Abstract: A tool adapted for connection to the lower end of a fluid supply line comprising: a housing; a tubular stem telescopically received by the housing for relative reciprocal movement therewith in response to fluid pressure communicated to the housing through the supply line; a working element attached to one end of the stem for movement therewith; and a valve assembly carried by the housing and responsive to predetermined movement of the stem relative to the housing to relieve fluid pressure within the tool, permitting a return of the stem and housing to their initial position relative to each other. In the method, the tool is attached to the end of a fluid supply line and inserted into a well conduit, the continuous supply line is inserted into the conduit until the tool reaches a preselected level; the tool is operated by applying fluid pressure thereto through the supply line; and the supply line is further fed into the conduit as the tool advances through the conduit.