Canada imports about 800,000 bbl/day.  About half of that comes from the USA, including through a pipeline from Portland Maine to Montreal that isn't used much since the Enbridge line 9 was commissioned several years ago.  Enbridge Line 9 to Montreal (which I believe is east of the Ottawa valley) has a 300,000 bbl/day capacity.  Refineries east of Montreal (there are three including Come by Chance, Nfld) generally get their oil from a variety of overseas sources, including North Sea, Algeria, Africa and the middle east.

My facts come from Statscan.  Where do yours come from?