The Russians would have destroyed the oil fields before the Germans could have taken them. Even of the Germans got the oil fields producing, how were they going to transport it of refine it? They had no tankers or a surface fleet to protect them even if they did. Hitler should have used the forces he sent to capture the caucus’ to secure the Volga and drive to Moscow. In the end it probably didn't matter because eventually the Russians would have overwhelmed them.
The quote you used wasn’t mine. You’re probably right that Stalin would have destroyed the fields. Even Stalin didn’t have the necessary tankers to transport it. One thing he forgot with his war production was to produce trucks, etc. to move supplies. He even stopped production of farm machinery to focus on tanks, etc. It’s why so many people starved. The U.S. designed, and sent over building parts for Stalin to build factories for war his production. We even sent engineers there to help them put them together. When the Germans invaded Russia, Stalin ordered all those factories in HItler’s path, to be dismantled, placed on trains, and moved further east, to be reassembled so they could begin production again. I can’t remember how many hundreds of miles they moved them, laid all the parts out in fields, and worked from there to put them back together. We provided many train engines and flat cars, etc. to Russia.