UKOOA FPSO Studies
The offshore oil and gas industry has been using floating production, storage and offloading systems around the world since the mid-1970s. The technology is sophisticated, proven and reliable, having evolved through many years' research and development. But however successful the track record, FPSO operators recognise the need to review their activities continually and identify areas where safety and operational improvements could still be made.
The following section highlights the range of key issues currently being investigated by the FPSO committee and provides information on recent studies commissioned by the industry.
Operations Best Practice
One of UKOOA's roles is to identify areas of common interest amongst its members and to encourage companies to share their experiences so that others may build on the lessons learned. In this way, the industry's performance as a whole may be improved, in both safety and operational matters.
In September 2000, the FPSO committee commissioned the Offshore Management Centre of Robert Gordon University in Aberdeen to carry out a study of the problems and issues encountered during the first 12 to 18 month's operation of FPSOs in UK waters. The study focussed on:
- the effect of motion of FPSOs on process pipework, product swivels, rotating equipment and crane performance;
- start-up operational problems;
- the impact of CRINE (a cost-saving pan-industry initiative which ran throughout the 1990s);
- quality assessment and control;
- mechanisms for sharing experience and lessons learned amongst companies.
FPSO specialists in 11 different companies were interviewed and two one-day workshops were held in Aberdeen to gather further information for analysis. The study suggested that many of the operational problems encountered during the first 12 to 18 months could be addressed in the design and construction phases, and recommended greater input in these stages from personnel who actually live and work on FPSOs.
The researchers also found that the sharing of individual experiences and the lessons learned could be improved. They are currently working with UKOOA to investigate the feasibility of establishing an "FPSO Improvement Network" to encourage more effective sharing of knowledge within the FPSO community.
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Design and Construction
FPSO design and construction has evolved over the years in response to the industry's demands for safe and efficient facilities to operate in ever more challenging environments. However there is always room for improvement and opportunities to learn from experiences in the design, construction and operations of FPSOs built to date. One of the perennial difficulties of FPSO design and construction is applying the appropriate combination of marine (ship) and offshore production practice.
UKOOA commissioned RM Offshore Ltd and Project Reviews Ltd in June 2000 to review the Rules and Regulations for floating installations of three Classification Societies (Lloyd's Register of Shipping, American Bureau of Shipping and Det Norske Veritas), including the requirements for structure, production, utilities and supporting systems. The study also examines the extent to which these Rules resolve possible gaps and conflicts between the requirements for marine systems and those for the systems normally associated with fixed production platforms.
It found that as the Rules for floating installations are not FPSO specific, they do not recognise the special requirements of an FPSO, nor do they fully address the interfaces between marine and offshore production systems.
UKOOA has consequently commissioned RM Offshore to develop industry guidance notes for FPSOs in UKCS service. The notes are intended to guide designers, owners and operators when planning and building new FPSOs. They will deal with range of topics covering the life span of the facility, including location and environment, facility layout, crew-related issues, safety evaluations and preliminary risk assessments, environmental strategy and objectives, and the legislative framework.
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The Health and Safety Executive's (HSE) target is to reduce shuttle tanker "loss of station keeping events" by 25 percent over three year, against a baseline of seven events per shuttle tanker per year. In response, UKOOA, in conjunction with the HSE and the industry's Step Change in Safety initiative, is developing guidelines on managing collision risk for publication in two volumes later this year. Part one will address performance standards for controlling the risks associated with tandem offtakes involving shuttle tankers at FPSOs; while the second will deal with the use of towing assistance during offtake operations.
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Flexible risers are the "pipelines" that connect between seabed installations and the FPSO, bringing untreated liquids to the surface for processing. In July 2000, MCS was commissioned by the UKOOA FPSO committee to investigate current industry practice for managing the integrity of flexible risers so as to minimise the risk of system failure. The work is mainly focused on the UK sector of the North Sea and West of Shetland although significant information was also gathered from Norway's offshore fields.
The study provides:
- statistical information on the number of flexible risers currently in use in the North Sea and West of Shetland, their type, operating pressure and temperature, contents duty and other relevant issues;
- information on the various flexible pipe inspection and monitoring techniques currently available to the industry;
- details of flexible pipe damage and types of failures experienced) and some of the lessons learned from using flexible pipe offshore.
- a list of key research and development activities being carried out by the industry into flexible pipe technology at present.
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Guidance Notes for the Monitoring and Integrity Assurance of unbonded
This guidance has been compiled from the experiences of leading operators
and users, suppliers, regulatory bodies, and other specialist consultants
involved in the specification and use of flexible pipe systems
for riser and
It includes information on risks specific to the use of flexible pipe, and
on actions which the project or operations manager can take to minimise
those risks - through for example specific QA/QC actions, or the
implementation of relevant monitoring strategies. Examples are provided.
The guidance notes can be applied during the specification, manufacture,
installation, commissioning, and operations stage of any project
use unbondded flexible pipes.
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A significant proportion of UKCS hydrocarbon reserves are produced by turret moored FPSOs which will remain permanently on location for periods between five and 25 years. Over the years, mooring line quality control has improved significantly and designs have evolved to minimise the consequences of possible failure. However, many different types of mooring system are used in UK waters today, and approaches to their inspection, repair and replacement can vary from company to company. UKOOA is keen to identify which management procedures are the most effective, so that the highest standards of safety and operation may be promoted across the whole of the industry.
In April 2001, UKOOA commissioned Noble Denton Europe Ltd to look into the design, construction and operation of mooring systems over the last five years, including seabed anchors, mooring lines, the turret interface and associated systems such as winches and thrusters. The work includes recommendations for improving mooring system integrity.
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Personnel Competency and Training Standards
OPITO, the industry National Training Organisation, has developed a suite of occupational standards for personnel working on FPSO facilities in the UKCS, with emphasis on marine operations (crude oil washing, shuttle tanker operations, ballast control and loading/discharging operations, for example). In all, thirty-nine different standards are proposed, and these are currently in the process of being formally approved as "national occupational standards".
The next stage is to ensure that appropriate, accredited training is available. OPITO is already working with training providers across the UK to identify which programmes would support the new standards and which, if necessary, would have to be modified. The outcome of this research will be submitted to the FPSO committee for their comments in December 2001.
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A Study into FPSO Inspection, Repair and Maintenance Best Practice
UKOOA commissioned Lloyds Register to undertake a study into FPSO Maintenance, Repair and Inspection Best Practice on the UK continental shelf. FPSO facilities are relatively new and pose challenges to offshore operators and the purpose of the study is to pool the available knowledge base within the membership to improve safety, drive down operating and maintenance costs and spread the lessons learned.
The study has been completed by Lloyds Register and concentrated on specific areas where potential problems have occurred and where a number of tactics have been employed to resolve the issues. These were:
- Ballast Systems,
- Oil Storage,
- Deck Structures,
- Tank Venting, System Pipework,
- Swivels and drag chains,
The study concentrated on producing a report on the issues based on a questionnaire circulated within the membership, analysis of the issues supported by recommendations and a register of vendors with experience in dealing with the practical solutions. The completed report is intended to be a living document to allow contributions to be made from time to time by the members as further experience is gained.
Grateful thanks are expressed for the support within the UKOOA membership and particularly the UKOOA FPSO Committee for their guidance and patience. Lloyds Register are thanked for their perseverance in dealing with a difficult and challenging study.
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