I believe that shale will (permanently) become a brake on oil prices. It’s my understanding that unlike conventional oil wells, they are fairly easy to “turn on and off”. Oil high = turn on; oil low = turn off. So, we may have $60-80/barrel oil for quite a while.
Nobody spent 5~10 million dollars on putting in a new shale field well and shut it down because price fell to $50~60.
What is happening is far fewer wells are being drilled at this price.