes.In contrast,cationic solute geothermometers are unsuitable for SQ20 and RH07,which are categorized as immature water in the Na-K-Mg diagram;a quartz geothermometer was adopted to evaluate the corresponding subsurface temperatures of these samples.According to the reservoir temperature estimation made in this study,there is at least one high-temperature reservoir below Rehai with a possible temperature range of 210-270 ℃.

关 键 词：温度采样 地热区 阳离子 地温 溶质 腾冲 储层 地质温度计 

分 类 号：P314[天文地球—固体地球物理学] P618.13[天文地球—地球物理学]