Vortex shedding flow around a pipeline with a spoiler is simulated by solving the Navier-Stokes equations. The effect of spoilers on the velocity profile under the pipe and the seabed shear stress were investigated by a series of numerical tests. It was found that the attachment of a spoiler increased both the flow rate through the gap between pipe and seabed, and the shear stress on seabed. The increases are quantified for different spoiler lengths and gap ratios.