Tetragon Energy triples prospective gas resource estimate at Halcon prospect in the Philippines to 8.0 TCF

Tetragon Energy has tripled the Mid Case prospective recoverable gas resources at its Halcon exploration prospect in the Philippines, revising the 2U estimate sharply upward from 2.6 TCF to 8.0 TCF. The Low and High case estimates also climbed, with the 1U rising from 188 Bcf to 1.7 TCF and the 3U moving from 19.9 TCF to 22.6 TCF.

The Australian-listed company operates a 37.5% interest in the SC-80 permit alongside partners Sunda Energy, Philodrill, and PXP Energy. It announced the revision after a more detailed evaluation of available seismic data.

Tetragon revises Halcon resource estimates sharply upward

The scale of this revision isn’t easy to brush off. Tripling a Mid Case estimate isn’t routine maintenance — it reflects a fundamentally different read of what Halcon might hold.

A higher chance of success paired with substantially larger estimated volumes reshapes the risk-reward profile of the asset in ways that are hard to ignore.

The 2U Prospective Resource now sits at 8.0 TCF of recoverable gas, up from 2.6 TCF — a jump of more than 5 TCF in the P50 estimate alone. The Low Case (1U) moved from 188 Bcf to 1.7 TCF, while the High Case (3U) rose from 19.9 TCF to 22.6 TCF. Every scenario shifted materially upward.

The geological chance of success also improved, from 18% to 24%. That’s still an exploration-stage probability, not a guarantee. But direction matters here. A higher chance of success paired with substantially larger estimated volumes reshapes the risk-reward profile of the asset in ways that are hard to ignore.

Tetragon operates SC-80 with a 37.5% working interest, with joint venture partners Sunda Energy, Philodrill, and PXP Energy. The permits — SC-80 and SC-81 — sit north of Borneo in waters jointly licensed by the Philippine government and the Bangsamoro Autonomous Region in Muslim Mindanao (BARMM).

Detailed seismic analysis and regional comparisons drove the upgrade

The revised numbers didn’t come from new drilling. They came from a closer look at existing data, with some outside expert input along the way.

Tetragon obtained seismic data from the Philippines Department of Energy and ran a more detailed evaluation than had previously been attempted. A sedimentological expert was brought in to support that work — comparing Halcon with analogous discoveries in nearby basins and helping the team develop a clearer picture of the geological setting.

That comparison pointed to significant regional reference points. ENI’s Geng North discovery in Indonesia — made in 2023 — was identified as a key geological analogue, holding an estimated 5 TCF of gas in place plus around 400 million barrels of condensate. Petronas deepwater discoveries in Malaysian Borneo waters were also cited as comparable. Tetragon believes its Philippine acreage shares geological characteristics with those finds, and that the region could prove to be on a similar scale to the productive basins already established in adjacent waters.

Upgraded estimates could influence farm-out negotiations and asset valuation

Tetragon was direct about the commercial implications. The company stated that the increases in prospective resources could have a material impact on any farm-out deal — and therefore on the value created for Tetragon and its joint venture partners.

Farm-out agreements are a standard move in exploration. A company with promising acreage brings in a partner willing to fund drilling in exchange for an equity stake, and the larger and more credible the resource estimate, the stronger the negotiating position of whoever holds the asset. Tetragon is already in discussions with international companies, seeking partners to fund the drilling of exploration wells. Successful drilling, in the company’s view, would prove up the volume and deliver what it describes as a material value multiplier.

The broader corporate context is worth keeping in mind. Tetragon recently listed on the Australian Securities Exchange (ASX), and Managing Director Conrad Todd noted that the company is looking not only to grow the prospectivity of its existing acreage but also to expand through new ventures. The Halcon upgrade gives Tetragon a stronger story to tell as it builds its profile with investors and potential partners.

Ongoing seismic reprocessing to further define Halcon and adjacent prospects

This resource revision may not be the last word on Halcon. Tetragon is currently reprocessing 1,776 square miles of existing 3D seismic data — work that’s expected to sharpen the picture considerably.

Early results from the reprocessing program are due in early 2027, though the full dataset won’t be available until mid-2027. That means Tetragon is working through a multi-year technical program, and the current upgrade reflects improved interpretation of existing data — not the final output of that effort.

Beyond Halcon, the reprocessing work will also help delineate two existing discoveries on the permits: Dabakan and Palendag, which hold combined 2C contingent resources of 470 Bcf. The seismic program is expected to mature a range of other prospects across the acreage as well.

Here’s what to carry forward: Tetragon has tripled its Mid Case resource estimate at Halcon to 8.0 TCF, backed by improved seismic analysis and regional analogues including ENI’s Geng North find. The geological chance of success has risen to 24%. Farm-out discussions are underway, with the company seeking partners to fund exploration drilling. An ongoing 3D seismic reprocessing program — with early results due shortly — could refine the picture further across SC-80 and SC-81.

Kelly Lippke

Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.