REMOVABLE AND RELOADABLE ORIFICE FOR A DOWNHOLE TOOL

Disclosed is an apparatus and method for providing an activation pressure for a down hole too comprising a tool string having a pressure activated tool located at a distal end thereof, an opening passing through the tool string from an interior to an exterior thereof and a blocking body locatable in said opening operable to block a portion of said opening while leaving a reduced opening therethrough selected to produce a pressure within the tool string sufficient to activate the tool at a first fluid flow rate, wherein the blocking body is formed of a material operable to be dissolved by a solvent. The method comprises pumping a fluid down the tool string at a first fluid flow rate to activate the tool, pumping a solvent down the tool string operable to dissolve the blocking body, pumping the fluid down the tool string at a second fluid flow rate above the first flow rate and transporting a replacement blocking body down the tool string to the opening.