Optimized Structural Integrity Management System and Inspection Program for a Converted FPSO
Authors: Altmann Joshua , Nezamian Abe 
Published: June 2014

Floating structures for production, storage and offtake (FPSO) have been used safely and reliably throughout the oil industry for many years. Asset Integrity is increasingly important to optimising safety and operational efficiency in the Oil / Gas industry. Operators need to comply with Corporate and Regulatory requirements but recognise that developing and managing an effective and compliant Asset Integrity Management System is both time consuming and costly.

Maximising the availability and productivity of an FPSO, whilst operating safely and with minimal impact on the environment, is a major concern of operators. FPSOs have certain loading characteristics and damage consequences that make them different to other offshore installations and conventional ships, and often more challenging to maintain and operate. Structural integrity management and inspection campaigns are important inputs in the Asset Integrity Management (AIM) system of FPSOs and other ?oating offshore facilities [1]. Considering that the unit shall stay at site during the whole life of the ??eld, where disconnection or the removal of the mooring system is not planned, a comprehensive methodology for the survey and inspection of the unit during this period needs to be developed and subject to review based on the results of the scheduled inspections. So further than subjected to class and statutory requirements, inspection and survey plans should re?ect the required availability, functionality, survivability and durability of the unit regarding the ??eld life as part of safety management of the facility. Among the several degradation mechanisms covered by the inspection and survey plans, fatigue is an important issue to check carefully. Risk Based Inspection methodology has been adopted in several projects and is an important tool to establish rational inspection campaign for structural components, mainly for those located in areas where access is critical and operational constraints are an important parameter [2].

The aim of this paper is to present the methodology to establish inspection and survey plans, combining RBI analysis and the industry expertise. The several steps to achieve the ??nal inspection campaign are described based on the experience of a converted FPSO. An optimized structural integrity management (SIM) and risked based inspection program were developed for a converted FPSO as part of the Health, Safety and Environment Management System (HSEMS). The SIM comprises the organization, responsibilities, procedures, processes and resources' by which HSEMS policies are implemented.

The paper gives an overview of the challenges and discusses various aspects of aging related to offshore facilities, represented risk to the integrity of a facility and the required procedures and re assessment criteria for maintains the structural integrity. This paper also provides an overall view in the regulatory requirements, documentations and calibrations/validations of the original design values to maintain the safety level by means of a maintenance and inspection programs balancing the aging mechanisms and improving the reliability of assessment results.