Heat Flow Correction for the High-Permeability Formation: A Case Study for Xiong’an New Area

Abstract

Abstract The Xiong’an New Area is located at the western Bohai Bay Basin, 150 km south of Beijing, China. The area has tremendous high heat flow value within the sedimentary layer, and the average value can reach 90 mW·m-2 within the Niutuozhen Uplift. However, combining the basal heat flow at the top of the metamorphic layer with the heat flow value which was contributed by the radiogenic heat production from the overlying formation, the surface heat flow value was only 65.1 mW·m-2 in this area. Thus, the heat flow value within the sedimentary layer was greatly influenced by other factors. In this study, based on the continuous temperature measurements data from 4 boreholes, thermos-physical parameters (conductivity, radioactive heat production, density, and heat capacity) from 90 rock sample measurements, and the regional stratigraphic development, a two-dimensional thermal-hydraulic modelling was carried out to study the influence of the heat refraction and groundwater convection on the heat flow value. According to calculation results, the heat flow disturbance caused by heat refraction was 10 mW·m-2, and the disturbance value was 20 mW·m-2 for the groundwater convection. Furthermore, when the high-permeability layer thickness was a certain value, with the increasing high-permeability layer buried depth, the influence of the groundwater convection on the temperature field which was used for the heat flow calculation became weak. While when the high-permeability layer buried depth was set up, the influence of the groundwater convection on the above temperature field became stronger with the increasing high-permeability layer thickness.