Azerbaijan's Energy Minister Natiq Aliev has said there should be tighter control over the work of an international consortium led by British Petroleum.
Aliev said production at the Azeri-Chirag-Gunsehli site was "abnormal."
The Energy Minister's comments come after President Ilham Aliev said on October 12 that "numerous mistakes" by the BP-led consortium might have cost his country some $8 billion in lost revenue.
BP Azerbaijan says it is working with Azerbaijan's state company SOCAR to address production issues.
In 2010, production at the Azeri-Chirag-Guneshli site peaked at more than 823,000 barrels per day but in 2011 averaged only some 717,600 barrels per day.
Based on reporting by AP and ITAR-TASS