Theoretical Study on the Mechanics of a Coiled Tubing Working within a Marine Riser

Abstract

Abstract Due to its unique advantages, coiled tubing is now widely used in marine oil and gas exploitation operations, while the mechanical behavior of coiled tubing working within a marine riser is still unknown. The mechanical model of this special pipe-in-pipe system was built by analyzing the force of coiled tubing and marine riser, using quasi-static method. And the model was verified by experimental study. Based on the established model, the effects of different coiled tubing dimensions and platform transversal on the axial force of coiled tubing within a marine riser were analyzed. It was found that increasing the size of the coiled tubing can improve the axial load of the coiled tubing without affecting the force of the riser. While changing the platform transversal would have less impact on the coiled tubing, and a greater impact on the riser’s force. The mechanical model built can provide theoretical guidance on coiled tubing marine operations.