Well packers using metal to metal seals
AssigneeExxon Production Research Company
InventorsHarry R. Hanson, Hollis A. Baugh, Thomas W. Childers, James B. Greer
Life of this patent
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Abstract
An improved well packer for use in sour gas wells is disclosed. The improved packer includes a cylindrical mandrel encircled with a resilient metal seal ring, means for anchoring the packer at a predetermined vertical depth, means for radially expanding the seal rings so as to cause sealing engagement with the casing and mandrel, and ratchet means for maintaining the seal rings in expanded form. The packer is adapted to be run into the cased wellbore on tubing and is particularly useful in sour gas wells.
Claims27
A packer for insertion into a well casing which includes an anchor collar and a length of polished bore section located at a predetermined depth in the well, the packer comprising:
- (a) a hollow, cylindrical mandrel;
- (b) a resilient, frusto-conical rigid metal seal ring circumferentially disposed around said mandrel, said ring being sufficiently rigid such that application of an axial compressive force on the ring is capable of sustaining at the circumferential edge surfaces of the ring a transverse sealing force which exceeds said compressive force;
- (c) means for retracting said seal ring for passage through said casing;
- (d) means for anchoring said packer on said anchor collar, said seal ring being disposed within said length of polished bore section with said packer anchored;
- (e) means for expanding said seal ring into sealing engagement with said mandrel and said casing, and for applying sufficient force for effecting fluid tight metal-to-metal seals thereon;
- and
- (f) means for maintaining sealing force.
A packer for a cased wellbore wherein the packer is used to seal an annular space between tubing and casing in said wellbore, the packer which comprises:
- (a) a cylindrical, tubular mandrel for insertion into said cased wellbore,
- (b) anchoring means for engaging said packer with said casing at a specific vertical depth,
- (c) a plurality of frusto-conical, resilient metallic seal rings circumferentially disposed around and spaced longitudinally in groups of at least two along said mandrel, the frusto-conical surfaces of said rings parallel to each other, said rings being sufficiently rigid such that application of an axial compressive force on the rings is capable of sustaining at the circumferential edge surfaces of the rings a transverse sealing force which exceeds said compressive force,
- (d) means for elastically deforming said rings until sealing engagement with the walls of said mandrel and said casing occurs, and
- (e) means for maintaining said sealing engagement.
A well packer for sealing the annular space between tubing and casing in a well which comprises:
- (a) a longitudinally extending mandrel adapted to be lowered into said casing on said tubing:
- (b) means for anchoring said packer to said casing;
- (c) a plurality of frusto-conical, resilient metal seal rings encircling said mandrel, said rings being arranged in a stacked and nested relationship, and said rings being sufficiently rigid such that application of an axial compressive force on the rings is capable of sustaining at the circumferential edge surfaces of the rings a transverse sealing force which exceeds said compressive force;
- (d) means for applying force to said rings such that said rings are expanded into sealing engagement with said mandrel and said casing, and
- (e) means for maintaining said force.
A packer for insertion into a well casing which includes an anchor collar and a polished bore casing section located at a predetermined depth in a well, said packer comprising:
- a mandrel;
- a seal assembly encircling said mandrel and including a plurality of resilient, metal, frusto-conical seal rings, said assembly being movable relative to said mandrel, said seal rings having a normal retracted position, and said rings being sufficiently rigid such that application of an axial compressive force on the rings is capable of sustaining at the circumferential edge surfaces of the rings a transverse sealing force which exceeds said compressive force;
- means for anchoring said seal assembly on said anchor collar with said seal rings positioned in said polished bore section;
- means for moving said mandrel longitudinally relative to said seal assembly to a set position such that an axial compressive force is applied to said seal rings causing said rings to be expanded radially outwardly into sealing engagement with said polished bore section and radially inwardly into sealing engagement with said mandrel;
- means for maintaining said mandrel in said set position.
The packer as defined in claim wherein said seal ring comprises an alloy cobalt based austenitic stainless material.
The packer as defined in claim wherein said seal ring is formed of a corrosion-resistant metal which will not yield appreciably when said seal ring is in sealing engagement with said mandrel and said casing.
Dependencies are inferred from the claim text.