Abstract: A subsurface tool adapted to extend within a wellbore includes an integrally formed single-component body that defines an external surface and an internal chamber isolated from the external surface. When the tool is subjected to one or more stresses, a stress concentration is created within a stress zone of the single-component body, the stress zone being adjacent the internal chamber.

Abstract: Wellbore systems containing a hydraulically regulated primary safety valve may have their hydraulic regulation transferred to an insert safety valve disposed in a nipple. Transfer of the hydraulic regulation may take place mechanically, such as through axial displacement of a sliding sleeve or by replacement of a hydraulic spool. Wellbore systems configured for axial displacement of a switching mechanism may comprise: a tubing string comprising a nipple and a primary safety valve, the primary safety valve being disposed in the tubing string above or below the nipple; a control line and a balance line in hydraulic communication with the primary safety valve and in latent hydraulic communication with an internal flow pathway within the nipple; and a switching mechanism that is axially displaceable to establish hydraulic communication between an insert safety valve positioned in a bore of the nipple and both the control line and the balance line.

Abstract: A subsurface tool adapted to extend within a wellbore includes an integrally formed single-component body that defines an external surface and an internal chamber isolated from the external surface. When the tool is subjected to one or more stresses, a stress concentration is created within a stress zone of the single-component body, the stress zone being adjacent the internal chamber.

Abstract: A subsurface tool adapted to extend within a wellbore includes an integrally formed single-component body that defines an external surface and an internal chamber isolated from the external surface. When the tool is subjected to one or more stresses, a stress concentration is created within a stress zone of the single-component body, the stress zone being adjacent the internal chamber.

Abstract: A subsurface tool adapted to extend within a wellbore includes an integrally formed single-component body that defines an external surface and an internal chamber isolated from the external surface. When the tool is subjected to one or more stresses, a stress concentration is created within a stress zone of the single-component body, the stress zone being adjacent the internal chamber.

Abstract: Wellbore systems containing a hydraulically regulated primary safety valve may have their hydraulic regulation transferred to an insert safety valve disposed in a nipple. Transfer of the hydraulic regulation may take place mechanically, such as through axial displacement of a sliding sleeve or by replacement of a hydraulic spool. Wellbore systems configured for axial displacement of a switching mechanism may comprise: a tubing string comprising a nipple and a primary safety valve, the primary safety valve being disposed in the tubing string above or below the nipple; a control line and a balance line in hydraulic communication with the primary safety valve and in latent hydraulic communication with an internal flow pathway within the nipple; and a switching mechanism that is axially displaceable to establish hydraulic communication between an insert safety valve positioned in a bore of the nipple and both the control line and the balance line.