SANTOS LIMITED — Merger & Acquisition 2021

Aug 1, 2021

2 August 2021

Santos agrees proposed merger ratio with Oil Search

Santos and Oil Search have today reached agreement on the merger ratio under the proposed merger and the additional terms set out in this release ("Revised Merger Proposal").

Under the Revised Merger Proposal, Oil Search shareholders will receive 0.6275 new Santos shares for each Oil Search share held via a Scheme of Arrangement. Following approval of the Scheme, Oil Search shareholders will own approximately 38.5 per cent of the merged group and Santos shareholders will own approximately 61.5 per cent.

The Board of Oil Search has confirmed that, subject to the completion of confirmatory due diligence and the agreement of a binding Merger Implementation Agreement, their intention is to unanimously recommend the Revised Merger Proposal, in the absence of a superior proposal and subject to an independent expert concluding that the scheme of arrangement is in the best interests of Oil Search shareholders.

The Revised Merger Proposal implies a transaction price of A$4.29 per Oil Search share, based on the closing price of Santos and Oil Search shares on 19 July 2021 (being the day prior to disclosure of the first proposal). This represents a 16.8 per cent premium to the Oil Search closing price on 19 July and a 16.4 per cent premium to the one-month VWAP on that day. In addition, the proposal represents the opportunity to deliver compelling value accretion to both sets of shareholders.

The merger of Santos and Oil Search would create a regional champion of size and scale with the following features:

• Diversified portfolio of high quality, long-life, low-cost assets across Australia, Timor-Leste, Papua New Guinea and North America with significant growth optionality
• Pro-forma market capitalisation of A$21 billion which would position the merged entity in the top-20 ASX-listed companies and the 20 largest global oil and gas companies
• Combined 2021 production of approximately 116 million barrels of oil equivalent
• Combined 2P+2C resource base of 4,983 million barrels of oil equivalent
• Investment grade balance sheet with more than US$5.5 billion of liquidity to self-fund development projects, whilst maintaining further optionality and flexibility to optimise the portfolio
• Target gearing of less than 30 per cent
• Strong ESG credentials including maintaining Oil Search's social and community investment in Papua New Guinea and North America, including the Oil Search Foundation
• Substantial potential combination synergies. Santos has an excellent track record of integration and recently merged Quadrant Energy and ConocoPhillips' WA and NT business unit into Santos, delivering more than US$160 million in annual synergies

The combination would also create greater alignment in Papua New Guinea supporting the development of key projects including Papua LNG, deliver new jobs and help support the local economy.

Media enquiries James Murphy +61 (0) 478 333 974 james.murphy@santos.com Investor enquiries Andrew Nairn +61 8 8116 5314 / +61 (0) 437 166 497 andrew.nairn@santos.com

Santos Limited ABN 80 007 550 923 GPO Box 2455, Adelaide SA 5001 T +61 8 8116 5000 F +61 8 8116 5131 www.santos.com

Oil Search shareholders would continue to participate in the merged entity and retain the opportunity to realise a premium for control as part of the merged entity.

Santos Managing Director and Chief Executive Officer Kevin Gallagher said the potential merger of Santos and Oil Search is consistent with Santos' disciplined strategy to grow around our core assets.

"It represents a compelling combination of two industry leaders to create an unrivalled regional champion of size and scale with a unique diversified portfolio of long-life, low-cost oil and gas assets.

"The merged company would have strong cash generation from a diverse range of assets which provides a strong platform for sustainable growth and continued shareholder returns.

"The merger also builds on our industry-leading approach to ESG through the combination of Santos' net-zero 2040 pathway, including its sector-leading CCS projects, and Oil Search's unique social programs in PNG, underpinned by a strong balance sheet to fund the transition to a lower carbon future.

"The Revised Merger Proposal represents an extremely attractive opportunity to deliver compelling value accretion to both Santos and Oil Search shareholders."

Santos and Oil Search have committed to conduct best endeavours due diligence subject to appropriate confidentiality arrangements over a period of approximately four weeks with the aim of entering into a Merger Implementation Agreement, which would contain conditions to completion of the merger such as regulatory approvals.

Each party will be free to declare ordinary dividends in accordance with existing dividend policy through to signing of the Merger Implementation Agreement. Should a party declare a dividend outside its existing dividend policy before the signing of the Merger Implementation Agreement, there would be an appropriate adjustment to the merger ratio.

Citigroup and JB North & Co are acting as financial advisers and Herbert Smith Freehills and Dentons are acting as legal advisers to Santos.

Ends.

This ASX announcement was approved and authorised for release by Kevin Gallagher, Managing Director and Chief Executive Officer.

Santos Limited ABN 80 007 550 923 GPO Box 2455, Adelaide SA 5001 T +61 8 8116 5000 F +61 8 8116 5131 www.santos.com

Oil Search Merger Rationale 2 August 2021

Strategic rationale for merger

Merger would create a regional champion of scale and provide shareholders with an opportunity to participate in a new company that can optimally fund the development of a diverse portfolio of high-quality O&G assets

A	CREATES A REGIONAL CHAMPION OFSIZE AND SCALE		Positioned within S&PASX-20index and top 20 largest global O&G companiesOperated footprint gives ability to control cost and deliver growth
B	DIVERSIFIED PORTFOLIO OF LONG-LIFE,LOW-COST ASSETS WITH GROWTH OPTIONS		Balanced portfolio of geographically and product differentiated assetsRobust development pipeline with flexibility
C	STRONG BALANCE SHEET AND INVESTMENTGRADE FUNDING PLATFORM		>US$5.5bn of liquidity and an investment grade credit ratingSufficient capacity to self-fund development pipeline
D	UNLOCKS SYNERGIESAND LATENTSHAREHOLDER VALUE		Substantial potential combination synergies to the benefit of all shareholders
E	PORTFOLIO OPTIMISATION OPPORTUNITIES		Opportunities to align joint venture interests across PNG projectsOptimise portfolio to further strengthen balance sheet and high grade portfolio

Creates a regional champion of size and scale A

A Creates a regional champion

MergeCo would become the largest ASX-listed O&G company and can leverage its scale and operating capability across procurement, marketing and trading to be competitive against global peers

MergeCo would become the largest ASX-listed O&G company

Sources: FactSet, IRESS, Company filings. Market Data as at 30 July 2021. Assumes AUDUSD = 0.75

Notes: (1) Enterprise value excludes lease liabilities and financial derivatives. Santos, Oil Search, and Beach net debt as at 30 June 2021. Woodside net debt as at 31 December 2020; (2) Mid-point of latest company guidance. Santos Ltd

A MergeCo would benchmark against global O&G large-caps and the S&P/ASX-20

The combined group would be positioned within the S&P ASX-20 index and the top 20 largest global O&G companies

Top 20 largest global O&G players – Market Cap (US$bn)

Positioned within the S&P/ASX-20(1) – Market Cap (US$bn)

Source: FactSet, IRESS. Market data as at 30 July 2021 Notes: (1) ASX-20 Index ("XTL") as per IRESS at 30 July 2021.

Santos Ltd

Diversified portfolio of long-life, low-cost assets with growth options B

Diversified portfolio of long-life, low-cost assets B

MergeCo would have multiple independent sources of low-cost cash flows making it resilient throughout the oil price cycle. MergeCo's operated footprint across all major assets would allow it to control development timelines and maximise value.

Alaska

• • Large scale oil development with upside and low emissions intensity
• • Leveraging existing infrastructure

Engineering Office Offshore Northern Territory

• • Barossa provides low cost backfill of DLNG
• • Potential to re-purpose Bayu-Undan to CCS hub
• • Backfill and expansion opportunity

West Australia

• • Leading domestic gas supplier
• • High value liquids revenue
• • Major growth upside with Dorado and Bedout basin exploration
• • Exploring CCS opportunities

PNG

• • Tier 1 asset with backfill opportunities to maximise value
• • Growth through Papua LNG
• • Operated oil assets
• • Strong community relationships

Onshore Australia

• • Supplying LNG and domestic gas markets
• • Major growth potential in NT shale supports GLNG or DLNG backfill or DLNG expansion
• • Scalable Moomba CCS opportunity
• • Growth through Narrabri development
• • Liquids export via Port Bonython

High quality portfolio of long-life assets B

Diversified portfolio providing a platform for sustainable growth and shareholder returns

Sources: 2020 Santos and Oil Search Annual Reports Notes: (1) Reserves & Resources as at 31 December 2020.

Diversified across LNG, domestic gas and liquids B

Multiple pricing benchmarks provide price diversification while fixed price CPI-linked sales contracts and tolling revenue would create a natural hedge that can provide sustained cash flows through the oil price cycle with uncapped upside

Strong balance sheet and investment grade funding platform C

MergeCo provides a strong balance sheet & funding platform C

MergeCo's diverse asset portfolio, balanced commodity price exposure and investment grade credit rating make it resilient to commodity price shocks and interruptions at individual assets

• MergeCo is resilient to commodity price shocks and asset level interruptions
• Strong balance sheet with >US$5.5bn of liquidity to fund near term growth projects
• Investment grade credit rating and strong ESG performance facilitate lower cost of capital

D MergeCo could realise substantial potential synergies

MergeCo is well positioned to benefit from operational and corporate synergies

D Proven track record of delivering integration synergies

Delivered more than $160 million in synergies from the Quadrant and ConocoPhillips transactions. Substantial potential combination synergies expected from the Oil Search merger

Quadrant integration pre-tax synergies

20%

US$50-60m synergies delivered through:

• • Gas marketing and operational efficiencies
• • Removal of non-operated duplication for WA gas assets
• • Reduced corporate costs by consolidating Perth offices, support functions, IT costs and insurance

ConocoPhillips AW integration pre-tax synergies

More than US$100m synergies delivered through:

• • Significant reductions in corporate and IT costs from global parent and local office
• • Optimisation of maintenance activities across operations
• • Restructured to an integrated organisation

MergeCo would provide flexibility for portfolio optimisation E

MergeCo would have the opportunity to optimise portfolio balance and project timing through the lens of capital efficiency and risk allocation

E Papua New Guinea opportunities

MergeCo would hold an enhanced position in the world-class PNG LNG project and create better alignment between this foundation project and Papua LNG, supporting Papua FID, jobs growth and long term revenue for PNG and its people

		Would better align equity interests across PNGLNG and Papua LNG facilitating progress to FID	PNG LNG	Papua LNG
Keybenefits		Potential opportunity to further optimiseownership across PNG LNG and Papua LNG	42.5%	17.7%
		Supports alignment on backfill resources for PNGLNG enhancing value for all parties	33.2%	28.7%
		Both Santos and Oil Search have strong existingrelationships with PNG government and KumulPetroleum	-	31.1%
Sociallicense		Opportunity to build on existing relationship forfuture collaboration	19.6%	22.5%
		Strong Australian-PNG government relationshipOil Search Foundation, Port Moresby Office	4.7%	-

Potential for additional value to be unlocked in midstream E

MergeCo would have a unique portfolio of midstream infrastructure assets with long term stable cash flows without commodity price risk

Backdrop of unprecedented appetite for infrastructure assets

• Total Energies' recent GLNG infrastructure deal implies an ~US$820 million value for Santos' 30% interest
• MergeCo's diverse portfolio with long term, stable cash flows is expected to be attractive to infrastructure investors
• Opportunity to expand Midstream business with growth portfolio, non-operated assets and low carbon business
• Leverages proven track record as operator and investment grade credit rating

Disclaimer and important notice

The proposed merger of Santos and Oil Search outlined in this presentation (Proposal) is non-binding and indicative only and is subject to due diligence and the agreement of a binding Merger Implementation Agreement. There is no certainty that a binding transaction will result from the Proposal. In addition, any binding Merger Implementation Agreement entered into between the parties would be subject to a number of additional conditions to completion of the merger, such as regulatory approvals.

This presentation contains forward looking statements that are subject to risk factors, including those associated with the oil and gas industry as well as those in connection with the Proposal. It is believed that the expectations reflected in these statements are reasonable, but they may be affected by a range of variables which could cause actual results or trends to differ materially, including but not limited to: price fluctuations, actual demand, currency fluctuations, geotechnical factors, drilling and production results, gas commercialisation, development progress, operating results, engineering estimates, reserve estimates, loss of market, industry competition, environmental risks, physical risks, legislative, fiscal and regulatory developments, economic and financial markets conditions in various countries, approvals and cost estimates.

All references to dollars, cents or $ in this document are to United States currency, unless otherwise stated. The symbol "~" means approximately

Underlying profit, EBITDAX (earnings before interest, tax, depreciation, depletion, exploration, evaluation and impairment) and free cash flow (operating cash flows, less investing cash flows net of acquisitions and disposals and major growth capex, less lease liability payments) are non-IFRS measures that are presented to provide an understanding of the performance of Santos' operations. The non-IFRS financial information is unaudited however the numbers have been extracted from the audited financial statements. Free cash flow breakeven is the average annual oil price at which cash flows from operating activities (before hedging) equals cash flows from investing activities. Forecast methodology uses corporate assumptions. Excludes one-off restructuring and redundancy costs, costs associated with asset divestitures and acquisitions, major growth capex and lease liability payments.

The information set out in this presentation does not take into account any person's individual financial objectives or circumstances.

Disclaimer and important notice

The estimates of petroleum reserves and contingent resources (other than pro-forma statements incorporating Oil Search reserves and contingent resources) contained in this presentation are as at 31 December 2020, as contained in the Santos 2020 Annual Report. Santos is not aware of any new information or data that materially affects the estimates of its reserves and contingent resources and the material assumptions and technical parameters underpinning the estimates continue to apply and have not materially changed.

Santos prepares its petroleum reserves and contingent resources estimates in accordance with the 2018 Petroleum Resources Management System (PRMS) sponsored by the Society of Petroleum Engineers (SPE). Unless otherwise stated, all references to petroleum reserves and contingent resources quantities in this presentation are Santos' net share. Reference points for Santos' petroleum reserves and production are defined points within Santos' operations where normal exploration and production business ceases, and quantities of produced product are measured under defined conditions prior to custody transfer. Fuel, flare and vent consumed to the reference points are excluded. Petroleum reserves are aggregated by arithmetic summation by category and as a result, proved reserves may be a very conservative estimate due to the portfolio effects of arithmetic summation. Petroleum reserves are typically prepared by deterministic methods with support from probabilistic methods. Petroleum reserves replacement ratio is the ratio of the change in petroleum reserves (excluding production) divided by production. Organic reserves replacement ratio excludes net acquisitions and divestments. Conversion factors: 1PJ of sales gas and ethane equals 171,937 boe; 1 tonne of LPG equals 8.458 boe; 1 barrel of condensate equals 0.935 boe; 1 barrel of crude oil equals 1 boe.