|dc.description.abstract||History matching is an inverse problem with several possible solutions. The degree of nonuniqueness reduces when seismic observation data becomes incorporated. This thesis contains a history match of the Norwegian Sea oil field, Norne. The approach is both manual and computer-assisted. Time-lapsed Acoustic Impedance is used to qualitatively track both the oil-water contact movement and the flooding pattern. The observed behavior is manually reproduced, before the model is optimized using a gradient based optimization algorithm.
Vertical transmissibility, fault zonation and fault transmissibility are the history matching parameters of choice. Vertical transmissibility in Norne’s field wide stratigraphic barriers are used to control the water rise, and reduction of fault transmissibility and fault zonation are used to guide and establish observed flooding.
New flooding patterns are established for 4 of Norne’s injectors. F-1H is guided west of E-segments main fault E_01 and communicates across the northern part of E_01. F-3H is guided south along the main west fault into the C-segment and east into the E-segment before entering the D-segment. C-1H in the east side of the C-segment is guided northwest towards the mid part of C-segment and towards the D-segment. C-3H in the southwest part of the C-segment is guided north along the main west fault.
The overall vertical communication is reduced by implementing field-wide vertical barriers between Garn 1/Garn 2, Ile 2.1.1/Ile 1.3, Ile 1.2/Ile 1.1, Ile 1.1/Tofte 2.2, Tofte2.1.1/Tofte 1.2.2, Tilje 3/Tilje 2. Local holes, areas with increased transmissibility, are added to the field wide barriers to allow the water to rise in the south-east and mid-west part ofthe C-segment, the southern part of the D-segment, and into each producer.
There are two important recommendations for future work on the Norne simulation model. The injectors must be controlled and guided as observed. The fault zonation upscaled from the geological model will not allow a proper flooding pattern, and it’s recommended that the geological model is inspected for possible faults, or high permeability channels, around the injectors. The aquifer support in the Norne field is regarded as poor, and it is mainly the vertical communication that determines the field’s water production.The field-wide carbonate barrier in Ile 1.1 should be thoroughly inspected, as it is regardedas the key factor controlling the water rise.||nb_NO