Blocked umbilicals – UMF goes back to basics
  from: Offshore Engineer
  by: Dave Stables
  Thursday, April 03, 2008

Blockages occurring in umbilical systems in service have posed very real problems for offshore operators, although seldom publicised. Duco’s Dave Stables explains how manufacturers’s body UMF, through its BASICS JIP, is shedding new light on the subject and providing invaluable assistance to the subsea production industry.

UMF, the Umbilical Manufacturers' Federation, was established in 2001 to enable member companies to exchange views and implement actions in respect of improvements in safety, environment, materials, technologies, etc, thereby increasing the industry's confidence in umbilical products.

The UMF is a membership-based society, presently comprising Aker Kvaerner, Duco, JDR Umbilical Systems, Oceaneering Multiflex and Nexans, who between them account for the majority of umbilical systems installed in subsea production systems. In 2006, a massive total in the order of 1500km (938 miles) of production control umbilicals was delivered by UMF members.

For many years, umbilical manufacturers had been aware of blockages occurring in umbilical systems in service but, because of secrecy within the industry, such blockages were rarely made public. All of this changed with an initiative by the UMF to hold a workshop to address the subject.With the assistance of the Society for Underwater Technology, who organised the workshop on behalf of the UMF, this was duly held in Aberdeen in January 2005 and comprised a two part arrangement:

• A morning session whereby operators and fluid manufacturers provided examples of blockages, or, events which could lead to blockages.
• An afternoon session involving working groups to discuss the morning's presentations and how to prevent blockages occurring.

The workshop culminated in a distillation of the outputs from the working groups and was followed by a report on the findings and suggestions as to the way forward. To enable the very useful information from the workshop to be put to good use for the benefit of the subsea production industry, the UMF decided that the best way forward would be to undertake a joint industry project (JIP) with the aim of developing two documents: 

• A Recommended Practice (RP) document on how to avoid blockages in umbilical systems. 
• A Design Verification (DV) document for the purpose of qualifying control and chemical injection fluids for use in umbilical systems.

Industry soundings indicated there would be sufficient support for the JIP and upstream technology management consultants OTM, a small firm specialising in the implementation and management of such projects, was given the task of making this happen. This started with a launch meeting late 2006 and, to date, 16 companies have signed up to the JIP representing operators, fluid manufacturers, equipment manufacturers, and engineering organisations.

One of the main points to come out of the launch meeting was that blockages are not just associated with umbilical systems but encompass the whole of a subsea production system (SPS). It was, therefore, decided to extend the remit of the JIP to cover the complete SPS. Known as BASICS (Blockage Avoidance in Subsea Injection and Control Systems), the JIP is now fully operational and making good headway with Duco providing support on behalf of the UMF.

To-date, six meetings have been held and very good progress has been made in the development of the RP document. The work scope associated with the document extends from project FEED stage through to fluid injection or hydraulic power/signal application at the points of use in the operation of a SPS. In between, it embraces such subjects as fluid design, cleanliness, bunkering, operational handling/protocols, materials of construction, fluid change-out, seawater ingress.

The RP has established that there are very many factors that can cause or contribute to blockages in SPS's. The challenge for the subsea production industry is that when the RP document becomes available, the industry takes notice of its content and uses it for the benefit of the offshore hydrocarbons production industry, especially as the cost of a blockage in terms of remediation and lost production is of very high order of magnitudes.

With the deliberations well advanced in the formulation of recommended practice, this has highlighted issues that need to be considered for inclusion in the DV document. What is becoming clear is that there are very many well service fluids in existence and that very many more will be developed in the years to come. Such fluids have a diverse range of formulations, solvent bases, pH values and expected service uses. They all, however, have one thing in common: a potentially long and tortuous journey after leaving the manufacturers’ facilities, involving shipping offshore, bunkering and transmission through small bore fluid conduits to remote points of application.

The aim of the DV document will be to qualify SPS fluids for such transportation and storage, taking into account the factors which could impact on the fluids and result in blockages. Such factors include environment (temperature, humidity, UV), materials of construction of the SPS fluid circuitry, interaction with change-out fluids, fluid stability, (solids formation, phase separation), seawater ingression, and so forth.

Discussions are currently ongoing with a view to having the documents adopted as national/international standards to ensure they have a meaningful status within the subsea production industry. Currently, the JIP is targeting to have both documents drafted by the end of 2008 and to get them adopted as quickly as standards protocol will allow.

With 16 participants, it has been decided to limit the JIP to this number. However, if any OE readers wish to make any suggestions or provide examples of blockages/causes or remedies for unblocking for consideration, or wish to make any other relevant suggestions, these can be sent to OTM by e-mail (crispin.keanie@otmnet.com).

The JIP is demonstrating that here is a trade association (UMF) working for the benefit of the subsea production industry. What is questionable is why has it taken the industry so long to achieve this goal considering the very many blockages it has and continues to experience, and should the operators have been the instigators?

With the success of this approach, the UMF is considering further topics which may form the basis of future workshops, potentially leading towards JIPs on umbilical-related subjects. Also under consideration is the development of a template specification to enable umbilical systems to be better specified and to a standard format. Currently the industry has many different formats with the quality of many of the produced documents being far from satisfactory. OE

About the author

Dave Stables is sales and business development manager of Newcastlebased Duco, one of the five member companies of the UMF. A 30-year veteran of product development, project management, sales and business development in the umbilical systems market, Stables has served on API and ISO drafting committees for umbilical specifications.

IWIS raises the global standard

Another major JIP reached a successful conclusion last year, producing an oil and gas industry standard for subsea wells that is expected to substantially reduce subsea project costs.

Sponsored by operators BP, ChevronTexaco, Eni, Hydro, Petrobras, Shell, Statoil, Total and Woodside, the IWIS (Intelligent Well Interface Standardisation) project group - involving some 200 individuals from across the upstream spectrum - has worked for a decade to develop a global standard that would help simplify and reduce costs and man-hours for companies involved in subsea developments.

The JIP brought together instrumentation specialists and controls systems suppliers to achieve a common interface, and a demonstration in Aberdeen in 2006 is acknowledged as one of the key milestones leading up to the final document, the IWIS Recommended Practice.

'After a decade of unflagging commitment, the IWIS project has reached its goal,' says Paul Johnson, associate director at OTM, which manages the JIP. 'Its success is due to unparalleled collaboration across more than 30 companies on five continents, and now we have a global standard to be proud of. We have published a Recommended Practice document that helps all in the subsea industry comply with the international standard ISO13628-6.' 

'Such collaborative projects are fairly unique to the global oil and gas industry,' adds Johnson. 'It means that an oil and gas operator, for example, will now be able to specify the IWIS Recommended Practice - available from the IWIS web site (www.iwis.com) to anyone in the world - and any control systems used will be compatible. This will give subsea contractors anywhere in the world a wider range of equipment vendors to choose from and it will speed up the development process as intelligent well interfaces will now be simpler to manage.'

'Some of the individual participants were engaged with the JIP for up to seven years and others for a much shorter period, but the overall commitment was terrific and we now have the document to prove it. It's a real testament to the determination of the oil and gas industry to deliver this successful outcome.'

Subsea system vendors and downhole equipment suppliers involved in the JIP were Aker Kvaerner, Baker Hughes, Baker Oil Tools, Cameron, DG O'Brien, Dril-Quip, FMC, GE Sensing, JP Kenny, Luna Energy, National Coupling, ODI, ProductionQuest, Promore, Roxar, Schlumberger, Seacon, Sicom, Siemens, Tronic, VetcoGray,Weatherford, WellDynamics and the Wood Group.

Technical agreement was reached on a wide range of topics, including:

• subsea power systems;
• communication systems; 
• hydraulic systems; and 
• christmas tree physical interface systems. 

'This success has spurred on other groups engaged in JIPs,'f says Johnson. 'It's an effective route to promoting best practice across the industry and we are now applying the learning from this JIP to others, including the projects SIIS . Standardising the Interface between Subsea Instrumentation and the control system - and SEAFOM: promoting the growth of fibre optics subsea.'

'The final IWIS JIP meeting was held in Houston last September in an atmosphere of real accomplishment, when the JIP was officially finished.' OE

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