Method and apparatus for locking out a subsurface safety valve

A lockout tool dimensioned to be received within a housing of a subsurface safety valve (SSV). The lockout tool generally comprises an elongated housing, and an expander mandrel slidably received within the housing. Together, the elongated housing and expander mandrel are run into the wellbore and landed into the housing of the SSV such that the end of the expander mandrel opens the flapper valve. A portion of the lookout tool housing shoulders against the flow tube in the SSV to drive the flow tube downward, thereby maintaining the flapper of the SSV in its open position. As the expander mandrel moves downward through the hard scat of the SSV, the mandrel engages the flow tube and expands it against the hard seat. In this manner, the flow tube is expanded into permanent, frictional engagement with the hard seat. This, in turn, looks the flapper member of the SSV in its open position.