Samenvatting

• The Bonny Terminal Integrated Project is a project, where 2 new pipelines are
going to be installed in Bonny Area of South coast of Nigeria. This Final thesis
covers the mayor project execution statement.
• The Barge, which is used for this project is the Jascon-30, which can operate at
depths of 3m or less. Beaching the barge at low tide is an option provided that the
seabed and weather conditions are suitable.
• Onshore a turning sheave will be set up and sheet piles driven to protect the
beach in the surf zone. The cable will be pre-installed from the beach offshore for
immediate pick up by the Jascon-30 when it arrives on site.
• The Jascon-30 will be mobilized to the area and set up near shore over the
pipeline route with its stern aiming to shore. Using her front anchors and preinstalled
anchor pattern on the stern, bow and port side.
• Pipelaying of the 48-inch oil loading line will commence first and continue pipe
laying till the PLEM location,
• The pipeline is produced on the barge and pulled to the shore, as the barge is
moved forwards in steps on its anchors as a concurrent operation,
• The shore pull operation is considered complete when the pipeline end has been
pulled inside the cofferdam. Barge has then laid approx. 1000 mtr of pipelines.
• The pull-wire will be disconnected and buoyed, together with the retrieving wire,
to be both picked up by tugboat for re-installation the 36”line.
• The 36” line will be flooded from the sea-side with filtered water.
• The 36” line will be hydro-tested from the shore. The hydro-test spread will be
demobilised.
• The barge will return to the 48”, retrieve the pipeline and the 48” line will be
flooded from the seaside with filtered water and approved inhibitor. Then the 48-
inch pipeline and spool piece are hydro-tested in one operation from the Barge,
• The pipeline trenching machine is mobilised, brought to site and 48” line is
trenched to specification, that is from the cofferdam to kp 0.480 to a depth of
cover of 2 m and flush with the seabed to kp 4.0. It is anticipated that the full
depth of trench, especially close to the shore, will only be achieved after a few
passes of the trenching machine. The Trenching machine will be demobilised.
• During pipelay X-ray will inspect the completed welds and the joints coated with
field joint coating system.
• In addition to coating the exterior field joints of the 36” pipeline, also the inside of
the field joint is coated using mortar-cement-type.
• Since the diffuser is an integral part of the pipeline it will be laid as a conventional
pipeline. On completion of laying the pipeline and diffuser, the pipeline end will be
terminated with a lay down head (with pig-launcher) and the pipeline laid on the
seabed,.
• The 48-inch pipeline is then connected to the PLEM via a spool piece,
• The SBM is installed and afterwards connected with double hoses.