Study on Features of Water/Rock Equilibrium Due to Exploitation in Beijing Urban Geothermal Field

Abstract

Geothermal monitoring including water level, well yield, temperature, chemistry etc. items has been carrying out in Beijing Urban Geothermal Field throughout whole reconnaissance, detailed survey and exploration periods. Water/rock equilibrium computation and study were carried out recently. It revealed that the changing of hydrodynamic condition brought corresponding geochemical behavior changing in deep geothermal reservoir along with the process of long term exploitation. The exploitation promoted and accelerated recharge from heat source. It induced also cold groundwater recharge. It means that if we do not drain the pond to get all the fish, e. g. keeping a proper drawdown of water level, artificial exploitation will bring benefit of increased recharge from both sources of heat and water. We have to pay attention to the reservoir engineering monitoring, in order to advise further scientific and reasonable development.