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. The wells will now be permanently plugged with cement and the associated facilities (platforms, pipelines, cables, subsea structures and onshore terminal) will be 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 occur over a period of 2-3 years, commencing in July 2020. The onshore works at Inch Terminal works will occur over a much shorter period (less than 6 months).

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 Gasfield and the Seven Heads Gasfield 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

 

Decommissioning – 2021 Activities

The final gas production from the fields occurred on 5th July 2020 and since then we have been preparing the facilities for the final stages of decommissioning and removal. This has included the mobilisation of a specialised well intervention unit – a Hydraulic Workover Unit – and the installation of accommodation modules on the Bravo platform, which had been unmanned since 2000. These preparations are now complete and the final decommissioning of the platforms and subsea wells are ongoing and will be completed during 2021, which is going to be a very busy year offshore – highlights will include:

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

Platform “Cold-Stacking” – it is anticipated that all of the wells will be plugged by mid-2021 and following this the platform systems will be wound down in preparation for the final de-manning of the platforms. Solar powered warning lights will be installed and the now unused platforms will be left “cold-stacked” until they are removed by a specialist removal contractor in 2022.

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 must all be plugged with cement, like the platform wells – a specialised rig, the “Stena Spey” will be used for this purpose and this is due to commence work in early April. The rig is anchored over each well location and is supported by a number of service vessels for anchor handling, equipment supply etc. This campaign will run until Sept – Oct.

 

Stena Spey

 

Stena Spey Anchor Handler

 

Subsea Infrastructure Removal - in addition to plugging and sealing the subsea wellbores, there is a large amount of infrastructure on the seabed which must be removed – for example, steel and concrete protection structures, valve assemblies, piping manifolds and the like. A specialised marine contractor – Technip FMC – will do 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 will be taken to dismantling locations for eventual disassembly and recycling.

Deep Discoverer

North Sea Giant

 

Decommissioning – Future Activities

The main activity remaining for 2022 will be the final removal of the two platforms – Alpha and Bravo. This will be undertaken by a very large crane vessel “Thialf” operated by one the world’s leading heavy-lift contractors – Heerema Marine Construction – of the Netherlands. The platforms will have their upper sections (topsides) removed initially, followed by the lower sections – they will be transported to a dismantling yard in Europe for disassembly.

 

Thialf



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