if you interpret "need to burn one barrel of oil" as "need the energy of one barrel of oil", there will probably be some leeway, even below 1:1; oil is a very good energy carrier, and pumping up oil carrying a kWh of energy at the cost of more than one kWh of solar electricity or solar heat will probably be more efficient than using that energy to produce (in the literal sense, by chemistry, starting with CO2 and H2O) oil for some time.