Operation of one of the main installations at the Baku-based Heydar Aliyev oil refinery was suspended on April 18, 2014, because of the repair.
SOCAR reported that it is planned to replace the entire vacuum column.
Repair of the primary refining installation will be completed within 30 days and the atmospheric sector of the installation within 21 days.
The repair of the catalytic cracking installation, which produces petrol, continued at the Heydar Aliyev oil refinery.
Heydar Aliyev oil refinery specializes in fuel production. It refines about 4.5 million tons of oil a year, of which about 1.4 million tons is petrol and 2.43 million tons is diesel fuel.