THE ROV ON YOUR XMAS TREE
The standardisation of subsea interfaces between ROVs and subsea structures has just come a step nearer. The North Sea Subcommittee of the American Petroleum Institute (API), chaired by Shell Expro's Tim Marsh, has taken the initiative with considerable support from Mobil/BP, amongst many others. API have now produced a working standard on "Recommended Practice for ROV Interfaces with Subsea Production Equipment - API RP17H" which is expected to be out shortly for consultation with principal interested parties.
The aims include:
The report emphasises that the intention is specifically not to standardise proprietary equipment nor to reduce the choice of supply sources.
Timothy Marsh, in his capacity as the Chairman of the subcommittee, has kindly provided Underwater Contractor with the following background to this pioneering work.
An initial serious effort at subsea standardisation was made in the late 1980's by API with the introduction of the API 17 series of standards. This series of standards has been developed over the intervening years and there is a proposed suite of some eight API standards covering all aspects of a subsea development. The API standards have been produced by engineers from both sides of the Atlantic. In parallel to this development with the API, the Crine and Norsok initiatives were being progressed, which have been overtaken in the subsea area by a concerted effort to develop the API standards into an international format as formal ISO (International Organisation for Standardisation) documents.
The international standards will be developed under the auspices of the ISO Technical Committee ISO/TC 67 set up with participants from both sides of the Atlantic with a view to standardising Materials, Equipment and Offshore Structures for Petroleum and Natural Gas Industries.
A Subsea Sub Committee of TC 67 was set up and the series of standards has the generic heading of "Drilling and Production Equipment - Design and Operation of Subsea Production Equipment".
The 13628 series of ISO standards consist of nine different Standards, eight of which have direct API equivalents:
13628-9: Subsea Intervention by ROT. New Standard in ISO
All the standards are in draft form and several are already in use by industry.
The standard for ROV intervention on subsea production equipment is being drafted by a committee that represents the oil companies, consulting engineers, ROV manufacturers and operators and equipment manufacturers/suppliers from the UK and Gulf of Mexico with input from Australia and the European continent. As the work on this standard commenced prior to the ISO initiatives, it is still referred to as the API 17H Committee and the document will probably be released under API cover prior to the ISO process being formalised.
When initiated, it is the view that the document would be a series of industry accepted interfaces. During the development of the working drafts it became apparent that the industry required more and the document in its final form will certainly contain the interfaces requested, and agreed, but will also address the philosophy of intervention and various other operating criteria to be used when designing subsea systems. For cost-effective intervention and through life-cycle costs, the intervention philosophy is required early and with standardised interfaces and space envelopes, concepts can be frozen and designs completed without having to commit to an individual contractor or set of tooling. Great efforts have been made to ensure that the standard does not hinder innovation or development and the operators are left to choose their own vehicles etc., the gains being made from a common set of interfaces that allow intervention from vehicles of opportunity.
(Ed: The task before the API is a deceptively simple one. The participants are to be congratulated for their achievement to date in rationalising the subject, particularly when there are so many factors and vested interests to be taken into consideration. The final report is eagerly awaited.)
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