What Economist’s title? You mean the nytimes article? If so the comment here implies they are the oil power because they are shifting energy demands while the truth is that it’s because they are the largest buyer.
That article argued correctly that the World's greatest oil power is the one that has the greatest control upon oil price.
For now, that is China due to both high consumption and huge facilities for oil storage. They maintained a relatively low oil price until now, but they could rise the price of oil at any time.