Dynamical characteristics analysis of a deepwater test string induced by high-pressure gas and its experimental verification. (15th August 2021)

• Record Type: Journal Article
• Authors: Mao, Liangjie; He, Xin; Xia, Dongqing
• Is Part Of: Ocean engineering. Volume 234(2021)
• Publication Date: 2021-08-15
• Subjects: Deepwater test string -- Fluid–structure coupling -- Method of characteristics -- Vibration -- Displacement; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2021.109011
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: To explore the dynamical characteristics of the deepwater test string, a fluid–structure coupling vibration model of the deepwater test string was established, and the model was solved by using the method of characteristics. A similarity experiment of the deepwater test string was performed to verify the model. Combined with the related data of a well in the South China Sea, the dynamical characteristics of the test string were analyzed to obtain the vibration regulation of the test string. Results showed that the test string vibrated periodically when gas passed through it, and its lateral deformation in the seawater segment was evidently larger than that in the formation. The test string's largest deformation was in the middle of the seawater segment, and its deformation in the upper part of the formation segment was larger to the middle and lower parts. A large longitudinal amplitude occurred in the lower part of the formation segment. With the increasing of surface current velocity, the lateral and longitudinal displacements of the test string in seawater segment increased. The lateral and longitudinal displacements of the test string increased with gas production and decreased with test string's thickness. Besides, the interaction effect between the gas and the test string increased with the gas density increasing. These results are highly significant for reducing the vibration of the deepwater test string and protecting its safety. Highlights: Established the calculation model of a fluid-structure coupling vibration for deepwater test string. Considered the deformation of the test string in the seawater segments. Verified the model with a similarity experiment. Discussed the influence of different factors on the dynamic characteristics for deepwater test string.