Deepwater Oil & Gas developments consist of many more components designed to extract, transport and store the oil when compared with developments in shallower waters.
Designing cathodic protection [CP] systems to protect individual components is problematic without an appreciation as to how CP systems fitted to the various components will interact with one another once the entire asset is commissioned.
A modeling study was commissioned to predict the performance of the CP systems and:
- The protection provided at the initial, mid and final life condition of the structures
- The interaction currents flowing between the FPSO and the subsea systems
- For each component a BEM model was developed representing the Surface areas, Coatings, Coating breakdown factors, Internal resistances and the Anodes [ICCP and sacrificial].
The model provided valuable information on how the ICCP system should be managed and identified changes which may be necessary during the future operation of the field.
The model also identified critical anodes whose life may be compromised if the system was not managed correctly.
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.