The paper presents the results of reeling pipeline stresses and strains amplification investigation and describes the practical proved method to suppress the phenomenon, prevent a failure, and provide pipelay reliability and safety. Advantages of pipeline laying by reeling are the cause of worldwide use of this method for pipe diameters up to 12-inch and even more. Some time ago there were several occurrences of pipe rupture during reeling in area of pipe properties changes (wall thickness or pipe grade) from previous joint to the next one. The rupture surface inspections have shown significant and unusual overstress in the area as a result of stress/strain reallocation. Stress/strain amplification occurs at any joint with different properties along the pipeline on a reel drum and especially when the connection is leaving a drum surface. The pipeline reeling failures have caused companies significant losses. It is suggested an amplification suppression method by utilizing a special form transition joint between different properties adjacent joints. The presented procedure allows control of the transition joint stress/strain values depending upon joint geometrical and steel property variations. The analysis is based on curvilinear beam non-linear stress-strain consideration and presented in spreadsheet form. The above method has been successfully used during BPX Pompano Phase II Project and Pennzoil Flowline and Riser Project.
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