The temporary abandonment or suspension of a well is a vital early stage of decommissioning whereby the well is isolated using methods such as bridge plugs, cement squeezes and packers. This allows the wellhead and/ or blow out preventer (BOP) to be safely removed. For subsea mudline wells, temporary abandonment (TA) caps are fitted to the hanger system, providing additional well and environmental barriers.
With high costs related to permanent subsea abandonment, suspended wells can often be in-situ for more than 10 years. During this time, it is possible for pressure to build up in the well, corrosion to take place and marine build-up to accumulate.