Patent ID: 7823646

Claim:
A tensioner for applying tension to a subsea member extending to a floating offshore structure, comprising: inner and outer barrels telescopingly engaging each other, one of the barrels adapted to be mounted to the offshore structure and the other to the riser; the barrels having interiors in fluid communication with each other, defining a chamber containing a gas under pressure, the gas pressure urging the barrels toward an extended position: a primary seal between the inner and outer barrels at an interface between the inner and outer barrels, the primary seal sealing the gas pressure within the chamber, the primary seal separating a high pressure portion of the interface, which is exposed to the gas under pressure, from an atmospheric pressure portion of the interface; an annular lubricant reservoir mounted in the chamber to an interior wall surface of the inner barrel, the lubricant reservoir containing a lubricant that is exposed to the gas pressure; a lubricant port extending from the lubricant reservoir through a sidewall of the inner barrel to an exterior wall surface of the inner barrel in the high pressure portion of the interface for dispensing lubricant to the high pressure portion of the interface.