Abstract: A float collar tool for running a casing string assembly into a wellbore includes a non-fragmenting rupture disc that temporarily isolates light fluid trapped in a lower portion of the casing string from heavier fluid in the upper portion of the casing string, thereby reducing the horizontal weight of the casing string by an amount sufficient to overcome a drag force. After the casing string is landed at a final location in the wellbore, the rupture disc is burst by increasing fluid pressure in the upper portion of the casing string. The increased pressure activates a piston that then moves the burst rupture disc into a protective region of the tool so that the inside diameter of the casing string is substantially restored.

Abstract: An apparatus for at least partially sealing an annulus of a wellbore comprises a hollow mandrel pipe adapted to attach to a tubing string, and a cylindrical cage surrounding and attached to an exterior length of the mandrel pipe, the cylindrical cage having a plurality of generally lengthwise tortuous path apertures generally parallel with one another between the two open ends of the mandrel pipe, the plurality of generally lengthwise tortuous path apertures defining a plurality of bow springs therebetween, the plurality of bow springs bowed outward from the mandrel pipe.

Abstract: A float collar tool for running a casing string assembly into a wellbore includes a non-fragmenting rupture disc that temporarily isolates light fluid trapped in a lower portion of the casing string from heavier fluid in the upper portion of the casing string, thereby reducing the horizontal weight of the casing string by an amount sufficient to overcome a drag force. After the casing string is landed at a final location in the wellbore, the rupture disc is burst by increasing fluid pressure in the upper portion of the casing string. The increased pressure activates a piston that then moves the burst rupture disc into a protective region of the tool so that the inside diameter of the casing string is substantially restored.

Abstract: An apparatus for at least partially sealing an annulus of a wellbore comprises a hollow mandrel pipe adapted to attach to a tubing string, and a cylindrical cage surrounding and attached to an exterior length of the mandrel pipe, the cylindrical cage having a plurality of generally lengthwise tortuous path apertures generally parallel with one another between the two open ends of the mandrel pipe, the plurality of generally lengthwise tortuous path apertures defining a plurality of bow springs therebetween, the plurality of bow springs bowed outward from the mandrel pipe.

Abstract: A liner flotation system comprises a liner, a first valve, and a second valve configured to form a gas filled chamber within the liner. The first valve is operable to allow fluid flow into the chamber, and the second valve operable to allow fluid flow out of the chamber. A sleeve is disposed in the chamber, and the first valve is movable into engagement with the sleeve to provide an indication of a position of the first valve. A method of securing a liner in a well comprises lowering a liner having a gas filled chamber in the well, actuating a valve to open fluid flow into the chamber, removing the gas from the chamber, and moving the valve into engagement with a sleeve coupled to the liner to provide an indication of a position of the valve.

Abstract: A liner flotation system comprises a liner, a first valve, and a second valve configured to form a gas filled chamber within the liner. The first valve is operable to allow fluid flow into the chamber, and the second valve operable to allow fluid flow out of the chamber. A sleeve is disposed in the chamber, and the first valve is movable into engagement with the sleeve to provide an indication of a position of the first valve. A method of securing a liner in a well comprises lowering a liner having a gas filled chamber in the well, actuating a valve to open fluid flow into the chamber, removing the gas from the chamber, and moving the valve into engagement with a sleeve coupled to the liner to provide an indication of a position of the valve.