swell with a band that grows with them not shown because of its elastic qualities or one that stretches and snaps at a given point of swelling in that way the petals retain their relative positions better as they swell the length can vary to suit the desired application the cross sectional shape can also vary and the contact surfaces during swelling do not need to be arcuate but could also be straight regardless of the cross sectional shape the interaction of the petals 12 upon swelling is to interact with each other so that the sealing force they ultimately provide is not simply defined solely by expansion that occurs during swelling rather it is a combination of the dimension change from swelling as enhanced by the overlapping layout of the petals 12 that boosts the sealing force beyond that simply provided from mere swelling of a plurality of petals a shape change for at least one of the petals 12 is contemplated as seen by comparing fig1 and 2 however in the ultimate shape created the adjacent petals 12 interact with each other when sealing is complete to enhance the force against the surrounding tubular or wellbore not shown the petals 12 can preferably have an individual covering 14 that is preferably a resin coated initially porous bag the bag initially lets well fluid though to the petal 12 to initiate its swelling process the well fluids.