In the state of Gujarat, north-west India, lies Jamnagar, the world’s biggest oil refining complex, which covers 7,400 acres.

As Reliance Petroleum, the Indian company, prepares to send the first barrel of oil through the complex’s 4,000km of snaking piping, its newly-built second refinery on the site will become the most visible symbol yet of the shift in an industry that is moving east after a century of western dominance.