Viscous Oil Polymer Flood Milne Point Field Case History Concept to Full Field Implementation

Abstract

Abstract Milne Point Field initiated the first polymer injection pilots on the North Slope of Alaska starting in 2018 and have rapidly progressed to full-field polymer injection within four years. The two initial pilot projects injected at an initial total rate of 6,000 bwpd utilizing 5 horizontal injection wells. Expansion activities began two years later in 2020 with the addition of 4 additional polymer injection units. By the end of 2021, total field polymer injection rate was 32,000 bwpd via 29 horizontal injection wells. Targeted reservoirs have average permeabilities ranging from 100 – 1000md and in-situ oil viscosities ranging from 40 cp to 1300 cp. Both secondary and tertiary floods are being conducted in both greenfield and brownfield development areas each with varying, yet all promising, results. The highest observed recovery is in a secondary polymer flood pattern at 27% of OOIP with an oil viscosity of 850 cp and no water breakthrough observed to date. Responses in injection well injectivities have ranged from as low as 0% up to 50% loss to date and are observed to be correlated by well spacing and total reservoir mobility. Multiple polymer injection designs exist throughout the field which were driven by existing infrastructure, specific needs from pattern to pattern, and increased learning over time. A logistics system has also been successfully developed that allows for large scale polymer flood on the North Slope of Alaska. The intent of this paper is to a.) provide sufficient historical context to give insight into field development when polymer flood was started b.) highlight what has been done to date in regards to moving from polymer flood concept to near full field expansion and c.) present observed results with the hope that they can help set expectations for future polymer flood projects.