Ann: MOU with Santos to progress studies for Darwin LNG Expansion, page-23

The first 51,000 acres…

Applying Hannam’s valuation methodology to the Shenandoah South (SS2) project, we consider the following steps:

1. Key Metrics from SS2 Data

•EUR (Estimated Ultimate Recovery): 18 bcf per well (higher than the base case of 15 bcf).

•Number of wells: 138 wells planned.

•Incremental gas resource: 220 bcf attributable to TBN from the higher working interest.

•Well costs: Likely in the range of A$20-25 million per well based on industry assumptions and prior estimates.

•NPV10 (Net Present Value at 10% discount rate): A$0.5-0.7/mcf in the base case for 15 bcf EUR wells; higher for 18 bcf EUR wells.

2. Adjust NPV for 18 bcf EUR Wells

The provided data suggests higher EUR (16.8-18.5 bcf) improves per-unit NPV10 over the base case:

•Base case NPV10 (15 bcf EUR): A$0.5-0.7/mcf.

•Adjusted NPV10 for 18 bcf EUR: Using the trend, likely ~A$0.65-0.8/mcf.

3. Estimate NPV for 220 bcf Incremental Gas

•Valuation Formula:

NPV = Incremental Gas × NPV10 (per mcf).

•Incremental Gas: 220 bcf = 220,000,000 mcf.

•NPV10 (Adjusted): A$0.65–0.8/mcf.

NPV Range:

•Lower bound: 220,000,000 × A$0.65 = A$143 million.

•Upper bound: 220,000,000 × A$0.8 = A$176 million.

4. Total Potential Valuation for SS2

For the full development of the DSU area (138 wells, ~2.5 tcf gas):

•EUR per well: 18 bcf × 138 wells = 2,484 bcf.

•NPV10 for total resource:

•Lower bound: 2,484,000,000 × A$0.65 = A$1.61 billion.

•Upper bound: 2,484,000,000 × A$0.8 = A$1.99 billion.

5. Adjust for Well Costs

NPV values can further refine based on well costs and IP (Initial Production) rates:

•For well costs of A$20-25 million, NPV10 per well ranges from A$0.35-0.77/mcf (base case).

•With higher confidence in performance (6.5–8.0 mmcf/d IP rates):

•NPV per well increases, reducing sensitivity to costs.

If SS2 wells replicate SS1H’s strong performance, the project’s valuation will align closer to the upper NPV10 estimates.

Conclusion

•Incremental 220 bcf valuation (TBN):A$143–176 million.

•Full SS2 potential valuation:A$1.61–1.99 billion.

•Improved well performance (higher EUR/IP rates) and optimized costs would push TBN’s stake toward the higher end of the valuation range.