Pipeline Repair and Intervention Technology
16 September 2010 London Evening Meeting
Chairman Dr Bob Allwood, Chief Executive, Society for Underwater Technology
Sponsored by Subsea 7
Presentations
Girassol Pipeline Repair Project
Allan Glennie, Engineering Manager – Pipeline Repair and Intervention, Subsea 7
In August 2004 after 9 months operation, a water injection line failed in service on the Total operated Girassol field situated offshore Angola. The failure was the result of problems encountered during the installation of the pipeline, which resulted in a rupture at one of the J-lay collars. The rupture was located approximately 3.5 km from the riser tower in a water depth of 1350 metres.
Subsea 7 was approached by Total, the operator for the Block 17 Consortium, as Contractor of Sonangol Concessionnaire, in the summer of 2005 to participate in a pipeline repair feasibility study. The solution forwarded by Subsea 7 was selected by Total for further detailed evaluation which resulted in Subsea 7 being awarded the contract for the design, manufacture, assembly, testing and offshore operation of a diverless Pipeline Repair System (PRS) in early 2007.
The entire project has been technically and operationally challenging as the PRS was developed from a new concept incorporating diverse technologies with the majority of equipment designed in-house by Subsea 7. The key differentiator with this PRS was to use a small in-field support vessel as the platform for all repair operations without any stand-by for metrology and spool fabrication.
The presentation gave an overview of the pipeline damage, equipment and technology, and feedback on the system performance during the offshore operations, which were successfully completed in December 2009.
Pipeline Repair and Intervention Projects
Mick Fowkes, Remote Technology Manager, Subsea 7
Subsea 7 gave an overview on the different types of pipeline intervention challenges based on recent and future project examples.