The Case for Geothermal Power in Singapore

Oliver, Grahame J.¹; Palmer, Andrew C.²; Tjiawi, Hendrik²
¹Department of Geography, National University of Singapore, Singapore, Singapore.
²Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore.

Singapore lies adjacent to a world class heat flow anomaly (160 mW/m²) centered on the Central Sumatra Tertiary Basin. The heat flow in Singapore is estimated from nearby oil and gas wells to be between 110 and 130 mW/m². Singapore and the neighbouring Malaysian Peninsular have numerous hot springs. Shallow bore holes in a hot spring area in Singapore have geothermal gradients of more than 10 degrees C per 100 m. Application of the Na/K geochemical thermometer gives a mean temperature of 160° C for the reservoir for this hot spring. It is hypothesized that the high head of groundwater in the Central Catchment area in Singapore (120 m above sea level) drives a fresh water lens down to 4 to 5 km depth. TOUGH-2 computer modeling simulates the groundwater flow under Singapore, locates the sea water-fresh water transitions, successfully positions the hot spring area and matches its low salinity. These 2D models show plumes of mixed fresh and sea water with reservoirs at 150° C between 2 and 2.75 km depth in the Bukit Timah Granite and Jurong Formation sediments, respectively. Geothermal water from suitably engineered geothermal reservoirs could be used to power electricity generation, desalination, process heating and district cooling. A feasibility study is required: i.e. more shallow boreholes, deep geophysics and a deep geothermal exploration borehole.

AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012