Pipetech was tasked to clear a suspected blockage inside a riser on an offshore installation. Access was to be via the pig launcher door and negotiate round a “Y” junction into the riser.
Challenges
A specialist cleaning team working along side platform production technicians, who ran a total length of 270 meters of Aqua Milling® line, utilising a step down cutting nozzle. Once a clear path was established and the line had been retrieved, a polishing run was carried out to clear internal diameter of wax deposits. The polishing run to 270 meters ran at 1 foot per minute to ensure total effective cleaning of the pipe wall internal. All waste deposits were collected via a scale collector and stored in vacuum skips for disposal.
Achievements
■ Successful cleaning and recovery of waste from 270 meters negotiating 11 bends.
■ All waste material fully contained from pipeline to waste handling skips with no loss of containment and/or environmental impact
■ Aqua Milling of 6” line negotiating a diverter valve.
■ Recovery of waste from subsea pipeline that included a vertical lift of 120 meters
Benefits
Safety – Fully contained remotely operated jetting nozzle prevented work party and platform personnel coming into contact with potentially hazardous waste and high pressure water.
Environmental – All waste material recovered to Aqua Milling entry point and removed from scale collector via vacuum pump to closed vacuum skips for specialist disposal.
Flexibility – Workscope carried out utilizing the minimum of deck space as possible.