Residual or capillary trapping is one of the key trapping mechanisms for geological storage of CO2 (Burnside and Naylor, 2014; Juanes et al., 2006). Yet, very few studies so far have attempted to evaluate residual trapping and the related characteristic parameters, in situ. To meet this challenge, two single-well experiments were carried out at Heletz, Israel pilot CO2 injection site with the objective to quantify CO2 residual trapping. The experiments were performed in 2016–2017 in a saline reservoir at 1.6 km depth as part of EU project TRUST, with extensive preparatory work being carried out in preceding EU projects MUSTANG, PANACEA and CO2QUEST (e.g. Niemi et al., 2016a). This Special Section of articles summarizes the main findings of these experiments and insights obtained on residual trapping of CO2 in deep saline aquifers.

We as guest editors to this special section would like to, also on behalf of the authors, especially acknowledge the role of EU FP7 projects TRUST (grant number 309067), PANACEA (grant number 282900), MUSTANG (grant number 227286) and CO2QUEST (grant number 309102) for the financial support that has enabled the work. We would also like to express our special thanks to Editor Sean McCoy from International Journal of Greenhouse Gas Control for all his help and support during the preparation of this Special Section.

Peer reviewed