Harbour Energy : Financial Report document (ospar report 2025 for website)

Harbour Energy plc

UK NORTH SEA REGION

Annual Environmental Statement 2025

INTRODUCTION 2

OUR UK NORTH SEA PORTFOLIO 4

Our operated assets 5

Production operations 5

Operated by others 6

Our drilling rig activities 6

Decommissioning 7

ENVIRONMENTAL PERFORMANCE 8

Atmospheric emissions 8

Greenhouse gas (GHG) emissions 8

Other atmospheric emissions 9

Oil discharges to sea 10

Chemical discharges 12

Waste 14

Spills to sea 15

APPENDIX 16

2025 environmental objectives 16

2026 environmental objectives 17

HSES policy documents 18

This is the annual environmental statement for Harbour Energy plc for 2025, as required by OSPAR Recommendation 2003/5[1]. The statement covers offshore installations operated by the company in the UK North Sea and installations owned by third parties while providing services to us.

Harbour Energy was founded in 2014 and has grown by acquisition. Across our diversified portfolio of interests, we have around 3,200 employees. Production averaged 474 kboepd during 2025, split c.40 per cent liquids, c.40 per cent European natural gas and c.20 per cent other natural gas. The 84 per cent increase versus 2024 reflects a full year's contribution from the Wintershall Dea assets acquired in 2024, including 169 kboepd from Norway and 73 kboepd from Argentina. The UK averaged 155 kboepd in 2025.

This report contains the environmental performance for Harbour's activities in the UK North Sea region in 2025. The report aims to:

• describe our main assets and activities

• provide a brief overview of our environmental management

• provide details on key environmental aspects and their impact, and

• summarise our UK environmental performance and progress against objectives for the year

  [1] To fulfil the requirements of OSPAR Recommendation 2003/5, all operators of offshore installations on the United Kingdom Continental Shelf (UKCS) are required to produce an annual environmental statement which is made available to the public and the Department for Energy Security and Net Zero (DESNZ).

  ENVIRONMENTAL IMPACTS

  Harbour is committed to addressing the environmental impact of our operations and playing a role in the transition to a lower carbon economy.

  We aim to achieve our goal of no damage to the environment by:

• systematically identifying environmental impacts and seeking to avoid or minimise them

• improving environmental performance, including reducing our GHG emissions, and

• putting plans in place to reduce environmental risks associated with our projects and operations

  ENVIRONMENTAL MANAGEMENT

  We conduct our operations in such a way as not to harm people and to minimise any impact on the environment. This is enacted by our Health, Safety, Environment and Security Policy (see HSES policy documents in Appendix).

  Our UK Environmental Management System (EMS) is certified to ISO standard 14001:2015. Our external verification body carries out regular site visits to verify we are meeting the objectives of our management system.

  We apply the EMS to manage the impacts of any activities, products and services on the environment. It provides a structured approach for continuous planning, implementing, reviewing and improving environmental protection measures, and working towards increasing environmental sustainability.

  CLIMATE CHANGE AND ENERGY TRANSITION

  Harbour aspires to achieve net zero for our gross operated Scope 1 and 2 CO2e emissions by 2050, with an interim target of a 50 per cent reduction versus a 2018 baseline by 2030. In addition, we have set ourselves the target to achieve zero routine flaring

  by 2030. In 2025 we achieved our methane intensity target of less than 0.2 per cent across our operated sites.

  Our priority is to additionally reduce emissions through our emissions reduction action plans (ERAPs) as well as safely and responsibly decommissioning assets as they reach the end of their commercial life. We reviewed our ERAPs regularly throughout 2025 to ensure that the decarbonisation activities were progressing as planned and to update them with newly identified opportunities. This ensured that our reduction plans were up to date and integrated with the business plan as detailed in the objectives for 2025.

  In addition, Harbour has a leading CO2 storage position in Europe and the UK with net storage resources in excess of 880 million tonnes of CO2, where we are seeking to deploy our skills

  and utilise existing infrastructure to build a competitive business. In 2025, we continued to progress our most advantaged Carbon Capture and Storage (CCS) projects, including our operated Viking project in the UK.

  FOR MORE INFORMATION

  2025 Annual Report & Accounts

  
  
  

  Net

  zero

  aspiration

  For our gross operated Scope 1

  and 2 emissions

  2018 2025 2030 2050

  50%

  Reduction in our Scope 1 and 2 gross operated emissions vs 2018

  Zero

  Routine flaring

  <0.2%

  Methane emissions intensity across our operated sites

Harbour Energy plc

UK North Sea Region

3

2025 Annual Environmental Statement

Southern North Sea

East Irish Sea

Tolmount Area

Rivers Terminal

Teesside

Kerse of Kinneil

J-Area

Elgin/ Franklin

Catcher Area

Aberdeen

St Fergus

AELE Hub

Greater Britannia Area

Buzzard

Beryl

Solan

Sullom Voe

Schiehallion

Clair

We work hard to maximise the value from our existing UK North Sea portfolio, investing in short cycle, high return opportunities to add reserves, improve recovery and extend field life while continuing to generate material free cash flow.

Our UK offshore operated assets include:

• The Production Operations Centre comprising: J-Area (Judy, Jade, Jasmine and Joanne) and Greater Britannia Area (GBA) (Britannia and subsea tiebacks Enochdhu, Callanish, Brodgar and Alder), Armada, Everest, Lomond (and Erskine) (AELE), Solan

• The Operated by Others (OBO) Operations Centre comprising: Catcher Area, Tolmount Area and East Irish Sea (EIS)

Harbour has ongoing decommissioning activities in the East Irish Sea, Southern and Central North Sea, and West of Shetland.

Harbour's Production Operations Centre consists of the operated hubs of J-Area, GBA, AELE and Solan.

Judy, Joanne and Jasmine are located in Block 30/07a of the Central North Sea (CNS). Jade is located in Block 30/02c. In 2024, the Talbot field was tied-back to Judy, Talbot is located in Block 30/13e. Talbot, Jade, Joanne and Jasmine export gas and liquids via the

Judy platform. Commercial oil and gas sales from J-Area began in 1997. Gas from the J-Area is transported through the Central Area Transmission System (CATS) pipeline and liquids are transported to Teesside through the Norpipe system.

Britannia is in Block 16/26 of the CNS. Britannia satellites - Brodgar, Callanish and Enochdhu subsea developments - are controlled from Britannia. Condensate is exported through the Forties Pipeline System to the Kerse of Kinneil processing plant near Grangemouth. Gas is exported via a dedicated Britannia pipeline to the Scottish Area Gas Evacuation (SAGE) facility at St Fergus.

Armada is in Block 22/5b, North Everest is in Block 22/10a and Lomond in 23/21a of the CNS. First production was achieved from the assets in 1997, 1993 and 1993 respectively. Production from Armada, North Everest and Lomond is exported via the Forties Pipeline System to the Kerse of Kinneil processing plant near Grangemouth. Gas is exported via the CATS pipeline to Teesside.

Solan is located in Block 205/26a of the CNS. First production was achieved in 2016. Oil from Solan is produced into a 300,000-barrel subsea storage tank and offloaded via shuttle tankers. Cessation of production (CoP) was completed for Solan in April 2025, following CoP the platform underwent a flushing, cleaning and disconnection programme to reach hydrocarbon safe status. The Solan platform removal is planned for 2026.

Harbour Energy plc

UK North Sea Region

5

2025 Annual Environmental Statement

Harbour's Operated by Others Centre consists of the non-operated Catcher Area, Tolmount Area and the East Irish Sea.

The Catcher Area Development is located in Block 28/9 of the CNS. The subsea wells from the Catcher, Varadero and Burgman fields are tied back to a floating production, storage and offloading vessel (FPSO). BW Offshore Catcher UK Limited (BWOCUK) is

the owner of the FPSO and the appointed production installation operator. They are responsible for the day-to-day health, safety and environmental management of the facility including all environmental permitting requirements for production operations including the Pollution, Prevention and Control (PPC), chemical and oil discharge permits.

Harbour is the licensee, pipeline and well operator for the Catcher Area development. We are responsible for the FPSO's GHG Emissions Trading System (ETS) permit, and the flare and vent consents. The data presented in this report relates to our activities for the Catcher Area development.

The Tolmount field is located in Block 42/28d in the southern North Sea (SNS). Tolmount is a minimum facilities platform, which exports gas via a 20-inch pipeline to the Easington Terminal. ODE Asset Management Limited is the Tolmount installation operator and reports on environmental performance.

Harbour has a 100 per cent equity interest in EIS assets comprising the fields of Calder, Millom and Dalton, and the Rivers Terminal at Barrow-in-Furness. Spirit Energy operates the Calder asset and Rivers terminal at Barrow in Furness under contract. The environmental performance of these is reported by Spirit Energy for 2025. Millom and Dalton are being decommissioned.

VALARIS 92

In 2025, the Valaris 92 drilling rig successfully completed the Southern North Sea (SNS) abandonment campaign, by carrying out the last four well abandonments at: NW Bell, Rita 44/22a-12, Johnston 43/27-1 and the Hunter Production well 44/23a-12z. This brings the total number of wells that have been abandoned to 149 during this plug and abandonment campaign. The rig departed the SNS in Q3 2025.

VALARIS 120

In 2025, the Valaris 120 drilling rig continued to support Harbour's planned operations at the Judy Riser platform (JRP), completing the drilling of Jocelyn South in Q1 2025. Jocelyn South achieved first production in Q1 2025.

Two further development wells at the JRP were also drilled and completed in 2025 by the Valaris 120: Judy North (R4) and Judy East Flank (R5). The Judy North (R4) well came on stream Q3 2025 and Judy East Flank (R5) in Q4 2025. The rig departed the JRP in Q4 2025.

PAUL B. LOYD JR (PBLJ)

The PBLJ semi-submersible mobile offshore drilling unit continued to support Harbour operations by undertaking drilling, plug and abandonment and well intervention operations in 2025.

Drilling operations at the Brodgar H5 subsea development well were successfully completed in Q2, with first production also in Q2. An abandonment campaign at Caledonia 16/26-25 (Q2) and Nicol (Q3) was then completed before the rig underwent its five-yearly maintenance programme in Norway. After a comprehensive work scope the rig returned to Harbour towards the end of Q3

to carry out two further work scopes in 2025. This included a well abandonment at Caledonia 16/26-30Y, followed by an acid stimulation workover at the Joanne subsea manifold.

NOBLE INTREPID

The Noble Intrepid was used in accommodation mode to support the Talbot tie-in operations throughout 2024 and the rig departed the Judy Platform in Q1 2025.

Our decommissioning activities in the SNS continued throughout 2025. By the end of 2025, we had removed a total of 38 platforms from the SNS. A further four subsea wells were successfully plugged and abandoned, completing our SNS campaign with 149 wells since 2014.

The Solan asset ceased production in April 2025, and following a successful flushing, cleaning and disconnection campaign, the

asset was cold-stacked in September 2025. Additionally, the Boka Da Vinci Dive Support Vessel (DSV) carried out decommissioning activities as part of the cold-stack, including removal of parts of the subsea infrastructure.

In 2025, work continued at the Balmoral, Brenda, Glamis, Stirling, Caldonia and Nicol fields (B-Block) in preparation for future plug and abandonment activities as well as recovery of parts of the subsea infrastructure.

The Decommissioning Programme and associated Environmental Appraisal and Comparative Assessment were approved in August 2025.

Harbour Energy plc

UK North Sea Region

7

2025 Annual Environmental Statement

The main source of atmospheric emissions from our operations are from the combustion of fuels (gas and diesel) for electrical power generation, compression of gas, and export of oil to shore. A small quantity of reservoir gas provides the primary fuel source, and we use diesel as a back-up.

Flaring and venting emissions are associated with routine maintenance activities, equipment and plant trips plus shutdown and start-up activities, whilst maintaining a safe route to disposal in the event of an emergency scenario. Flaring and venting is restricted to the minimum required for the safe operation of the installations.

Atmospheric emissions from well operations are mainly associated with running diesel-driven engines for rig power generation. Flaring is also undertaken to remove hydrocarbons produced during well testing and clean-up operations.

The Offshore Combustion Installations (Pollution Prevention and Control) Regulations 2013 (as amended) (PPC) regulate

NMVOC(t)

SOx(t)

N20(t)

CH4(t)

CO(t)

NOx(t)

North Everest

Lomond

Judy

Britannia

Armada

0

200

400

600

800

1000

1200

1400

PPC emissions from operations, 2025

1600

atmospheric emissions (except for CO2) from offshore oil and gas facilities. Armada, Lomond, North Everest, Judy and Britannia hold PPC permits, with specific limit values for methane (CH4), sulphur oxides (SOX), nitrous oxide (N2O), carbon monoxide (CO) and non-methane volatile organic compounds (NMVOC). The quantities of gases emitted to air are calculated based on fuel gas and diesel consumption data on each installation and agreed emissions factors. Throughout 2025, our operations remained within all PPC permit limits.

We present no PPC emissions for the Catcher FPSO.

This data will be reported by the operator in their 2025 annual environmental statement. Solan, Jade and Jasmine are below the PPC requirement threshold and are therefore not eligible for a PPC permit.

The primary GHGs in the Earth's atmosphere are water vapour, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ozone (O3).

Tonnes of pollutant

The emission of CO2 is governed under the United Kingdom (UK) Emissions Trading System (ETS) which launched on 1 January 2021. As part of the UK ETS, Harbour's qualifying offshore installations (Armada, Lomond, North Everest, Britannia, Judy, Solan and Catcher) hold GHG emissions permits, which authorise them to emit CO2 from the combustion of fuels.

Atmospheric emissions from Jade, Jasmine, plug and abandonment and rig-based activities are not reportable under the UK ETS, but they are included in our environmental metric reporting as Other CO2 (non-UK ETS).

CO2 emissions from operations, 2025

450000

20000

300000

10000

150000

0

0

Fuel

Flare

Diesel

Other

UK ETS Reportable tCO2

Armada

Britannia

Catcher

Judy

Lomond

North Everest

Solan

Jade

Jasmine

Noble Intrepid

Paul B. Loyd,Jnr

Valaris 92

Valaris 120

Non-UK ETS Reportable tCO2

Harbour Energy plc

UK North Sea Region

9

2025 Annual Environmental Statement

‌INTRODUCTION

OUR NORTH SEA PORTFOLIO

The OSPAR Commission recommendations are regulated through the Offshore Petroleum Activities (Oil Pollution Prevention and Control) Regulations 2005 (as amended) (OPPC).

Water produced alongside oil and gas operations, known as produced water, contains dispersed oil which we treat to

reduce concentration of oil in water to permitted levels, before discharging it to the marine environment. Produced water is one of the largest sources of hydrocarbon discharges to the sea from the offshore oil and gas industry. While there are treatment systems in place offshore to separate oil from the

produced water, the discharge still has some residual oil content. Our installations discharge only a small percentage of the total produced water generated by the industry.

The Armada and North Everest platforms have single discharge points for produced water, while Lomond (and Erskine via Erskine Production Module (EPM)), Judy (and the Judy riser platform (JRP)) and Britannia (and the Britannia bridge-linked platform (BLP)) each have two permitted discharge points.

Solan has a bespoke produced water treatment package, however water rates were so low in 2025 that this operated below its turndown rate. Instead, ballast water from oil displacement within the subsea oil storage tank (SOST) was discharged or reinjected once treated through the dedicated ballast water filters.

Short-duration (term) OPPC permits were in place to support the Valaris 120 and PBLJ well operations and various DSVs for subsea work scopes.

The quantity of oil discharged to sea under permitted conditions for 2025 is illustrated for all operated installations in relation

to the total permitted quantity. The quantity of oil discharged depends on the volume of produced water discharged and its associated concentration.

All assets remained within their annual consented limit with the exception of Armada. The cumulation of all events throughout the year resulted in Armada exceeding the annual maximum

oil discharge limit.

The Production Operations centre reported 89 produced water discharge OPPC non-compliance events in 2025. Of these, 21 were with respect to the OPPC maximum monthly flow-weighted average concentration of oil per litre of water (mg/l) exceeding 30mg/l and 60 events were with respect to the concentration of individual oil in produced-water samples exceeding 100mg/l OPPC

permit limit. A further seven OPPC non-compliances were reported under the category 'other' and include issues with the produced water meters on Lomond and Britannia, missed samples and a missed monthly calibration validation check, late submission of reports, and a sheen observed during the flushing and cleaning following of Solan during CoP activities.

UK North Sea Region

2025 Annual Environmental Statement 11

Harbour Energy plc

Various chemicals are used offshore in drilling, production, subsea and well intervention operations.

Any chemical used offshore must first be approved by the Centre for Environment, Fisheries and Aquatic Sciences (CEFAS) in

line with the Offshore Chemical Regulations (OCR) 2022 (as amended). The chemicals are subject to strict environmental risk assessment and, once approved, their use is controlled and monitored through a permit granted by the Offshore Petroleum Regulator for Environment and Decommissioning (OPRED).

Some chemicals are regarded as PLONOR (PLO), which means that they have been determined to pose little or no risk to

Each platform holds a separate chemical permit, which includes justification for the use of chemicals that hold a substitution warning. We have presented the use in kgs of substitution versus non-substitution chemicals, with the percentage contribution to total use also provided.

Annual chemical use and discharge from operated production activities, 2025

Discharge

Use

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

SUB (kg) Non-SUB (kg)

Short-duration chemical permits were also in place in 2025 to support drilling activities, pipeline operations and decommissioning activities.

Drilling activities represent the largest chemical use and discharge, comprising drilling mud, cement, completion and additive chemicals.

Drilling activities included operations from the Valaris 120, the Noble Intrepid and the PBLJ. Operations from the Valaris 92 and Boka

Da Vinci are included within the decommissioning activities.

Annual chemical use and discharge from drilling activities, 2025

Discharge

Use

0%

10% 20% 30% 40% 50% 60% 70% 80%

90% 100%

SUB (kg)

Non-SUB (kg)

the environment.

Any chemicals which have been identified as posing potential environmental risks (such as bioaccumulation or slow biodegradation) are subject to controls, under which their use must first be approved by OPRED. This is backed up by detailed justification for use of the chemical. Such chemicals carry a 'substitution warning' (SUB) which aims to phase-out the use of these chemicals.

Chemical use and discharge in 2025 covered by pipeline chemical permits included two pipeline campaigns undertaken at Brodgar and the Norpipe Wye, where spools were replaced at the J-Area PL998 Wye into Norpipe.

Annual chemical use and discharge from pipeline activities, 2025

Discharge

Use

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

SUB (kg) Non-SUB (kg)

We present chemicals used for rig-based plug and abandonment and DSV scopes associated with our decommissioning under the chart for decommissioning. We minimised

discharges to the sea during pipeline cleaning operations by containment for onshore treatment and disposal wherever practicable.

Annual chemical use and discharge from decommissioning activities, 2025

Discharge

Use

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

SUB (kg) Non-SUB (kg)

We carry out frequent reviews of chemical requirements with our chemical suppliers and strive to reduce the number of chemicals flagged for substitution.

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2025 Annual Environmental Statement

Waste is categorised as hazardous or non-hazardous, dependent on whether the waste has one or more of the 15 hazardous constituents specified in Annex III of the EU revised Waste Framework Directive (WFD, European Directive 2008/98/EC).

Waste is divided into three main categories: recycled, non-hazardous and hazardous waste. We work with contract waste management companies to reduce waste, and to recycle and reuse items wherever possible. Non-hazardous waste types include packaging, galley and accommodation wastes, scrap metal and wood. Examples of hazardous waste include bulk liquid wastes from mobile accommodation or drilling units on hire, process sludges, oily rags, used chemicals, paint, batteries, fluorescent light tubes and electrical and electronic equipment.

Tonnes

Waste generated from our operated assets include Armada, Lomond, North Everest, Britannia, Judy, Jade, Jasmine and Solan.

High recyclable values for some assets below are associated with works where large amounts of metals and heavy recyclables are being removed or replaced. High hazardous waste figures relate to shutdown activities where large quantities of oily water, condensate and sludges were removed from vessels

and separators.

Waste generated from well operations and decommissioning includes the domestic and operational wastes from the Valaris 92, Valaris 120, Noble Intrepid and PBLJ. High hazardous waste figures comprise water-based slops, oil-based mud slops and high contaminated fluids which require onshore treatment.

In addition to the data reported in OPRED's Environmental and Emissions Monitoring System (EEMS) a further 1,009Te was associated with the decommissioning of Solan.

Quantity of regulatory reportable spills to sea (kg), 2025

1600

1400

1,509

1200

1000

800

600

400

200

351

0

PON1 Classification

Chemical (kg) Oil (kg)

Non-permitted releases of oil or chemicals to the sea are reported to OPRED using a Petroleum Operations Notice 1 (PON1).

These notices provide details of the event and actions taken to prevent reoccurrence. All spills to the sea are reported and investigated, regardless of size.

Across our operations, 28 unplanned releases to the sea occurred in 2025. Of these, 15 were chemical spills and 13 were oil spills. None of the spills to sea were over 1 tonne in 2025.

Number of regulatory reportable spills to sea, 2025

CNS

Decom

Recycling

Noble Intrepid

PBLJ

SNS

Decom

Solan Decom

Valaris 92

Valaris 120

Hazardous

Non-Hazardous

Waste disposal from drilling and decommissioning activities, 2025

6000

5000

4000

3000

2000

1000

0

Solan

North Everest

Lomond

Judy

Jasmine

Jade

Britannia

Armada

300,000

250,000

200,000

150,000

100,000

50,000

0

Waste disposal from operated production activities, 2025

Tonnes

Harbour Energy plc

UK North Sea Region

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2025 Annual Environmental Statement

We outlined several environmental focus and improvement areas in our 2025 Health, Safety, Environmental and Security (HSES) Plan. In 2025, we successfully completed the following objectives:

Our focus for 2026 is to ensure the continuation of safe and environmentally responsible activities.

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2025 Annual Environmental Statement

‌INTRODUCTION

OUR NORTH SEA PORTFOLIO

ENVIRONMENTAL PERFORMANCE APPENDIX

Our Health, Safety, Environment and Security (HSES) Policy is implemented through our Business Management System (BMS), which comprises a comprehensive set of standards and procedures that define our expectations and requirements for managing all our business activities.

Our Board established the Group's purpose, values and strategy, and is also responsible for our Environmental, Social and Governance (ESG) performance. It approves our Sustainability Policy and endorses the management of significant sustainability-related risks and opportunities.

For more information, or to see these policies, harbourenergy.com/about-us/our-policies.

UK North Sea Region

2025 Annual Environmental Statement 19

Harbour Energy plc

Harbour Energy plc

Health, Safety, Environment and

Security

Policy

Harbour Energy is committed to operating responsibly and securely, never compromising our Health, Safety, Environmental or Security (HSES) standards. Harbour Energy will do all that is reasonably practicable to reduce HSES risks, ensure the safety and security of everyone affected by our operations, protect the environment by minimising our environmental impacts, and protect our assets and business data.

To achieve this Harbour Energy will:

• Provide strong, visible leadership and commitment at all levels of the business

• Effectively identify hazards, threats and vulnerabilities to assess and manage risks

• Meet or surpass our legal and other requirements (e.g., compliance obligations)

• Set objectives and targets to drive improvement

• Support and train our people and assure their competence

• Provide appropriate resources

• Encourage open and honest communication

• Effectively manage the HSES risks associated with contracted work

• Maintain safe, clean, healthy and secure workplaces to protect our people, environment, assets and data

• Maintain protected high quality documented systems and processes;

• Plan and prepare for potential emergencies

• Report, investigate and learn from any incidents and near misses

• Routinely inspect the workplace and audit systems and processes;

• Seek opportunities to continually improve our performance

It is the responsibility of everyone in Harbour Energy to conform to our Policies and Standards and to assist the business in their implementation.

Linda Z Cook

CEO Harbour Energy Plc 01 December 2023

Health, Safety, Environment and Security Policy

Revision 2

harbourenergy.com

Registered office Harbour Energy plc 4th Floor Saltire Court 20 Castle Terrace Edinburgh

EH1 2EN

Registered No. SC234781

Head office

Harbour Energy plc

151 Buckingham Palace Road London

SW1W 9SZ

Tel: +44 (0)20 7730 1111