After a subsea mudslide near the mouth of the Mississippi River Delta, several sections of production or export pipelines were severed. The pipelines could not be retrieved to surface because they were buried deeply in the mud. Coiled tubing was successfully used to clean and abandon these pipelines insitu under 200-feet of water. The coiled tubing was conveyed through a flexible riser from a Dynamic Positioning mono-hull vessel. The lengths of the four sections of pipeline cleaned were 2400-feet, 1200-feet and 1800-feet with diameters of 8-10 inches.

You can access this article if you purchase or spend a download.