Basalt-CO2-brine wettability at storage conditions in basaltic formations

© 2020 Elsevier Ltd CO2 geo-storage in basaltic formations has recently been demonstrated as a viable solution to rapidly sequester and mineralize CO2. In case CO2 is injected into such basalt reservoirs in supercritical form, a two-phase system (reservoir brine and supercritical CO2) is created, and it is of key importance to specify the associated CO2-basalt wettability so that fluid distributions and CO2 flow through the reservoir can be predicted. However, there is a serious lack of data for basalt CO2-wettability. We therefore measured water contact angles on basalt substrates in CO2 atmosphere. The results indicate that at shallow depth (below 500 m) basalt is strongly water-wet. With increasing depth the basalt becomes less hydrophilic, and turns intermediate-wet at a depth of 900 m. We conclude that basalt is more CO2-wet than chemically clean minerals (quartz, calcite), especially at depths below 900 m. However, the basalt had a CO2-wettability similar to some caprock samples and a gas-reservoir sandstone. The data presented in this paper will thus aid in the prediction and optimization of CO2 geo-storage in basalt formations

CO2 wettability of caprocks: Implications for structural storage capacity and containment security

© 2015. American Geophysical Union. All Rights Reserved. Structural trapping, the most important CO2 geostorage mechanism during the first decades of a sequestration project, hinges on the traditional assumption that the caprock is strongly water wet. However, this assumption has not yet been verified; and it is indeed not generally true as we demonstrate here. Instead, caprock can be weakly water wet or intermediate wet at typical storage conditions; and water wettability decreases with increasing pressure or temperature. Consequently, a lower storage capacity can be inferred for structural trapping in such cases

Dependence of quartz wettability on fluid density

Wettability is one of the most important parameters in multiphase flow through porous rocks. However, experimental measurements or theoretical predictions are difficult and open to large uncertainty. In this work we demonstrate that gas densities (which are much simpler to determine than wettability and typically well known) correlate remarkably well with wettability. This insight can significantly improve wettability predictions, thus derisking subsurface operations (e.g., CO2 geostorage or hydrocarbon recovery), and significantly enhance fundamental understanding of natural geological processes

CO2 – brine – sandstone wettability evaluation at reservoir conditions via Nuclear Magnetic Resonance measurements [dataset]

The dataset contains capillary pressure (Pc), relperm (kr) of non-wetting phase, pore-size distribution (PDS) and T1-T2 images and supplementary file contains python programming codes

Coal wettability after CO2 injection

Increasing energy demand and associated global warming are unarguably the two major challenges that the world currently faces. One of the ideas to reduce the carbon footprint while increasing the efficiency of the energy extraction is CO 2 sequestration in coal seams. This can additionally enhance the coal-bed methane production. However, this process depends on many factors, among which coal wettability is of particular importance especially because of its pressure and temperature dependency. To evaluate this process, coal wettability was tested by measuring the contact angle of CO 2 and water as a function of pressure, temperature, and salinity (DI water and brine (5 wt % NaCl + 1 wt % KCl), i.e., wt % is the weight percentage of salt to water. The results show that the CO 2 -water contact angle increases significantly, with increasing pressure, temperature, and salinity indicating more-effective CO 2 wetness of coal. This, in turn, can reduce the CO 2 residual trapping capacities and increase methane recovery. Furthermore, we demonstrated that CO 2 density correlates well with coal wettability