I don't recall petroleum fires being a huge part of the dialog, back when nuclear winter was a big public topic, such that I'd bring it up first thing and to the exclusion of other concerns.

It was part of it, for sure. There was at least one apocalyptic science fiction story about the Soviets testing a bomb underground and accidentally setting a massive oil field on fire. (it was called Anvil? Or written by Christopher Anvil? jeez, it's been a while...) But it's strange to see it commented on as the main concern.