Image
Installation of direct electrical heating cable (DEH) flowline system to tie back the Tommeliten Alpha gas field to existing infrastructure at the Ekofisk complex in the southern Norwegian North Sea.
Company: ConocoPhillips Skandinavia AS
Location: Greater Ekofisk Area, southern Norwegian North Sea
75 m
Max. water depth
Scope of work
- Engineering, procurement & fabrication of line pipe and PLET, PLEM and ILT structures
- Installation of 30-km, 16-inch CRA gas line & 4-inch direct electrical heating (DEH) cable, piggybacked onto the pipeline over the full length
- Installation of 500-m, 6-inch DEH feeder cable, piggybacked onto the pipeline
- Fabrication & installation of CRA/Duplex PLEM / ILT / PLET structure & CS installation aids
- Fabrication & installation of mattresses & GRP covers
- Support activities (incl. pre-lay & post-lay surveys)
- Trenching 24-km stretch of pipeline
- Pre-commissioning of the completed flowline system
30-km
16-inch CRA gas line
500-m
6-inch DEH feeder cable
Image
Specials & challenges
- Design, fabrication & installation on board Pioneering Spirit of new DEH cable routing equipment
- Installation of DEH feeder cable, piggybacked onto the pipeline (partly disconnected subsea, re-routed underneath platform bridge & pulled into the platform J-tube)
- Design & fabrication of CRA/Duplex PLEM / ILT
- First-time installation of large PLEM / ILT structures with Pioneering Spirit
- Installation of CRA pipeline with first-time use of surface tension transfer technology (STT) for root pass welding
- Simultaneous welding of double joints during offshore platform installation / removal work
- Pipeline laydown with PLEM in sidestep operation near drill rig (10 m steel-to-steel clearance)
10 m
steel-to-steel clearanc
Image
Image
Image
Display on a map
Off