Fluid Geochemistry of Habanero Site, Cooper Basin, Australia during First Circulation Test in 2008-2009

Abstract

At Habanero site, Cooper Basin, South Australia, the first circulation test and tracer test was conducted in December 2008 to February 2009. During the circulation test, the production fluids for tracer test and geochemical analysis were collected at a sampling panel after a cooling tower near the re-injection well Habanero #1. At the sampling panel the fluid was cooled down to about 45°C and the concentrations of Na, K, Ca, Mg, F, SO4, Cl, SiO2 and Sb were analyzed by ion-chromatography, ICP etc. During the circulation, these concentrations are almost constant. The average Na concentration was 5,107 mg/l, K was 694 mg/l, Cl was 8,885 mg/l. These values were slightly higher than the values at the wellhead of the production well Habanero #3 of the first open loop production test in March 2008 before circulation. The discrepancy may be due to dissolution of feldspars of granite in the reservoir. The temperature of Na/K/Ca geothermometer during circulation is about 270°C. This corresponds with the temperature estimated by fluorescein decomposition in the tracer test