Abstract: A wellbore system comprises a borehole formed in an earth formation, the borehole having a borehole section containing a volume of gravel pack particles and at least one body of a swellable material. Each body of swellable material is adapted to expand from an unexpanded state to an expanded state upon contact of the swellable material with a selected fluid, wherein a flow passage is present in said borehole section allowing fluid to bypass the volume of gravel pack particles when the body of swellable material is in the unexpanded state. The body of swellable material is arranged to substantially close the flow passage upon expansion of the body of swellable material to the expanded state.