Chinese oil and gas company Sinopec Group is planning to invest CNY200bn ($29.05bn) to upgrade its four main oil refineries in the country through 2020.

The investment is intended to help the firm produce higher-quality fuels at the four refineries which are located in the cities of Shanghai, Nanjing, Zhenhai on the east coast, and Maoming-Zhanjiang in southern Guangdong province.

Sinopec said that the upgrade work is expected to increase the refineries’ combined annual processing capacity by 30% to 130 million tons of crude oil a year, reported Nikkei Asian Review.

As part of the investment plan, the refineries will also be installed with new equipment to increase production ethylene capacity from 5 million tons to 9 million tons per year.

Sinopec chairman Wang Yupu was quoted by Reuters as saying in a statement: "It's a strategic move that fits the global industrial trend for clustered and scaled growth and helps transform China's petrochemical products to medium and high quality.”

The state-run refining and petrochemical giant expects the upgrades to allow it to more efficiently operate the four plants and generate revenue of CNY800bn ($116.1bn) by 2020.

The firm has already commenced upgrade work at the greenfield oil refinery and petrochemical complex in Maoming-Zhanjiang.

Upon completion of the work, the refinery will have capacity to produce gasoline and aviation fuel at the expense of diesel.

In 2015, Sinopec announced the completion of $1bn expansion program at a refinery located in Jiangxi province in eastern China. The upgrade project involved addition of 100,000 barrels per day (bpd) crude unit.

Image: Sinopec headquarters in Beijing, China. Photo: courtesy of WhisperToMe/Wikipedia.