General Fixed Platform Installation is divided into 3 (three) methods: 1. Lifting; 2. Launching; 3. Float-over.
Tanya – muhammad yusuf
General Fixed Platform Installation is divided into 3 (three) methods:
1. Lifting
2. Launching
3. Float-over
1. Lifting:
a. Vertical Lifting
– Fabricate & transport by vertical
– Lift vertically from cargo barge then emplace into its position
b. Upending
– Fabricate & transport by horizontal,
– Then lifting horizontal then upending gradually until vertical (Assisted by flooding system if necessary)
– Then vertically emplacing to sea bed. (Assisted by flooding
system if necessary) – Applicable for jacket (not topside)
2. Launching: (applicable only for jacket)
a. Free launching.
– Fabricate & transport by horizontal
– After launching from launch barge (specific trim angle), jacket will go into water,
– Then by buoyancy and structural configuration, the jacket will be automatically positioned into vertical floating condition
– Then crane will pick up the sling and emplace ther jacket vertically to sea bed.
b. Typical launching plus controlled upending.
– Fabricate & transport by horizontal
– After launching from launch barge (specific trim angle), jacket will go into water, but it will be floated in horizontal position,
– Then it will be towed into final location (as necessary)
– Then it will be upended up to vertical position (assisted by flooding system)
– Then it will be emplaced vertically (assisted by flooding
system)
3. Float-over (applicable only for topside)
a. Typical float-over.
– Topside is positioned on skid beam float-over barge
– Then float-over barge move into final position,
– then by ballasting, topside leg will be positioned above pile/transition piece (above leg)
b. Float-on and float off method.
– Topside is positioned on top of cantilever beam above float over barge,
– Then topside is skidded up to edge of cantilever beam,
– Then by ballasting, topside leg will be positioned above pile/transition piece (above leg).
Note. Float-on and float-off method is useful for condition of topside removal and then re-installation.
topside removal by this float-on float off method will be a reverse sequence from the installation as above.