Patent ID: 7401645
Filing Date: 2008-07-22
Classification: E21B

Abstract:
1. A downhole stuffing box for use in a subterranean well, said downhole stuffing box comprising: a substantially tubular housing having a first end and a second end; an elongated rod positioned through said housing; a first primary annular seal set positioned around said rod and within said housing between said first end and said second end, said at least one first primary annular seal set having an orientation to inhibit first end fluid flow axially along said rod from said first to said second end of said housing, said first primary annular seal set being primarily energized by said first end fluid; and a second primary annular seal set positioned around said rod and within said housing between said first primary annular seal set and said second end, said second primary annular seal set having an orientation to inhibit second end fluid flow axially along said rod from said second to said first end of said housing, said second primary annular seal set being primarily energized by said second end fluid, wherein the housing has a reduced diameter central passage between the first primary annular seal set and the second primary annular seal set, and the first primary annular seal set and the second primary annular seal set face oppositely from each other and away from the reduced diameter central passage, wherein the housing further defines a first annular shoulder between the reduced diameter central passage and the first primary annular seal set and a second annular shoulder between the reduced diameter central passage and the second primary annular seal set, said downhole stuffing box assembly further comprising a first annular adapter positioned between the first primary annular seal set and the first annular shoulder, a second annular adapter positioned between the second primary annular seal set and the second annular shoulder, a first spring positioned within said housing and carrying a first spring retainer which acts to compress said first primary annular seal set against the first annular adapter and provide secondary energization of said first pximary annular seal set, a second spring positioned within said housing and carrying a second spring retainer which acts to compress said second primary annular seal set against the second annular adapter and provide secondary energization of said second primary annular seal set, a first annular secondary seal positioned around said rod and within said housing between the first primary annular seal assembly and the first end of the housing, and a second annular secondary seal positioned around said rod and within said housing between the second primary annular seal assembly and the second end of the housing.