New Zealand Oil & Gas today said that wireline surveys of the Pateke-1 wellbore showed the 9¨ý¡± casing had buckled, due to settling of the 30¡± conductor, and drilling of Pateke-1 could not be continued.
The rig will now be moved 50m and Pateke-2 spudded - with the Eocene-aged Kapuni F sands target depth, of about 3700m, expected to be reached in approximately 16 days.
Following Pateke-2, it is planned to drill Kiwi-1, located 4km southwest of the Amokura oil field.
NZOG exploration manager Eric Matthews has declined to comment to EnergyReview.Net on rumours of a different drilling technique, modelled on Apache¡¯s Harriet wells, being used for the Pateke and Kiwi wells.
It is believed intermediate casing is not being used, thus saving time and money, though this restricts the amount of information able to be gathered through downhole logging. It is also believed this could halve well costs to approximately US$6 million.
It is further understood the partners already plan to plug and abandon Pateke-2 and Kiwi-1, whatever the outcome of the wells, in order to try to avoid the extra tax costs associated with having a rig in New Zealand waters over 182 days.