Finlayson told shareholders in New York overnight that this had come about thanks to Total and Oil Search becoming partners in the Elk-Antelope field.
He said the company was on schedule to a preferred development concept shortly, and would then begin front-end engineering and design for the LNG plant later this year.
The concept selection will include the LNG site selection, location of the central processing facility, a gas export scheme and acid gas treatment.
Finlayson is confident Elk-Antelope LNG will go ahead because the lowest cost gas will always be commercialised, and he expects Interoil's inaugural LNG development to be one of the world's lowest-cost LNG projects.
Its estimated construction costs are just $US2051 per tonne. That is less than PNG LNG and all the Australian LNG projects, and less than half of Prelude's estimated $US4500/t.
With shipping times to Asia of about 10 days Interoil says its LNG project should break even at $US6 per million British thermal units, well below recent Japanese contract prices of US$7/MMBtu.
The company will start financing and marketing of the project in anticipation of first gas early in the 2020s.
On all metrics the company says its project beats the highly profitable, trailblazing PNG LNG project because Elk-Antelope is a single field rather than a series of seven fields that need to be aggregated. It is also much closer to the coast, so pipeline development costs will be considerably lower.
Direct river access will also substantially reduce transportation costs, and the overall cost profile is being helped by lower oil field prices.
The day rates for drilling rigs, barging and logistics have come down by as much as 25%, seismic rates have dropped nearly 20% and there is no reason to suspect there will not be savings in the construction phase.
The company believes it will deliver into a market that will have demand in excess of the contracted supply, so prices will be higher than today.
According to Wood Mackenzie, the ExxonMobil LNG project in PNG will be generating an average of about $4 billion of gross cash flow per year in the coming years.
Using these metrics, a similar two-train project at Elk-Antelope could generate about $US1 billion of cash-flow per year for Interoil.
From there the sky is the limit, because all the work so far suggests that not only can Elk-Antelope potentially support a third train, there is significant proven exploration potential.
At 7 trillion cubic feet equivalent, the net present value to Interoil is nearly $US3 billion and at 9Tcfe, the net present value would be more than $US4 billion.
Work is focused on supporting the two initial trails, and, of course, reserves certification will also determine how much Total will ultimately pay to earn into the project.
On a base volume of 7.1Tcfe, the certification payment Interoil will receive from Total will be nearly $US600 million, plus an additional $US517 million at the final investment decision.
For every Tcfe above 7.1Tcfe, InterOil will receive an additional $US400 million plus $US65 million for every Tcfe above the first Tcfe found in the Antelope South prospect.
Ongoing appraisal and exploration is important to the health of Elk-Antelope, because the ongoing drilling keeps improving the resource.
So far work on the buried reef complex supports a single gas column with field-wide communication and no evidence of compartmentalisation.
Further, drilling on the reef slope, where the rock was expected to be of poorer quality with lower gas storage capacity, turned up a much better reservoir than expected in Antelope-4: dolomite from the top of the reservoir and throughout the cored interval with porosity as high as 25%.
The positive contribution to gas volumes from this dolomite could be considerable, and the JV has agreed to a side-track to determine the total dolomite section in the southern flank.
Antelope-5 also came in 230m higher than expected, increasing the extent of the structural high, so the previous mid-case for reservoired hydrocarbons has become the low case.
Antelope-5 also uncovered some of the best reservoir in the field, extending the margins of the reefal rim further to the west than previously interpreted.
A well to the west is being considered, but it seems likely gas volumes will rise even further.
Likewise, Antelope-6 on the eastern flank is expected to test the slope, but could encounter the reefal rim.
Site preparation for Antelope-6 is well advanced and it is expected to spud in the second half of 2015.
Every 3Tcfe of additional resources equates to an extra LNG train, and, based on Wood Mackenzie data, each LNG train in the Exxon-led PNG LNG project generates about $US2 billion a year in gross cash flow.
Interoil will share one third of that.
Turning to exploration, with the success at Raptor-1 and Bobcat-1 in 2014 Interoil has had five consecutive discoveries in the basin.
With 16,000 square kilometres under licence the company believes it has the running room and the skills to deliver further exploration success in what Finlayson called "one of the most exciting emerging oil and gas provinces in the world".
The company's high-graded exploration targets are Wahoo and Antelope South, with appraisal targets at Triceratops, Raptor and Bobcat.
Together they could host about 8Tcfe of gross unrisked contingent resource and 9Tcfe of gross unrisked prospective resource on a P50 basis.
Wahoo-1 was suspended last year due to pressures that were up to 50% more than what the company encountered at Antelope so a sidetrack has been designed to handle the pressures, with drilling to resume this month.
Given the pressures and the confirmed presence of the seal the only remaining question is the presence of the reservoir.
Success could deliver a mid-case 3.5Tcfe just 170km south of Elk-Antelope, close to the coast and Port Moresby.
A successful Wahoo would therefore be one of the closest gas discoveries to Port Moresby with potentially lower development and production costs than other discoveries in Papua New Guinea.
Success at Wahoo will also de-risk other leads that have been identified, such as Mako to the south.
Antelope South-1 will test a mid-case estimate of 5.5Tcfe beneath the Antelope field, and a deep well is still being considered. All things being equal, it is likely it will be drilled.
Triceratops-3 will assess the potential for 1Tcfe later this month, while the Raptor gas-condensate discovery has the potential to be another giant, with a mid-case of 5.5Tcfe.
Successful appraisal at Rapor-1 with a sidetrack later this year will also derisk the White Tail and Mule Deer structures.
Bobcat was drilled around the same time as Raptor and also flowed gas to surface.
The well penetrated the reservoir in a transition zone between an up-dip gas field and a down-dip water leg.
Seismic is being acquired to delineate the field, which could hold 1.5Tcfe.
Interoil says there are already 35 targets defined in the Eastern Papuan Basin, and with one giant field found and a 100% success rate, it expects to add more molecules.
The explorer is acquiring aerial gravity over its entire 16,000sq.km in the Eastern Papuan Basin, which it says will provide a step-change in its ability to image future opportunities.
Finlayson said the short-term issue with lower oil prices was a concern to shareholders, however, he urged them to consider the development of long-term gas pricing in Asia, not the short-term oil price.
"Indeed the oil price correction has impacted contracted goods and services and we have benefited from this because service companies are having to compete much harder for our business," he said.
"In the longer term, we are confident that prices will stabilise and that we will benefit from strong LNG demand in Asia.
"As the lowest cost project in the region we are extremely well placed under all likely price scenarios."
Finlayson said PNG LNG had derisked the development of LNG in PNG, and the nation's location on the doorstep of the world's biggest LNG market meant it was well placed to benefit from economic growth.