A valve housing has a first flapper moveable from an open position in the housing in which two-way flow is allowed to a closed position in which only one-way flow is permitted. A first collet sleeve is moveable from a first position to a second position in the valve housing. The first collet sleeve in the first position retains the flapper valve in the open position. The collet sleeve is moveable from a first position to a second position which allows the flapper to move to a closed position.

A circulation test tool and method of performing a circulation test in a wellbore during single-trip casing cutting and removal. An anchor mechanism (20), a mechanical-set retrievable packer (22) and a cutting mechanism (18) allow gripping and cutting of casing (14) with the mechanical set-retrievable packer (22) being set after the cut to carry out the circulation test. The well is kept under control during the cut by application of tension on the drill string to set the packer (22) at any time. The arrangement provides full annulus flow pass at the packer during cutting. Embodiments describe additional features of a drill to dress a cement plug or a settable bridge plug.

A circulation test tool and method of performing a circulation test in a wellbore during single-trip casing cutting and removal. An anchor mechanism (20), a mechanical-set retrievable packer (22) and a cutting mechanism (18) allow gripping and cutting of casing (14) with the mechanical set-retrievable packer (22) being set after the cut to carry out the circulation test. The well is kept under control during the cut by application of tension on the drill string to set the packer (22) at any time. The arrangement provides full annulus flow pass at the packer during cutting. Embodiments describe additional features of a drill to dress a cement plug or a settable bridge plug.

The present disclosure generally relates to a flapper valve including a pressure relief assembly. The pressure relief assembly is operable to activate when a pressure differential across the flapper approaches or exceeds a design pressure of the flapper.

The present disclosure generally relates to a flapper valve including a pressure relief assembly. The pressure relief assembly is operable to activate when a pressure differential across the flapper approaches or exceeds a design pressure of the flapper.

A downhole tool includes an upper flow tube connected to a lower flow tube, an upper flapper sub-assembly including an upper flapper, and a lower flapper sub-assembly including a lower flapper. The upper and lower flapper sub-assemblies are installed with respect to the upper and lower flow tubes in an “O” configuration such that the upper and lower flapper sub-assemblies are in a closed position. The upper and lower flapper sub-assemblies are capable of being independently actuated. The upper and lower flow tubes remain stationary when the upper flapper sub-assembly or the lower flapper sub-assembly is actuated from the closed position to an open position.

A downhole tool includes an upper flow tube connected to a lower flow tube, an upper flapper sub-assembly including an upper flapper, and a lower flapper sub-assembly including a lower flapper. The upper and lower flapper sub-assemblies are installed with respect to the upper and lower flow tubes in an “O” configuration such that the upper and lower flapper sub-assemblies are in a closed position. The upper and lower flapper sub-assemblies are capable of being independently actuated. The upper and lower flow tubes remain stationary when the upper flapper sub-assembly or the lower flapper sub-assembly is actuated from the closed position to an open position.

A well safety valve, comprising: a first sub assembly, wherein the first sub assembly comprises: an outer housing having a central bore extending axially through the outer housing, wherein the outer housing comprises an outer wall having a receptacle formed in the outer wall; a piston disposed in the receptacle; a rod, wherein the rod is disposed at an end of the piston, wherein a first magnetic sleeve is disposed around the rod; a flow tube disposed in the central bore of the outer housing, wherein the flow tube comprises a second magnetic sleeve on an exterior surface of the flow tube; and a valve member disposed in the outer housing; and one or more magnetic sensors disposed in the outer housing between the first magnetic sleeve and the second magnetic sleeve; and a second sub assembly, wherein the second sub assembly is coupled to the first sub assembly.

A well safety valve, comprising: a first sub assembly, wherein the first sub assembly comprises: an outer housing having a central bore extending axially through the outer housing, wherein the outer housing comprises an outer wall having a receptacle formed in the outer wall; a piston disposed in the receptacle; a rod, wherein the rod is disposed at an end of the piston, wherein a first magnetic sleeve is disposed around the rod; a flow tube disposed in the central bore of the outer housing, wherein the flow tube comprises a second magnetic sleeve on an exterior surface of the flow tube; and a valve member disposed in the outer housing; and one or more magnetic sensors disposed in the outer housing between the first magnetic sleeve and the second magnetic sleeve; and a second sub assembly, wherein the second sub assembly is coupled to the first sub assembly.

A method can include directing fluid flow longitudinally through a well tool connected in a tubular string downstream of a longitudinally compressed circulating valve assembly, thereby causing the well tool to operate, and longitudinally elongating the circulating valve assembly while the fluid flow is ceased, and then increasing the fluid flow, thereby causing the fluid flow after the elongating to pass outwardly through a housing of the circulating valve assembly to an external annulus. Another method can include directing a fluid flow through a well tool connected in a tubular string downstream of a circulating valve assembly, thereby causing the well tool to operate, and decreasing then increasing a flow rate of the fluid flow, thereby causing the fluid flow to pass outwardly through a housing assembly of the circulating valve assembly to an external annulus. Circulating valve assemblies are also disclosed.