Abstract: A retrievable float valve hanger tool assembly provides a hanger sub having a first upper connection for attaching the hanger sub, for example, threadably, to a drill string or work string. A second lower connection means on the sub provides both external and internal threaded (for example) connections, which allow the sub to be connected on its inner threads to a float valve canister and at its external threads to an extension which forms a protective housing about the float valve and its valve canister during operation. The device places the float valve below the joint of the sub and the extension so that an explosive charge can be detonated at the joint allowing easy removal of the float valve from the drill string in the event that the drill pipe becomes stuck. A continuous bore through the assembly allows fluid circulation through the tool in the work string and also allows the explosive charge to be lowered by wireline, for example, to the tool assembly at the appropriate joint.

Abstract: A retrievable float valve hanger tool assembly provides a hanger sub having a first upper connection for attaching the hanger sub, for example, threadably, to a drill string or work string. A second lower connection means on the sub provides both external and internal threaded (for example) connections, which allow the sub to be connected on its inner threads to a float valve canister and at its external threads to an extension which forms a protective housing about the float valve and its valve canister during operation. The device places the float valve below the joint of the sub and the extension so that an explosive charge can be detonated at the joint allowing easy removal of the float valve from the drill string in the event that the drill pipe becomes stuck. A continuous bore through the assembly allows fluid circulation through the tool in the work string and also allows the explosive charge to be lowered by wireline, for example, to the tool assembly at the appropriate joint.