Bright prospect for oil bids

By Laurel Stowell


Fresh opportunities to prospect for oil and gas off the west coast of the lower North Island are likely to be well received, geophysicist Rosemary Quinn says.

"I think there will be a lot of interest, from new entrants and existing players. It's an exciting time for the [petroleum] business here," she said.

"There are plans to bring four drilling rigs to New Zealand this summer season."

Ms Quinn is the head of petroleum geoscience at GNS Science, a New Zealand body that provides geological consultancy services.

The New Zealand Government offered fresh blocks of land and seabed for oil and gas prospecting last week, some, as our graphic shows, only about 70km off the Wanganui coast.

The tender period ends in September, and formal bids usually come in close to that time, after companies have investigated the likelihood of success.

There have been 15 offers of New Zealand blocks, both on and offshore, since 2002.

The 2012 block offer was a success, with two offshore Taranaki areas taken up, one by Todd Exploration Ltd and the other by NZOG. There were also five onshore Taranaki blocks taken up.

Those on offer this year surround others already allocated, some as long as 40 years ago.

Drilling oil wells is expensive and there's a risk nothing will be found. Ms Quinn said that was why most such prospecting was financed by joint ventures.

Taranaki is the only part of New Zealand where oil and gas is being extracted at the moment.

The region is thick with petroleum wells, some for exploration and some for production.

Many are now decommissioned, but information recorded there is available to prospectors who want to assess productivity in the general area.

All the blocks on offer this year show evidence of a working petroleum system, a Ministry of Business, Innovation and Employment spokesman said.

The Taranaki basin is especially attractive to companies because it has the perfect conditions for creating and holding underground reserves of oil and gas.

The area was a low point at least 60 million years ago, Ms Quinn said.

Conditions were swampy, with lots of vegetation on land, or many living things under the sea.

Those plant and animal remains were covered by layers of material carried into the basin by rivers, over millions of years. They were then compressed, and heat and a chemical reaction transformed the material into oil or gas. Some of the covering material was porous enough to store it, with solid layers on top.

New Zealand is surrounded by similar sedimentary basins, Ms Quinn said, but most of them lacked that perfect combination.

- WANGANUI CHRONICLE

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