- Title
- Experimental study of static and dynamic interactions between supercritical CO₂/water and Australian granites
- Creator
- Zhou, Cheng; Remoroza, Alvin I.; Shah, Kalpit; Doroodchi, Elham; Moghtaderi, Behdad
- Relation
- University of Newcastle, Australia
- Relation
- Geothermics Vol. 64, Issue November, p. 246-261
- Publisher Link
- http://dx.doi.org/10.1016/j.geothermics.2016.05.007
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2016
- Description
- Recent research in Enhanced Geothermal Systems (EGS) have given rise to the interests of a CO₂-based EGS concept due to the unique thermo-physical properties of supercritical carbon dioxide (scCO₂) in EGS applications. However, available studies related to CO₂-based EGS are mostly theoretical investigations and relevant experimental study is highly scarce. To support the development of the new concept, this study conducts both static and dynamic fluid-rock interaction experiments between scCO₂/water and three different Australian granites. A tailored fluid-rock integration apparatus was designed to conduct the above investigation. The pulverised granites were exposed to scCO₂/water for up to 15 days at the simulated reservoir temperatures of 200 °C, 250 °C and pressures of 20 MPa and 35 MPa. The results of static fluid-rock interactions show that the elements of Na, Si, K, Ca, Mg, Fe, Al were found dissolved into the scCO₂-rich geofluid at an average rate of 4.5, 2.7, 1.6, 0.5, 0.3, 0.2, and 0.1 ppm/day, respectively. The dynamic fluid-rock interactions shows that the average rate of mineral dissolution in the pure water was around 183 ppm/day of Si, 14 ppm/day of Na, 12 ppm/day of Al, and 4 ppm/day of K, while only 0.4–2.5 ppm/day of Si, 0.4–1.6 ppm/day of Na, and 0.1–0.3 ppm/day of K for using scCO₂-rich stream as the geofluid. The typical composition of the trace elements dissolved in both pure water and scCO₂-rich geofluids were also identified. Fluid-rock equilibrium analyses shows that the geofluids obtained after the 15 days of static fluid-rock interaction may have reached/were approaching geochemical equilibrium for some elements (e.g. Si), whilst for the flow-through experiments the reacted geofluids were far from geochemical equilibrium. The examination of the fluid-rock interaction using the three Australian granites highlighted the importance of mineral composition to fluid-rock interaction. The research provides valuable experimental data and insights for understanding the CO₂-based EGS system.
- Subject
- fluid-rock interaction; EGS; geothermal; supercritical CO₂
- Identifier
- http://hdl.handle.net/1959.13/1329065
- Identifier
- uon:26057
- Identifier
- ISSN:0375-6505
- Language
- eng
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