Refining New Zealand will pay a dividend for the first time in two years, thanks to higher margins.
The operator of the country's only refinery made $65.2 million in the six months to June, compared with a $7 million loss in the same period a year earlier.
Revenue doubled to $204 million, which the chief executive at Refining New Zealand, Sjoerd Post, said was due to consistently high margins, a lower dollar and strong volumes.
"We've hit a bit of a golden period."
The company will pay an interim dividend payout of 5 cents a share.
Strong cash flows also allowed the company to reduce debt by a fifth from a peak of $342 million to $269 million.
Sjoerd Post said he expects the factors driving higher margins will remain in place for now.
Mr Post said it will continue to invest in the refinery to wring more high value product out of a barrel of oil