A Preliminary Study on Fluid-Rock Interactions of the Hot Fractured Rock Geothermal System in Cooper Basin, South Australia.
Kuncoro, G., Ngothai, Y., O'Neill, B. Pring, A. Brugger, J. and Yanagisawa N.Y.
Proceedings, Australian Geothermal Conference Adelaide 2010
A study of the interactions between rock and circulating fluid is essential to determine the chemical changes and mineral alteration of a geothermal system. Preliminary mineralogical investigation and geothermal experiments have been performed to investigate the hydrothermal alteration of the Habanero geothermal system in the Copper Basin, South Australia.
Samples of drill cuttings from a borehole 5m deep were contacted with reverse osmosis water in a thermosyphon induced loop reactor at 250 degrees C and 50 bar. Fluid and rock samples were analysed prior to, and after circulation of the water through crushed samples of the rock (100 to 200 microns in diameter) for 1, 2, 3, 7, 14 and 21 days. Water analyses were performed using ICP-MS, and rock analyses were conducted using an optical microscope, SEM and XRD. The experimental results indicated that mineral dissolution was more rapid in the early stages of the experiment.