Oil Search and Santos say it will take about eight weeks to fix and restore production at their earthquake-damaged liquefied natural gas project in Papua New Guinea.
The 7.5 magnitude quake killed dozens of people and caused widespread damage.
Strong aftershocks are rocking Papua New Guinea's remote and rugged highlands, a week after the largest quake to hit the region in nearly a century killed at least 31 people.
"The death toll reported by the National Disaster Centre and disaster management teams on Friday is 67", the Papua New Guinea country head of the International Federation of Red Cross and Red Crescent Societies Udaya Regmi told AFP from the capital Port Moresby.
Papua New Guinea is located in a seismically active zone known as the Ring of Fire and regularly suffer from powerful earthquakes.
Emergency deliveries have been hampered due to landslides, damaged roads, collapsed buildings and the remote location of the area.
Aid agencies have said almost 150,000 people remain in urgent need of emergency supplies.
"New Zealand is working with Papua New Guinean authorities, the United Nations, donors and aid agencies on the ground to identify how New Zealand can best assist".