Study on Vortex-Induced Vibration of Deep-Water Marine Drilling Risers in Linearly Sheared Flows in consideration of Changing Added Mass

Abstract

In order to more accurately predict the coupled in-line and cross-flow vortex-induced vibration (VIV) response of deep-water marine drilling risers in linearly sheared flows, an improved three-dimensional time-domain coupled model based on van der Pol wake oscillator models was established in this paper. The impact of the in-line and cross-flow changing added mass coefficients was taken into account in the model. The finite element, Newmark-β, and Newton–Raphson methods were adopted to solve the coupled nonlinear partial differential equations. The entire numerical solution process was realized by a self-developed program based on MATLAB. Comparisons between the numerical calculations and the published experimental tests showed that the improved model can more accurately predict some main features of the coupled in-line and cross-flow VIV of long slender flexible risers in linearly sheared flows to some extent. The coupled in-line and cross-flow VIV of a real-size marine drilling riser, usually used in the deep-water oil/gas industry in the South China Sea, was analyzed. The influence of top tension force and seawater flow speed, as well as platform heave amplitude and frequency, on the riser in-line and cross-flow VIV was also discussed. The results show that the platform heave motion increases the VIV displacements and changes the magnitudes of peak frequencies as well as the components of frequencies. The platform heave motion also has a significant influence on the vibration modes of the middle and upper sections of the riser. The impact level of each factor on the in-line and cross-flow VIV response of the riser is different. The improved model and the results of this paper can be used as a reference for the engineering design of deep-water marine drilling risers.

Dynamic Analysis of Marine Drilling Risers Considering Steady Current, Surface Wave, Internal Solitary Wave, and Vessel Motion

“…The rotation inertial term of the riser is also neglected. The lateral dynamic response governing equation of the riser can be written as follows [19,24]:…”

“…where T top is the top tension force (T top ¼ f top wH); f top is the top tension force coefficient; w is the wet weight per unit length of the riser; H is the water depth; K is the equivalent spring stiffness of the heave compensator (K ¼ wH=A c ); A c is the critical amplitude associated with the heave compensator (usually set as 10 m); A n is the amplitude of the vessel's heave motion; k n ; ω n , and ϕ n are the wave number, angular frequency, and phase angle of the random surface wave, respectively; α n is the difference of the phase angle between the vessel's heave motion and surface wave. The formulas of the wet weight and the corresponding mass are as follows [24]:…”

The Application Potential of Artificial Intelligence and Numerical Simulation in the Research and Formulation Design of Drilling Fluid Gel Performance

“…AI technology has been applied in all stages of oil and gas exploration and development, including reservoir modeling and characterization [ 24 , 25 , 26 ], drilling and production optimization [ 27 , 28 ], and enhanced recovery scheme selection [ 29 ]. In the drilling fluid industry, combining numerical simulation and AI technologies with the expertise of drilling fluid specialists can significantly improve the design and optimization of drilling fluids [ 30 , 31 , 32 , 33 ]. According to the existing literature, research on the design and performance optimization of drilling fluids has emerged [ 34 ].…”

Flow Past of a Drilling Riser System with Auxiliary Lines in Laminar Flow

“…Besides, Gao et al, [10] studied the effect of VIV on the heave movement by adjusting the added mass dependent. The rotation of the platform heave often had a major impact on the vibration modes of the riser.…”