Innovation Brings Pipeline Back to Normal

Before the operator of a gas export pipeline offshore Asia could isolate the line and replace leaking pig trap valves on their platform and perform in-line inspection (ILI), they had to remove a serious obstacle: a cleaning pig that had stalled just beyond the pig launcher. Because there is no standard tool for recovering a stalled pig, at least not without blowing down the pipeline, the operator contracted T.D. Williamson (TDW), who engineered, tested and deployed a bespoke recovery tool. The pig was removed in an operation that resulted in only five hours of downtime. TDW then used in-line technology to isolate the pipeline and create a safe work zone for the valve replacement. TDW also developed a customized cleaning pig and a progressive pigging program to ensure the pipeline was sufficiently clean for both normal operation and ILI.