US Patent 7469750 Expandable seal

In one aspect, the present invention provides a sealing apparatus for use in a tubular member. In one embodiment, the sealing apparatus includes an expandable sleeve and an expandable a toroidal/ring-shaped seal. The seal seats within a circumferential saddle or groove formed in the sleeve. An exemplary seal has an enlarged diameter portion and presents a radially outward sealing surface. During expansion, the enlarged diameter portion is compressed against the tubular member but, at least initially, the remainder of the sealing surface is not compressed. Thus, the pressure associated with the compression is focused on the limited contact area between the seal and the tubular. Continued expansion can increase the contact pressure and/or the amount of contact area. In one arrangement, the seal is configured to provide a gas tight seal.