Average retail gasoline price stood at $3.178 per gallon, according to the American Automobile Association — down from the record high at $5.02 in June and nearly 15 cents below the year-ago level. The Energy Department will start with an initial request for 3 million barrels, asking companies for the barrels to be delivered in February, the administration official said on a call with reporters. Companies participating in the process must submit their offers by Dec. 28 and will offer oil at a fixed price. “There’s still quite a bit of volatility in the system,” the official said. “When we think the price is in the range where we think it’s a good deal for taxpayers and good for the market, we will buy. The buyback will take months, it will take years.” The administration had announced in October that it would set up a process to purchase oil from companies to refill the SPR at a price of $67 to $72 a barrel. The department will also offer 2 million barrels for exchange to fuel producers looking to make up the lost supply because of the Keystone pipeline transporting crude from Canada to refineries in the US Midwest and Gulf Coast going idle after a spill last week, the official said.