The Moturoa-6 well flowed at rates in excess of 200 barrels of oil per day earlier this month from a second sidetrack, with Greymouth saying this confirmed the discovery of significant extensions to New Zealand’s historic first commercial oil and gas field.
Greymouth and joint venture partner Ngati Te Whiti Hapu Society are now considering zone testing operations to assess possible gas flows and potential gas reserves.
“This is the first shallow onshore oil pay we have had,” Greymouth chief operating officer John Sturgess told PetroleumNews.net this morning.
“That’s always been my target – to get good flows from shallow zones, less than 1000m down, that are often heavily faulted in onshore Taranaki.
“The well is still flowing naturally from multiple zones, though you really need to pump these to get reliable reserves estimates, as the waxy crude can clog wellbores.”
Sturgess said by applying state-of-the-art drilling techniques, Greymouth was able to achieve the best oil flow rates ever recorded in this area.
Operator Greymouth (98% interest) and Ngati Te Whiti (a 2% carried interest) drilled Moturoa-5 and 6, in licence PEP 38464, during late 2006-early 2007, and encountered multiple oil and gas sands.
Moturoa-5 was drilled as a deviated well to a measured depth of 2571m and hydrocarbons were encountered in a number of sections.
Moturoa-6 was drilled to a measured depth of 1250m, then sidetracked horizontally twice to test the lateral extent of one of the oil reservoirs discovered.
Sturgess also said gas had been discovered in both wells in several intervals.
The Moturoa oil field, which almost surrounds the present-day port, was one of the first commercial fields in the former British Empire, producing over 250,000bbl of crude over several decades until 1972. Previous producing horizons have included shallow Pliocene-aged formations, such as the Matemateaonga and Manutahi sandstones.
Sturgess said increasing subsurface pressures in recent years had re-activated petroleum production from faults and a number of poorly abandoned wells in the Moturoa area.
Greymouth brought the Republic New Plymouth-4 (RNP-4) well, drilled in 1976, back into production in 2000 and it had remained on intermittent production since.
He said RNP-4 well had been valuable in the collection of data used in the recent drilling program.
Cumulative production from RNP-4 totalled 5000bbl over seven years.
In contrast, cumulative production from the second Moturoa-6 sidetrack had been 1600bbl over a week or two.
However, Shell New Zealand, owner and operator of the Omata Tank Farm above Port Taranaki, is claiming Greymouth and Ngati Te Whiti have no ongoing rights to store Moturoa crude at the tank farm and has said it will not accept further crude deliveries.
Sturgess said Greymouth was using every available storage tank it could to hold Moturoa crude and was looking at options for transporting it – either to the Marsden Point oil refinery in Northland, New Zealand or to east coast Australian refineries for processing.
Last month, departing Austral Pacific Energy chief executive Rick Webber said limited available storage at or near the port meant production from the onshore Taranaki Cheal oil field was limited to about 500bpd.
