Abstract
The Mauddud carbonate, a ‘Major' reservoir in Sabiriyah field, North Kuwait, is about 400 feet thick dominated by carbonates deposited in a ramp environment. The reservoir has ten sub-zones named alphabetically from top MaA to MaJ. Current drilling campaign is being executed on fast track exclusively using Non-Conventional Wells (NCW) in order to achieve production targets.
The planned NCWs are located in flank areas to have optimum exploitation of flank potential. ‘MaB' is target zone as water flood development of the reservoir, as a whole, calls for enhancing the production from MaB and provide the pressure support via water injection at the MAE (Bottom-up approach). The laterals planned are in the range of three to five thousand feet.
Several subsurface challenges were dealt with during design and execution phases. The trajectories are planned with strike parallel azimuths to have minimum inclination changes in lateral sections. The objective is to enable trouble-free operation during ICD deployment. This task was extremely difficult due to local dip changes and variations of actual strike directions. Structure models were constantly updated with real time data and gradual azimuthal shifts were made to achieve this objective. The wellbore must remain in "sweet spot?? throughout. Geological models were used to design trajectories accordingly. This mission was arduous due to sparse well density thereby reducing reliance on models. Presence of sub-seismic faults could place wellbore in undesired stratigraphic positions. Such occurrences were perceived and predicted as best as possible based on regional structural picture and calculated steps were taken. In the eventuality of wellbore hitting unexpected faults, gradual azimuthal-inclination changes were made to correct well paths.
With all these efforts and strategies, the operations team was able to successfully execute drilling and completion of Sabiriyah Mauddud Horizontal wells. The paper is aimed at sharing the success story achieved in North Kuwait.
