Geothermal waters are contained in formations in large sedimentary basins around the world. However, injection of used water is difficult issue to handle. It is therefore neccessary to improve or enhance the formation PORO by weak acids. CO2 is recommended due to the fact that it helps to reduce emmissions to the atmosphere.
There is quite some work published on this topic, both, experimentally and numerically. Most the work can be found in Chemical Geology or Journal of Greenhouse Gas Control. If you like I can direct you to some of the papers. The problem is that modeling relies on a well calibrated database for the mineral reactions and some knowledge on mineralogy and petrophysical data such as surface area or porosity. These properties bear uncertainties that are quite difficult to quantify. The same holds for experiments where many artifacts can impact your geochemical system and I am not sure if this is understood well enough.
I think for what you need carbonic acid might be too weak which means that if, then only carbonates would dissolve and this will still take considerable amounts of time until a significant increase in porosity and therefore permeability is achieved. Acid treatment is usually done using HCl or similar simply because it is a much stronger acid and it would mainly be feasible in carbonate but not in sandstone reservoirs.
I hope this help.
Best wishes, Andreas
- Badges
- Science topic
- Similar topics
- Geoscience
- Atmospheric Sciences
- Climate Science
- Climate Change