Characteristics of Geothermal Geology in Wucheng Uplift Geothermal Field
WANG Di, WANG Xinwei, SU Shangguo, MAO Xiang, ZHANG Xuan, WANG Tinghao, LIU Huiying
[China University of Geosciences (Beijing), China]
Driven by the "Xiongxian model" and environmental pressure, Hebei Province has become the largest geothermal heating urban agglomeration in China. Therefore, the study of geothermal geological characteristics of the Wucheng uplift has important guiding significance for geothermal development in Gucheng County, Hebei Province. In this paper, we studied the distribution of different types of thermal reservoirs, physical properties of reservoirs, characteristics of geothermal water recharge and circulation path, and evaluation of geothermal resources by combining the logging, seismic and regional geological data with the analysis of hydrochemical characteristics and isotopic results. The results show that the geothermal field has two thermal reservoirs: sandstone reservoir and karst reservoir. The former is widely stable distributed,and the main aquifer is in lower Guantao Formation ,with a floor depth of 1200-1600m. The geothermal water temperature range is 52~54℃, and the water yield of well is 75~123m3/h . The favorable zones of karst thermal reservoir are mainly in the anticlinal core of the Cambrian-Triassic and extend in a north-south zonal direction, with a roof depth of 2100-2900m. The geothermal water temperature range is 82~85℃, and the water yield of well is 75~98 m3/h . The geothermal water originates from recharge area of Taihang mountains in the west and Yanshan mountains in the north, moving horizontally along the NE-SW fracture zone and the karst unconformity to enter the shallow thermal reservoir. It mixes in Wucheng uplift to form medium-low temperature geothermal water through Cangxian uplift and Xingheng uplift, and the water quality is Cl-Na type. The dating results of 14C indicate that the geothermal water is older than 20ka, with a recharge depth of more than 2407m. The Minghuazhen Formation and the Carboniferous-Permian strata are cap rocks of the two thermal reservoirs, respectively. According to the fine evaluation results of geothermal resources, the total geothermal reserves amount to 7.99×1010 GJ, equivalent to 27.25×108 of standard coal. The annual exploitation of geothermal resources can meet the indoor heating area of 38.9 thousand square meters with huge potential for development.
|        Topic: Geology||Paper Number: 12069|