Decommissioning and abandonment

Decommissioning and abandonment

29

RECOVERY

ƒ Recovery methods: ƒ Small diameter rigid or flexible flowlines – reel barge ƒ Thin walled downhole or flowline tubing – reeled ƒ Larger diameter pipelines – laybarge ƒ Pipeline and bundle recovery – cut and lift process or float and tow method ƒ Bundle recovery – off-bottom towing method

A number of different approaches have been used, as listed above. Where the wall and particularly the welds can withstand the stresses, small lines can be removed by reel barge. A simple laybarge can be used to dispose of larger diameters. An alternative used for larger lines in poor condition (unable to withstand stresses) is to cut into short sections and lift vertically. If buoyancy can be provided to bundles, then these could be towed to shore using an off- bottom method. This may be accomplished either with individual buoys or use of gel to flush the water from the annulus. A similar process may be used for pipelines.

RECOVERYBYREELBARGE