Present Geothermal Characteristics And Its Influencing Factors In Xiong'an New Area

Xiong'an New area is located in the middle of jizhong depression.The tectonic background of Bohai Bay basin provides a good foundation for the formation of geothermal resources.In order to explore the collecting mechanism of geothermal resources in Xiong'an New area,present geothermal characteristics and genetic factors are analyzed.It is found that Xiong'an New area has a good thermal background conditions.The average value of current terrestrial heat flow is 73m W·m^-2.In the uplifts,the reservoirs buried shallow and the thermal conductivity is high,which has a good heat accumulation effect.The average value of terrestrial heat flow is 77.4mw·m^-2.The reservoirs is deep in the sags and the heat flow is low around 60.4m W·m^-2.And it is found that there is a good correspondence between the plane distribution of terrestrial heat flow and the tectonic basement.Based on the analysis of geothermal formation conditions,it is concluded that the main factors affecting the occurrence of geothermal resources are the differences in thermal conductivity between the carbonate reservoirs in proterozoic and the neogene,the groundwater convection channels formed by fractures,and the convection mechanism of groundwater in the thermal reservoirs.It is also found that the geothermal resources in the study area are easy to be concentrated in the fault controlled uplift or the proterozoic thermal reservoir with low uplift.Meanwhile,the high value area of heat flow,the reservoir with high permeability and the overlying regional caprocks are also good geothermal development zones.In conclusion,the genetic model summarized as:In the background of high heat flow in rift basin,mantle source heat is given priority to,atmospheric precipitation as the main source of groundwater in the deep circulating heat transfer through the deep fracture,the underground water through vertical tensile normal fault towards high thermal conductivity of thermal reservoirs,reach Jxw reservoirs after mixed with shallow groundwater,lateral heat transfer through reservoir with high permeability layers,forming geothermal anomalous area.The overlying Cenozoic sand and mudstone layer is used for heat preservation.