The advisory firm predicts West Texas Intermediate will average US$100 per barrel for 2014, decreasing to US$93 per barrel in 2015 and US$85 by 2018.
Alberta natural gas prices are expected to be C$4.80 per 1,000 cubic feet this year, dipping to C$4.40 next year and rising to C$6 by 2024.
Meanwhile, Deloitte is lamenting the fact that Canadian spot oil prices are becoming increasingly difficult to discern, with big oil companies choosing to stop publicizing their data in recent months.
Without the daily spot numbers, Deloitte has worked out a way to compile its forecasts using near-term futures market data.
It sees a US$7 price-gap between West Texas Intermediate, a key U.S. benchmark, and its Canadian counterpart, Edmonton Par, for 2014, decreasing to US$2 per barrel over the long term.