Philip Ringrose has worked as a geoscientist for over 30 years on many aspects of the design and construction of fluid flow models of geological reservoir systems, both for environmental applications (groundwater and CO2 storage) and for petroleum reservoir field development. He is currently at the Equinor Research Centre in Trondheim, Norway, and Adjunct Professor at NTNU, Trondheim, Norway. In 2018 he was appointed Honorary Professor in Sustainable Geoenergy at the University of Edinburgh, School of Geosciences. He holds Bachelor and Doctorate degrees in Geology (Edinburgh and Strathclyde) and has published widely on flow in rock media.Mark Bentley is a geoscientist with 30 years' experience in the oil and gas business. He worked for 11 years as a production geologist for Shell in the UK, Oman and the Netherlands and has subsequently worked as a geoscientist consulting and training internationally with TRACS, based in Aberdeen, Scotland. He has been building reservoir models since 1993 and has a particular interest in the expression of subsurface uncertainty through reservoir modelling. He holds Bachelor and Doctorate degrees in geology and structural geology from the University of Wales and since 2018 has been an Associate Professor in the Institute of GeoEnergy Engineering at Heriot-Watt University in Edinburgh.