FULL STEAM: A $15 billion buyout attempt by CNOOC of a Canadian oil and gas company shows that China’s appetite for energy remains as strong as ever despite its current economic slowdown. Weaker oil prices and a resolve to capture technologies China needs to unlock its own sizable but hard to extract reserves are powerful incentives.

NEW TACT: The bid for Nexen Inc. is strategically calibrated to win regulatory approval — unlike its failed 2005 attempt to buy Unocal. Back in 2005, protests that the sale of Unocal might jeopardize U.S. national security prompted CNOOC Ltd. to withdraw its $18.5 billion bid. CNOOC is also pledging to set up a regional headquarters in Calgary, Alberta, where Nexen is based. It would keep the Canadian company’s management and projects in place and list shares on the Canadian exchange.

HEADWINDS: The deal will face a review by Canada’s industry minister and the Competition Bureau, an independent regulatory agency. Canada has balked at past foreign bids for natural resources, but with U.S. interest in Canadian gas and oil dented by the surge in supplies of natural gas, it now may be more open to such acquisitions.