China's state-owned oil companies have been beaten down by low oil prices and stagnant demand at home. PetroChina and Cnooc reported dismal earnings this week, and offered little reason for hope moving forward. PetroChina said its profit fell by 98 percent in the first half of 2016 compared to the same period a year earlier. The company's crude oil output fell by 4.2 percent as aging fields continue to deplete. Cnooc put up even worse numbers, reporting a 7.7 billion yuan loss, a remarkable downfall from the 14.7 billion yuan profit in the first half of 2015. Cnooc has been dragged down by its $15 billion purchase of Nexen a few years ago, a Canadian oil sands producer that has bedeviled its Chinese parent company for quite some time. Nexen has suffered oil spills, explosions, and other safety issues.