Abu Dhabi National Oil Company (ADNOC) said on Wednesday it plans to invest USD3.1bn to upgrade its Ruwais oil refinery to free up more crude for export from its flagship Murban grade. The refinery modification, known as the Crude Flexibility Project (CFP), is scheduled to be completed by the end of 2022, ADNOC said in a statement. The project will enable ADNOC’s Ruwais Refinery-West complex to process up to 420,000 barrels per day of the Upper Zakum crude, or similar grades, freeing up more exports from ADNOC’s Murban crude, which is sold at a premium, the company said. The planned modification will add an Atmospheric Residue De-Sulphurisation (ARDS) unit to enable the refinery to process other types of crudes. ADNOC awarded an engineering and construction contract to a joint venture between South Korea’s Samsung Engineering and CB&I from the Netherlands.