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v3.25.3

Supplementary Information for Exploration and Production Activities - Narrative (Details) $ in Millions, Bcf in Billions | 12 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2025 USD ($) pUDLocation Bcf | Sep. 30, 2024 USD ($) pUDLocation Bcf | Sep. 30, 2023 USD ($) Bcf | Sep. 30, 2022 | Sep. 30, 2021
Reserve Quantities [Line Items] |  |  |  |  |
Amount spent for developing proved undeveloped reserves | $ | $ 246.3 | $ 305.6 | $ 342.0 |  |
Proved undeveloped reserve volume (in Bcfe) | 1,316 | 1,267 | 985 |  |
Percentage of PUD reserves to the total proved reserves | 26.40% | 26.70% | 21.70% |  |
Increase in PUD reserves (in Bcfe) | 49 | 282 |  |  |
New PUD reserve additions (in Bcfe) | 473 | 602 |  |  |
PUD upward revisions (in Bcfe) |  | 76 |  |  |
PUD conversions to developed reserves (in Bcfe) | 399 | 291 |  |  |
Proved undeveloped reserves removed (in Bcfe) | 18 | 105 |  |  |
Number of PUD well locations removed | pUDLocation | 1 | 9 |  |  |
Adjustments to remaining PUD reserves (in Bcfe) | 7 |  |  |  |
Investment made to convert proved undeveloped reserves to developed reserves | $ | $ 246.0 | $ 306.0 |  |  |
Conversion of undeveloped proved reserves to developed proved reserves after revisions (in Bcfe) | 415 | 374 |  |  |
Conversion of PUD to developed to PUD reserves booked at end of prior year (as a percent) | 31.00% | 30.00% | 47.00% | 45.00% | 34.00%
Arbitrary discount rate (as a percent) | 10.00% |  |  |  |
Total PUD Reserve Additions Estimated in the Next Fiscal Year |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |
Amount to be spent on developing proved undeveloped reserves | $ | $ 295.0 |  |  |  |
Utica Shale |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |
Proved undeveloped reserve volume (in Bcfe) | 1,119 | 925 | 873 |  |
PUD conversions to developed reserves (in Bcfe) | 254 |  |  |  |
Marcellus Shale Fields |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |
Proved undeveloped reserve volume (in Bcfe) | 197 | 342 | 112 |  |
PUD conversions to developed reserves (in Bcfe) | 145 |  |  |  |
Appalachian Region |  |  |  |  |
Reserve Quantities [Line Items] |  |  |  |  |
Number of well locations developed with net PUD reserves | pUDLocation | 27 | 20 |  |  |
Number of well locations to be developed with net PUD reserves | pUDLocation | 73 | 73 |  |  |

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