https://oilprice.com/Energy/Crude-Oil/Permian-Bottleneck-Could-Impact-Global-Oil-Markets.html
https://oilprice.com/Energy/Crude-Oil/A-Crisis-At-The-Heart-Of-US-Shale.html
https://oilprice.com/Energy/Energy-General/Oil-Prices-Spike-As-OPEC-Compliance-Hits-New-Record.html
One key bullish wildcard for oil is the potential for U.S. shale to underperform. Concerns have grown about the possible bottlenecks in the Permian, which could slow growth. To be sure, it is still a little too early to tell if shale drilling will bump up against some production constraints. Weekly EIA surveys continue to show rapid growth. However, steep discounts for oil in Midland, TX suggest that the pipeline bottlenecks are real. It could be a few months before the full extent of the problem becomes visible, but if U.S. shale growth slows sooner and by a larger magnitude than most forecasts assume, oil prices will almost certainly move higher.
https://seekingalpha.com/article/4167770-eia-914-u-s-oil-production-hits-new-high
http://money.cnn.com/2018/05/08/investing/oil-pipeline-permian-basin/index.html?iid=EL