Abstract: A buoyancy assist tool has an outer case and a sleeve disposed in the outer case. The sleeve is movable from first to second positions in the outer case. A permeable membrane is attached to the movable sleeve at a lower end thereof. A rupture disk is mounted in the outer case. Fluid flow through the permeable membrane detaches the sleeve from the outer case and moves the sleeve from the first to the second position. In the second position, the sleeve creates an open bore for the passage of downhole tools therethrough.

Abstract: A buoyancy assist tool has an outer case and a rupture disk connected in the outer case. A sleeve is disposed in the outer case and movable from first to second position in the outer case. A rupture disk membrane of a rupture disk prevents the sleeve from moving to the second position prior to the rupture disk membrane rupturing. The outer case is configured to be connected in a well casing. A lock ring holds the sleeve in the first position.

Abstract: A buoyancy assist tool has an outer case with a rupture disk assembly connected therein. The buoyancy assist tool defines the upper end of a buoyancy chamber in a well casing. A sleeve in the outer case traps the rupture disk membrane after it has ruptured to provide full bore flow through the casing.

Abstract: A buoyancy assist tool has an outer case and a sleeve disposed in the outer case. The sleeve is movable from first to second positions in the outer case. A permeable membrane is attached to the movable sleeve at a lower end thereof. A rupture disk is mounted in the outer case. Fluid flow through the permeable membrane detaches the sleeve from the outer case and moves the sleeve from the first to the second position. In the second position, the sleeve creates an open bore for the passage of downhole tools therethrough.

Abstract: A buoyancy assist tool has an outer case and a rupture disk connected in the outer case. A sleeve is disposed in the outer case and movable from first to second position in the outer case. A rupture disk membrane of a rupture disk prevents the sleeve from moving to the second position prior to the rupture disk membrane rupturing. The outer case is configured to be connected in a well casing.

Abstract: A downhole tool. The downhole tool may include a tubular body and an inner sleeve that is slidable within the tubular body. The tubular body may include a port that allows fluid flow between a bore of the downhole tool and an area outside of the tubular body. The downhole tool may be sequentially positionable in a run-in position that blocks fluid flow through the port in the tubular body, then in an open position that allows fluid flow through the port in the tubular bod, and then in a closed position that blocks fluid flow through the port in the tubular body.

Abstract: A buoyancy assist tool has an outer case with a rupture disk assembly connected therein. The buoyancy assist tool defines the upper end of a buoyancy chamber in a well casing. A sleeve in the outer case traps the rupture disk membrane after it has ruptured to provide full bore flow through the casing.

Abstract: A method of isolating an open-hole section of a wellbore includes positioning, a liner, a valve, and a liner hanger that are attached to a working string adjacent an interface between the open-hole section and a cased section of the wellbore. The method includes injecting cement through the liner and the valve to form a first balanced cement plug within the open-hole section of the wellbore. Generally, the liner, the valve, and the liner hanger are secured within the balanced cement plug. After the balanced cement plug is set, the liner hanger is actuated and the liner, the valve, and the liner hanger are detached from the working string, which causes the valve to close and creates a mechanical barrier between the balanced cement plug and the working string. Additionally, the mechanical barrier is covered in cement to form another balanced cement plug.

Abstract: A method of isolating an open-hole section of a wellbore includes positioning, a liner, a valve, and a liner hanger that are attached to a working string adjacent an interface between the open-hole section and a cased section of the wellbore. The method includes injecting cement through the liner and the valve to form a first balanced cement plug within the open-hole section of the wellbore. Generally, the liner, the valve, and the liner hanger are secured within the balanced cement plug. After the balanced cement plug is set, the liner hanger is actuated and the liner, the valve, and the liner hanger are detached from the working string, which causes the valve to close and creates a mechanical barrier between the balanced cement plug and the working string. Additionally, the mechanical barrier is covered in cement to form another balanced cement plug.

Abstract: A method of isolating an open-hole section of a wellbore includes positioning, a liner, a valve, and a liner hanger that are attached to a working string adjacent an interface between the open-hole section and a cased section of the wellbore. The method includes injecting cement through the liner and the valve to form a first balanced cement plug within the open-hole section of the wellbore. Generally, the liner, the valve, and the liner hanger are secured within the balanced cement plug. After the balanced cement plug is set, the liner hanger is actuated and the liner, the valve, and the liner hanger are detached from the working string, which causes the valve to close and creates a mechanical barrier between the balanced cement plug and the working string. Additionally, the mechanical barrier is covered in cement to form another balanced cement plug.

Abstract: A method of isolating an open-hole section of a wellbore includes positioning, a liner, a valve, and a liner hanger that are attached to a working string adjacent an interface between the open-hole section and a cased section of the wellbore. The method includes injecting cement through the liner and the valve to form a first balanced cement plug within the open-hole section of the wellbore. Generally, the liner, the valve, and the liner hanger are secured within the balanced cement plug. After the balanced cement plug is set, the liner hanger is actuated and the liner, the valve, and the liner hanger are detached from the working string, which causes the valve to close and creates a mechanical barrier between the balanced cement plug and the working string. Additionally, the mechanical barrier is covered in cement to form another balanced cement plug.