Shared 50:50 by the two gold miners through the Morobe Mining Joint Venture, the project already hosts 26.6 million ounces of gold and nine million tonnes of copper resources.
During a recent site trip, MMJV general manager of sustainability and external relations David Wissink told The National there was a lot of drilling underway.
"Hopefully, we should have a pre-feasibility document done by the end of July, [or] sometime in August," he reportedly said.
Wafi-Golpu, named after two separate deposits, could end up hosting open cut and underground mining like Barrick Gold's Porgera mine in PNG.
According to a MMJV job advertisement for a senior geotechnical engineer posted in late June, Golpu operations will use block cave underground mining methods and there is an indicative processing plant capacity of 20-30 million tonnes per annum.
The Wafi deposit has been considered as amenable to open pit "and/or" bulk underground mining.