The Strategic Oil Reserves is for an national emergency only.There is enough oil their for 34 days(taking into account consumption levels)in an emergency
That is not a real description of the quantity.
For starters, the total volume of 695.9 million barrels would last far longer. The maximum withdraw rate from the SPR is 4.4 million Barrels per Day (MMBPD). Taken as fast as possible, it would last over 158 days.
http://fossil.energy.gov/programs/reserves/spr/spr-facts.html
We currently use around 18.8 MMBPD of petroleum. But that number includes Natural Gas Liquids. Our total refined product has been ~16.7 MMBPD, but fallen off recently.
Total Petroleum Product Supplied:
http://205.254.135.7/dnav/pet/pet_cons_psup_dc_nus_mbblpd_m.htm
Weekly Gasoline Supplied:
http://205.254.135.7/dnav/pet/hist/LeafHandler.ashx?n=PET&s=WGFUPUS2&f=W
We would never have to replace our total oil supply from the SPR. Even if Iran closes the Persian Gulf, that isn't going to effect the oil supply from Texas, North Dakota and many other places.