A deal to build a $10bn oil refinery on the Red Sea coast of Saudi Arabia is expected to be signed soon – but under terms revealingly different from those originally foreseen.

Saudi Aramco, the Riyadh state oil group, was due to have constructed the facility with ConocoPhillips of the US – only for the American company to pull out last year and leave the field open China’s state-controlled Sinopec.

The changed dance card for the 400,000 barrel a day project is one sign of a gradual switch in oil-rich Middle Eastern states’ attention away from Washington and towards Beijing. Analysts says the trend is significant but also slow, nuanced and unlikely to lead any time soon to China replacing the US as the main outside security force in the region.