And with more oil than markets needs there's no reason for prices to rise.
The change in shale drilling techniques has enabled US oil production to remain near multi-decade high despite a collapse in the number of oil rigs being used.
Supply has been outpacing demand for the last few years, leading to those massive inventory builds in charts 1 and 2.
Did the Fed's post-crisis quantitative easing plan lead to a surge in oil production investment? Certainly, the lines fit.