Some industry commentators say the Eocene-aged Kapuni and deeper Cretaceous formations in central Taranaki hold great promise, though that potential may be tempered by over-pressured, tight conditions.
Swift executive vice-president Bruce Vincent outlined Swift Energy's New Zealand operations and its 2003 plans at the recent UBS Warburg 2003 Global Energy Conference at Scottsdale, Arizona.
He told the conference that Swift Energy had been active in New Zealand since the mid-1990s and was now a significant established player, with several long-term gas supply contracts in place.
The company's most significant discoveries were the southern onshore Taranaki Rimu-Kauri finds, while the most significant New Zealand acquisition was the purchase of the Tariki, Ahuroa, Waihapa and Ngaere (Tawn) fields in central Taranaki.
At the start of 2003, Swift Energy New Zealand had proven reserves of 155 billion cubic feet equivalent (bcfe), 56% of which was gas and 90% of which was already developed.
Vincent said that when Swift Energy last year acquired the Shell New Zealand majority stake in the Tawn licences, stated reserves were 64.7 billion cubic feet equivalent (bcfe). Swift's own additions, revisions, or extensions had subsequently increased that reserves figure by 16.2 bcfe; while net oil and gas production in 2002 was 14 bcfe. Reserves at the start of 2003 were 66.9 bcfe, or 103% of the original estimates.
That production and revenue represented a return on investment of 35% on the acquisition costs. Costs per unit at start of 2003 were $US0.53 per Mcfe.
Vincent added that Swift Energy believed there were significant probable and possible reserves additions in the southern onshore Taranaki Rimu-Kauri, Tawa and Matai fields and prospects, along with the more northern onshore Tuihu and Waihapa licences.
Further southern reserves additions could be handled by the under utilised Rimu production station, with its 3500 bpd oil and 10 mmscf/d gas capacity, while additional reserves further north could be processed by the significantly unused Tawn facilities. Total processing capacity there is 60 mmscf/d for gas and 15,000 bpd for oil-condensate.
Vincent told EnergyReview.Net that Swift Energy was hopeful further reserves additions could be made in the Waihapa-Ngaere area.
"Our view is that there is definitely a deeper prospect there. (Former operator) Fletcher Challenge Energy did conduct a drill stem test on one well in the Kapuni sands that tested at a rate of approximately three million cubic feet per day.
"We have not quantified the probable and possible reserves at Waihapa publicly and we have additional activity under consideration at Tawn, but we have not specified anything publicly as of now."
It is known FCE tested the Eocene-aged Kapuni sands when it drilled Waihapa -1A in the late 1980s and may also have drilled to the Kapuni sands at the nearby Toko-1 and some of the Ahuroa wells.
Vincent also told ERN that Swift Energy planned to shoot some new seismic this year near the Tawa and Matai prospect areas in its newly acquired licences PEP 38756 and 759.
Later this year Swift Energy also planned to re-enter the Tuihu-1 well, which was drilled in PEP 38718 by then operator FCE two years ago, as well as possibly drilling the Tawa or Matai prospects before the end of this year, added Vincent.
It is known some of the PEP 38718 partners believe FCE stopped short of the target formation at Tuihu-1 and that by deepening the well a commercial Kapuni discovery may be made.
Shell NZ may or may not elect to join Swift Energy in any exploration of the so-called "Tawn deep rights" as it has Commerce Commission authorisation to farm-in to any prospective intervals before the presently producing formations. Waihapa-Ngaere produces from the fractured Tikorangi limestones, while Tariki-Ahuroa produces from the Oligocene-aged Tariki sandstones.
