My thesis is that the industry has gone to a just in time inventory system, because of the SPR (we used to carry up to 30 Days of Supply), and these five year numbers just reflect small variations in a thin margin of supply above MOL. Currently, we appear to have about two days of supply in excess of MOL.

But its not easy to actually get SPR oil to various refineries throughout the country. I think they have trimmed for cost reasons but depending on the SPR probably does not make a lot of sense for most oil producers.

I think it probably has a lot more to do with the fact that imports are increasing and you have a lot of oil effectively in storage as its in transit. If you think about it they have tankers spaced out across the glob about a day or so apart. Thats a hell of a lot of oil and you only need to deal with delays. So why store it in the ground when you can store it in a moving tanker ?

I think your idea is right but tankers to me make more sense than the SPR.