SHAPE MEMORY MATERIAL PACKER FOR SUBTERRANEAN USE

A shape memory polymer is initially fabricated to a size where its peripheral dimension will be at least as large as the borehole wall in which it is to be deployed. After the initial manufacturing the material temperature is elevated above the transition temperature and the material is stretched on a mandrel (22) to retain its inside dimension as its outside dimension is reduced to size that will allow running the seal to a desired subterranean location without failing the material during the stretching. The material is allowed to cool below the transition temperature to hold the new shape. The material on the mandrel (22) is then secured to a tubular string and delivered to the desired location. Wellbore fluid at given temperature raises the material again above the transition temperature, which causes the material to revert to its originally manufactured shape. FIG.I