US 4,413,682 A · Method and apparatus for installing a cementing float shoe on the bottom of a well casing

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. After seating of the replacement shoe, initial rotation of the workstring in a first direction will produce a partial unthreading of the coupling sleeve and an axial displacement of the retaining sleeve, thus freeing the slips to radially expand into engagement with the casing wall. Upward movement of the workstring will effect the setting of the slips. Further rotation of the tubular workstring will effect the complete disengagement of the coupling sleeve, permitting the workstring, coupling sleeve and retaining sleeve to be withdrawn from the well with the replacement cementing float shoe unit sealingly secured in the bottom of the well casing.

Claims8

Dependent claims

A replaceable float shoe apparatus for securement to the bottom of a well casing, comprising:

a casing extension sleeve attachable at its upper end to the bottom of a well casing;
inwardly projecting means in the bottom bore portions of said casing extension for cement adherence of a drillable float valve;
a seal bore in said casing extension sleeve immediately above the position of the drillable float valve, said seal bore having a larger internal diameter than said inwardly projecting means, thereby permitting the drilling out of any cement adhered float valve without damage to said seal bore;
an upwardly facing annular locating shoulder adjacent said seal bore;
a replacement float shoe unit comprising a tubular housing containing a float valve, means in said tubular housing defining a threaded connection to a tubular workstring, an external locating shoulder on said tubular housing engagable with said upwardly facing annular locating shoulder in said sleeve when said tubular housing is run in on a tubular workstring;
an external annular seal on said tubular housing engagable with said seal bore, radially expandable slip means on said tubular housing above said external annular seal, a retaining sleeve for holding said slip means in a radially retracted position, and means connecting said retaining sleeve for axial co-movement with the tubular workstring, whereby rotation of the tubular workstring in the direction opposite the direction of the threads shifts said retaining sleeve upwardly to permit said slip means to radially expand into engagement with the inner wall of said casing extension sleeve.

3 more elements

For use with a casing string having a tubular bottom element defining an upwardly facing shoulder and a seal bore above said shoulder, a float shoe unit comprising a tubular housing containing a float valve, means in said tubular housing defining a threaded connection to a tubular workstring, an external locating shoulder on said tubular housing engagable with said upwardly facing annular locating shoulder in said sleeve when said tubular housing is run in on a tubular workstring;

an external annular seal on said tubular housing engagable with said seal bore, radially expandable slip means on said tubular housing above said external annular seal, a retaining sleeve for holding said slip means in a radially retracted position, and means connecting said retaining sleeve for axial co-movement with the tubular workstring, whereby rotation of the tubular workstring in the direction opposite the direction of the threads shifts said retaining sleeve upwardly to permit said slip means to radially expand into engagement with the inner wall of said bottom element.

Dependencies are inferred from the claim text.

Method and apparatus for installing a cementing float shoe on the bottom of a well casing

Life of this patent

Method and apparatus for installing a cementing float shoe on the bottom of a well casing

Life of this patent

Abstract

Claims8