There are number of circumstances in which the Luftwaffe is well suplied with fuel:
1 Field Marshall Halder gets his way and Army group North take Moscow leading to total collapse of the Soviet Union
2 Operation case blue is effective and the Germans take the strategic Oil fields of the Caucuses and Baku.
3 Erwin Rommel smashes his way through the middle East Up through Iraq and takes the Caucasian oil fields.
(Just having secure enigma codes might have done that)
4 Albert Speer authorises greater precautions to be taken in hardening and dispersing synthetic oil refineries.
All of these nearly succeeded, having oil fields of such a scale would have revolutionised German supply logistics and tank warfare.