Abstract: Mechanism for achieving the radial expansion of an annular elastomeric pack-off unit between the bore of a casing and the exterior of a liner, comprises a tubular sealing assembly threadably connected between the liner and the hanger and defining two inwardly projecting annular seals, an annular fluid pressure chamber, and radially disposed fluid inlet ports for the fluid pressure chamber located between the two inwardly projecting annular seals. An annular piston mounted in the annular pressure chamber effects the compressible expansion of an annular elastomeric seal element. A tubing extension of the work string is provided which may be selectively moved into sealing relationship with either or both of the internally projecting annular seals. During the cementing operation, the tubing extension engages both annular seals.

Abstract: This invention provides a method and apparatus for effecting two stage cementing of well conduits by supplying cement through a tubular member. The apparatus involved provides a tubular conduit extension attachable to the bottom end of a well conduit and defines a cementing passage through its bottom end. Cementing ports are provided in the extension at a distance above its bottom end. A pair of concentrically adjacent valve units are communicable with the extension with the inner valve unit positioned in a closed position relative to the cement ports. The inner valve unit defines a seal bore which receives a mandrel which is secured to the tubular member. The mandrel incorporates two pilot sleeve valves which are positioned in closing relationship to radial passages in the hollow mandrel and each of which defines an upwardly facing surface for reception of sealing balls or plugs.

Abstract: A cementing float valve for subterranean wells is provided wherein a wiping plug retaining sleeve is concentrically positioned on the top of a float valve and secured to an outer housing by cementitous or other drillable material. the retaining sleeve provides a downwardly facing latching surface and a seal bore disposed above the latching surface for cooperation respectively with an expandable ring and an annular seal conventionally provided on a wiping plug.

Abstract: An apparatus for effecting two stage cementing of well conduits by supplying cement through a smaller diameter tubular member. The apparatus involved provides a tubular assembly attachable to the bottom end of a well conduit. The tubular assembly defines an axial cementing passage through its bottom end. Cementing ports are provided in the tubular assembly above its bottom end to implement the second stage cementing operation. A tubular member is sealingly secured in the upper end of the tubular assembly and valve units are provided between the end of the tubular member and the cementing ports. The lower annular valve unit is selectively releasably positioned in a closed position relative to the radial cement ports. At the conclusion of the first stage of cementing, a first sealing plug is dropped through the tubular member into sealing engagement with the bore of the lower annular valve unit and fluid is applied through the tubular member to shift the lower annular valve unit to an open position.

Abstract: A method and apparatus are provided for effecting the replacement of a cementing float shoe on the bottom of a well casing. A casing extension sleeve defines an upwardly facing locating shoulder and a seal bore adjacent such shoulder. A new or replacement float shoe is run into the well casing on the end of a tubular workstring and seated on the locating shoulder with an external seal engaging the casing seal bore. A plurality of radially expandable slip elements are provided in the replacement unit at a position above the external seal and such slips are retained in a retracted position by a retaining sleeve. Connection of the replacement cementing shoe to the workstring is achieved through a coupling sleeve having a threaded engagement with the replacement shoe and also being connected to the retaining sleeve.

Abstract: The disclosure relates to an improved apparatus for effecting the cementing of a liner at the bottom of a well bore. The liner sleeve assembly is inserted into the well bore on a hanger which is detachably connected to a running tool, which, in turn is connected to the work string by a torque transmitting expansion joint. The running tool may be fluid pressure actuated to set the hanger. In the event of failure of the fluid pressure setting operation, the hanger may be mechanically set by rotation of the work string transmitted to the running tool by the torque transmitting expansion joint.

Abstract: A centering device is provided which is adapted to be mounted on a running-in string for subsequent disposal in a well bore. Upper and lower companion supporting members having a plurality of circumferentially spaced openings therein and shoulders circumferentially extending around the uppermost interior of each of the supporting members are provided for receipt of circumferentially spaced and outwardly bowed springs having upper and lower ends overlying the lower portion of the exterior of the supporting members and extending inwardly through the openings. The springs have portions disposed in the openings with the upper and lower ends of the springs respectively engaging the upper and lower shoulder of the support members.

Abstract: Apparatus for and method of gravel packing a well, wherein a well liner is run into a well bore on a hydraulically set packer assembly which is releasably supported on a setting tool which provides a fluid flow crossover and seals which are selectively positionable within the packer body and a sealing receptacle in the liner. A ball is dropped to enable pressure to set the packer. The running tool is released and moved upwardly to a circulating position at which fluid can circulate downwardly through the running pipe string and the running tool, through the crossover to the annulus outside the liner to deposit gravel, the fluid flowing upwardly through the crossover and past the packer into the annulus outside of the running pipe string. The running tool is then moved further upwardly to position the seals for reverse circulation of fluid down the annulus outside of the running pipe string and through the crossover into the liner, and then back through the crossover into the running in pipe string.