Rigid pipelines are laid using conventional S-Lay method employing the PLB Hafar Neptune equipped with 2x30T tensioners and 60T A/R winches.
Hafar have also undertaken installation of a piggyback system, whereby a smaller pipeline is attached to the larger pipeline and simultaneously laid.
A purpose-built tensioner and pipe chute are placed on the lay barge deck to deploy the flexible pipe from its hydraulic reel.
Risers and spools are installed using the stalk-on method. This involves lifting the riser and tie-in to the spool at platform deck level. Alternatively tie-in to the pipeline can be performed at seabed.
Tie-in between 2 subsea pipelines or between main pipeline and spool above water level by using davit cranes stationed at portside of PLB Hafar Neptune.
Disconnecting and preserving machineries on a FSO for tow to shipyard. Removal of all FSO related machineries and converting back to a trading tanker.
Installed a Single Point Mooring (SPM) system, of Catenary Anchor Leg Mooring (CALM) buoy type, and connecting flexible flowline to a Pipe Line End and Manifold (PLEM).
Screw piling is installed to make pipeline support in heavy current area, with high scouring probability on pipeline. Screw piling installation uses a hydraulic torque drive with maximum torque 14000 NM.
Dredging is performed to form a channel for the lay-barge access and simultaneously a trench for pipeline to be laid to cover burial depth requirement by using cutting suction dredger.
Pipeline fabricated on lay barge at nearshore is towed/pulled to shore using a specially designed 300T linear winch along the designed route and then connecting it to an existing shore pipeline. Preparation for beach pull operation usually includes pre-trenching, temporary cofferdam and backfilling.
In preparation for the beach-pull, Pre-Trenching is performed along the nearshore pipeline route to meet burial depth requirement. Where necessary, temporary sheetpiles are placed to prevent untimely backfilling. After the pipeline is laid, sheetpiles are removed and deliberate backfilling is done to bury the pipelines for safeguarding.
Post-Trenching
In shallow waters where burial depth requirements still apply, Post-Trenching is done by using high pressure jet sled to remove the seabed beneath the pipeline.