Polymer Screening for the Hebron Field, Offshore Eastern Canada - Facing High Salinity Brines

The Hebron Project is the fourth major offshore development in the province of Newfoundland and Labrador, with an estimated 2620 MBO in place and 800 MBO recoverable. Hebron Field oil and reservoir properties are similar to previous successful offshore polymer flooding projects. However, the formation water salinity, which is greater than 60,000 ppm, is higher than offshore field analogues used for the EOR screening.

This paper reports viscosity variations due to salinity and temperature changes observed in two commercial, partially-hydrolyzed polyacrylamides, FP-3430S and FP-5115, and the biopolymer Guar Gum, using offshore Eastern Canada seawater and synthetic formation water brine.

FP-3430S and FP-5115 showed similar viscosity responses in relation to salinity and temperature changes compared with Guar Gum, which was more salinity tolerant over the range of salinity investigated, but showed a greater viscosity decrease at salinity values higher than seawater. Guar Gum was also found to be more unstable at temperatures higher than 62°C. FP-3430S showed a higher viscosifying power, requiring less polymer mass to reach the same viscosity values even in different brine salinities. This indicates that FP-3430S is the most suitable for use with the Hebron Field brines, according to the conditions evaluated in this study.