Few companies can match Inocean when it comes to working out problems like this and finding solutions that satisfy the customer as well as its classification society.

In the case above, the vessel was built in the 1960s and is nearing a final appointment with the breakers. Operations in a demanding environment and insufficient maintenance are a formula for serious rust problems. The owner has been warned that production on the field will be halted immediately if nothing is done. 

Structural Analysis

Inocean's engineers evaluate all the data required to judge the vessel's status and ascertain the scope of damage. Then we conduct an analysis to establish a basic requirement for steel thickness in the tanks. To keep this as low as possible and thus avoid superfluous replacements and rectifications, one option is to get acceptance for restrictions on load volumes. In other words, the ship is allowed to continue operations for a limited period as long as its tanks are only filled to a certain level. 

Restrictions or enhancements

From this point of departure Inocean analyzes all the measurements made on board that reveal the condition of each steel plate and every support. All the tanks are subjected to a ULS (Ultimate Limit State) analysis for a range of loading conditions. This analysis computes utilization against yield, buckling and shear in the structures. If utilization factors exceed requirements then restrictions must be made on tank load capacities or structures must be reinforced, for instance by additional stiffening or replacing entire steel plates and/or supports.

Major benefits

Inocean's job is to get Class acceptance for its calculations, analyses and conclusions.  Then it's up to the FPSO owner to weigh the costs of the proposed improvements against profitability and operations on the oil field in question. A two-year extension on the life of a vessel that has an ongoing contract can easily bring in additional millions for the owner.