  We study the Navier-Stokes equations in dimension 3 (NS3D) driven by a noise
which is white in time. We establish that if the noise is at same time
sufficiently smooth and non degenerate in space, then the weak solutions
converge exponentially fast to equilibrium. We use a coupling method. The
arguments used in dimension two do not apply since, as is well known,
uniqueness is an open problem for NS3D. New ideas are introduced. Note however
that many simplifications appears since we work with non degenerate noises.
