The paper focuses on the integrity of pipelines containing stress corrosion cracks (SCC) and whether shallow cracks can be recoated and returned to service without their removal by grinding, without the risk of failing later by fatigue.
The paper results from a collaboration between the pipeline operator, a research institute and a university department; it draws together several observational, experimental and analytical aspects concerning the shape and disposition of SCC revealed by inspection, the manner and extent of fatigue crack growth due to operational loading, and the failure pressure of groups of complex-shaped cracks. The benefit of utilising Clockspring repairs to reduce fatigue loading and crack growth is also explored both analytically and experimentally.
By drawing together the results of this widely ranging work, the authors have provided simple defect-acceptance guidance enabling the continued safe operation of the pipeline containing recoated shallow SCC, saving the operator substantial remediation costs. The same approach, principles and potential benefits could be applied to other pipelines containing shallow SCC.
In David’s opinion, the paper demonstrates several of the ingredients that make for an excellent JTM paper; collaboration between a range of organisations and disciplines, from operator field staff to academic researchers; a multi-stranded assessment of the problem and identification of the steps needed to achieve the overall solution; and the development of a user-friendly deliverable that provides tangible, implementable, financially significant benefit. All this has been set out in a clear and easy-to-read paper.
The work reported in the paper has since led to several million dollars’ worth of savings on one major Australian pipeline and is expected to go on substantial annual savings into the future in Australia and elsewhere around the world.
The award was given for the paper that makes the greatest contribution to the safety, reliability or operational/installation economy of energy pipelines. The paper should also demonstrate novel thinking, either in the manner in which it addresses an issue or in the way it brings together several threads of a topic in order to advance understanding or deliver a solution. Finally, the paper should present the evidence, arguments, logical steps and conclusions in a clear and understandable way.