Study on geothermal flux and geothermal genesis of typical geothermal fields in North China

Abstract

Rongcheng geothermal field is located in the middle of Jizhong depression in North China. It is a Paleogene and Neogene sedimentary depression with rich geothermal resources. In this paper, the core samples of borehole in Rongcheng geothermal field were collected to test and analyze the rock thermal conductivity and rock heat generation rate. Combined with the temperature measurement data, the composition of geothermal flux and layered heat flow in this area were studied. Through the hydrochemical analysis of typical geothermal fluid samples, the circulation path of geothermal fluid in this area was established. Comprehensively analyzed the water heat source of geothermal field, and put forward the genetic model of geothermal resources in the region. The results show that the thermal conductivity of Jixian system is the highest, followed by the Changcheng system, while the thermal conductivity of Neogene and Paleogene formation is lower as a whole. The overall terrestrial heat flow value is between 45 ~ 90 MW / m2, which is a high value area of terrestrial heat flow density in Jizhong depression. Geothermal resources mainly accumulate heat in the form of conduction. The heat conduction efficiency is low, but the distribution range is wide. The thermal convection of deep bedrock reservoir is a useful supplement. The research results can provide certain theoretical support for the development and utilization of geothermal resources in this area.