Opec price war offers meagre rewards as shale learns to survive

London

WHEN the Organization of the Petroleum Exporting Countries (Opec) started its price war, the US shale boom looked doomed. Two years and one Opec policy U-turn later, executives at the annual Oil & Money conference in London painted an upbeat outlook for shale, with giants such as ExxonMobil Corp and ConocoPhillips saying the industry hasn't just survived the bust, but will continue to have a global influence.

"We have confirmed the viability of a very large resource base in North America," said ExxonMobil CEO Rex Tillerson…