Port Lyttelton says Monday's strong earthquakes set back repair work from earlier shakes.
The port company says the damage is still being assessed, but notes that its wharves have been hit further, including new cracks in areas paved since the earthquake in February.
General cargo operations will start again on Thursday morning, but the company does not expect to load or unload ships until after midday on Friday at the earliest.
The port expects the oil berth to be operational by the time the next tanker arrives on Monday.
