For centuries, the tribal people of the Barmer district in Rajasthan have had their windblown corner of India’s Thar desert near the Pakistan border to themselves.

But in recent months, workers from Cairn India, a unit of London-listed Cairn Energy, have moved in next door to the villagers’ mud-and-thatch compounds, braving blazing heat and sandstorms to erect the group’s giant Mangala oil processing terminal.