The big four projects are continuing to drive the Taranaki economy, particularly the energy sector, adding another layer of expertise and capability to this industry.
The Petroleum Exploration and Production Association of New Zealand says the projects are raising the capability of New Zealand upstream petroleum and its support industries - both in terms of the number of people employed and their levels of expertise.
"The projects also bring significant boosts to the national and local Taranaki economies," Pepanz executive officer John Pfahlert said.
Two of the Pohokura gas and condensate project's largest contractors were New Zealand-owned companies - New Plymouth's Fitzroy Engineering Group, which built the topsides, and Fletcher Construction, the main contractor for the onshore production station.
New Zealand firms are also heavily involved in building the Kupe gas and condensate scheme's production station.
Offshore Solutions - a partnership between the ETL Group, Swire Pacific Offshore NZ and Seaworks - has seen its workload and staff numbers increase significantly over the past few years.
Company director Mike Murdoch said the company had made "a seamless transition from project to project", with more work and with staff numbers rising by over 50% to about 260.
"We have bid for and won the marine support, pilotage, support vessel contracts for the FPSOs Umuroa and Raroa [for the Tui and Maari oil projects]," he said. "We are also currently setting up the procedures, marine specialists and vessel spread for the installation of the Raroa.
"And we are providing ongoing offshore supply vessel and logistics support to the Maui, Pohokura, Tui and Maari fields, together with offshore exploration drilling programs in Taranaki and elsewhere."
Another Offshore Solutions director, Deepak Ahluwalia, said the company had now also done field operations audits in Australia, Dubai, India, Singapore, Hong Kong, Taiwan and Japan.
"The whole New Zealand industry is growing up, growing in experience and expertise," Ahluwalia said.
The Wendell Offshore Group, part of Perth-headquartered commercial services and supplies company Integrated Group, is another firm that has grown significantly. It supplies manning, catering and logistics packages to offshore rigs, the Umuroa and other vessels.
In addition, worldwide group Offshore Marine Services has chosen the last few years to enter New Zealand.
"The experience of OMS in New Zealand has been one of exponential growth, having been a significant service supplier on all four major offshore developments," New Zealand general manager John Spurway said.
"While we are now approaching the sunset of the last big four developments, I believe we will yet see more intense activity off the New Zealand coast," Spurway said.