High Quality Content by WIKIPEDIA articles! Although there are numerous oil companies operating in Canada, the majority of production, refining and marketing is done by fewer than 20 of them. According to the 2012 edition of Forbes Global 2000, canoils.com and any other list that emphasizes market capitalization and revenue when sizing up companies, as of June 29, 2012 these are the largest Canadian-based oil and gas companies (they are either based entirely in Canada or majority Canadian owned). However more recent changes, possibly mergers or a stronger showing in the price of oil may mean a few of the oil sands producers are underrepresented (many Canadian companies are increasingly dependent on production from that source, which is hurt severely when oil prices decline below 50 to 60 dollars a barrel since costs per barrel traditionally exceed $28 and non-upgraded bitumen (...