The purpose of this talk will be to analyze the 2d Navier-Stokes equations in a half plane with no-slip boundary conditions, when the initial vorticity is a Dirac mass (point vortex) located at finite distance from the wall. Our main result is the well-posedness of the system for arbitrary Reynolds number, thereby generalizing a previous result of Abe when the Reynolds number is small. The strategy of the proof relies on a careful decomposition of the solution into a vortex part and a boundary layer part, and on the properties of the Navier-Stokes system linearized around a point vortex in the whole plane. This also allows us to compute the initial speed of the vortex. This is a joint work with Thierry Gallay.