The company also expects to incur a non-cash post-tax impairment of US$102 million, including an impairment of $181 million for its Haile operation in North Carolina and an impairment reversal of $79 million to fully reinstate the carrying value of Didipio.
Acting CEO Scott Sullivan said the company had a bright future.
"Over the next three years, we expect to increase gold production by about 70% compared with 2021, representing a compounded annual growth rate of approximately 15%," he said.
"More importantly, we are expecting increasing free cashflow margins, particularly in 2024 with the step change in production and a decrease in capital investments.
"Additionally, copper production is expected to increase to steady-state production levels beyond this year as Didipio has ramped-up well ahead of expectations."
OceanaGold provided a three-year outlook which sees gold production rising to 490,000-530,000 ounces of gold plus 12,000-14,000t of copper in 2023 from 445,000-495,000oz of gold and 11,000-13,000t of copper in 2022.
Output is then forecast to reach 580,000-620,000oz of gold plus 12,000-14,000t of copper in 2024.
The company attributed the Haile impairment to almost 25% higher open pit life of mine unit costs at Haile following a technical review, where open pit unit costs are forecast to average $2.48 per tonne inclusive of capitalised stripping compared with $2/t previously assumed.
Processing costs are now assumed to average $11.64/t milled compared with $9.98/t previously. G&A costs are now expected to be $4.89/t milled over life of mine compared with $3.48/t previously.
Higher life of mine operating costs are attributed to increased capital requirements related to waste stripping, potential acid generating storage and tailing storage facility expansion, as well as continued inefficiencies related to the re-handle of waste material due to delays in the supplemental environment impact statement and increased water management resulting from higher than normal wet seasons in 2018 and 2019.
Shares in OceanaGold closed yesterday at A$2.22, valuing the company at $1.6 billion.