Canada remains a critical region for oil and gas production, and its oil sands have become an area of increasing importance for many energy companies. There's good reason for this, as the sheer amount of energy resources in Canada is truly enormous. According to the U.S. Energy Information Administration, Canada is one of the world's top five largest energy-producing nations, and is the principal source of U.S. energy imports. Canada holds the third largest proven oil reserves in the world, 97% of which are located in the oil sands.

With this in mind, the following energy giants are devoting billions of dollars to the Canadian oil sands, which should help boost production for many years.

Head north for profits
Among the U.S.-based majors staking a claim on Canadian oil sands are ConocoPhillips (NYSE:COP) and Marathon Oil (NYSE:MRO).

ConocoPhillips stated in a recent presentation that it's investing $5 billion over a five-year period in its oil sands projects. ConocoPhillips considers the Canadian oil sands to be one of its major projects going forward, and the company plans to reap significant growth from it. Total oil sands production is expected to grow at 16% compounded annually over the next several years.

Canadian oil sands are set to be a major contributor to ConocoPhillips' future production. Of its major projects in development, the Canadian oil sands should produce 100 million barrels of oil equivalents per day by 2017, a higher total than any other geographic play.

Marathon Oil's interests in Canadian oil sands should pay off in short order. It holds 52,000 net acres, where recoverable resources are estimated at greater than 1 billion barrels. Third-quarter net production increased 11% in the oil sands versus the prior quarter, and fourth-quarter expectations call for another strong increase. And, thanks to higher price realizations and stronger production volumes, profits in the company's oil sands segment increased five-fold in the third quarter versus the second quarter.

A local player to consider
For a company profiting from the Canadian oil sands that's located closer to the action, consider Canadian Natural Resources (NYSE:CNQ). Canadian Natural is one of the largest independent crude oil and natural gas producers in the world. In fact, it's the largest heavy oil producer in Canada, according to the company. And, it's set to reap huge benefits from oil sands production. That's because Canadian Natural's Horizon Oil Sands operations support between 232,000 and 250,000 barrels per day of crude oil production for over 40 years, with no production declines. In all, the company sees its Horizon Oil Sands project as a 'world-class' opportunity, and it's hard to disagree: Total resource potential is pegged at six billion barrels.

These efforts helped boost Canadian Natural's results so far this year. Earnings per share are up 21% through the first nine months of 2013, due in large part to strong production growth. Natural gas production has dipped slightly, but oil is what's most important to Canadian Natural, by far. Production of crude oil, combined with natural-gas liquids, stood at 478,000 barrels per day, up 7.5% over the first three-quarters of the year.

Canadian oil sands to boost future results
Canada remains one of the world's premier energy-producing nations. In response, both American and Canadian energy giants are devoting billions to invest in the area. Production of oil, natural gas, and natural gas liquids in Canada is already significant and is only poised to increase in the future.

ConocoPhillips, Marathon Oil, and Canadian Natural Resources are at the forefront of Canadian oil sands exploration and production. Their efforts are already paying off, which is evident in their results. Continued investment and production increases in this region should help these businesses generate plenty of profits.

Bob Ciura has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.