DECOMMISSIONING

Why are we decommissioning?

Gas production from the wells was shut in on the 5th of July 2020 when all the gas reserves in the various fields were depleted. All of the gas production wells have now been permanently plugged with cement and the associated facilities (platforms, pipelines, cables, subsea structures and onshore terminal) are also being decommissioned.


What is the Decommissioning Project?

Kinsale Energy has developed a comprehensive plan to decommission all of the Kinsale Area gas fields. The offshore decommissioning activities are expected to be completed by 2023, having commenced in
July 2020. The onshore works at Inch Terminal works will occur over a much shorter period (less than 6 months) during 2022.

You can read more about our preparations and planning for the Decommissioning project HERE


Decommissioning Consent Application

In June 2018, Kinsale Energy applied to the Minister for Communications, Climate Action and Environment for approval of Decommissioning Plans for some of the facilities in the Kinsale Head and Seven Heads gas fields, including:

– Platform and Subsea Well Abandonments
– Platform Topside
– Subsea Infrastructure

The following Consent Application documents are available on the website:

Decommissioning Plan – Kinsale Head

Decommissioning Plan – Seven Heads

Environmental Impact Assessment Report:
Vol 1 Non-Technical Summary
Vol 2 Main Report Sections 1-9
Vol 3 Main Report Appendices Parts 1 & 2

Appropriate Assessment Screening Report

A Request for Further Information in relation to the Consent Application was received from the Department of Communications, Climate Action and Environment (DCCAE) on 24th Sept. 2018. Kinsale Energy have prepared a comprehensive response to this request and this was submitted to DCCAE on 14th November 2018. The response documents can be viewed below:

Response to Request for Further Information

Draft Environmental Management Plan

Draft Resource and Waste Management Plan

The Department of Communications, Climate Action & Environment (DCCAE) issued approval of Consent Application No 1 to Kinsale Energy on 26th April 2019 and the approval letters can be viewed below. The approvals for both the Kinsale Head Gas field and the Seven Heads Gas field contain a number of conditions in relation to reporting, environmental management and so on and these conditions will be incorporated in the planning for the decommissioning project.

Kinsale Head Plan of Development

Kinsale Head Screening Determination for Appropriate Assessment

Seven Heads Plan of Development

Seven Heads Screening Determination for Appropriate Assessment

In August 2019, KEL submitted a further application to DCCAE in respect of removal of the Kinsale Alpha and Kinsale Bravo platform sub-structures or jackets (Consent Application No 2) – this application covers complete removal of the jackets down to seabed level. The application is accompanied by supplementary documents (addenda) to the Environmental Impact Assessment Report (EIAR) and Appropriate Assessment Screening Report to highlight any updates to the previously approved documents.
The additional documents can be viewed below:

Decommissioning Plan – Consent Application

EIAR Addendum

AA Screening Report Addendum

The Department of Communications, Climate Action & Environment (DCCAE) issued approval of Consent Application No 2 to Kinsale Energy on 26th Feb. 2020. This approval also contains a number of conditions in relation to reporting, environmental management and so on and as for the conditions associated with Consent Application No1 these conditions will be incorporated in the planning for the decommissioning project.

The approval letters from DCCAE can be viewed below:

Determination on Kinsale Decommissioning Plan

Determination on Kinsale AA Screening

October 2021 Submissions in relation to Subsea Pipelines & Umbilical’s:

In October 2021, further Consent Applications were submitted to the Department of the Environment, Climate & Communications (DECC) and to the Environmental Protection Agency (EPA) in respect of the subsea pipelines and umbilical’s for the Kinsale Head, Ballycotton and Seven Heads gas fields. These applications are for the retention of the existing pipelines and umbilical’s in-situ on the seabed and for the installation of protective materials (rock berms) to guard against any snagging hazards which might pose a risk to fishing activity.

The applications are accompanied by supplementary documents (addenda) to the Environmental Impact Assessment Report (EIAR) and Appropriate Assessment Screening Report to highlight any updates to the previously approved documents.

Petroleum and Other Minerals Development Act/Continental Shelf Act submissions:

The following Consent Application documents were submitted to DECC on 13th October 2021 and can be viewed at the links below:

Decommissioning Plan – Kinsale Head Petroleum Lease (OPL1) – Consent Application No.3

Decommissioning Plan – Seven Heads Petroleum Lease – Consent Application No 2

Kinsale Area Decommissioning Project – EIAR Addendum No 2

Kinsale Area Decommissioning Project – AA Screening and Article 12 Assessment Screening Addendum No 2

Further Information submission to DECC

Further information in relation to surveys to be carried out as part of the proposed rock placement program was submitted to DECC on 28th January 2022. The documents can be viewed at the links below:

Addendum to AA Screening and Article 12 Assessment

Addendum to EIAR

Pre and post rock placement Fisheries Assessment

Approval from the Dept. of Environment, Climate and Communications (DECC) in relation to these applications was received on 16th Dec. 2022.

Click here to view


Dumping at Sea Act submissions:

The documents listed below were submitted to the Environmental Protection Agency (EPA) on Oct. 20th 2021 – these are for permission under the Dumping at Sea Act 1996 (as amended):

Kinsale Head DAS Application Form and Attachments

Seven Heads DAS Application Form and Attachments

Kinsale Area Decommissioning Project – EIAR Addendum No 2

Kinsale Area Decommissioning Project – AA Screening and Article 12 Assessment Screening Addendum No 2

These may be read in conjunction with the Project EIAR at the link shown under Decommissioning Consent Applications above.

The applications under the Dumping at Sea Act were approved by the Environmental Protection Agency (EPA) on 16th Feb. 2023 and Dumping at Sea permits were issued for the Kinsale Head and Seven Heads pipelines and umbilical’s – see links below:

Kinsale Head: 090151b2808651c5.pdf (epa.ie)

Seven Heads: 090151b2808651ca.pdf (epa.ie)


Decommissioning Activities

2021

The final gas production from the fields occurred on 5th July 2020 and since then we have completed a significant program of facilities decommissioning and removal. This has included the mobilisation of a specialised well intervention unit – a Hydraulic Workover Unit – and the installation of temporary accommodation modules on the Bravo platform, which had been unmanned since 2000. Offshore activities continued during 2021 and a substantial program of works was completed by November 2021 – highlights include:

Well Plugging – there are 7 wells on each platform which were all drilled in the late 1970’s and had been operating continuously since then – their production equipment have now been removed and the wellbores have been filled with cement to ensure they are sealed for posterity. Following removal of the platforms in 2022, there is no trace of these wells remaining on the seabed.

Subsea Well Plugging – in addition to the platforms, there are production facilities installed underwater on the seabed, as all of the smaller satellite fields developed between 1990 and 2003 utilised subsea technology. There are 10 subsea wells, which have been plugged with cement, like the platform wells – a specialised rig, the “Stena Spey” was used for this purpose and the work is was completed in November 2021.

Subsea Infrastructure Removal – in addition to plugging and sealing the subsea wellbores, a large amount of infrastructure on the seabed has been removed – for example, steel and concrete protection structures, valve assemblies, piping manifolds and the like. A specialised marine contractor – Technip FMC – completed this work in 2 separate campaigns in May and August 2021, utilising a Dive Support Vessel (DSV) and a Construction Support Vessel (CSV). The equipment recovered has been taken to dismantling locations for eventual disassembly and recycling.

2022

The main activity undertaken in 2022 was the final removal of the two platform structures – Alpha and Bravo. This was undertaken by a floating crane vessel, the “Thialf”, one of the largest crane vessels in the world, which is operated by Heerema Marine Contractors of the Netherlands. As described below, the platforms have now been removed from their offshore location and have been transported to a dismantling yard in Vlissingen in the Netherlands for disassembly and eventual recycling.

Platform Removal

The first big milestone in the removal of the offshore platforms was achieved on June 1st – the Bravo topsides was removed in one lift by the THIALF from the jacket structure and transferred to the transport barge – the photos below tell the story.

Rigging on – Ready to lift:

Topsides lift-off:

Subsequent to removal of the topsides, the supporting structure – the jacket – was removed by cutting and recovering the upper section and then removing the foundation sections.

The entire process was then repeated for the Alpha platform and the crane barge completed operations and departed mid-Sept.

The weight of the topsides was 2,755 tonnes (the two accommodation blocks weighing 680 tonnes having been removed previously) and the upper jacket was a further heavy lift of 3,460 tonnes, making these some of the largest crane lifts ever carried out in Ireland.

Inch Terminal

Inch Terminal, located in East Cork was also decommissioned by May 2022, which involved the removal of all mechanical and process equipment from the site. The telecommunications tower remains in use as it supports a number of mobile phone providers.

2023

The final decommissioning activities are planned to occur in 2023 – these are:

Post-decommissioning surveys

A number of surveys will be carried out on the sites of decommissioned facilities and pipelines to identify any debris or pipeline spans which might be hazardous to fishing or marine activities in the future. The results of these surveys will be used to plan the final site clearance and rock placement activities. A number of sediment samples will also be taken to confirm that no contamination has occurred during the decommissioning program.

Debris removal and site clearance

A Construction Support Vessel (CSV), the “Dina Star” operated by Deep Ocean Subsea Services will undertake a campaign to remove any debris identified during the clearance surveys.

Placement of protective rock-berms on subsea pipelines and umbilical’s being left in-situ

A specialised rock placement vessel the “Flintstone” operated by DEME bv, will place specially engineered rock berms at the ends of all subsea pipelines and in any areas where pipeline free-spans have occurred, which could be hazardous to fishing activity.

A post-decommissioning monitoring program will be put in place to ensure that no further protective measures are needed in the future.

These works will mark the end of a significant program of works lasting from 2020 which has been carried out safely and effectively with no significant environmental issues being recorded.

Decommissioning – Highlights

Gas Production Finished: July 2020
Platforms De-manned: August 2021
Platforms Removed: Sept. 2022
Works Complete: Sept. 2023
No. of Wells Plugged and Abandoned: 24
Tonnage of Material Removed: 28,000 tonnes
Percentage Material Reused/Recycled – Target: >90%
Manhours expended (March ’23): 1,600, 000
Number of Offshore Vessels Used: 36