In face of increasingly challenging production scenarios, the oil industry has been forced to expand operational limits to higher flow rates, temperatures, and pressures. Therefore, challenging production scenarios are found, from integrity standpoint, leading to reduction in current equipment life expectancy. Premature failure of control lines due to fatigue in wells with intelligent completion is one of the problems that arises from those extreme conditions. These lines are exposed to turbulent flow in the annular region of the production string, causing sufficiently high vibrations and stresses. These dynamic stresses can lead to premature failure of the lines due to fatigue. To prevent these problems, and to develop more efficient designs, it is necessary to investigate the phenomena associated with the interaction of the line vibration with the vortex shedding of the flow. We modeled the phenomena using the DES (Delayed Detached Eddy Simulation) methodology, which has high computational cost due to the need of using small time steps and high mesh refinement. In order to reduce these computational costs, this work proposes to deal with structural and fluid dynamics analysis in a decoupled way. The forces acting on the control lines in the annular space of the completion well are obtained neglecting the flexibility of the lines. In parallel, the critical damping factor, necessary for the structural vibration analysis of control lines, is obtained through a Fluid-Structure Interaction (FSI) simulation of an elastic cylinder subjected to cross flow. The results obtained show that the present methodology is promising, allowing a better representation of the involved phenomena, compared to procedures currently available in the literature.