China National Offshore Oil Corporation
Zeng spent the early part of his career as a technician in the military defense industry in Beijing. He was sent down to do manual labor on People's Liberation Army bases in Hunan and Guangdong during the Cultural Revolution. With the opening of the reform era, Zeng joined the State Development and Reform Commission in 1979 and then held a series of management positions in the state petroleum sector, including a series of foreign liaison positions with the China National Offshore Oil Corporation.