The principals of Laslett International were involved in the temporary decommissioning of an oilfield offshore Tunisia. The oilfield had to be safely and securely decommissioned. This included the moving of an FPSO and dealing with the risers, anchors, wells, subsea manifolds, etc.
A significant amount of detailed planning was necessary to ensure that the sequencing of works was carefully scheduled to safeguard the very sensitive environment of the oilfield area.
The decommissioning work was continually hampered by the arrival of migrants in make-shift and un-seaworthy boats as the oilfield was a magnet for these unfortunate people being on a direct line between Libya and Italy.
A major consideration was the danger of trawl nets in respect to the subsea as the area was subject to heavy and regular commercial fishing. Any damage to the subsea facilities had to be avoided during the necessary work as there was a danger of potential pollution of beaches.
The seabed area was surveyed and videoed prior to decommissioning and after the decommissioning was completed to ensure a complete record was available for re-commencement of operations following a proposed exploration drilling programme.
It was necessary to install additional anodes and other protection on the sub-sea wells and process control facilities, the FPSO anchor chains were tagged and laid out on the seabed with semi-submersible buoys to facilitate retrieval. Likewise, the flexible risers were attached to submersible buoys.