SHIJIAZHUANG, June 7 (Xinhua) -- PetroChina, China's largest oil and gas producer, has started full operation of an oil refining expansion project that doubles its annual processing capacity to 10 million tonnes.

The PetroChina North China Petrochemical Company in the city of Renqiu, Hebei Province, will now be able to produce eight million tonnes of high-end diesel, gasoline and aviation kerosene annually.

This upgrading and expansion project, listed in the national energy development plan, involved a total investment of more than 31 billion yuan (4.48 billion U.S. dollars) and took 23 months to complete.

As PetroChina's only refinery expansion project under the 13th Five-Year Plan (2016-2020), it will help ensure energy security and provide new impetus for the development of the Xiongan New Area and the Beijing-Tianjin-Hebei region.

The PetroChina subsidiary is the only refining company that directly provides aviation fuel for Beijing Daxing International Airport, 46 km south of downtown Beijing.