President Obama will push again for Congress to eliminate tax breaks for oil companies, in a speech Thursday at the White House Rose Garden.

The president's renewed attack on "big oil" comes as U.S. oil companies are facing the stiffest competition they've ever faced.

PetroChina, a young Chinese oil company, is now the world's biggest public oil company, surpassing Exxon Mobil.

The 13-year-old company was created by the Chinese government to meet that country's booming demand for oil and gas.

PetroChina has been quickly locking up oil around the globe, outspending Western companies to acquire oil reserves in places like Canada, Australia, and Iraq.