Abstract: The improved annular seal of the present invention provides a seal across an annular space between facing cylindrical surfaces and includes an outer annular ring, inner annular ring, the gap between the outer annular ring and the inner annular ring being suitably sealed at one end thereof so that the open end is open to admit pressure which is to be sealed between the two rings, an outer sealing element on the exterior of said outer annular ring, and an inner sealing element on the interior of the inner annular ring so that pressure exerted between the annular rings urges them apart and their sealing elements against the surfaces of the annular space. In another form of the invention three annular rings are provided with one end of the inner and outer rings being sealing to the end of the intermediate ring and with sealing elements on the exterior of the outer ring and on the interior of the inner ring so that the sealing elements are urged into sealing engagement with the surfaces of the annular space.

Abstract: The present invention relates to an improved well structure and the method of connecting the support ring to the well string within the well bore which includes the steps of lowering the support ring into the well bore in surrounding relationship to the well string and into seated position in the housing seat, lowering a pressure forming tool through the well string to the level of the support ring, pressurizing the tool to form the well string into tight secured and sealed relationship within the support ring and recovering the tool from the well string. The tool includes a means of increasing the pressure used in the forming process without subjecting the interior of the string along its full length to such forming pressure. The structure includes a support ring with an exterior shoulder for engaging the seat within the housing, a sealing profile of a plurality of internal grooves each of which is partially filled with pressure compensating material and a gripping profile of a plurality of gripping teeth.

Abstract: The improved wellhead structure of the present invention includes a casing or tubing string which is sealed to the housing without the aid of elastomeric seals and an internal bushing to assist in providing the tight gripping and sealing engagement between the string and the housing. The structure provides a substantial inner diameter which is unrestricted unless landing shoulder is included in the structure. Also, the internal bushing used with the cold forging of the string into the housing recess improves the gripping and sealing engagement therebetween. In one form the bushing includes a series of external projections which alternate with the gripping and sealing projections within the housing recess and in another form includes a resilient annulus between the interior of the bushing and the string to ensure the uniform application of pressure against the interior of the string.