The sentence means his punishment could be commuted to life in prison if he is deemed to have repented.
Chen joins a string of high-level Chinese officials and heads of state industry who have been convicted of corruption.
Chinese leaders view simmering public anger over corruption as a threat to communist rule and have launched repeated crackdowns in an effort to be seen as tough on the issue.
Reporting on the sentence, China's state-run Xinhua news agency said Chen was granted a reprieve after he "confessed and repented, provided tips about other people's criminal acts, and returned all the bribes".
Sinopec, also known as China Petroleum & Chemical Co., is Asia's biggest oil refiner by volume and China's second-biggest oil company after China National Petroleum Corp.