During the drilling and cementing wells, many fluids circulating in the annular space between the column jacket and rock formation. The good adherence of the cement column and the formation of coating depend on how well the drilling fluid is displaced out of the annular space for fluid washers and spacers and how well the grout displaces the latter. Failures may compromise the cementing hydraulic sealing of the well, causing serious environmental damage and production losses. Therefore, it is important to study the process of displacement of fluids in annular spaces. In this work we investigated experimentally the displacement of fluids in laminar regimes annular space formed by concentric tubes, but of variable eccentricity. The efficiency of displacement was associated with the configuration of the interface formed between the fluids. Visualization tests were conducted at the experimental plant at the existing Wells Hydraulics Laboratory, PUC-Rio. For better visualization of the fluid shifter were added to it, micro particles that reflect the incident light beam laser forming a viewing plane. The major difficulty for this technique was to find fluids with refractive indices similar. We studied several cases with different fluid pairs and different flow rates. The first case was a Newtonian fluid displacing less viscous to different flows, they are miscible. From the observed results, we started to use fluids immiscible with each other. Then we used a Newtonian fluid displacing a less viscous. Finally, we studied the behavior of a Newtonian fluid displacing a more viscous.