Sinopec may be the worst off of China’s three big oil companies. China’s three state energy giants won’t dare blame their own country. But thanks to China’s slowing demand pulling down the oil price, the pain those companies feel is about to get worse. The suffering wasn’t necessarily on display Thursday, when oil prices rebounded as global fears ebbed. Shares of Cnooc , CEO 15.95 % the Chinese offshore oil producer, soared 14%, the largest one-day increase in the last decade, partly also because it reported a dividend worth 63% of net profit during the first half of the year, higher than the usual 30% to 40% ratio. Yet a high payout isn’t sustainable when Brent crude has fallen 16% in the past month despite Thursday’s rally, and is now worth about $45 a barrel. Cnooc requires Brent at $46 just to break even in the second half of […]