The US is preparing to buy up to 3 million barrels of sour crude oil to begin refilling its depleted Strategic Petroleum Reserve, according to people familiar with the matter. After selling more than 200 million barrels from the emergency stockpile last year, in part to curb high energy prices, the Energy Department plans to solicit offers to replenish the reserve, which has fallen to the lowest level since 1983. In addition to direct purchases, the agency has said part of its strategy for refilling the reserve includes a return of oil from previous exchanges, and avoiding “unnecessary sales unrelated to supply ... (full story)