For a recent deep-water project, a computer modeling study was commissioned to provide information on the performance of the CP systems protecting each of the subsea structures and in particular the interaction currents flowing between them. The principal aim was to ensure that the impressed current CP (ICCP) system on the hull of the FPSO would be operated in such a manner as to reduce interaction with the sub sea sacrificial anode CP systems to the minimum possible throughout the operating life of the field and to develop an understanding of the probable behavior of CP systems on the key components (FPSO, Oil offloading lines & Buoy, Riser Structures, etc.) particularly in respect of sacrificial anode lives.

 In addition, a further aim was to provide a working tool for Operations that could be used to aid ICCP control beyond the design and construct phases, and to provide input to Risk Based Inspection and maintenance planning.

 The paper will describe the strategy and rationale behind the modeling studies and some of the major lessons learned