Effect of annulus drilling fluid on lateral vibration of drillstring

• Main Authors: Chunxu Yang, Rui-He Wang, Laiju Han, Qilong Xue, Lixin Li
• Format: Article
• Language: English
• Published: JVE International 2020-02-01
• Series: Journal of Vibroengineering
• Subjects: annular drilling fluid; lateral vibration; drillstring; added mass coefficient; cfd
• Online Access: https://www.jvejournals.com/article/20473

Annular drilling fluid between the drillstring and borehole wall has a great influence on lateral vibration of drillstring and the influence involves the added mass. Assuming the drilling fluid is incompressible, we derive the added mass coefficient that annular drilling fluid influences on lateral vibration of drillstring in the case of axial flow of drilling fluid. When the axial flow of drilling fluid is considered, the added mass coefficient is difficult to solve. We apply CFD method and dynamic mesh technique to establish the calculation model for the flow in the annulus caused by the vibration of drillstring in the annulus. The pressure distribution and velocity distribution of annular drilling fluid are obtained. The added mass force of the drilling fluid acting on the drillstring along the direction of the drillstring is obtained from the pressure distribution, and the added mass coefficient of the lateral vibration of the drillstring is obtained. This paper provides the basis to solve the added mass coefficient of the lateral vibration of drillstring considering axial flow of drilling fluid.