(Bloomberg) — Stiff global competition for sour crude oil is threatening to complicate the Biden administration’s plan to buy up to 3 million barrels to refill the depleted US Strategic Petroleum Reserve.Most Read from BloombergPrices for sour crude — the kind the US government is trying to buy — have jumped amid expectations for the SPR purchases, buoyed by tighter supplies due to OPEC+ production cuts and the startup of new refineries. While the Biden administration is targeting $67 to $72 a barrel, tra …