Guardian: The tumbling oil price has led to a trebling of insolvencies among UK oil and gas services companies so far this year, while £55bn of further oil projects reportedly under threat. Brent crude closed below $62 a barrel on Friday, a five-and-a-half-year low, amid fears of falling demand and oversupply as the global economy slows down. A decison last month by Opec, which supplies about 40% of the world’s oil, to keep production unchanged despite the price fall only served to send crude sliding even…