Uncertainty in reserve estimates and the potential for future revisions
First written in FY2016. 3 of 7 entries say "Restated". Latest entry: FY2026.
No other company in this theme has enough history to compare yet.
- FY2026AdvancedAnnual report
「Third-party evaluation and appraisal have been conducted for the portion [2] equivalent to approximately 82% of total proved reserves as of 31 March 2026 shown in the table above.」
The proportion of total proved reserves subject to third-party evaluation and appraisal increased from approximately 70% in the previous fiscal year to approximately 82%. - FY2025WorsenedAnnual report
「As of 31 March 2025 1,336 6,988 9,016 918 10,351 7,906 8 315 10,359 8,220」
Proved reserves declined from 13,755 thousand kL of crude oil and 9,016 million m³ of gas in the previous fiscal year to 10,359 thousand kL of crude oil and 8,220 million m³ of gas. The table reflects the sale of JUK and other changes, and the company expects gas reserves to increase by approximately 7% as a result of future participation in the Guban block and other developments. - FY2024AdvancedAnnual report
「In addition, to verify the validity of the reserves evaluations and judgments made by the company itself, it has commissioned Ryder Scott Company, L.P. to conduct a third-party evaluation and appraisal of the portion [1] equivalent to approximately 82% of the proved reserves in Japan held by the company and its consolidated companies as of 31 March 2024, as shown in the table above. Overseas, third-party evaluations have been conducted of the reserves of Japex (U.S.) Corp., JAPEX UK E&P Ltd., Kangean Energy Indonesia Ltd. and Blue Spruce Operating LLC. Third-party evaluations have been conducted for the portion [2] equivalent to approximately 60% of total proved reserves as of 31 March 2024 shown in the table above.」
The proportion of total proved reserves subject to third-party evaluation increased from approximately 47% in the previous fiscal year to approximately 60%, and stood at approximately 82% for Japan. Blue Spruce's reserves were also added to the scope of evaluation. - FY2022RestatedAnnual report
「Reserves are inherently an uncertain estimate of the volume that can be produced in the future and may be revised upward or downward based on reviews using newly obtained data, changes in economic conditions, changes in internationally recognized reserve definitions and other factors.」
The company continues to disclose the possibility that reserves may be revised upward or downward due to data, economic conditions and changes in definitions, even after the substantial decline in proved reserves. - FY2020RestatedAnnual report
「Reserves are inherently an uncertain estimate of the volume that can be produced in the future and may be revised upward or downward based on reviews using newly obtained data, changes in economic conditions, changes in internationally recognized reserve definitions and other factors.」
The company continues to disclose that reserves may be revised upward or downward due to new data, changes in economic conditions and changes in definitions. - FY2017RestatedAnnual report
「Reserves are inherently an uncertain estimate of the volume that can be produced in the future. The company strives to make accurate estimates based on scientific evidence, including geological and engineering data currently available. However, reserves may be revised upward or downward based on reviews using newly obtained data, changes in economic conditions, changes in internationally recognized reserve definitions and other factors.」
The company continues to explain the possibility of upward or downward revisions to proved reserves in relation to data, economic conditions and changes in definitions. - FY2016First statedAnnual report
「Reserves are inherently an uncertain estimate of the volume that can be produced in the future. The company strives to make accurate estimates based on scientific evidence, including geological and engineering data currently available. However, reserves may be revised upward or downward based on reviews using newly obtained data, changes in economic conditions, changes in internationally recognized reserve definitions and other factors.」
The company explicitly stated that disclosed proved reserve figures may be revised upward or downward due to data, economic conditions and changes in definitions.