The newly developed workflow is based on a 4-D sector modeling study on a west flank of Field A, offshore Saudi Arabia. The approach involves the use of time-lapse monitoring of reservoir saturation profile for injectors and producers as well as 4-D water flood front movement in the reservoir to understand dynamic reservoir challenges. These challenges are zones with future water breakthrough, dynamic injection/production interaction, impact of reservoir drive mechanism on well injectivity or productivity, initial and future reservoir conditions.
With this understanding, rate optimization process is performed on the open hole injectors and producers. Thereafter, completion is optimized to achieve uniform influx profile, flow restriction and zonal isolation where required along the horizontal section. Four different completion strategies were evaluated by alternating between Inflow Control Devices (Nozzle based) completion and open hole in injectors and producers.
Even though the sector model used in this study is subject to further calibrations as more geological, petrophysical and production data become available; the study outcome based on the novel workflow demonstrated the challenges involved in making a completion strategy with ICD's in injectors and producers. The results showed an incremental cumulative oil gain of (5%) with a one year delay in water breakthrough over a period of 20 years. It also indicated that further improvement in oil recovery can be achieved by ICD completion above that achieved in the rates optimization process of injectors and producers. The study showed a positive indication that ICD completion is beneficial in challenging reservoirs with mobility ratios considerably greater than one. The industry should consider a novel 4-D well – reservoir integrated modeling approach to making completion strategy and evaluating ICD completion design prior to deploying them in a field wide campaign.