FPSO teenage angst

Today, over 200 vessels are deployed worldwide; an increase of over 100 percent in the past 15 years.

Advisian and the wider Worley group have worked on over 90 percent of them since the very earliest days of FPSOs, so we understand the associated issues in their ongoing asset management. Here are a few of them.

The teenage years

Many of these assets are relatively young, but the ageing process has inexorably started.

In the current demanding market conditions, including the high cost of operations of these remote assets, it is imperative that an effective integrity management strategy is put into place that aims to increase the availability of the facilities and reduces maintenance costs, while retaining an acceptable risk profile.

‘You don’t understand me’

We all know that an effective asset integrity management program can increase economic return by minimizing downtime and eliminating “no added value” inspection and maintenance activities, maximizing the availability of the facility while maintaining an “As Low as Reasonably Practicable” risk profile (see image below).

Additionally, operators can benefit by using integrity assessment analysis where the probability of failure of each component is assessed and risk ranked to enable an understanding of current and future conditions. This can enable the operator to extend the life of their assets rather than having to replace/decommission equipment when they approach the end of the design life. However, whilst the benefits can be substantial, the asset management of FPSOs and subsea facilities comes with a number of additional complex challenges.

Immaturity

You wouldn’t think that the relative immaturity of the assets would be an issue, but with that comes limited late life experience from which to draw historical data and trends. The majority of FPSOs have been in operation for less than 20 years. The same applies for related subsea facilities such as flexible risers and flowlines, mooring lines and subsea hardware. As a result, there is limited data for effective risk assessment and decision making. The uncertainties caused by lack of performance history may result in future unforeseen additional costs and catastrophic failures. However, while there is limited operational data, there is a wealth of industry experience around the original design challenges and early operational failures which may assist in reducing the uncertainties.

Aggression and stress

Aggressive offshore environments, vessel motions, and production demands can put floating and subsea facilities under significant stress, resulting in decline in availability and lower efficiency due to accelerated deterioration mechanisms. Inspection and maintenance programs play a key role in managing the integrity of the asset; however ineffective inspection and maintenance regimes not only negatively impact the safety of the asset but can introduce onerous and unnecessary costs.

The cultural challenge

Risk-based methodologies can be used to provide justification for fitness for purpose and life extension, and can be systematically applied to the whole FPSO installation or to individual components as an alternative to maritime classification. Incorporating the understanding of the original design intent and safety factors into this assessment in critical.

However, even performing an RBI (Risk Based Inspection) exercise and identifying the most critical equipment of an asset can be a standard task, in the same way implementing the findings and managing the day-to-day activities using this approach can be a real challenge. For an RBI program to be effective and to produce real benefits, it must be continuously managed and updated by competent personnel and embedded into the company culture. That’s where Advisian’s input can be critical.

Building trust

Our experts know that integrity management decisions must be supported by technical justification, which often requires advanced analysis to be performed in a timely fashion. Nowadays advances in inspection tools and numerical solutions enable us to reduce uncertainties and therefore lower inherent safety factors.

When an anomaly is detected, it is essential to find a practical and cost-effective solution that can reinstate an adequate safety level; therefore, it is crucial that FPSO operators can trust results from expert technical consultants. The evaluation of the fitness for service of FPSO components including; turrets, swivels, flexible risers, moorings, fairleads, the hull structure, and corrosion protection systems require extensive knowledge of FPSOs and subsea specific potential failure modes. Ultimately having the right people and performing the right analysis at the right time can deliver significant value.

To find out more about how we can help with asset integrity or production optimization for your FPSO, contact Neil.Allen@advisian.com