The event brought geoscience, engineering and energy professionals together from across the energy transition, and included parallel meetings on CCS, geothermal energy, hydrogen storage and offshore wind energy.

At the CCS conference, Josh presented his work on the influence of trapped brine on sealing of legacy boreholes by natural salt creep. Legacy boreholes can compromise the integrity of a store and are thus a key challenge for CCS projects. Halite formations can be considered part of the seal in the long term, after engineered barriers have failed, and Josh's presentation considered the impact of trapped brine on this natural sealing process.

CCS is a rapidly evolving field, with many projects in development across the North Sea. Josh and Peter took the opportunity to attend a wide variety of sessions, including discussion of specific CCS projects (such as Northern Lights in Norway and Project Greensand in Denmark), and dedicated technical sessions on containment modelling, seal characterisation and monitoring technology. They also enjoyed discussions on innovative applications of AI and machine learning for interpreting geological datasets and for surrogate modelling, as well as methods for quantifying and understanding key uncertainties in subsurface projects.

The conference offered a good mixture of keynotes, plenary, panel discussions and oral presentations. Accompanying the technical discussions was an excellent strategic programme, exploring key policy issues influencing sustainable use of the subsurface, and the important role of geoscience in the energy transition. With four conferences running in parallel there was opportunity to explore synergy between CCS and geothermal projects, and the use of salt caverns for underground gas storage.

Both Peter and Josh enjoyed exploring Rotterdam, including attending the conference dinner at the medieval St Lawrence Church, and Peter was also able to visit the Kinderdijk Windmills on the edge of the city.