Mangahewa is a small gas-condensate field adjacent to the McKee oil field in North Taranaki. The field is linked to the McKee Production Station, which was extended with some high pressure gas processing facilities to accommodate the produced fluids from Mangahewa.

The field is 100% owned by Todd Taranaki Ltd, a subsidiary of Todd Petroleum Mining Ltd, who also operate the field.

Field Location

The field is located in Taranaki, 18 km SE of New Plymouth, next to the McKee field some 10 km inland from the Methanex Motunui complex. To date the field has been developed with one vertical production well, Mangahewa-2, and a multi-phase flowline to the McKee Production Station where the wellstream is processed.

Field History

The Mangahewa Structure was recognised as a prospect in the early days of exploration in New Zealand, with the exploration well Mangahewa-1 drilled in 1961 by the Shell-BP-Todd Joint Venture. The well found traces of gas in the Kapuni Group (ca. 3500-3600m below sea level), and on testing produced water with a small, sub-economic amount of gas (1-2 mmscf/d). The well was subsequently plugged and abandoned.

Further exploration occurred in the mid 1990s, with Fletcher Challenge Energy drilling the Mangahewa-2 gas discovery well (1996/97) in this low relief anticline situated to the west of the McKee overthrust. This was followed by short and long term production testing of this well (1997), acquisition of 3D seismic (1997), and testing of the northern flank of the Mangahewa structure with Ohanga-2 well (1998).

Permanent production from the field commenced in September 2001.

In 2001 Fletcher Challenge Energy was sold to Shell, and, to achieve Commerce Commission clearance for their purchase of FCE, Shell onsold the Mangahewa asset (PMP 38150), and the nearby McKee asset (PML 38086), to Todd Taranaki Ltd.

Since acquiring these assets, Todd Energy has reassessed the reserves based on well performance, and subsurface studies are continuing to identify further development opportunities within the Kapuni formation.

Field Facilities

The Mangahewa facilities consist of a single well, with a wellhead de-sander, connected with a flowline to the McKee Production Station. Fluids are treated in a single high pressure gas train. The McKee facilities are used for the provision of utilities and for treating condensate, water and LTS liquids.