OBJECTIVE:
Industry needs widely accepted and consistent practices for addressing Vortex-Induced Motions (VIM) of spars in order to ensure the integrity of existing and future spar designs. However, industry has not yet had the opportunity to share and review the collective data/knowledge on spar VIM in order to establish a common understanding of the problem and an industry consensus on how to deal with spar VIM in design. Currently there are multiple perceptions of the spar VIM problem, with different organizations having different design procedures along with different views on the associated design uncertainties. To address the need for an industry-wide dialogue on spar VIM, a workshop will be conducted with the following major objectives:
· initiate a path for development of an industry-acceptable design practice/methodology on spar VIM,
· identify uncertainties and technical needs in spar VIM and a path forward to fill the identified gaps,
· educate industry on the technical challenges involved.APPROACH:
The workshop will be planned with the assistance of a Steering Group (SG) of technical experts representing the major spar stakeholders (operators, designers, technologists, and regulators). Since much of the information and knowledge derived from spar VIM technology development efforts conducted over the past decade is proprietary, the main responsibilities of the SG members will be to identify what information needs to be presented to achieve the workshop objectives and then to seek the necessary releases of confidential information within their respective organizations.
Assuming the SG is successful in coordinating the necessary resources, the first part of the workshop will be devoted to industry presentations reviewing the current regulatory perspective and design practices as well as various design validation studies. Structured discussion sessions will be held for the latter part of the workshop to identify and prioritize technical uncertainties and gaps on the basis of design impact, and to recommend new initiatives to resolve the identified gaps and advance spar VIM design practice.
DEPLOYMENT OF RESULTS:
The success of the workshop will largely depend on industry’s willingness and ability to share certain proprietary information that can substantially contribute to any of the three major objectives listed above. To the extent that the workshop will produce concrete recommendations for new industry initiatives to advance VIM design practice, it is understood that proprietary information exposed by workshop participants will be made available to participants in such new initiatives, that is, information presented at the workshop will be released to the public domain. In particular, workshop presenters will be requested to submit their presentations for publication in the workshop proceedings.
ANTICIPATED PROJECT DURATION: 1 year
PROJECT PLAN FOR YEAR 2003-2004:
Scope of Work:
Seek buy-in for workshop from major industry stakeholders and form a Steering Group of technical experts from the stakeholder organizations. Engage the SG in a series of meetings to define the case for action, plan the workshop agenda, and identify specific presentation topics and speakers. Recruit workshop speakers, arrange venue and coordinate logistics. Workshop will be held in fall 2003 and will likely require three days.
Anticipated Results:
A workshop proceedings will be published documenting all presentations, discussion group summaries and recommendations for new initiatives.
SPONSORSHIP: MMS
PRINCIPAL INVESTIGATORS: R.S. Mercier, E. G. Ward
Date: June 2004
Project Name: Spar VIM Workshop
Project Number: 482 Task Order: 73616
Principal Investigators: Richard S. Mercier and E.G. Ward
Estimated Completion Date: August 2004
Project Description:
Industry needs widely accepted and consistent practices for addressing Vortex-Induced Motions (VIM) of spars in order to ensure the integrity of existing and future spar designs. To address the need for an industry-wide dialogue on spar VIM, a workshop will be conducted with the following major objectives:
• initiate a path for development of an industry-acceptable design practice/methodology on spar VIM,
• identify uncertainties and technical needs in spar VIM and a path forward to fill the identified gaps,
• educate industry on the technical challenges involved.Progress:
No progress has been made since the previous status report. However plans are to complete the draft workshop report by end of June 2004 and issue it to the workshop Steering Group for review. A final meeting of the Steering Group will be held in July to review the workshop recommendations, identify any follow-up initiatives that need to be pursued, and close out the project.
Reports & Publications:
R. S. Mercier and E. G. Ward, “Spar Vortex-Induced Motions Workshop – Proceedings”, in preparation.
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Date: December 2003Project Name: Spar VIM Workshop
TEES Project Number: 32558-60250 MMS Task Order: 73616 MMS Project Number: 482
Principal Investigators: Richard S. Mercier and E.G. Ward
Estimated Completion Date: August 2004
Project Description:
Industry needs widely accepted and consistent practices for addressing Vortex-Induced Motions (VIM) of spars in order to ensure the integrity of existing and future spar designs. To address the need for an industry-wide dialogue on spar VIM, a workshop will be conducted with the following major objectives:
Progress:
- initiate a path for development of an industry-acceptable design practice/methodology on spar VIM,
- identify uncertainties and technical needs in spar VIM and a path forward to fill the identified gaps,
- educate industry on the technical challenges involved.
A Steering Group (SG) of technical experts from the major industry stakeholders was formed to define the case for action, plan the workshop agenda, and identify specific presentation topics and speakers. The SG met on a monthly basis for 6 months prior to the workshop to solidify what turned out to be a 3-day agenda. The workshop was held from October 22-24, 2003 at the Camp Allen Retreat and Conference Center in Navasota, TX. Over 100 representatives from 38 organizations participated in the workshop.
The first part of the workshop was devoted to industry presentations reviewing the current regulatory perspective, design and model testing practices, and various design validation studies based on field measurements. Structured discussion sessions were held for the latter part of the workshop to identify and prioritize technical uncertainties and gaps on the basis of design impact, and to recommend new initiatives to resolve the identified gaps and advance spar VIM design practice.
Some of the higher priority gaps that were identified included:
- a need for oceanographers and designers to work more closely together in understanding the uncertainties associated with
so that credible cost-benefit trade-offs can be made to justify future investments in sophisticated field and laboratory measurement programs,
- metocean (particularly current) data and criteria and
- modeling & prediction of spar VIM,
- a need to better understand the uncertainties associated with existing model test practices (which vary significantly from one organization to the next) and to validate these practices using benchmark field data
- a need for test data on high stress/low cycle fatigue behavior of mooring chain and industry consensus design criteria for strength design of mooring and risers under repeated high stress fatigue loading associated with spar VIM.
A workshop report documenting all presentations, discussion group summaries and recommendations for new initiatives is being prepared. The draft report is nearly complete and will be distributed to the SG for review prior to publication.