New Zealand Oil and Gas says there's been a further delay to production at its Pateke-3H well, in the offshore Taranaki Basin.
Pateke is one of four producing wells at the Tui area oil fields, and was shut in late June because of problems with its artificial lift system.
Repairs have been completed but production is being constrained because of technical problems.
The well operator, AWE, says it is conducting a thorough review to determine the cause of the problem, and the most efficient remedy.
New Zealand Oil and Gas owns 12.5% percent of the well, with AWE, Mitsui E and P, and Pan Pacific Petroleum the other venture partners.