System and methodology for providing bypass through a swellable packer

A system for use in a well, comprising:

• a swellable packer having:
• an elastomeric element formed of an elastomer which undergoes swelling following contact with certain types of well fluid;
• and
• a mandrel extending through the elastomeric element and sealed with respect to the elastomeric element, the mandrel having an interior passage which is offset with respect to an external geometry of the mandrel such that the mandrel has a thicker wall section on one side of the mandrel relative to the other side of the mandrel, the thicker wall section containing a plurality of bypass conduits extending longitudinally through the mandrel, wherein the mandrel comprises an undercut region along an exterior of the mandrel and located between longitudinal ends of the elastomeric element, and wherein the elastomeric element abuts a transition of the exterior of the mandrel to the undercut region.

A method, comprising:

• forming a mandrel with an internal geometry and an external geometry such that an internal geometry cross-sectional center is offset from an external geometry cross-sectional center;
• providing the mandrel with an undercut region disposed along its exterior;
• positioning a swellable elastomeric element around the mandrel and along the undercut region, wherein the swellable elastomeric element abuts a transition of the exterior of the mandrel to the undercut region;
• sealing the swellable elastomeric element to the mandrel;
• and
• routing a bypass conduit longitudinally through the mandrel externally of the internal geometry and radially inside of the swellable elastomeric element.