Multi-shot tubing perforator

A perforator apparatus for punching holes in tubing within a well bore in which the apparatus is positioned comprises a punch (60) mounted within a housing (66) and retained in a holder (58) positioned on a tapered track (62); an opening in the housing (66) aligned with the punch (60); and hydraulically controlled means (20) including a movable ram (38) connected to the punch (60) within the housing (66). The housing (66) is adapted for positioning within tubing of a well bore. The hydraulically controlled means (20) selectively moves the punch (60) through the opening and into punching contact with the tubing with force sufficient to punch a hole therein. Thereafter the hydraulically controlled means (20) returns the punch (60) to the position within the housing. The punch may be operated to perform repeated punching operations without requiring removal from the well bore and associated tubing. The hydraulically controlled means can comprise a piston (48). A first valve (24, figure 3b) is provided for selectively metering fluid to a first side of the piston to move the piston linearly within the housing in a first direction, and to selectively prevent fluid flow to the first side of the piston to permit the piston to move linearly within the housing in a second direction opposed to the first direction. A second valve (26, figure 3c) is provided for preventing fluid flow to a second side of the piston opposite the first side thereof during metering of fluid flow to the first side of the piston by the first valve, and for metering fluid flow to the second side of the piston when the fluid flow to the first side of the piston is prevented by the first valve to move the piston in the second direction. The valves' (24, 26) conditions change as flow rate changes.