Marathon Oil Corp. said Wednesday it will spend up to $1 billion this year on three of its highest “growth assets,” all U.S. shale projects: North Dakota’s Bakken play, the Eagle Ford in Texas and the Anadarko Woodford in Oklahoma.

The Houston-based producer has earmarked $5.27 billion worldwide for capital, investment and exploration spending in 2011, which is about 9% higher than in 2010. Close to $3.7 billion, or 71%, is for the upstream. Around $1.9 billion in capital spending is to be allocated to exploration and production growth projects, with more than half in the three U.S. shales.

“Having completed a number of major investment projects over the last few years, Marathon’s 2011 budget has shifted toward an emphasis on more scalable and lower-risk activities, largely aimed at liquids-rich opportunities such as the Bakken, Anadarko Woodford, Eagle Ford and Niobrara resource plays in the U.S.,” said CEO Clarence P. Cazalot Jr.

“Oil projects make up more than 80% of our upstream budget; and importantly, we continue to grow the percentage of Marathon-operated projects within our portfolio with roughly two-thirds of our 2011 spending being directed toward company-operated activity, affording us greater control of outcomes and flexibility in changing conditions.”

Marathon highlighted planned activity this year in two of its domestic shale plays. In the Bakken Shale the producer plans to drill 70-75 operated wells and participate in 50-70 more wells. Up to 25 operated wells are to be drilled in the natural gas-weighted Anadarko Woodford play; Marathon said it would participate in up to 50 more wells there.

Marathon entered the liquids-rich Eagle Ford Shale play last year through a deal with Houston-based Denali Oil & Gas (see Shale Daily, Nov. 30, 2010).