Offshore staff
HOUSTON – Workstrings International provided the 4-in. CTM26 drill pipe used in a record-breaking 28,789-ft (8,775-m) flowline cleanout operation in the Gulf of Mexico.
The company supplied the drill pipe as an alternative to coiled tubing in the multi-phase project to decommission about 29,000 ft of 10 in. x 6 in. insulated pipeline in the Gulf of Mexico. The project, deployed in the Ozona Garden Banks block 515, set a new offshore snubbing unit/hydraulic workover world record, onboard the Q4000 vessel.
The project was completed in 22 days, ahead of Hurricane Laura. It consisted of retrieving and removing a pipeline end termination (PLET) to surface of a DP-3 drilling intervention vessel. The second objective was to use a 340k snubbing unit to rig up and intervene inside the pipeline with an optimized drill pipe workstring to perform washing/flushing operations until reaching the second PLET. A cap was then installed on the first end of the pipeline and placed back in the original trench on the seafloor with the deployment rigging and drill string for permanent abandonment in-situ.
To date, this is the longest subsea flowline cleanout conducted via this method. The previous snubbing record depth of 23,800 ft (7,254 m) was set in 2006 on the Q4000 during the Mariner Energy Pluto pipeline cleanout. Workstrings’ drill pipe and engineering string design was used for this operation as well.
David Warner, project engineer at Workstrings, said: “In this project, the operator was able to clean out the pipeline in record time with the snubbing unit onboard the Q4000, so that it could be left on the seafloor without asphaltenes inside it. This project was a continuation of a cleanout project from 2016, where the operator attempted to use coiled tubing to clean out the pipeline.
“When they were unable to clean out all ~30,000 ft [9,144 m] of pipeline with coiled tubing, they reverted to Workstrings’ CTM26 drill pipe and successfully completed the project.”
03/03/2021
