Exxon Mobil formally warned Kazakhstan that the giant Tengiz oilfield is nearing peak output. Production at the country's largest field will plateau next year before beginning a decade-long decline.
Exxon projects Tengiz output will slump 40% from its peak by 2035. Daily production is expected to fall to approximately 500,000 barrels.
Exxon is currently proposing a major investment to expand the separate Kashagan oil field. The company made this venture contingent on Kazakhstan resolving long-standing financial disputes.