During the summer of 2004 the Åsgard Transport pipeline System (ÅT) was successfully inspected by a Multi Diameter in-line Pipeline Tool (MDPT) launched sub-sea at a water depth of 300m. The project faced the following operational challenges:
Minimize reduction in ÅT production during MDPT installation and inspection
Installation of a 44 tonnes sub sea pig launcher module requiring strict weather limitations
Tie-in to a live gas system at 300 meter water depth
Removal of sea water - risk of hydrates
350 valve operations and 700 procedure steps
High focus on HSE&Q and Risk Management
The worlds first internal inspection of an offshore, dual diameter, high pressure gas export pipeline, with a subsea launched Extra High Resolution (XHR) Magnetic Flux Leakage (MFL) tool, was successfully carried out both operationally and a with respect to inspection results. The offshore work took 11 days, the pig travelled for 5 days through the pipeline and the operation was completed on schedule and within budget. The main success factors of the Åsgard Transport inspection can be summarised as follows;
The responsibility for follow up of interfaces and contractors, where divided between the Statoil project members to ensure clear lines of communication and responsibilities.
All contractors were included in an integrated project team (ÅTPP) to ensure close co-operation and to make sure all parties had a good understanding of what was required.
Based on the criticality of the operation an extraordinary high focus on HSE and risk management was implemented.
A software procedure training model (colour coded P&ID's, 3D models, animations) was developed and used for training of operational personnel (ROV pilots) as a risk reducing measure and to increase the operating efficiency.