Reserves and Resources Statement

Woodside produced a total of 201.0 MMboe in 2023, including 186.1 MMboe produced for sale and 15.0 MMboe of production consumed primarily as fuel in operations.¹ At 31 December 2023, Woodside's remaining proved (1P) reserves were 2,450.1 MMboe, proved plus probable (2P) reserves remaining were 3,757.1 MMboe, while the best estimate (2C) contingent resources remaining were 5,902.0 MMboe (Table 1).

The first-time booking of reserves at Trion in Mexico and Mad Dog Southwest in the US Gulf of Mexico increased proved reserves by 204.1 MMboe and proved plus probable reserves by 300.0 MMboe (shown as extensions and discoveries in Table 2), of which:

·      final investment decision and regulatory approval of the field development plan at Trion in August 2023 increased proved reserves by 194.8 MMboe and proved plus probable reserves by 287.2 MMboe; and

·      approval of the Mad Dog Southwest Extension project increased proved reserves by 9.3 MMboe and proved plus probable reserves by 12.7 MMboe.

Revisions of previous estimates and transfers in 2023 resulted in a net increase of 61.8 MMboe for proved reserves and 17.8 MMboe for proved plus probable reserves. Key drivers for these revisions include:

·      asset optimisation, including injector to producer conversions, and field performance at Angostura and Ruby in Trinidad and Tobago contributed to proved and proved plus probable reserves increases of 13.0 MMboe and 19.3 MMboe, respectively

·      improved overall field performance and technical updates in North West Shelf increased proved reserves by 49.7 MMboe. North West Shelf proved plus probable reserves decreased by 8.9 MMboe, due to the transfer of several late life undeveloped projects to 2C contingent resources, partially offset by improved overall field performance 

·      performance based revisions at Shenzi resulted in decreases in both proved and proved plus probable reserves of 13.4 MMboe and 30.2 MMboe, respectively

·      improved overall field performance and technical updates at Pluto and Macedon contributed to proved plus probable reserves increases of 28.4 MMboe and 14.7 MMboe, respectively.

Additionally, in 2023, Woodside completed a transaction whereby Calgary-based Paramount Resources took a 50% equity interest in, and operatorship of, 28 leases of the Liard field in Canada. The transaction resulted in Woodside's 2C contingent resources decreasing by 2,241.2 MMboe. Voluntary relinquishment of Magellan in Trinidad and Tobago, and Wildling in the US Gulf of Mexico resulted in a 77.2 MMboe decrease in 2C contingent resources.

The reclassification of undeveloped reserves to developed reserves is discussed in the Undeveloped Reserves section of this Reserves and Resources Statement.

Unless stated otherwise, the following apply to this Reserves and Resources Statement²: The effective date for reserves and resources estimates is 31 December 2023. Proved reserves are calculated using SEC-compliant economic assumptions and pricing. Production is reported for the period from 1 January 2023 to 31 December 2023. Reserves, resources and production stated are Woodside's net share and inclusive of fuel consumed in operations. All numbers are internal estimates produced by Woodside. Estimates of reserves and contingent resources should be regarded only as estimates that may change over time as further production history and additional information becomes available.

Table 1: Woodside's reserves^3,4,5,6 and contingent resources⁷ overview (net Woodside share, as at 31 December 2023)

Methodology

Reserves and contingent resources estimates have not been adjusted for risk. Proved reserves are estimated and reported on a net interest basis, excluding royalties owned by others, in accordance with the United States Securities and Exchange Commission (SEC) regulations and have been determined in accordance with SEC Rule 4-10(a) of Regulation S-X. As defined by the SEC, proved reserves are those quantities of crude oil, natural gas, and natural gas liquids that, by analysis of geoscience and engineering data, can be estimated with reasonable certainty to be economically producible from a given date forward from known reservoirs and under existing economic conditions, operating methods, operating contracts, and government regulations. Unless evidence indicates that renewal of existing operating contracts is reasonably certain, estimates of economically producible reserves reflect only the period before the contracts expire. The project to extract the hydrocarbons must have commenced or the operator must be reasonably certain that it will commence within a reasonable time.

Proved reserves are estimated by reference to available well and reservoir information, including but not limited to well logs, well test data, core data, production and pressure data, geologic data, seismic data and, in some cases, similar data from analogous, producing reservoirs. A wide range of engineering and geoscience methods, including performance analysis, numerical simulation, well analogues and geologic studies, have been used to develop high confidence in estimated quantities.

Proved plus probable reserves and 2C contingent resources are estimated in accordance with the 2018 Society of Petroleum Engineers/World Petroleum Council/American Association of Petroleum Geologists/Society of Petroleum Evaluation Engineers Petroleum Resources Management System (SPE-PRMS) guidelines. SPE-PRMS guidelines allow (amongst other things) escalations to prices and costs and, as such, volume estimates in accordance with those guidelines would be on a different basis than volumes estimated as prescribed by the SEC. Proved plus probable reserves and 2C contingent resources estimates are inherently more uncertain than proved reserves estimates.

Governance and assurance

Woodside has several processes designed to provide assurance for reserves and contingent resources reporting, including its Reserves and Resources Policy, Petroleum Resources Management Procedure, Reserves and Resources Guideline, annual staff training and minimum experience levels. The Woodside Reserves and Resources Policy requires external audits of all projects or fields with material reserves at least once every four years. In addition, Woodside has a dedicated and independent Corporate Reserves Team (CRT) that provides oversight and assurance of the reserves and resources assessments and reporting processes. Reserves and resources are estimated by staff in teams directly responsible for development and production activities. These individuals are trained in the fundamentals of reserves reporting and are approved by the CRT on an annual basis. Reserves assessments are reviewed annually by the CRT to ensure technical quality, adherence to internally published guidelines and compliance with SEC and SPE-PRMS reporting requirements (as applicable). All reserves and resources are reviewed and approved by Woodside's Qualified Petroleum Reserves and Resources Evaluator and approved by senior management and the Board prior to public reporting.

Qualified Petroleum Reserves and Resources Evaluator statement

The estimates of petroleum reserves and contingent resources are based on and fairly represent information and supporting documentation prepared by, or under the supervision of Mr. Ben Stephens, Woodside's Vice President Reserves and Subsurface, who is a full-time employee of the company and a member of the Society of Petroleum Engineers. The Reserves and Resources Statement as a whole has been approved by Mr. Stephens. Mr. Stephen's quali?cations include a Bachelor of Engineering (Petroleum Engineering) from the University of New South Wales, Australia, and 20 years of relevant experience.

Table 2: Proved and proved plus probable developed and undeveloped reserves reconciliation (net Woodside share, as at 31 December 2023)

Table 3: 2C contingent resources reconciliation (net Woodside share, as at 31 December 2023)

Small differences are due to rounding

Table 4: Proved developed and undeveloped reserves (net Woodside share, as at 31 December 2023)

Small differences are due to rounding

Table 5: Proved plus probable developed and undeveloped reserves (net Woodside share, as at 31 December 2023)

Small differences are due to rounding

Table 6: 2C contingent resources summary by region (net Woodside share, as at 31 December 2023)

Small differences are due to rounding

Undeveloped reserves

At 31 December 2023, Woodside's remaining proved undeveloped reserves were 1,712.5 MMboe, representing an increase of 97.2 MMboe from the 1,615.2 MMboe as at 31 December 2022 (Table 7).

Extensions and discoveries increased proved undeveloped reserves by 204.1 MMboe following the final investment decision and regulatory approval of the field development plan at Trion, and approval of the Mad Dog Southwest Extension project.

In 2023, 87.7 MMboe of proved undeveloped reserves were converted to proved developed reserves with start-up of development wells in Mad Dog Phase 2 (56.0 MMboe), Shenzi North (10.5 MMboe), Atlantis (8.7 MMboe), and Pyrenees (1.1 MMboe), and completion of offshore Pluto water handling (11.3 MMboe). Technical studies and performance resulted in a 3.4 MMboe decrease to proved undeveloped reserves. The effect of commodity prices relative to 2022 resulted in a 15.8 MMboe reduction to proved undeveloped reserves at Sangomar.

Undeveloped reserves in Julimar Brunello have remained undeveloped for longer than ?ve years from the dates they were initially reported and are expected to be developed in a phased manner to meet long-term contractual commitments.  The project is included in the company business plan, demonstrating the intent to proceed with the development.

The changes in proved undeveloped reserves in 2023 are summarised by category in Table 7.

Table 7: Proved undeveloped reserves reconciliation (net Woodside share, as at 31 December 2023)

Small differences are due to rounding

At 31 December 2023, Woodside's remaining proved plus probable undeveloped reserves were 2,682.3 MMboe, representing an increase of 157.7 MMboe from the 2,524.5 MMboe as at 31 December 2022.

Extensions and discoveries associated with Trion and Mad Dog Southwest increased proved plus probable undeveloped reserves by 300.0 MMboe.

In 2023, 130.1 MMboe of proved plus probable undeveloped reserves were converted to proved plus probable developed reserves with start-up of development wells in Mad Dog Phase 2 (71.7 MMboe), Shenzi North (28.6 MMboe), Atlantis (15.8 MMboe), and Pyrenees (1.3 MMboe), and completion of offshore Pluto water handling (12.7 MMboe).  Additionally, 22.0 MMboe of late life North West Shelf undeveloped projects were transferred to 2C contingent resources.

During 2023, Woodside spent US$5.3 billion on development activities worldwide. Of this amount, US$4.7 billion was spent progressing the conversion of proved undeveloped reserves for projects where development status was achieved in 2023 or is expected to be achieved when development is completed in the future.

Additional information for US investors

The SEC prohibits oil and gas companies, in their filings with the SEC, from disclosing estimates of oil or gas resources other than 'reserves' (as that term is defined by the SEC). In this Reserves and Resources Statement, Woodside includes estimates of quantities of oil and gas using certain terms, such as 'proved plus probable (2P) reserves,' 'best estimate (2C) contingent resources,' 'reserves and contingent resources,' 'proved plus probable,' 'developed and undeveloped,' 'probable developed,' 'probable undeveloped,' 'contingent resources' or other descriptions of volumes of reserves, which terms include quantities of oil and gas that may not meet the SEC's definitions of proved, probable and possible reserves, and which the SEC's guidelines strictly prohibit Woodside from including in filings with the SEC. These estimates are by their nature more speculative than estimates of proved reserves and would require substantial capital spending over a significant number of years to implement recovery, and accordingly are subject to substantially greater risk of being recovered by Woodside. In addition, actual locations drilled and quantities that may be ultimately recovered from Woodside's properties may differ substantially. Woodside has made no commitment to drill, and likely will not drill, all drilling locations that have been attributable to these quantities. U.S. investors are urged to consider closely the disclosures in Woodside's filings with the SEC, which are available at www.sec.gov.