DeepReservoir – Predicting reservoir properties in deep structures on the Norwegian Continental Shelf: The critical role of chlorite-coats

In 2024, the project is well underway, with most data collected and analyses in progress. The most important step has been conducting the field expedition to Jameson Land in East Greenland, where we had two successful weeks and accomplished all our data collection goals. As expected, there were large variations in the degree of cementation in the sediments of Greenland, and we have sampled and gathered data to map the dimensions of the uncemented zones, which is the project's key focus. The next steps will be processing and analyzing the new data, then correlating it with well, core, and possibly production data from the Tilje Formation on the Norwegian Continental Shelf. The first papers from the project are expected in 2025.

With the largest and most easily accessible hydrocarbon resources on the Norwegian Continental Shelf already discovered, the future of Norwegian exploration lies in developing deeper and technically complex prospects close to existing infrastructure. Reservoir quality generally decreases with depth, leading to greater uncertainty in deeper prospects. However, some reservoirs contain sand grains coated with the mineral chlorite, which inhibit cementation and preserve excellent reservoir quality at great depth (3-6 km). It is difficult to predict where good reservoir properties are preserved with current models, and measures that can improve the predictability of chlorite coats in deep reservoirs will increase the commercial discovery rates, delay decommissioning, and maintain the competitiveness of the NCS. Chlorite-coated reservoirs, and reservoirs with precursor clays to chlorite coats, are well-suited storage sites for CO2 because chlorite promotes rapid, permanent mineralization of CO2. The DeepReservoir project promotes future value creation on the NCS by developing knowledge important for screening the potential of subsurface aquifers. In this project, we will map the distribution of chlorite coats on the NCS and investigate the processes controlling porosity preservation in deeply buried reservoirs. We will do this by investigating data from subsurface fields and utilize the globally unique outcrops on E Greenland, where chlorite-coated sandstones can be studied in unprecedented detail, and the well-studied modern occurrences of chlorite coat precursor clays in the Ravenglass Estuary, UK. To combine findings into a predictive model, we will integrate sedimentology, petrography, geophysics and hydrodynamic modelling in both subsurface, outcrop and modern analogue systems. This integrated approach was selected as the answers to our research questions lie in the intersection between these disciplines.