Well packer and method of use thereof

• US 4,403,660 A
• Filed: 08/08/1980
• Issued: 09/13/1983
• Est. Priority Date: 08/08/1980
• Status: Expired due to Term

• Current Assignee: Davis-Lynch Incorporated
• Original Assignee: MGC Oil Tools, Inc.
• Inventors: Coone, Malcolm G.
• Primary Examiner(s): Novosad, Stephen J.
• Application Number:
  US06/176,403
• Time in Patent Office: 1,131 Days
• Field of Search: 166/315, 166/187, 166/196, 166/179, 166/373, 166/387, 166/386
• US Class Current: 166/387
• CPC Class Codes: E21B 33/1277 characterised by the construction or fixation of the sleeve
• CPC Class Codes: E21B 33/128 with a member expanded radially by axial pressure E21B33/122, E21B33/124 take precedence

Abstract

A packer and a method of setting a packer is disclosed that combines features of both compression-set packing elements and inflatable packing elements. The packing element of the packer includes elongated strips of reinforcing material that are bent away from the packer mandrel, when the packer is set, to move an annular body of elastomeric material into sealing engagement with an adjacent surface. Upstream pressure is supplied to the space between the mandrel and the packing element to help hold the packing element in such sealing engagement.

Claims

1. A well packer for controlling the flow of fluid through a conduit in a wall bore, such as through the annulus between the drill pipe and the wall of the well bore comprising a tubular mandrel positioned along the longitudinal axis of the conduit, spaced annular packer heads mounted on the mandrel with at least one movable along the mandrel toward the other packer head, a packing element including a plurality of elongated, relatively narrow, strips of reinforcing material connected to and extending between the packer heads and arranged in a circle to bend away from the mandrel when the packer heads are moved together and inner and outer sheaths of elastomeric material positioned inside and outside the reinforcing strips and between the packer heads with the ends of the inner sheaths in sealing engagement with the packer heads, means for moving one of the packer heads toward the other to cause the reinforcing strips of the packing element to bend away from the mandrel to move the center portion of the packing element away from the mandrel and into sealing engagement with the well bore, and an opening in one of the packer heads through which the fluid in the conduit that is upstream from the packing element can enter the space between the mandrel and the packing element to exert pressure on the inside of the packing element and provide an additional force holding the packing element in its set position that varies directly with upstream pressure and combines with the force exerted on the well bore by the reinforcing strips to provide sufficient friction between the packing element and the well bore to hold the packer from movement relative to the well bore.

2. The packer of claim 1 in which the reinforcing strips are made of spring steel.

3. The packer of claim 1 in which the means for moving the movable packer head toward the other includes a sleeve extending over one end of the mandrel for axial movement relative to the mandrel, said sleeve having one end connected to the drill string and one end connected to the movable packer head whereby with the mandrel held against movement the drill string can move the sleeve and movable packer head toward the other packer head and set the packer.

4. The packer of claim 1 in which the means for moving the movable packer head includes an annular chamber, a piston member in the chamber and movable relative thereto, means connecting the piston member to the movable packer head, and means for supplying the chamber with fluid under pressure to move the piston member and movable packer head and set the packer.

5. A packer for sealing the annular space between the packer and a well bore comprising a tubular mandrel, first and second annular packer heads mounted on the mandrel in axially spaced relationship, a plurality of reinforcing members of resilient material attached to the packer heads and arranged around the outside of the mandrel between the packer heads and parallel to the longitudinal axis of the mandrel, an inner sheath of elastomeric material located between the reinforcing members and the mandrel with each end in sealing engagement with one of the packer heads, an outer sheath of elastomeric material surrounding the mandrel, means for moving one of the packer heads toward the other along the mandrel to cause the reinforcing members to bow outwardly and move the outer sheath outwardly into sealing engagement with the wall of the well bore, and a passageway in one of the packer heads through which upstream fluid may flow into the inside of the inner sheath and exert pressure through the inner sheath urging the inner and outer sheath and reinforcing members outwardly against the well bore to anchor the packer in the well bore and to enhance the sealing ability of the packing element in direct proportion to the pressure differential across the packer.

6. A method of sealing the annular space between a pipe string and the wall of the well bore comprising applying a compressing force in an axial direction to an imperforate tubular packing element carried by the pipe string to force the packing element to bow outwardly away from the pipe string and into engagement with the well bore while holding the ends of the packing element from moving outwardly away from the pipe string, holding the compressing force on the packing element, and supplying the space between the bowed out packing element and the pipe string with fluid from the annular space that is upstream of the packing element to allow the pressure of such fluid to enhance the seal between the packing element and the wall of the well bore in proportion to the pressure differential across the packing element and to anchor the packing element in the well bore.

7. A method of using a downhole well packer to close the annulus between a drill string and the well bore, or the annulus between a string of casing and the well bore, comprising the steps of applying a longitudinal compressive force to a plurality of longitudinally extending reinforcing strips to bend the strips away from a mandrel located in the drill string while holding the ends of the reinforcing strings from movement away from the mandrel, casing string or the like to move an imperforate elastomeric sheath into sealing engagement with the well bore and supplying the space between the sheath and the mandrel with fluid from upstream of the packer after the annulus has been closed by the elastomeric sheath to enhance the sealing ability of the sheath and to anchor the packer in the well bore.