Detailed in its recent quarterly report, Horizon said the almost completed design work included the condensate stripping plant, the pipeline from the field to the base in Kiunga and a loading facility on Fly River.

"The various reports and documents required for the petroleum development licence application are at an advanced stage," Horizon said.

"These include the social mapping and landowner identification report, environmental impact statement and gas agreement."

However, plans to convert the Stanley field-holding petroleum retention licence 4 into a PDL have not gone unnoticed.

"With engineering and design work nearing completion, but production licences yet to be finalised (and largely out of the JV's influence), the approvals process could emerge as another risk to [a] final investment decision at Stanley," Macquarie Private Wealth said in a report on Horizon.

Talisman Energy owns half of PRL4, and both companies plan to export the condensate from the Stanley-2 and Stanley-4 wells while there are less finalised plans to enter a gas export phase down the track.

Including the Stanley field and the Eval and Ketu discoveries in PRL21 (Horizon 45%, Talisman 35%), Horizon estimates that possible recoverable resources could be 1-2 trillion cubic feet of gas and 40-70 million barrels of condensate.