The object of this project was to research current methods involving mathematical analysis of pipeline spans resulting from various configurations, i.e., bottom profiles, pipeline crossings, outcrop pinnacles, etc. Results of the analysis were compared with results from modern finite elements analysis (FEA) programs. The effects of thermal expansion, residual lay stresses and on-bottom stability will also be included in the analysis. The project encompassed the design process related to span analysis. A design procedure was generated that will allow engineers and designers to analyze incurred span stresses in subsea pipelines subjected to commonly experienced geometric configurations.
Research was done to determine the current industry 'state-of-the-art' for unsupported subsea pipeline spans. Information, from this research was used to develop a method to assess and analyze pipeline free spans. Preventive and corrective measures were also outlined. Five assessment and analysis methods were developed using variations from different sources. A different loading on pipeline free spans was addressed by each method. Combining the five methods resulted in a combined analysis method (CAM). The CAM can be performed by hand or using a spreadsheet.
The project is complete.