Steeper drops in the price of oil are needed for US shale and other unconventional production to take a meaningful hit, the International Energy Agency said on Tuesday. Although an oil price slump since June has cast doubt on the sustainability of current high supply growth rates, the energy watchdog for wealthy nations said in its closely watched monthly report that a “close analysis of light, tight oil supply suggests that most of it remains profitable at $80 a barrel.” Swelling supplies and faltering economic growth have led to slide in the price of Brent crude – the international oil benchmark – to four-year highs. ICE November Brent, which has fallen more than 20 per cent since mid June, dipped 31 cents to $88.58 in early Tuesday trading. Oil from deepwater reserves, oil sands, and particularly from North American shale – or “light, tight oil” – plays are widely […]