Study On The Evaluation Technology Of Geothermal Water Development Potential With Buried Depth Of 600-1600m In Kaifeng City

In order to strengthen the development,utilization and management of geothermal water resources in Kaifeng City,the paper takes 600-1600m aquifer in Kaifeng Central District as the research object,combines the combination weighting method with the theory of Fuzzy Variable Set,establishes the evaluation model of geothermal water resources development potential,and evaluates its geothermal water resources by layers and zones.At the same time,the groundwater flow model of Kaifeng City is established by MODFLOW to calculate the exploitable amount of geothermal water resources under different water level drawdown conditions.Research shows:(1)According to the hydrogeological conditions in the downtown area of Kaifeng City,the 600-1600m aquifer can be divided into five sub-aquifers:600-800m,800-1000m,1000-1200m,1200-1400m and 1400-1600m.According to the distribution of geothermal wells,the layout of urban roads and the current development and utilization of geothermal water resources,each sub-aquifer can be further divided into 2-3 zones.(2)The geothermal water temperature of the 600-800 m aquifer is between 30 and 45°C.When the depths are 30 m and 50 m,the recoverable geothermal water resources of the aquifer are 13867 m~3/d and 22884 m~3/d,respectively.The development potential of geothermal water resources in 600-800m aquifer is 3 level in vertical direction,and can be divided into three sub-areas A1,A2 and A3 in the horizontal direction.The development potential is 1,4 and 5 level,with an area of 5.31 km~2,14.43 km~2 and 205.26 km~2,respectively.(3)The geothermal water temperature of the 800-1000 m aquifer is between 40 and60°C.When the depths are 30 m and 50 m,the recoverable geothermal water resources of the aquifer are 12856 m~3/d and 20937 m~3/d,respectively.The development potential of geothermal water resources in 800-1000m aquifer is 3 level in vertical direction,and can be divided into B1 and B2 zones in horizontal direction.The development potential is 1 and 5level,with an area of 24.57 km~2 and 200.43 km~2,respectively.(4)The geothermal water temperature of the 1000-1200 m aquifer is between 45 and65°C.When the depths are 30 m and 50 m,the recoverable geothermal water resources of the aquifer are 15178 m~3/d and 23432 m~3/d,respectively.The development potential of geothermal water resources in 1000-1200m aquifer is 2 level in vertical direction,and can be divided into C1,C2 and C3 zones in horizontal direction.The development potential is 1,3 and 4 level,with an area of 34.27 km~2,56.5km~2 and 134.23 km~2,respectively.(5)The geothermal water temperature of the 1200-1400 m aquifer is between 50 and70°C.When the depths are 30 m and 50 m,the recoverable geothermal water resources of the aquifer are 6272 m~3/d and 8139 m~3/d,respectively.The development potential of geothermal water resources in 1200-1400m aquifer is 2 level in vertical direction,and can be divided into D1,D2 and D3 zones in horizontal direction.The development potential is1,2 and 5 level,with an area of 34.79 km~2,31.3 km~2 and 158.91 km~2,respectively.(6)The geothermal water temperature of the 1400-1600 m aquifer is between 60 and75°C.When the depths are 30 m and 50 m,the recoverable geothermal water resources of the aquifer are 10539 m~3/d and 14382 m~3/d,respectively.The development potential of geothermal water resources in 1400-1600m aquifer is 4 level in vertical direction,and can be divided into E1 and E2 zones in horizontal direction.The development potential is 1 and5 level,with an area of 9.2 km~2 and 215.8 km~2,respectively.