Probe isolation seal pad

摘要

A seal pad comprising a base plate and an expandable material engaged with the base plate. The expandable material comprises an outer surface where a portion of the outer surface is used to form a seal against a borehole wall. A portion of the outer surface of the expandable material is expanded during the sealing against the borehole wall. The seal pad also comprises a retainer for controlling the expansion of the expandable material. The retainer controls the expansion of the expandable material by engaging at least a portion of the outer surface of the expandable material. Thus when the seal is formed by expanding the expandable material, at least a portion of the expandable material is contained by the retainer.