The 1 million barrels Marathon borrowed last year has been replaced, but the previous 2011 sale of oil (30 million) has not.
U.S. Ending Stocks of Crude Oil in SPR
http://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=MCSSTUS1&f=M
STRATEGIC PETROLEUM RESERVE
http://energy.gov/fe/services/petroleum-reserves/strategic-petroleum-reserve