A late Polish oil discovery cannot mature before war

Discovering an immense Polish oil reserve just after Munich would attract money and hostile attention, but surveys and infrastructure could not turn it into wartime output quickly enough.

Question

What changes if an estimated 800 billion barrels of oil are discovered in Poland one week after the Munich Conference?

Short answer

Poland attracts investment and greater-power pressure, but the lead time for extraction means war arrives before the oil can transform its economy or defenses.

Notes

The scenario places an estimated 800 billion barrels of oil in Poland one week after the Munich Conference. One response predicts an immediate Soviet invasion, while another doubts the Red Army could achieve that easily against forces accustomed to preparing for a Soviet attack. Poland would probably attract investment, but finding oil does not provide instant production. Surveyors would still need to locate practical access points and build extraction infrastructure. The estimate given is five or six years before useful output, so war could overtake the development. How much Germany invested after taking control is raised as a further uncertainty.