To prepare for its new focus on U.S. oil, ConocoPhillips isn't just selling off parts of its foreign businesses -- it's also selling certain U.S. assets.

The Houston-based supermajor yesterday sold decades-old oil properties in North Dakota and Montana for $1.05 billion. Its business partner was Plano, Texas-based Denbury Resources Inc., which specializes in a method that pulls oil from fields that seem spent.

For ConocoPhillips, the deal is the latest in a torrent of divestitures meant to fuel its new emphasis on North America. The company had aimed for $8 billion to $10 billion of asset sales in 2012, but yesterday's deal brought the total to roughly $12 billion, analysts at Barclays Capital Inc. said.

Late last year, ConocoPhillips unloaded its Algerian and Nigerian divisions. The company has needed the cash to help fund a planned $15.8 billion capital spending plan for 2013, a program that will focus on oil- and natural-gas-liquids-heavy plays in the United States (EnergyWire, Dec. 21, 2012).

ConocoPhillips said the Denbury deal will allow it to concentrate its North Dakota and Montana investments on the Bakken Shale, a fast-growing unconventional oil play.

Oil and gas market observers expect brisk deal activity this year, given the unusual brew of commodity prices and financial pressures in the energy world.

While some energy producers have battled to switch from gas to oil and liquids, others have stayed put in gas -- sometimes for better, sometimes for worse. Companies have also pleaded with investors for patience, as many undertook costly investments in 2012 to beef up oil production with few immediate results.

Meanwhile, those with huge cash arsenals -- international supermajors, state-owned oil companies and Wall Street giants -- have been lurking, hoping for bargain prices on natural gas and other assets they expect to gain value in the long run.

For Denbury, the ConocoPhillips deal fits into an unusual strategy. Denbury specializes in enhanced oil recovery: injecting CO2 to tease oil out of old conventional reservoirs.

Late last year, it actually sold some of the most sought-after assets in the energy world -- oil fields in the Bakken -- to Exxon Mobil, raising $1.3 billion (EnergyWire, Oct. 1, 2012).

Denbury said it used $1.05 billion from that deal to buy the ConocoPhillips properties. The move will help Denbury defer more than $400 million in taxes that it would have otherwise paid on the Exxon Mobil transaction.

Through the deal with ConocoPhillips, which is expected to close near the end of the first quarter of this year, Denbury has expanded its holdings in the Cedar Creek Anticline, a carbonate reservoir that straddles the Montana-North Dakota border. Oil and gas drilling there dates back to the 1950s.

Some of the conventional-style oil is still there in Denbury's newest properties, spokesman Ernesto Alegria said. The company will produce some of it before turning to enhanced oil recovery. He said it's common for the company to acquire fields that have been producing oil for 50 years or more.

In this region, Denbury obtains much of its CO2 from human sources, such as processing plants in Wyoming. Some environmentalists have hoped that a scaling up of this method could make meaningful cuts in greenhouse gas emissions.

Brad Crabtree, policy director at the Great Plains Institute, said the Denbury deal bodes well for a larger network of CO2 pipelines.

"Now that Denbury has those assets, they'll be interested in expanding pipeline infrastructure to that region as well," he said. "It's unlikely that Conoco would have done that sort of thing."