Study on axial force characteristics of coiled tubing rotating operation in marine riser under helical post-buckling. (1st October 2022)

• Record Type: Journal Article
• Authors: Chen, Yingchun; Li, Yanfeng
• Is Part Of: Ocean engineering. Volume 261(2022)
• Publication Date: 2022-10-01
• Subjects: Coiled tubing -- Axial force -- Torque -- Ocean load -- Helical post-buckling; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2022.112098
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: When using offshore rotating platforms for deep-sea operation, coiled tubing (CT) is affected by both the ocean load and torque. Moreover, the variation law of axial force complexity increases when the CT is in a helical post-buckling state. Therefore, in this paper, a "pipe-in-pipe" system test bench was built to simulate the effects of ocean loads and torques on the CT. A helical post-buckling state was reached and the axial force variation law was analyzed. The results have shown that both the ocean load amplitude and the initial torque increased the axial force fluctuation of CT. The torsion direction of helical post-buckling was determined by the direction of applied torque. Additionally, given the equal injection force, the greater the torque, the greater the helical post-buckling degree of CT and the lower the axial force transmission efficiency. Obtained results supplement the theoretical system of pipe mechanics and improve the operation efficiency of offshore rotating platforms. Highlights: a "pipe-in-pipe" system was designed to study the buckling behavior of coiled tubing. both the ocean load amplitude and the initial torque increased the axial force fluctuation. the torsion direction of helical post-buckling was determined by the direction of applied torque. the initial torque affects buckling configuration of inner pipe once the axial force is applied. the initial torque has a significant effect on the axial force transmission efficiency.