Effect of reactive surface area of minerals on mineralization and carbon dioxide trapping in a depleted gas reservoir

In this study, a long-term (up to 1000 years) geochemical modelling of subsurface CO2 storage was carried out on sandstone reservoirs of depleted gas fields in northeast Netherlands. It was found that mineral dissolution/precipitation has only a minor effect on reservoir porosity. In order to validate this, we focused specifically on the reactive surface area of minerals which we measured by Scanning Electron Microscopy. In this way we obtained distributions for the measured reactive surface areas of each individual mineral. Subsequent parameter analysis and Monte Carlo sampling of these distributions revealed that in the Rotliegend sandstones, the surface area of quartz has by far the largest effect on SMCO2 (total amount of CO2 sequestered as mineral). The proportional relation of SMCO2 and quartz reactive surface area leads to the conclusion that CO2 injection in a sandstone reservoir with fine grained quartz has a higher potential for mineral trapping of CO2.In addition, using parameter analysis we also could determine the effect of surface area of each mineral on its own dissolution/precipitation mechanisms as well as on the other minerals. For example, the results showed that dawsonite precipitation is proportional to kaolinite and K-feldspar surface area. (C) 2013 Elsevier Ltd. All rights reserved.