Decommissioning Insight 2015
7.2 Facilities and Pipeline Making Safe and Topside Preparation ‘Making safe’ activities must be carried out in line with environmental and safety considerations in preparation for removing a facility or decommissioning a pipeline. ‘Making safe’ of facilities includes cleaning, freeing equipment of hydrocarbons, disconnection and physical isolation, and waste management. The ‘making safe’ of pipelines involves depressurising the pipeline and removing any hydrocarbons. The pipeline will then be cleaned and purged, with the cleaning programme based on the specific needs of the system. This may involve pigs, which are maintenance tools used to clean or inspect the inside of pipelines. Pipelines ‘making safe’ is sometimes carried out alongside facilities ‘making safe’, particularly in the case of small topside and pipeline tiebacks. In these cases, the same team and some of the same equipment can be used for both activities. ‘Making safe’ can be carried out several years prior to removing a platform or decommissioning a pipeline, leaving them hydrocarbon free until the next phase of decommissioning. For facilities, the next phase involves separating the topsides and process and utilities modules, and carrying out appropriate engineering, such as installation of lift points to prepare for removal. The topside preparation required will depend on the removal method used. For pipelines, this next phase of decommissioning is discussed in section 7.4. 7.2.1 Central and Northern North Sea/West of Shetland From 2015 to 2024, there are forecast to be 314 topside modules for ‘making safe’ and 340 modules for topside preparation in these regions. This is an increase of 113 modules for ‘making safe’ and 126 modules for preparation since the 2014 report, reflecting the new projects added to this year’s survey. Additional activity is included between 2017 and 2019, with a large increase from 2020 onwards. Near-term activity has smoothed out since the 2014 forecast and is spread more evenly across the decade. The total expenditure on facilities ‘making safe’ and topside preparation over the next decade in these regions is forecast to be £566 million, a rise of £146 million on last year’s estimate. In the CNS and NNS/WofS areas, topside preparation is typically carried out in the year prior to removal and ‘making safe’ two years before removal. As seen in Figure 12 overleaf, there is a higher number of modules for topside preparation than ‘making safe’ in the years 2015 and 2016, as the associated ‘making safe’ activities would have already been carried out.
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