Solutions Engine

Liquids Hold-up

When liquids in wet gas fall out and sit in the pipeline, it can affect more than pipeline flow properties. Large amounts of uncontrolled liquid can cause harmful slugs that can damage processing and other gas operating facilities. In addition, liquid that sits in the pipe system tends to collect debris, creating a site for localized corrosion and making compressors work harder to push product along, which can increase operational costs.

Pigging wet gas pipelines can help Offshore Pipeline operators:

  • Optimize natural gas pipeline capacity utilization by minimizing the fraction of liquids they contain.
  • Prevent or reduce slug flow.
  • Keep liquids from overloading and damaging refinery receiving separation vessels and tanks, and other processing equipment.
  • Recover and monetize valuable natural gas liquids (NGLs) that are building up in, or falling out, of wet gas. 



TDW offers a complete line of pigging tools that enable Offshore Pipeline operators to efficiently remove liquids hold-up. Most pigs are equipped with RealSeal® urethane cups – one of the industry’s most effective seals – for optimum performance and long life. 

  • UNISPHERE™ pig – Heavy-duty inflatable spheres that remove liquid hydrocarbons and water from pipelines and piping systems.
  • REDSKIN™ foam pig – Tough and abrasion-resistant; used for dewatering, air removal prior to hydrostatic testing, and drying after hydrostatic testing.
  • OptionAll™ batching pig – Designed for light cleaning, line filling and dewatering, batch separation, and liquid removal.
  • VANTAGE® V batching pig – Used for batching, displacing, and light cleaning.
  • ULTRA™ pig – All-urethane pigs that are batching- and displacement-capable.
  • X-Pig® multi-purpose utility tool – Flexible and versatile all-urethane pig can negotiate tight pipeline turns and is appropriate for cleaning, batching, and displacement operations.
  • VANTAGE® + pig – Can be used for batching and displacement; flexible in tight bend pipelines and can traverse a 20 percent reduction in interior pipe diameter. 

Technical assistance is available from TDW subject matter experts for special circumstances or if the path to a solution requires consultation.