Maui makes it 30 years of gas output

Operators of the Maui gas field celebrated 30 years of production last night and hope new development will keep it going for another five years at least.

The gas and oil field 35km offshore from Taranaki led to the building of gas fired power stations throughout the North Island and Think Big projects in the early 1980s. It was discovered in 1969 and was the eighth largest gas field discovered in the world to date, with reserves of gas estimated at that time of approximately 5400 petajoules.

The field covers 157sq km and lies 3000m below the sea floor.

Since it started producing it has accounted for an estimated 80 per cent of natural gas used.

Last month the sale was signed of the last gas under the 30-year-old Maui Gas Contract. Contact Energy was the last customer under the legacy deal.

Chairman of Shell and Maui Development, Rob Jager, said the field was in its twilight years, producing a third of what it did in its heyday in the 1990s.

"All the easily producible gas has been produced, so now its all about targeting gas in tighter rock zones and gas that's been bypassed. Inevitably that's higher risk and more costly and smaller volumes," he said. "We're looking at the possibility of Maui running out in the next five to 10 years - it does depend on some of the activities we have currently in the plan."

Jager had a holiday job on the Maui project in 1977, two years before it came onstream and said it has had a significant impact on the country.

In what was the first big example of a public private partnership, the Government entered into a 50:50 joint venture with Shell, BP and Todd Petroleum Mining to develop the field. Because Maui dwarfed other gas sources for years it effectively determined the price of gas, which spiked after the 2003 redetermination of reserves.

Shell Todd Oil Services operates the field on behalf of Maui's owners Shell (with 83.75 per cent), OMV NZ (10 per cent) and Todd Energy (6.25 per cent). About $60 million is now being spent on finding more gas in three existing wells at Maui B.