ExxonMobil (XOM) can weather the downturn in oil prices even if prices sink to $40 per barrel, CEO and Chairman Rex Tillerson told CNBC on Wednesday.

The oil giant's massive projects in areas such as liquefied natural gas and deepwater drilling are decade-long investments that have been tested to perform across a broad range of price ranges, from $40 to $120 per barrel, he told "Squawk Box" at a Business Roundtable summit.

Still, he added, the low-price market will force oil companies at all levels to refocus on the basics.

"It really means a return to fundamentals for us," Tillerson said. "It's important about watching your cash, watching your investment decisions, being very disciplined about everything, and then looking for opportunities that may present themselves in an environment like this."

Smaller nonconventional players in the market that have taken advantage of the shale gas boom are able to adjust their investment portfolios fairly quickly, but Tillerson said he expected some shaking out at the margins in a correction, he said. Barriers to entering the oil production industry have been fairly low, especially given low interest rates, he noted.

"There's been a lot of people entering this space. Some are good. Some are not as good. There will be some sorting out of that," he said.

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Benchmark oil prices fell to five-year lows on Monday three days after OPEC announced it would maintain its current oil output. Some member states had sought an agreement on production cuts in a bid to stem falling prices.

Futures for Brent and U.S. crude have plummeted up to 40 percent from their highs in June.

Demand for oil has weakened in the face of slowing economic growth in China and Europe. At the same time, the U.S. shale oil boom is seen as adding to an oversupplied market.