Construction phase
The Kupe Gas Project will include 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. It is expected the wells will be opened and first raw gas brought ashore in the December 2009 quarter.
The following illustration explains each component of the project.
- Production wells
- Offshore platform
- Offshore pipeline and shore crossing
- Onshore production station
- Onshore pipelines
1. Production wells
The purpose of the Kupe project is to extract natural gas (and associated liquids) from production wells to be drilled in the Kupe Field. Three wells have been drilled in the initial development phase by leading offshore drilling contractor, ENSCO International. The wells were drilled using the ENSCO 107 drilling rig. The drilling programme was completed at the end of May 2008. The production wells will produce up to 70 TJ/d of sales gas, with associated liquefied petroleum gas (LPG) and hydrocarbon liquids, and are expected to produce 20 PJ/yr of sales gas.
The ENSCO 107 drilling rig arrived in Taranaki in October 2007 and was released by the Kupe Gas Project in August 2008.
2. Offshore platform
The offshore platform is located above the Kupe Field, 30km south of Ohawe Beach on the southern Taranaki coast. The platform is situated in approximately 35 metres of water and comprises a topside deck supported by four legs fixed to the seabed. The topside deck contains four levels, including a helideck and sufficient space to accommodate wellheads, piping, safety equipment, a crane and other necessary facilities. The platform will not normally be manned. Staff will visit the platform periodically by helicopter to perform maintenance activities. No processing of raw gas will take place offshore. The topsides were transported by barge and ship to Taranaki in December 2007 and installed using the ENSCO 107 drilling rig.
The four-level offshore platform will be situated 30km off the Southern Taranaki coast and will include a helideck for access to the facility.
The topsides are installed using a jack-up rig.
3. Offshore pipeline and shore crossing
A single subsea pipeline will enable delivery of the raw natural gas and light oil to shore. Parallel to the subsea pipeline, utility lines and a power cable will transfer chemicals, power and fibre optic from the shore to the platform. The subsea pipeline will intersect land at the southern end of Inaha Road. To avoid damage or disturbance to the characteristic cliffs of the Taranaki coastline, a horizontal directional drilling (HDD) technique has been used to take the gas pipeline and utility lines underground from 500 metres inland of the coastline, under the beach and cliffs, out 1,800 metres offshore where they will connect to the subsea pipeline and utility lines. The HDD took place in early 2007. The installation of the offshore pipelines involves welding lengths of pipe together to progressively lay the pipe on the seabed.
The offshore raw gas pipeline was laid by the ‘Apache’ reel-vessel.
4. Onshore production station
The production station is being constructed at the southern end of Inaha Road, occupying roughly nineteen hectares of land. It will process the raw gas and light oil from the Kupe Field to meet sale specifications. The production station is being largely pre-fabricated offsite and construction is expected to take approximately 24 months. The production station will contain storage and truck loading facilities for LPG and condensate export. A low-pressure flare system will be located at ground level for operational control and an elevated flare will be installed for use in emergency situations only. A series of wetlands will provide a natural cleaning system for stormwater before discharging from the site.
An example of the construction of a production station.
5. Onshore pipelines
The onshore pipeline network involved the installation of a pipeline which will transfer raw gas from the HDD shore crossing to the production station (about 300m); and then transfer the sales gas from the production station to the Kapuni Gas Treatment Plant. The sales gas pipeline traverses a number of privately owned properties and also Inaha and Palmer Road reserves). New pipelines will transfer raw gas from the HDD shore crossing to the production station (about 300m); and to transfer sales gas from the production station to the Kapuni Gas Treatment Plant (along Inaha and Palmer Road reserves).
Timeline
| Date | Event |
|---|---|
| June 2006 | Approval to proceed |
| 2nd and 3rd qtr 2007 | Production well drilling |
| 1st qtr 2007 | Offshore platform installation commences |
| 3rd qrt 2007 | Platform topside installation |
| 2nd qtr 2007 – 4th qtr 2007 | HDD shore crossing commences |
| 3rd qrt 2007 – 4th qrt 2008 | Onshore production station construction |
| 1st qrt 2008 | Subsea pipeline installation |
| 2009 | Commercial production |
Alliance
Construction of the Kupe Gas Project is managed through an ‘Alliance’ arrangement in which the operator, Origin Energy, and the major contractor, Technip, will jointly implement the construction programme.
Origin and Technip have formed a single ‘Alliance’ construction management team, led by senior executives from Origin and Technip. The Alliance Team is predominantly resourced by Technip but includes Origin personnel in key strategic positions. The Alliance Team reports to a four-person Alliance Board with two representatives each from Origin and Technip.
Having one owner / contractor party managing all the facilities for the Kupe Gas Project has enormous advantages from a number of perspectives. The Alliance creates synergies between the work programmes for each component of the project, resulting in cost and logistic efficiencies. The arrangement has contributed to a more effective execution of the project.
The Alliance Team is responsible for the construction of the production station and associated infrastructure onshore as well as the construction of the offshore platform, the pipeline and umbilical connecting the platform to the gas plant and the Horizontal Directionally Drilled (HDD) shore crossing.
Diagram:
