The paper will review the most recent experience with completion techniques and production performance in horizontal wells in the Statfjord field. A total of 25 horizontal/extended reach wells have been drilled and completed to date. Wells with horizontal section up to 2230 m have been drilled and the longest horizontal displacement is 7290 m. Several well interventions have been performed in these wells, primarily for re-completion purposes. The paper will describe development of completion and intervention techniques with focus on perforating, well killing, well productivity and sand free production rates. Operational consequences in well interventions due to well design will be shown.
The first horizontal wells were perforated in overbalance on drillpipe, while today most intervals are perforated in underbalance with coiled tubing. Production and reservoir management for these wells will be discussed with focus on requirements for data acquisition and well intervention.
Future possibilities for horizontal wells on Statfjord and technology requirements will finally be discussed in the paper.