Abstract

The Knarr Field is located in the northern Norwegian North Sea, beyond the Brent Group delta fairway. Knarr was discovered in 2008 with the Jordbær well, additional resources were added to the field in 2011 with the successful Jordbær Vest well. The field extends over an area of approximately 20 km². The original oil in place is estimated to be 26 MSm³ (163 MBBL). The reservoir is the Late Pliensbachian Cook Formation and its current burial depth is approximately −3700 m true vertical depth subsea (TVDSS). In Knarr, the Cook Formation is split into five sandstones that are separated by four shale intervals which can be correlated across the field. The three lower sands (Lower Cook) are interpreted to have been deposited in a tidally-dominated environment, while the upper two sandstones (Upper Cook) were deposited in a wave-dominated shallow-marine setting. The reservoir properties of the Cook Formation in the Knarr area are remarkably good for a reservoir at this depth, with porosities up to 28% and permeabilities in excess of 1 D. The good reservoir properties are the result of grain-coating chlorite, which has inhibited diagenetic quartz development. The field is developed with three oil producers and three water injectors produced via a floating production storage and offloading vessel (FPSO). First oil was achieved in March 2015.