The fall of the Soviet Union, wrote Gaidar in a 2007 paper, "should serve as a lesson to those who construct policy based on the assumption that oil prices will remain perpetually high."
...in the mid-1980s, Soviet oil production topped off at 12 million barrels a day due to poor management, old technology and lack of investment. And then oil production started to drop. As oil fields ran dry, the authorities spent more cash to coax more petroleum from aging reservoirs with massive water flooding programs...
Just before Soviet oil production peaked in 1988 (the event walked hand in hand with a major drop in oil prices), the empire realized that it no longer had enough black gold to pay its bills.
The Tyee – What Really Killed Soviet Union? Oil Shock?