Method to evaluate technical solutions Handle external loads on subsea wellheads

• Main Author: Karlsson, Niklas
• Format: Others
• Language: English
• Published: KTH, Hållfasthetslära (Avd.) 2018
• Subjects: Applied Mechanics; Teknisk mekanik
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-252771

A method to evaluate technical solutions to handle external loads on subsea wellheadshas been developed. The solutions, or concepts, are compared with respect to load relief,cost and operation. As a basis, a Pugh matrix was used. It is well proven and commonlyused amongst engineers to evaluate concepts. However, it has some major cons due toits simplicity.Two more layers were added trying to solve or minimize these cons. This made up a totalof three layers.I. Evaluation - gather concept data, answer questions with valuesII. Transformation - transforms gathered values to a [1-5] scalingIII. Comparison - scaled values are presented in a Pugh matrixIn layer I, questions are to be answered by analyses and expert knowledge, carried outby developers.As for layer II, a value-scaling relationship should be set by developers and decisionmakers. They decide what is a good difference compared with a reference, and what isnot. The values for layer I can then be translated to layer III.Lastly, in layer III the performances of concepts with respect to different criteria are statedin a Pugh matrix. A scaling [1-5] is used for this. The decision maker decides what criteriaare most important by weighting them.Besides that, everything could be made automated. So when the method was carried outon two concepts, a winner could be decided immediately in layer III when the questionsin layer I had been answered.A simple and straightforward method to compare concepts have been done. Visualizingthe concept evaluation process and the connection between developers and decisionmakers. Making it easier for them to understand one another.The method can continuously be improved over time and might have the potential to makethe development process in many companies leaner.