Reservoir Characterisation Of Johansen Formation As Potential CO2 Storage Reservoir In The Northern North Sea
M. Fawad and N.H. Mondol
Event name: Fifth CO2 Geological Storage Workshop
Session: Session 2: Reservoir Management
Publication date: 21 November 2018
Info: Extended abstract, PDF ( 1.09Mb )
To evaluate subsurface reservoirs for CO2 sequestration, the grain scale properties and role of diagenesis is important for the injectivity and the subsequent mobilization. This study focuses on Johansen Formation of Jurassic age in the vicinity of Troll field within the northern North Sea. Johansen Formation is a saline aquifer and no hydrocarbon discovery has been reported in this reservoir so far. We analysed 24 wells using petrophysics and rock physics techniques to obtain net reservoir, net to gross ratio, effective porosity, volume of shale and level of cementation, and attempted to relate these parameters with the factors influencing them. The reservoir properties were found to be optimal approximately around depths shallower than 2000m (below sea floor, BSF). Even the shallowest sandstones exhibited cementation indicating calcite precipitation while the sediments deposited. Presence of shale however found to inhibit the quartz cementation possibly preserving the porosity. These findings will help understanding the complexity of the Johansen Sandstone as storage reservoir and the influence of heterogeneity on CO2 migration.