Oil production in Kazakhstan plummeted by around a fifth on July 4 to 1.46 million barrels per day from July 2, after the widespread power outages, official data from an analytical center at the energy ministry showed on Wednesday.
Oil refining volumes fell by 46% on July 4 to 20,200 tonnes from 37,300 tonnes on July 2, according to the data.
A source familiar with the statistics also said that oil production at Kazakhstan's Kashagan oilfield halved on July 4 from average June's level to 22,082 tonnes (175,045 barrels per day).
(Reporting by Reuters; writing by Vladimir Soldatkin and Louise Heavens)