The invention provides a method and a system for sealing an annulus enclosing a tubular element in a wellbore. The method comprises the steps of introducing a first drilling fluid in the wellbore; drilling an open hole section of the wellbore using a drilling tool suspended at the end of a drill string; replacing the drilling fluid with a sealing fluid; extending the tubular element into the open hole section of the wellbore; and flushing part of the sealing fluid out of the wellbore, leaving an annulus between the tubular element and a wellbore wall filled with a layer of sealing fluid. The aforementioned steps may be repeated as required.