China pumps more than 4 million barrels of oil a day (only Saudi Arabia, the United States, Russia, and on a good day Canada produce more), but output is expected to decline this year as the country’s oil fields mature and operations become more expensive. The WSJ reports : China is among the world’s top five oil producers, but its fields are growing depleted and are increasingly expensive to pump. The country’s leading companies are choosing to leave more of their oil in the ground and some analysts now say Chinese oil output may have peaked. […] As China’s production starts to decline, demand for oil from overseas should remain firm, which would be good news for prices, which have been languishing near multiyear lows amid a global supply glut and weak demand in the rest of the world. […] This news will be welcomed by oil producers elsewhere, […]