The scope of the subsea field abandonment comprises plugging & abandonment (P&A) of subsea well, topside preparation, pipeline flushing and removal of subsea equipments like the wellhead christmas tree, sections of pipeline (expansion spool) and sections of umbilical control line. The remaining pipeline on seabed toward host platform will be left in-situ. These are the scope of the concept selected in DOA, which were further matured in Abandonment Plan.

Objectives of the project are:

  • Improve safety and eliminate integrity risk

  • Eliminate OPEX for Well that has demonstrated no further potential for economical production

  • Fulfil PSC Abandonment Obligation Plan

The execution of the subsea field abandonment harnessed resources from various specialties ranging from CAT3 to Wells, CAT1 and Subsea, coherently progressing as a single team. A good deal of attention was paid to the technical integrity and long term plan of existing asset, which also played a major role setting the magnitude of work.

Lacking in experience in abandonment, we leveraged on the existing industrial resources and expertise where required, in order to realise a cost-effective execution. The activities were planned in accordance with applicable Production Sharing Contract, PETRONAS Procedures and Guidelines for Upstream Activities (PPGUA) 3.0, Shell Internal Guidelines, and the applicable local and international regulations.

Overall execution strategy and schedule was considerably influenced by pipeline flushing method and schedule of existing resources, which could be fairly aggressive, in contrary to popular belief that abandonment projects are not schedule driven.

Bundling of activities is the key to cost-effective execution, though the challenge escalates as we move from bundling of activities, to bundling of campaigns.

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