A lmost a decade ago, a price war broke out between petrostates in the Persian Gulf and the frackers in America, whose innovative drilling techniques gave rise to the shale revolution. In December 2014 The Economist put a picture on its cover of both antagonists standing back to back, frowns on their faces and petrol pumps at the ready. It called the new economics of oil “Sheikhs v shale”. Missing from that picture were two companies that until then had been the biggest stalwarts of America’s oil industry, ExxonMobil and Chevron. Had they been pictured, the two crusty supermajors would probably be standing awkwardly on the…
