About 120 protesters, many shouting, gathered outside a Wellington hotel hosting a conference on petroleum on Wednesday.
The conference was the target of an earlier demonstration when a small group of protesters invaded the main hall.
The larger group of protesters on Wednesday evening were kept on a footpath, away from the hotel entrance but made speeches on a bullhorn.
In the morning, six women protesters objecting to the continued search for oil and gas in New Zealand forced a temporary halt to a speech by Energy and Resources Minister Phil Heatley.
The attack came as the minister was praising the industry for becoming New Zealand's fourth largest exporter and producing 7700 jobs directly and indirectly, and denouncing protesters for opposing all forms of economic development.
But the protesters shouted the industry was polluting New Zealand and hastening climate change.
"We're not opposed to everything, we're opposed to the expansion of the oil and gas industry which is bullying communities. It's poisoning land, water and sea," one protester said.
"Obviously we're outnumbered here today but we're standing in solidarity for all the communities around the country,"
Security guards hustled the group out but they were not arrested.
Later oil industry executives complained that far from being too easy, oil exploration is too hard.
One called for resource consent to be granted for oil exploration before putting blocks of land or ocean bed out for tender, not afterwards.
Mr Heatley said this would be considered but noted it would be expensive for governments.
He said oil exploration had a good record in New Zealand.
"This has occurred in the Taranaki for many, many decades. There's been an excellent track record there over all those decades. In fact, the industry in Taranaki has gone under the radar for all that time."
The two-day Petroleum Summit, the biggest oil and gas industry event of the year, began on Wednesday.