The Strategic Petroleum Reserve (SPR) is an emergency fuel store of oil maintained by the United States Department of Energy .... As of August 31, 2009, the current inventory was 724 million barrels. ( http://en.wikipedia.org/wiki/Strategic_Petroleum_Reserve).
What impact would the SPR have on mitigating my hypothetical disruption resulting in a 35% short fall in oil?
An inventory of 724 M B oil is convertible to 14118 MG of gasoline and 6661 MG of dfo (http://www.txoga.org/articles/308/1/WHAT-A-BARREL-OF-CRUDE-OIL-MAKES).
At the USA’s present gasoline use of 368 MG/d, the SPR would only last about 38 days. At the present diesel use of 152 MG dfo/d, the SPR would last 44 days.
But, coupled with on-going oil production from the USA and Western Hemisphere oil imports during a 35% shortfall (240 MG gas/d and 99 MG dfo/d), the SPR could extend the USA’s present usage of 368 MG gas /d for 110 days, and diesel for 125 day.
Rather than squander the SPR in this manner during such a disruption, however, I expect that the SPR would likely be held in reserve for the critical gasoline and diesel uses.
The SPR could provide for the critical uses of gasoline (52 MG gas/d) for 271 days, but because the critical use demands are much higher for diesel (126 MG d/d), only for 53 days for diesel.
Again, if we coupled the SPR with on-going diesel production from the USA and from Western Hemisphere imports during a 35% shortfall and restricted this to critical uses only, then we can extend diesel critical uses to 247 days. Of course, that would mean no diesel what-so-ever for household transportation.
So the answer is no, unless we are considering a very short oil supply disruption, the SPR will not save us.