Big oil is investing more in U.S. shale, not less, after the recent tumble in crude prices. (Bloomberg) — Big Oil is investing more in U.S. shale, not less, after the recent tumble in crude prices. It’s a far cry from four years ago when OPEC declared war on American shale areas, which at the time had some of the highest costs anywhere in the world and were often the first on the chopping block during tough times. The cost of shale production has fallen so much since then that it’s becoming a safe haven for major oil companies in times of volatile prices, providing rapid, reliable growth and quick returns even with crude trading for just over $50 a barrel, down by almost a third since the start of October. The U.S. shale sector has helped boost American production to an average of 10.9 million barrels a day […]