The oil and natural-gas industry is increasingly looking to Canada as a home for big energy projects Americans don't want in their backyards. A patch of coniferous forest near here, on Canada's Atlantic coastline, represents both the promise and the challenges of that approach. The land, owned by closely held Canadian energy company Irving Oil, is earmarked for the possible construction of a 300,000-barrel-a-day crude-oil refinery that would cost $5 billion to $7 billion -- the first new refinery in the U.S. or Canada in more than 25 years. Irving hopes a refinery, if it chooses to build one, would...