After 70 years of production, more than 30% of the Arab C STOOIP has been recovered through various mechanisms including natural depletion, water flooding, gas-lift implementation and horizontal well development. Extending production into future years requires a strategic approach, focusing on innovative development optimization in order to target the remaining oil saturation. An aggressive drilling and intervention programme is ongoing to tap into the remaining oil. In addition to coupling evergreen reservoir models and flood-front surveillance, enhanced waterflood and CO2 WAG hold the greatest strategic potential to maximize recovery. Integration of a recently acquired, high-resolution 3D seismic survey complements the data available for subsurface description and characterization, positively impacting reservoir model history matching metrics. Utilizing the models to set appropriate production and injection targets and vice versa adjusting the models to new data acquired in the field maintains a tight coupling between our models and surveillance monitoring. The evergreen models facilitate optimization of infill drilling locations targeting bypassed/remaining oil for sweep improvements. Surveillance monitoring of flood-front encroachment and pressure behavior indicates that the permeable and connected beach and shoal lime grainstones of the Lower Arab C are sweeping according to simulation predictions. Conversely, the Upper Arab C exhibits a less favorable waterflooding potential due to the thin-bedded (1-2ft) grain- and mud-prone peritidal deposits that maintain significant lateral and vertical permeability contrasts. Sensitivity tests in our high-resolution full-field models support the addition of a line drive pattern to the existing peripheral waterflood for the Upper Arab C. CO2 WAG has also been identified and tested in the model as a potential EOR mechanism to improve recovery. Engineering studies are underway to develop the infrastructural requirements for a CO2 pilot. It is envisaged that the combined development strategy of both enhanced waterflood and CO2 EOR will greatly assist in producing the difficult oil and maximizing recovery in the process.

Appendix E The neural network prediction for the crosswell seismic traces-the verification set137 Appendix F: Crossplots of the seismic attributes: real values vs. predicted values (best network).