Phoenix has recently completed an abandonment campaign in the Gulf of Mexico utilizing its atmospheric diving system (ADS) Hardsuit and a surface supplied air diving spread mobilized onboard a vessel of opportunity.
The project was executed in two phases.
In Phase 1 of the project, Phoenix cut, plugged and abandoned a 6” pipeline and umbilical exiting a J-tube at a depth of 530 feet. Cuts were made using a guillotine saw and shears, followed by the ADS pilots capping the umbilical, plugging the pipeline, and abandoning both segments in place as per the Bureau of Safety and Environmental Enforcement (BSEE) permit. An ADS pilot then drilled a 2” hole in the platform side of the cut pipeline using a magnetic drill and a messenger wire was deployed for the pilot to connect to the cut pipeline which was laid on the sea floor for subsequent recovery.
Phase 2 consisted of removing two 6” risers and all riser clamps, two 3” umbilicals and two umbilical I-tubes and all I-tube clamps to a depth of 430 feet. ADS pilots, using a standard hydraulic impact wrench opened and removed all clamps below 160 feet, while surface divers completed the same from 160 feet to the surface. The risers were then lifted out and cut into sections by a platform based construction crew with embedded Phoenix safety personnel.
In total, 20 ADS missions were completed with 61 hours in the water and divers performed 38 dives with 33 hours of total bottom time. The entire project was performed over 18 days using 3,964 man hours without a lost time incident, the company noted.