Packer arrangements for oil wells and the like

#This invention relates to technology for subterranean recovery of oil and the like, and more particularly to seal arrangements for oil wells and the like.

#A variety of seal or packer arrangements have been devised to seal petroleum producing wells. A typical seal arrangement is of the baffle type, in which one or more cylinders are placed in longitudinal compression. Typical materials for these types of deformable seals are elastomers and special components such as graphite, asbestos, and wire. In oil recovery enhancement techniques, and in wells used in geothermal production, the packer frequently must seal the casing or tube annulus under conditions of elevated temperature, high pressure and corrosive surface environment. Because of the harsh environment and other technical requirements associated with such applications, a very durable seal that can be deployed with relative ease is necessary.

#In accordance with the invention, there is provided a packer that includes a body member with an annular recess in which a metal ring in its entirety is disposed. The recess has an annular opening at the outer surface of the body and has an outer peripheral surface for sealing engagement with the casing wall. Application of hydraulic pressure on the inner peripheral surface of the ring causes radially outward expansion and plastic deformation of the ring and forces the outer peripheral surface of the ring through the annular opening of the recess and into sealing engagement with the opposed surface of the casing or tube in which the packer is disposed.

#Further features and advantages of the invention will be seen as the following description of particular embodiments progresses, in conjunction with the drawings, in which:

#FIG. 1 is a diagram of a typical application of a packer in accordance with the invention;

#FIG. 2 is a sectional view taken along the line 2--2 of FIG. 1;

#Shown in FIG. 1 is a casing 10 that extends downwardly from the surface of the ground to an oil reservoir 12 or other subsurface geologic formation. Disposed within casing 10 is an integrated flowing system that includes tubing sections 14, 16 (and other appropriate hardware not shown) and a packer unit 20 that has an upper coupling 22 connected to tubing section 14 and a lower coupling section 24 connected to tubing section 16.

#Further details of the packer may be seen with reference to FIG. 2. Casing 10 has an inner diameter of about 63/8 inch. The packer includes a tubular body 26 of heat treated tool steel (e.g., 4140) that is about fifteen inches in length and defines a through passage 28 about 21/2 inches diameter. Formed integrally with body 26 is an annular flange 30 that has an outer diameter of about 57/8 inch and an axial height of about 11/4 inch. Formed on upper surface 32 is an annular peripheral recess 34 (FIG. 3) which receives sleeve 36; and formed in the lower surface of flange 30 is an inclined annular die surface 38. Seated on flange 30 are series of two die rings 40, 50 that are secured by nut 54 that is threadedly received on the lower end of tube 26. Formed in die ring 40 are two die surfaces 42, 44 each inclined at 71/2 degrees. Inclined die surface 52 is similarly formed in ring 50.

#A metal ring 60 of trapezoidal cross-sectional configuration is disposed in each recess defined by opposed die surfaces 38, 42 and 44, 52. Each ring has a width or radial dimension of 11/16 inch, a height at its inner peripheral surface 62 of 0.5 inch, a height at its outer peripheral surface 64 of 0.3 inch. The upper and lower surfaces 66, 68 of each ring 60 are clamped firmly between the opposed extruding die surfaces 38, 42 and 44, 52 when the die rings 40, 50 are clamped against die flange 30 by nut 54.