There is a prediction that up to 70% of shale oil operations...

There is a prediction that up to 70% of shale oil operations will go bankrupt despite Trumps attempts to save US oil. Apparently many may not return until the oil price stabilises above $50 per barrel.

The other problem for shale is that while start up is rapid, the cream is usually at the top, and after drawing down on the easy material, it becomes increasingly more difficult, and more expensive, to draw oil - so there is a constant moving of infrastructure chasing the cheap return. Drilling and fracking anew can't go on indefinitely - notwithstanding the environmental and geological issues that also plague this irresponsible type of mining.