FPSO Life Extension: A Systems Approach

Technology enhancements that are extending the life of existing production fields, coupled with successful drilling programs are creating situations where the typical FPSO will have to remain in operation beyond it’s intended 15 to 20-year design life. Given current economic conditions, the option of building a new FPSO when the old FPSO has reached the end of it’s design life is less economically feasible than it once was. As a result, FPSO life extension programs are gaining attention as a cost-effective way to keep the fields they support producing.

Class and regulatory approvals are contingent upon the FPSO being designed, constructed and operated in a manner that ensures safe operations for it’s intended design life. Obtaining a life extension requires proving to the class society and the relevant government and international maritime regulatory agencies that that the FPSO can continue operate safely beyond the original design life.

This “proof” involves a complete condition survey of the FPSO to determine if the remaining safe useful life of the critical systems are going to meet the desired extended life for the asset. For example, fatigue and corrosion are typically considered to be among the largest threats. The condition survey would determine the current fatigue and corrosion status of the FPSO structures, calculate the rate of fatigue and corrosion, and then perform a forward extrapolation to determine the actual useful life of the structures.

The condition survey should also evaluate the effectiveness of the asset’s current inspection, maintenance and repair protocols. These protocols are necessary (and required by most regulatory bodies) as a part of any FPSO asset lifecycle. These protocols however might not be sufficient if a life extension is desired. Procedures designed to keep the asset operating for the original design life might need to be modified to extend operations beyond the original design life. In addition, more rigorous data collection, inspections protocols and analysis may need to be performed and maintained.

The manner in which you execute the condition survey can have a major impact on the overall cost and effectiveness of the survey. Many traditional approaches are equipment-based and don’t take into account the current and desired performance of the overall marine and process systems over time. They also don’t consider the cost/benefit of re-using all of the available information pertaining to the asset. For example, existing recent maintenance and survey data can be re-used as part of the condition survey rather than re-executing full surveys. Equipment-based approaches also tend to ignore the overall impact of the inspection, maintenance and repair protocols on the ability of the marine and process systems to reliably function beyond their original design life.

Athens Group applies a systems approach to the Life Extension Planning process that leverages existing valid survey data to execute a cost-effective condition survey. An on-site analysis to determine which pre-existing data can be re-used can reduce the overall scope and cost of the condition survey. The systems approach also evaluates the overall inspection, maintenance and repair protocols to ensure they are designed for the desired extended life rather than just the original design life of the asset.

As an example of the systems approach, consider a traditional condition survey that results in a recommendation to replace a control valve. While this would satisfy the immediate issue of providing a new valve to meet the life extension requirements, it does not necessarily address the overall capability requirements of the fluid pressure control system of which the valve is only a small, albeit critical part.

A systems approach starts with identifying what the designed behavior of a system should be. Comprehensive systems survey and test plans testing would then be developed well prior to the on-site condition survey. Developing the systems based survey and test plans in advance enables the evaluation and use of pre-existing survey and test data to cut down on the scope of the on-site survey and testing. A systems approach would also evaluate the coating system and its failure potential and assess the systems current operating pressure and temperature in order to determine if the remaining wall thickness will be suitable, and if a reduction in system pressure is possible. The resulting modifications of the inspection, maintenance and repair program could potentially allow you to extend the design life without replacing equipment.

Athens Group FPSO life extension management services are designed to ensure you have programs and processes in place to perform and pass all regulatory and class inspections necessary to achieve FPSO life extension. Our systems-based approach that leverages valid pre-existing survey and inspection data as well as modifications to inspection, maintenance and repair protocols delivers these results at the most cost effective levels possible.

For more information about FPSO Life Extension or to discuss your project specifically, please email info@athensgroup.com, call us directly at 281-921-8989 or toll free at 877)499-8393.

Copyright 2015 Athens Group. All Rights Reserved.

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