Subsea cable laying: from theory to practice - · PDF filefrom theory to practice . HALIFAX, 6...
Transcript of Subsea cable laying: from theory to practice - · PDF filefrom theory to practice . HALIFAX, 6...
Subsea cable laying: from theory to practice
HAL
IFAX
, 6 N
OVE
MBE
R 2
014
Test site background 1. Location 2. Description
Our experience 1. Initial cable design 2. Contractor requested change 3. The compromise 4. Initial logistics 5. Unforeseen event 6. Agreed solution between all parties 7. Revised logistics 8. Cable burial
Conclusions
Test site background
LOCATION 1
BILBAO
DONOSTIA SAN SEBASTIÁN
VITORIA-GAZTEIZ
ARMINTZA
Biscay Marine Energy Platform
DESCRIPTION
Test centre ready to operate 2
• 4 Berths 20 MW connected to the grid • Environmental monitoring • Water depth 50-90 m • 24/7 Surveillance and emergency response • Close enough for fast access
Our experience
INITIAL CABLE DESIGN 1
Main Characteristics
•3 phases
•13.2 kV •5 MW
Counter helix double armour
2
Initial cable design required carousel
The contractor requested a change to simple armoured cable to avoid carousel
CONTRACTOR REQUESTED CHANGE
3
Double armoured cable without counter helix
•Storable in a hold
•No necessity for a carousel
THE COMPROMISE
4 INITIAL LOGISTICS
+
+ +
Sent vessel with connectors to Drammen Pick up subsea cables During journey to Bilbao technicians joined connectors and cables Laying of the four Subsea cables
Not viable – Alternative cable was not-sufficiently coilable
5 UNFORESEEN EVENT
6
Last minute all party meeting in Drammen Several solutions suggested
Barge with cables stored on a carousel
AGREE SOLUTION BETWEEN ALL PARTIES
7 REVISED LOGISTICS
+
+ +
Sent vessel with connectors directly to Bilbao
Barge with subsea cables from Drammen to Bilbao
Transfer cables and the connectors from barge to vessel one by one
Laying of the subsea cables one by one
+
+
8
•Non-consolidated substrate not as expected
•Inadequate equipment of the vessel
Cable burial carried out by divers
CABLE BURIAL
Conclusions
Lessons learnt
1
Expect the unexpected: technical & non-technical issues
Problem solving: all parties must work together as a team
Detailed seabed studies best carried out immediately prior to the cable laying
CONCLUSIONS
Thank you very much Dorleta Marina