Anadarko had run shipborne 3-D seismic testing early this year and interpretation of that data was ''well advanced'', Anadarko's New Zealand corporate affairs manager, Alan Seay, said.
''It's all still being interpreted in Houston. We should be close to [announcing] a decision by early next year,'' he said.
By regulation, Anadarko has until April next year to advise government permitting agency New Zealand Petroleum & Minerals (NZP&M) whether it intends ''to drill, or drop'' the permitted area.
Anadarko staff, including some from Houston, had in recent weeks been in Otago, Waitaki and South Canterbury to talk to iwi and local councils.
Mr Seay described them as just ''routine meetings'' held every two months.
He was unable to give any specific details on the results from the 3-D testing, or how far along Anadarko was in interpreting the data .
Last month Shell postponed its drilling plans for 2016 in the Great South Basin, south of Dunedin, as global oil prices fell to six-year lows.
In 2014, Anadarko spent about $400million in Taranaki and off Otago's coast on test drilling programmes, but came up empty-handed.
There has been speculation in the oil and gas sector that Anadarko was considering using two rigs in a drilling programme off Oamaru, but Mr Seay said that scenario was ''highly unlikely''.
''It's expensive enough as it is to bring one [to New Zealand],'' he said.
There was always potential to share costs with another operator bringing a rig to New Zealand, or to look at the availability of a rig in the Australasian area.
''[But] that's something we'll be considering closer to the time,'' he said.
The 2016 tender block offer, by NZP&M, closes at the end of the month, with the successful applicants to be announced in March next year.
The 2016 block offer encompasses 537,600sq km, with four offshore and one onshore, the latter in Taranaki.
The largest area is a combined Great South Basin and Canterbury Basin, covering 208,600sq km.
Five companies, including Anadarko, hold seven exploration permits in the Great South and Canterbury basins at present.
