Compared to U.S. crude, Canadian heavy crude traded at a 41 per cent price discount.
Environmentalists have delayed projects so they become non-economic and are terminated.
The Court also mentioned the potential impact of oil tankers on killer whales.
Bill C-69 would completely overhaul how major energy projects are reviewed by government in Canada.
Four provinces have increased their general corporate tax rates over the last three years, including B.C. and Alberta.