This article, written by Senior Technology Editor Dennis Denney, contains highlights of paper SPE 154665, ’Polymer Flooding in a Large Field in South Oman - Initial Results and Future Plans,’ by Faisal Salim Al-Saadi, SPE, Badr Ali Amri, Sami Nofli, John Van Wunnik, Henri F. Jaspers, SPE, Said Harthi, Khalfan Shuaili, Pradeep Kumar Cherukupalli, SPE, and Ravula Chakravarthi, Petroleum Development Oman, prepared for the 2012 SPE EOR Conference at Oil and Gas West Asia, Muscat, Oman, 16-18 April. The paper has not been peer reviewed. In heavy-oil reservoirs, waterflooding leaves unswept-hydrocarbon volumes behind because of unfavorable mobility ratios, resulting in low ultimate recoveries. Increasing the viscosity of the injected water with polymer improves the water/oil mobility ratio, resulting in improved recovery factors. Following field trials and laboratory studies, a full-field polymer project was implemented in 2010. A key risk was poor polymer injectivity. However, initial field results showed injectivity to be better than expected. Study data indicate that wellbore cleanup from polymer injection improved as a result of the improved mobility ratio and that small-scale induced fractures in some injectors contribute to the improved injectivity. These factors enabled injection of more volumes of polymer than planned, resulting in improved volumetric sweep efficiency and producer response. Introduction This large sandstone field was discovered in 1956 and is on the eastern side of the South Oman basin. Five wells were drilled from 1956 through 1964, with the conclusion that field development would not be economically feasible. Another drilling campaign commenced in 1976, and the field was brought on stream in 1980. The oil is heavy (22°API) and viscous (90 cp). The field is highly heterogeneous, with sand, diamictite, and shale bodies. However, in the main reservoir units the net-sand/gross-reservoir ratio approaches 1.0 and the permeability can be many darcies. Because of the relatively viscous nature of the crude oil and the resulting poor mobility ratio with the displacing water, the conditions for waterflooding were not ideal. The Buckley-Leverett analytical model indicated that no distinct flood front exists early in the field life and that water was mobile throughout the reservoir. Once water reached a producing well, the water cut would rise rapidly and many pore volumes (>2 pore volumes) must be flushed through the rock to produce the recoverable oil. The achievable recovery by waterflooding was estimated at 20 to 30%. Different enhanced-oil-recovery (EOR) field-scale pilots (polymer and steam) were completed. The two polymer pilots showed that the polymer would be stable in the reservoir for many years and that the incremental-oil response from the use of polymer would be substantial. Pilot testing polymer-EOR technologies in this field provided early insight that the use of polymer is the optimal EOR concept.