Exxon Mobil Corp (XOM.N) still sees potential in its western Canadian operations despite a recent write-down in the value of nearly all its oil sands reserves there, Chief Executive Officer Darren Woods said on Wednesday.

"The way we're managing that (Canadian oil sands) business is looking at the opportunity to drive efficiency, by bringing technology to bear, to bring costs that much lower and be successful in a low-price environment," Woods said on the sidelines of the company's analyst day in New York.

"And we've got a lot of opportunity to do that."

Exxon last month wrote down the entire 3.5 billion barrels of bitumen reserves at the Kearl oil sands project in northern Alberta operated by Imperial Oil (IMO.TO), a Calgary-based company in which Exxon has a majority stake.

Woods told investors that Kearl's cash operating costs have dropped more than 50 per cent in the past two years.

Oil sands cost more to develop than traditional or shale oil reserves.