With the start of oil flowing through new processing units at the refinery, Motiva Port Arthur now ranks as the country’s largest refinery, and doubles the facility’s daily processing capacity to 600,000 barrels of crude a day.

Shell CEO Peter Voser said, "By combining our upstream and downstream capabilities, integrated companies can drive innovation and match resource with demand."

Saudi Aramco CEO Khalid Al-Falih said the company’s investment in Port Arthur is an integral part of its global downstream expansion strategy.

"With the completion of this massive expansion, the Port Arthur Refinery alone would be capable of meeting the entire gasoline demand of France, Italy or all of Scandinavia," he added.

After the five-year expansion work, the refinery can process a wide variety of crude oils, including light and heavy as well as switch between primarily producing gasoline and diesel to adapt to varying market conditions.