Jotun Field Reservoir Facies

The Jotun Field was discovered in 1994 and production started in October 1999. The field consists of three structures located on the western flank of the Utsira High, close to the eastern pinch-out of the Tertiary submarine fan system. The field currently has 16 horizontal producers and one water injector. The reservoir at Jotun is comprised of Palaeocene Heimdal Formation sands shed from the East Shetland Platform and transported across the Viking Graben area onto the Utsira High by high density gravity flow processes dominated by sandy turbidites. These distal gravity flow deposits display both thin-bedded sands alternating with shales and thicker, more massive sandstones (tens of meters thick). Minor sand injections occur throughout the field but are volumetrically insignificant. The production wells in one of the structures are completed in a slump and injection complex above thick massive reservoir sands. Seven generic facies described from core is applied to characterise the Jotun Field reservoir: Facies 1: High Density Turbidite; Facies 2: Low Density Turbidite; Facies 3: Sandy Debrite; Facies 4: Muddy Debrite; Facies 5: Turbiditic Shale; Facies 6: Hemipelagic Shale; Facies 7: Injectite.