Genesis Analysis And Assessment Of Geothermal Resources In Tangquan Geothermal Field

Geothermal energy is one of the most competitive renewable energy resources,and the key problem is to achieve sustainable development and utilization of geothermalresources for China today and geothermal industry.in the world. Tangquan geothermalfield is located in north-west of Zhunhua city in Hebei province, and is the hillylandforms in front of hill, and has abundant geothermal resources. Geothermalresources began to be used early in Yuan, Ming and Qing dynasty, but the research forTangquan geothermal field is still in the initial stage. This paper systematically studiesthe causes and potential of geothermal resources by means of geological investigation,geophysical exploration, temperature measurement, hydrogeological test, heat fluidgeochemistry and isotope analysis basing on the low degree of exploration of Tangquangeothermal resources and the actual need of Qing Dongling Management Committeefor development and utilization of geothermal resources.The study found:(1) Heat reservoirs of Tangquan geothermal field are mainlygneiss this area. The thickness of gneiss is about0~1000M, and the weathering isserious, and the fissures is development, and the permeability is strong, and the gneisscan guide water, and storage water, and accept recharge from the south of Mao hill toGuozhuangzi village; The cover layer of geothermal field is the clay, silty clay and siltysand of Quaternarystrata, and the cover layer is very thin, and generally less than4M.The study area of geothermal anomaly center is located in the area of Tangquan Fuquanpalace to sanatorium, and the anomaly center was bipolar distribution,and thetemperature of50m depth of water in the geothermal anomaly center is about51～54°C,and100m is up to about60～67°C;(2) The geothermal field belongs to a low tomedium temperature geothermal system of convective type. The geothermal fluidorigins from the rainfall recharged in the mountainous area located to the north ofgeothermal field, with a recharge elevation of more than935m. The geothermal fluid is gradually heated by the surrounding rock under a normal heat flow backgroundduring a deep cycling of ca.4800m, with a reservoir temperature of ca.130℃. In thezone of Fuquan palace to sanatorium in Tangqan area where several faults cut throughthe monzonitic granite body, the geothermal fluid up flow along the faults and mix withthe fissure water stored in the gneisses.(3) The pH value of groundwater in Tangquanarea is7.83~8.29, and is the weak alkaline water; the average value of TDS is639.4mg/L, and is fresh water. The chemical types of groundwater is SO4-Na type in thethermal anomaly center and nearby,and the Ca2+、HCO3-ion contents of undergroundwater increase gradually in the periphery of thermal anomaly area.(4) Heat of hotstorage in Tangquan survey area is9.11×1016J, standard coal3.11×106tons; Recyclableresource quantity are2.28×1016J, standard coal are7.78×105tons; Static reserves ofheat fluid in herma reservoir aquifer are2.26×108m3, and the daily exploitation quantityare about4709m3.