The Kupe Field is in exploration permit PML 38146, located in the same general area as the giant Maui gas field which currently supplies most of the country’s needs. The field lies in 35 m of water, 30 km offshore, south of New Zealand’s Taranaki Peninsula.

Despite being discovered in 1986, the Kupe field remained undeveloped until quite recently because of the abundance of cheap gas from the Maui field. The combination of increased gas demand and a re-evaluation of the Maui gas reserves raised concerns about New Zealand’s future energy supply.

In June 2006, project approval was secured for the development, which is estimated to provide the New Zealand gas supply network with approximately 253 petajoules (PJ) of natural gas, as well as liquefied petroleum gas (LPG) and 15 million barrels (MMbbl) of light oil/condensate.

The $820 million project will involve installation and operation of new production wells, the installation of an offshore platform, the construction of an onshore production station, a shore crossing connecting the offshore pipelines from the platform to the onshore production station and a network of onshore pipelines. Commissioning is scheduled for mid-2009, with an initial phase of production at a rate of 20 PJ/a of sales gas, 1.7 MMbbl/a of condensate and 90,000 tonnes of LPG.

Progress on offshore components

In December 2007, topsides for the Kupe offshore platform arrived at Port Taranaki. The large steel structure was subsequently installed on the wellhead platform jacket. The four-level unmanned offshore platform will be situated 30 km off the Southern Taranaki coast.

As part of the initial development phase, three wells have been drilled by offshore drilling contractor, ENSCO International. The wells were drilled using the ENSCO 107 drilling rig, which also installed the wellhead platform jacket and the topsides of the offshore platform.

The Kupe Project drilling program was undertaken on a ‘batch-drilling’ basis, which involved completing the same depth of the Kupe South-6, Kupe South-7 and Kupe South-8 wells before proceeding to the subsequent depth for each well. This has been considered a more efficient approach than drilling the wells separately.

In March this year, the first of the three wells, Kupe South-6, reached a planned total depth of 3,385 m, with the Kupe South-8 well reaching a total depth of 3,834 m shortly after. In April, the Kupe South-7 well reached a total depth of 3,454 m, but was abandoned shortly after because of the failure to recover pipe that became stuck when making a connection after the well reached total depth. Subsequently, a sidetrack well was drilled to a final depth of 3,503 m. The well, renamed Kupe South-7 sidetrack, was directionally drilled away from the original hole and the reservoir section re-drilled.

Extending Kupe: The Momoho prospect

Given the drilling successes to date, it is not surprising that the Kupe Joint Venture has recently decided to undertake exploration drilling of the auspiciously-named Momoho prospect, which in Maori means fortunate or successful.

Located 6 km south of the Kupe Central Field and within PML 38146, if Momoho is found to be a commercial discovery it is likely to be connected to the Kupe platform and boost development from the field.

The well will be drilled to a total depth of approximately 3,150 m with primary reservoir targets in both the Farewell and Puponga Formations, the main hydrocarbon-bearing zone at the Kupe Field.

Pipelaying milestones and the road ahead

The second major component of offshore works has achieved a key milestone with the Apache vessel completing the final stage of pipelaying for the main offshore gas pipeline.

With a 12 inch diameter, the pipeline links the offshore wellhead platform to the onshore production station near Hawera through a tunnel drilled under the cliffs off the Taranaki coast. The Apache first laid the 30 km long umbilical pipe, which houses the controls, electrical and other components needed alongside the pipeline, and then the raw gas pipeline connects the offshore platform.

The pipeline laying was one of the development’s major challenges because of the height and steepness of the South Taranaki coastline cliffs and active surf. The project proponents employed horizontal directional drilling (HDD) to lay the pipelines below the cliffs, which also aimed to stop any damage or erosion to the landscape. Two 30 inch diameter HDD holes were drilled next to each other for the raw gas pipeline and the utility pipes.

“The laying of the pipeline marks a major achievement for the Kupe Gas Project,” said Mr Ashford. “The three 10 km sections of pipeline have been laid quickly, without any serious delays. This is the result of meticulous planning and preparation by the whole Kupe Gas Project team.”

The development’s focus has recently shifted to its onshore components, with construction progressing on the onshore production station. The port of New Plymouth recently received six LPG Storage Bullets, each 40 m in length, 5 m in width and weighing 170 tonnes. These have been transported to the Production Station and piperack modules have been erected for the main process area. The erection of the condensate storage tanks has also commenced along with the installation of sales gas pipeline between the Kupe Production Station and the Kapuni Gas Treatment Plant.

With the successful completion of the project’s drilling phase and the achievement of a number of major project milestones — from offshore pipelaying to the development of the onshore production plant — the massive Kupe gas project is in good stead to help the Land of the Long White Cloud meet its increasing energy demands.