Abstract: The present invention involves a tool for connection to a conventional drill string and operation therewith for punching holes in a standard casing located within a well bore to pass water or gas therethrough for recovery at the well bore surface, the invention involving a pivotally arranged blade that can be extended by air, water, or mud that has passed through the drill string to impinge on a trigger end of that blade, a point end thereof engaging the casing wall whereafter, by forcing the drill string and tool downwardly, the blade pointed end will puncture the casing, removal of the blade from the casing wall involving only ceasing passing of air or fluid against the blade trigger and lifting of the drill string and connected tool. The tool also involves a backup arrangement for connection to the tool body to increase the diameter thereof to allow the tool to be used in a number of different sizes of casings.

Abstract: The present invention consists of an under reamer tool for enlarging, scraping or smoothing a well bore. The tool is attached to a conventional drill string above a conventional bit and involves cutting elements that have retractable cutters arranged for extension from the tool to engage the well bore wall, each cutter, when the drill string is turned, being urged outwardly by centrifugal force until it engages the well bore wall, continued turning thereafter, pulling that cutter into its extended cutting attitude, reaming the wall to the desired diameter, cutter retraction involving ceasing turning the drill string and the pulling of the drill string and connected tool from the well bore.