Abstract Field X comprises a giant Palaeogene limestone reservoir with a long production history. An original geomodel used for history matching employed a permeability transform derived directly from core data. However, the resulting permeability model required major modifications, such as horizontal and vertical permeability multipliers, in order to match the historic data. The rationale behind these multipliers is not well understood and not based on geological constraints. Our study employs an integrated near-wellbore upscaling workflow to identify and evaluate the geological heterogeneities that enhanced reservoir permeability. Key among these heterogeneities are mechanically weak zones of solution-enhanced porosity, leached stylolites and associated tension-gashes, which were developed during late-stage diagenetic corrosion. The results of this investigation confirmed the key role of diagenetic corrosion in enhancing the permeability of the reservoir. Insights gained from the available production history, in conjunction with petrophysical data analysis, substantiated the characterization of this solution-enhanced permeability. This study provided valuable insights into the means by which a satisfactory field-level history match for a giant carbonate reservoir can be achieved. Instead of applying artificial permeability multipliers that do not necessarily capture the impacts of geological heterogeneities, our method incorporates representations of fine-scale heterogeneities. Improving the characterization of permeability distribution in the field provided an updated and geologically consistent permeability model that could contribute to the ongoing development plans to maximize incremental oil recovery.

Abstract The management and outcomes of the volcanic crisis on Montserrat, which began with the onset of activity at the Soufrière Hills Volcano (SHV) on 18 July 1995, might have been very different without the scientific precedents set by the Mount St Helens eruption, USA, on 18 May 1980, and the research advances that followed. This narrative is intended to show the steps taken by health scientists in response to the unfolding developments at the volcano to characterize the hazard presented by the volcanic ash and to devise mitigation measures to prevent the development of irreversible lung disease in the island population. Initial assessments of the health risk for silicosis were deterministic and based on industry exposure limits derived from published epidemiological and clinical studies of workers exposed to dusts containing free crystalline silica. However, by 2003, new research findings on the ash enabled the risk to be updated with a probabilistic approach incorporating the expertise of scientists from a wide range of disciplines including toxicology, volcanology and statistical modelling. The main outcome has been to provide reassurance to the islanders and policy makers that the chances of developing silicosis on Montserrat are very small given the preventive measures that were adopted during 1995–2010 and the change in style of the eruption.