Riser repairs involve replacing some sections of the risers and possibly replacing some whole riser sections/segments over sea level. This work entails cutting and welding operations.
IK-Norway has significant experience in this field, together with specially-designed flexible plugs for double block and bleed (DBB) weld isolating and cold cutting of the depressurised risers. A DBB barrier is essential when performing hot work operations on hydrocarbon process pipelines.
Tool specifications for riser change out operations:
- Double block & bleed function/facility
- All materials are tolerant to hydrocarbon process systems
- Maximum operation pressure: 60°C
- To hold a minimum differential pressure of 1 bar
- Double block seal verification pressure, maximum 3 bar
- Plug annulus can be filled and monitored with water or gas
- Operating temperature: -10°C to +60°C (+90°C intermittent)
- Flexible connection between isolation barriers
- Plug must navigate through miter joints and piggable bends