The government agency's director, Andrew Annakin, made the revelation at a public information session on oil and gas exploration at Dunedin's Araiteuru marae last night.
A timeline display of oil and gas activities in the Otago area showed ''exploration drilling'' was expected to occur eight times between now and the end of 2018, while ''seismic surveying'' was expected five times.
Mr Annakin said only Shell, which previously reported it planned to drill for gas and oil in the Great South Basin in early 2016, had made a commitment to drill.
Other ''exploratory drilling'', from companies including Anadarko, TAG Oil and Greymouth Petroleum, was yet to be confirmed. Whether the drilling went ahead would depend on the results of seismic data.
Mr Annakin also revealed another company had ''very recently'' applied to carry out a seismic survey covering a large area off the Otago coast.
A number of those at the meeting expressed concern over aspects of drilling and exploration, including the impacts on marine life from seismic surveying.
Department of Conservation technical adviser Dave Lundquist said there was a potential danger to sea mammals from seismic surveying, which involved bouncing sound signals off the ocean floor.
Seismic surveying was being investigated as the cause of a pilot whale beaching at Kaka Point in February. The results of a necropsy, paid for by Shell New Zealand, were yet to be confirmed, Mr Lundquist said.
In order to prevent surveying hurting sea life, independent advisers and monitoring equipment were mandatory on all seismic surveying expeditions, so work could be stopped if animals were nearby, he said.
Representatives from the Environmental Protection Authority, Maritime New Zealand, WorkSafe New Zealand, the Ministry for the Environment, and the Otago Regional Council were also at the meeting.
