Pipeline & Process
Pigging Program Restarts Production
Successful pigging programme enables continued production
42km pigging loop cleaned to less than 30 ppm
Challenge
To de-oil and hydrotest TAQA’s 42km pigging loop where the lines had to be cleaned to below 30 parts per million (ppm) in water.
Solution
A pigging programme to remove all wax and hydrocarbons from the line was actioned. As the lines were not in production, the 42km loop had to be pigged with flooding pumps using chemically-treated seawater. Samples were taken after every pig run and once the lines were cleaned to below 30 ppm oil in water, the loop was pressure-tested.
Result
The pressure-test was successful and TAQA restarted production at a lower maximum operating pressure until the lines were replaced later in the year. In June 2013, Altus Intervention returned to de-oil the lines to ensure that no hydrocarbons were released to the sea when the divers disconnected the lines subsea.