Natural State Modeling of Singapore Geothermal Reservoir

Abstract

The existence of hot springs coupled with the apparent anomalous high heat flow has sparked interest in the potential for geothermal development in Singapore. This geothermal resource may be potentially significant and could be exploited through Engineered Geothermal System (EGS) technology, i.e. a method to create artificial permeability at depth in granitic or sandstone formations as found under Singapore. The apparently ever-increasing fossil fuel price has made the cost of using the EGS technology more viable than it was in the past. Thus, to assess the resource, a numerical model for the geothermal reservoir has been constructed. Mass and heat flows in the system are simulated in 2D with AUTOUGH2.2, and the graphical interface processed through MULGRAPH2.2. Natural state calibration was performed to match both the observed and the expected groundwater profile, and also to match the hot water upflow at the Sembawang hot spring, with simulated flowrate matching the hot spring natural flowrate. The simulation gives an encouraging result of 125 - 150 °C hot water at depth 1.25 – 2.75 km.