A partnership of Japan’s Toyo Corporation and Iranian company Petropars has signed a memorandum of understanding for $600 million worth of maintenance and upgrade work at Iran’s Salman offshore oil and gas field.

The planned upgrade is part of a wider $1.3 billion rehabilitation plan by the Iranian Offshore Oil Company (IOOC) — a subsidiary of National Iranian Oil Company (NIOC) — to raise its overall crude output capacity by 145,000 barrels per day by 2020.

Other Iranian state oil companies recently listed another $4 billion in planned work involving foreign companies over the next few years.