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Supplementary Information for Exploration and Production Activities - Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves (Details) - USD ($) $ in Thousands | Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2021
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Supplementary Information for Exploration and Production Activities Unaudited [Abstract] |  |  |  |
Future Cash Inflows | $ 8,514,126 | $ 11,947,345 | $ 19,209,099 |
Less: |  |  |  |
Future Production Costs | 3,672,901 | 3,538,389 | 3,138,226 |
Future Development Costs | 1,191,708 | 1,095,096 | 781,847 |
Future Income Tax Expense at Applicable Statutory Rate | 826,094 | 1,867,457 | 3,876,272 |
Future Net Cash Flows | 2,823,423 | 5,446,403 | 11,412,754 |
Less: |  |  |  |
10% Annual Discount for Estimated Timing of Cash Flows | 1,486,968 | 2,874,295 | 5,964,424 |
Standardized Measure of Discounted Future Net Cash Flows | $ 1,336,455 | $ 2,572,108 | $ 5,448,330 | $ 2,353,572

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- Definition Amount of estimated future accumulated cash inflow from the sale of proved oil and gas reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Form 20-F -Number Part II -Section Item 18 -Subparagraph (Instruction 2) -Publisher SEC Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 932 -SubTopic 235 -Name Accounting Standards Codification -Section 55 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477916/932-235-55-6 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 932 -SubTopic 235 -Name Accounting Standards Codification -Section 50 -Paragraph 33 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477215/932-235-50-33 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 932 -SubTopic 235 -Name Accounting Standards Codification -Section 50 -Paragraph 29 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477215/932-235-50-29 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 932 -SubTopic 235 -Name Accounting Standards Codification -Section 50 -Paragraph 31 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477215/932-235-50-31 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 932 -SubTopic 235 -Name Accounting Standards Codification -Section 50 -Paragraph 33 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477215/932-235-50-33 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 33 -SubTopic 235 -Topic 932 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477215/932-235-50-33 + Details
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