iicorr Ltd

Structural Integrity Management Case Studies

iicorr have been involved in the integrity of Alwyn North and Dunbar topsides and MCP01 topsides and subsea in 2001 as a one year project for Total. Following the successful completion of this project iicorr was awarded the same contract for another 5 years as part of an open bid. This gives a good indication and reflection of the quality of work performed and also indicates the level of client satisfaction with the quality of work.

In order to perform this work, the team had to gather and review all the history of the three topsides, review of all available fabrication and design information as well as structural drawings, carrying out all the structural inspection. The work carried out involved the following:

1) The preparation of Questar®-S Risk Based Inspection Strategies for the three structures including:

Risk Assessment to establish critical components.
Review of Structural History and Performance taking into account the most recent structural survey.
Optimised inspection program for each structural component.

2) The preparation of structural inspection workbooks for the three Topsides consisting of the following:

Type of inspection required for each component.
Anomaly criteria.
Inspection procedures.
Operations reporting requirements.
Work instructions for visual inspection and related tasks.
Datasheets for structural visual inspection.

3) Conducting structural surveys for the three topsides, as part of this, great efforts were made to check all previously reported anomalies. These have been reviewed initially for the purpose of preparing the risk assessment strategy.

4) Comprehensive and detailed inspection integrity reports have been prepared for the three Topsides after the completion of the inspection surveys. The reports consist of the following sections as recommended by the Alwyn Area Asset Integrity Management System:

Introduction
Conclusions
Recommendations (Structural Maintenance/Repair, Fabric Maintenance Monitor).
Failures/Concerns
Inspection/maintenance
Monitoring
Mitigation
Other Integrity issues

5) A database has been created which has the following:

Inspection history.
Associated risk with each component.
Future inspection programme.
Relevant integrity data.
Risk based inspection philosophy definition and risk assessment results.
Workscope preparation

The contract was subjected to a performance measurement system, using Key Performance Indicators (KPIs), including budget control, key dates for workscope preparation and dates for final deliverables to the client. All the key dates and deliverables were achieved as agreed. The contract was also subjected to a competency measurement system, which required a submission of a Competency Assurance Document to the client at least once a year. This document highlights any changes to resources deployed for the contract and gives details of their qualifications and training. It also gives details of the Project Quality Plan.

In addition, iicorr has contributed in a serious of Global Integrity Presentations run by the Client. This contribution has helped to enhance communication between iicorr and Total and also to ensure that all Structural Integrity Issues are explained to all other interfaces within the Integrity Management System.

Project for Lundin Britain Ltd (previously DNO Britain Limited)

iicorr provided all the inspection / maintenance management services for the Heather A platform from 1990 onwards. Scope covered topsides and underwater structures, pipelines, process plant. Input included management, execution, supervision and reporting of inspection, preparation of Risk Based Inspection plans, corrosion monitoring and chemicals control as well as ad-hoc engineering studies.

The scope of work specific to jacket structures comprised:

Development of underwater inspection strategies. In the early 1990's these were on a five-year rolling certificate of fitness basis. However, from the mid-1990's, iicorr used their Questar®-S methodology to optimise activities based on risk. This extended the inspection interval between surveys and took a holistic approach to end of field life.
Workscope and workbook preparation.
Contract management including prequalifying underwater contractors, preparing the tender specification, contract review, technical audit of contractors (particularly pre-mobilisation) and contract execution, arranging DSV audits, etc.
Offshore supervision including the training and development of underwater inspection co-ordinators and the provision of both client representatives and inspection co-ordinators offshore.
Day to day project management on a 7-day x 24 hours basis during offshore campaigns.
Analysis of inspection results.
Reporting on a technical, commercial and operations data basis.
Updating of models and records.
Custodian for the underwater structural integrity management system, ensuring it is up to date (with changing legislation) and remained fit for purpose.

The job also included providing general support to the Heather asset and acting in a project capacity as and when required. Projects included caisson replacement, repairs to boat bumpers, geotechnical sampling of the drilling mud mound, retrofitting subsea clamps and input to platform and pipeline abandonment studies.