China National Offshore Oil Corp (CNOOC) announced on Friday the full completion of the Daxie Petrochemical refining and chemical integration project in Ningbo, Zhejiang province, marking the completion of country's largest world-class petrochemical industrial base in the region.

The 21 billion yuan ($3.2 billion) project is the largest of its kind in China and utilizes domestically developed technology for direct cracking of heavy oil to produce chemicals. The core production unit boasts a 100 percent domestic technology adoption rate.

The project will produce 1.2 million metric tons per year of polymer-grade ethylene and propylene, making it the largest single heavy oil direct conversion unit for polymer-grade olefins in the country.

These high-purity ethylene and propylene are essential raw materials for everyday products such as mineral water bottles, food packaging, and synthetic clothing.

The project is expected to significantly improve China's capacity for efficient conversion of heavy oil and boost the self-sufficiency of high-end chemical materials, it said.