Oil and gas is extracted by drilling a production bore. A steel pipe is place in the hole to provide structural integrity. Holes are then made in the base of the well to enable oil and gas to enter the bore. A collection of valves are located at the top of the bore to regulate pressure and control flows. Production facilities (onshore or offshore) and other infrastructure (e.g. underwater pipelines) are built to enable the oil and gas to be processed. 2174
Examples of production from existing offshore operations in New Zealand are:
- Maui A – Two fixed platforms offshore with pipelines to shore and further processing onshore
- Tui field – The Umuroa Floating production, storage and offloading facility
- Maari field – One fixed platform connected to the Raroa floating production, storage and offloading facility
Gas can be injected into an oil reservoir, known as re-injection. This process increases the pressure within the reservoir to help maintain reservoir pressure and production levels. In addition, it can assist with stimulating more oil recovery from mature oil field. This has been done at the Kapuni field to extend the economic life of this field.
To enable the development of the Māui gas field in 1973, one of the largest in the world at the time, a drilling platform had to be found which could withstand one of the most hostile environments of any offshore discovery. No existing designs were suitable for the extreme wind and waves. One of the largest steel manufacturers in Japan began construction in 1974. The tower was built at the Tsu shipyard before crossing more than 8,400 kilometres of ocean to New Zealand. Bad weather delayed the project for several months before the platform was officially handed over to the drilling teams in December 1977. 2178
Last updated at 1:41PM on February 25, 2015