ConocoPhillips earned $652 million in Alaska last year, nearly tripling its income from the year before as oil prices climbed, according to financial documents released Thursday.

The company also announced it is spending $400 million to buy out Anadarko Petroleum's 22 percent stake in the Alpine field and its western North Slope projects, including the Willow opportunity that ConocoPhillips has said could produce 100,000 barrels daily.

Analysts saw the acquisition as an excellent deal for ConocoPhillips.

Paul Cheng, a senior analyst with Barclays in New York, asked company executives during their public earnings call why Anadarko sold for so "cheap."

"Those are great numbers," he said, according to a meeting transcript.

Al Hirshberg, a ConocoPhillips executive vice president, told him the fields aren't a core Anadarko asset. But they are for ConocoPhillips.

ConocoPhillips will own 100 percent of leases on 1.2 million acres of exploration and development property, Hirshberg said.

The deal requires approval from regulators. It includes the Alpine development producing 63,000 barrels of oil daily.

Anadarko had wanted to sell that asset and other properties, said Ryan Lance, ConocoPhillips chief executive.

ConocoPhillips expects to see flat to growing production in Alaska over the next five to 10 years, Lance said during the call.

"A lot of that's driven by things like the Willow discovery," which competes very well with other investments worldwide, Lance said.

He said full ownership of the western North Slope acreage will allow ConocoPhillips to control the pace of capital spending there.

ConocoPhillips has expanded aggressively in that region in recent years, including snatching up large amounts of acreage in 2016 lease sales.

The company produced 181,000 barrels of oil daily in Alaska in 2017, up 6,000 barrels from the year before. It spent $815 million on capital expenses in the state last year, down from $883 million.

Paul Harvey, an energy analyst with S&P Global Ratings, said the buyout makes sense for ConocoPhillips, because full ownership gives it greater control of development.

Pat Galvin, a former Alaska Revenue commissioner, said ConocoPhillips seems to have done well in the deal.

Oil Search, which operates oil and gas fields in Papua New Guinea, announced its own $400 million deal in Alaska in October. The company bought into prospects owned by Denver-based Armstrong Oil and Gas, including a 25 percent stake in the Pikka discovery, not far from Willow. Pikka could produce 120,000 barrels of oil daily, Armstrong has said.

Oil Search paid $400 million for property that is valued at $611 million, Alison Wolters, a Wood Mackenzie analyst in Houston, Texas, said of that acquisition.

For the same price as Oil Search paid, ConocoPhillips got good exploration prospects and other opportunities. But it also got control of a producing oil field at Alpine, said Galvin.