Packing assembly for oilfield equipment and method

Abstract

An improved packing assembly is provided for forming a metal-to-metal sealing engagement between an outer cylindrical surface and an inner cylindrical surface within downhole or surface hydrocarbon recovery equipment having an axially extending flow path therein. The packing assembly includes an outer seal ring and a inner seal ring with upper and lower tapered surfaces, an upper energizing ring and a lower energizing ring each having tapered surfaces for sliding engagement with a tapered surface of the seal rings, and an interconnection member for limiting axial movement of the energizing rings. Projections on each of the seals rings are preferably provided for obtaining substantially line contact sealing engagement with the respective cylindrical surface, and each of these projections is spaced radially opposite and at substantially the same axial depth as a tapered surface on a respective upper or lower energizing ring, such that each of the projections is forced radially into sealing engagement with the corresponding cylindrical surface by a substantially equal force. According to the method of the present invention, the entire assembly is formed and may be lowered downhole to minimize installation costs, and the energizing rings thereafter moved axially together by the application of mechanical or hydraulic force to set the sealing assembly.