The average is used as the basis for the Abu Dhabi and Qatari retroactive September official selling prices (OSPs), which are set as differentials to Dubai. Oman crude oil quoted by Platts averaged $109.35 a barrel for November, up $3.26 from October, traders said. That would put the November Oman/Dubai average at $109.18 a barrel, up $4.16 from the previous month.