Tetragon Energy Triples Halcon Gas Estimate to 8 TCF Lifting Farm-Out Appeal
Key Takeaways
- Tetragon Energy (ASX: TET) has upgraded the Halcon prospect's Mid Case (2U/P50) Gross Prospective Resource from 2.6 TCF to 8.0 TCF of recoverable gas — a three-fold increase evaluated as at 3 September 2026.
- The geological chance of success has improved from 18% to 24%, while the Low Case (1U/P90) has surged from 188 Bcf to 1,700 Bcf gross — a nine-fold increase at the conservative end of the range.
- The upgrade is anchored by a seismic comparison to ENI's 2023 Geng North discovery (5 TCF GIIP, 400 million barrels condensate) in Indonesia's Kutei Basin, with Halcon appearing significantly larger in areal extent at the same scale.
- Tetragon's farm-out strategy targets international companies to fund exploration drilling, with the upgraded resource directly strengthening the company's negotiating position in those discussions.
- Near-term catalysts include early 3D seismic reprocessing results expected in early 2027 and a full reprocessed dataset available mid-2027, alongside ongoing farm-out discussions with international operators.
Halcon prospect resource upgraded to 8 TCF mid case — a three-fold increase
Tetragon Energy Ltd (ASX: TET) has announced a significant upgrade to the Prospective Resources at its Halcon exploration prospect in SC-80, Philippines. The Mid Case (2U / P50) Gross Prospective Resource has increased from 2.6 TCF to 8.0 TCF of recoverable gas, representing a three-fold increase, with the geological chance of success improving from 18% to 24%.
Tetragon holds a 37.5% interest in, and is operator of, the SC-80 permit. The scale of this resource upgrade directly changes the economics of any farm-out deal the company pursues — and that is the core investor story here.
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What the resource numbers mean — and why they matter
The full resource range in detail
The upgrade spans all three estimate categories. The Low Case (1U / P90) has risen from 188 Bcf to 1,700 Bcf gross, while the High Case (3U) has moved from 19,900 Bcf to 22,600 Bcf gross. The table below presents the full picture as at the evaluation date of 3 September 2026.
| Estimate | Classification | Gross 100% JV (Bcf) | Net TEG 37.5% (Bcf) | Previous Gross (Bcf) |
|---|---|---|---|---|
| Low (1U / P90) | Unrisked | 1,700 | 638 | 188 |
| Mid (2U / P50) | Unrisked | 8,000 | 3,000 | 2,600 |
| High (3U) | Unrisked | 22,600 | 8,475 | 19,900 |
Halcon Prospective Resources — Recoverable Gas (Unrisked). Evaluation date: 3 September 2026.
Understanding prospective resources — what investors need to know
Prospective Resources, as defined under the SPE 2018 Petroleum Resources Management System (PRMS), are estimated quantities of petroleum that may potentially be recovered from undiscovered accumulations. They carry both a risk of discovery and a risk of development — further exploration and appraisal is required before any confidence in actual recovery can be established.
The 1U, 2U, and 3U classification framework represents low, mid, and high-case probability estimates respectively (P90, P50, and P10). Think of it this way: the P90 (1U) figure is the volume you would expect to recover in nine out of ten scenarios; the P50 (2U) is the middle-ground estimate; and P10 (3U) represents the high-upside case.
All figures in the table are reported on an unrisked basis. The geological chance of success — now 24% — applies separately and reflects the probability that a commercially viable accumulation actually exists. That distinction matters: the resource numbers tell you the scale if hydrocarbons are there; the chance of success tells you the probability they are.
Why the analogy to Geng North matters
The resource upgrade follows a detailed review of seismic data obtained from the Philippines Department of Energy, combined with the engagement of a sedimentological expert to compare Halcon against recent analogous discoveries in nearby basins.
The headline analogue is ENI’s Geng North discovery in the Kutei Basin, Indonesia — a 5 TCF gas-in-place (GIIP) and 400 million barrels of condensate find made in 2023 that Tetragon considers highly analogous to Halcon. Figure 3 in the announcement presents a seismic amplitude comparison of both structures at the same scale, showing Halcon to be significantly larger in areal extent than Geng North. That comparison is central to how management has anchored the upgraded resource estimate.
Tetragon’s permits sit in a regional context populated by major international operators. ENI, Petronas, INPEX, TotalEnergies, and PTTEP are all active in adjacent analogous basins off the north coast of Borneo, spanning the deepwaters of NW Sabah (Malaysia) and the Kutei Basin (Indonesia). That peer group provides credibility for the geological thesis and gives potential farm-in partners a familiar reference point when evaluating Halcon.
On the data side, reprocessing of 4,600 sqkm of existing 3D seismic is ongoing. Early results are expected in early 2027, with the full reprocessed dataset available from mid-2027.
Conrad Todd, Managing Director
“This three-fold increase in our Mid Case (2U) prospective resource for a key prospect in our Philippines acreage highlights the true scale and opportunity we have in these exciting permits. We believe that with our extensive experience in this and the adjacent analogous basins Tetragon will unlock the potential of this basin and prove it to be on the scale of those in adjacent Malaysia and Indonesia waters where numerous gas and oil discoveries of significant volume have been discovered. Tetragon recently listed on the ASX and we are looking to grow the prospectivity of our existing acreage and to expand through new ventures.”
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Farm-out strategy and the path to drilling
Tetragon will be engaging with international companies with the objective of those companies funding the drilling of exploration wells. The farm-out model is the mechanism by which the company aims to prove up volumes and, in its own words, create a “material value multiplier” for Tetragon and its joint venture partners.
Halcon is not the only asset in play. The SC-80 permit also contains existing discoveries at Dabakan and Palendag, which carry a combined 2C contingent resource of 470 Bcf. That existing discovered resource base sits alongside Halcon as further collateral for any farm-in conversation.
Tetragon listed on the ASX in July 2026, and its stated growth strategy encompasses both growing the prospectivity of existing acreage and expanding through new ventures. Near-term catalysts the market will be watching include:
- Early 3D seismic reprocessing results expected early 2027
- Full reprocessed seismic dataset available mid-2027
- Farm-out discussions with international companies planned
- Continued delineation of Halcon, Dabakan, and Palendag prospects
The farm-out structure is a practical risk management tool for a newly listed explorer. If successful, Tetragon could secure drilling funding without bearing the full capital cost of an exploration well — preserving its balance sheet while retaining meaningful equity exposure to any discovery.
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