Tui Area project management team head Randy Stewart told the 2006 New Zealand Petroleum Conference in Auckland this morning that the development had posed several problems for the partners.
Foremost was the expected early water drive. Over the possible 10-year life of the project, expected (2P) oil recovery was about 27 million barrels of crude. But this came with an associated 400 million barrels of water, with a predicted 91% water cut within nine years.
However, if crude remained at US$50 per barrel or over, the Tui Area would still be economic even if water drive reached 98%, according to Stewart.
First production of 30,000 barrels of oil per day (bopd) would quickly decline to only about 9000 bopd by the third year. A third of total oil production would be during the first year.
The development, involving the Tui, Amokura and Pateke oil columns northwest of Maui, would feature long, extended-reach horizontal well completions.
There would be one in each of the Tui, Amokura and Pateke accumulations, and a possible second in Pateke later. The aim was to drill into the top metre or so of each of the 10-12m thick accumulations.
Four subsea completions would be tied into the proposed FPSO, which was currently being upgraded in Singapore, with 12 risers, three for each producing well.
The Diamond Offshore Drilling semi-submersible rig Ocean Patriot was due to start development drilling late this year, plus two additional wells – the Tieke and Taranui wildcats.
If these wildcats proved successful then additional development work would done for about a year to bring in the second phase of Tui Area development.
The gas in the accumulations would be used primarily to help lift the oil and would be burnt as fuel on the unmanned FPSO.
Stewart said the dry Kiwi-1 well, drilled about two years go, caused the partners to downgrade the possible field size from 50 million barrels to the 27 million. However, high world oil prices meant the continued viability of the project.
“The Tui Area project is challenging but, in the end, comfortable,” he said.
The Tui Area partners are: operator AWE (42.5%), Mitsui EP NZ (35%), New Zealand Oil and Gas (12.5%) and Pan Pacific Petroleum (10%).
