Why miraculous Saxon oil would not immediately solve Germany's fuel problem

What if enough oil to fuel the Axis suddenly appeared in Saxony in 1939?

The fields would take time to develop and become a concentrated bombing target, so discovery alone would not erase Germany's fuel constraints.

Finding a resource is not the same as delivering refined fuel to operational units. Germany would need wells, equipment, trained petroleum workers, transport, and refining capacity that could not appear at full scale in 1939. Saxony's Leipzig-Dresden area was reachable by British bombers, unlike a synthetic-fuel network whose dispersal made it harder to suppress completely. Soviet technical assistance might speed development, but casualties and destroyed equipment could also alter German-Soviet diplomacy before 1941.