Abstract: There is disclosed apparatus for use in maintaining a well pipe centered within a well bore, including a centralizer adapted to be disposed about the pipe, and stop collars above and below the centralizer for limiting endwise movement of the centralizer as a whole, while permitting its outwardly bowed springs to expand and contract.

Abstract: A releasable drill string stabilizer is provided which includes a stabilizer body, a pair of end caps mounted with said body and a pair of clamping wedges positioned relative to the end caps and stabilizer body to clamp the stabilizer to a suitable drill string in various desired locations. A pin means and retainer slot means is provided for connecting the body and wedges relative to each other to prevent movement of such elements relative to each other and the drill string.

Abstract: A releasable stabilizer is disclosed for adjustable positioning along a drill string. The stabilizer includes a body positionable around the drill string; a coil spring mounted within the tubular body with the spring having a first and second end; anchoring apparatus mounted with the body to prevent the first end of the string from moving circumferentially around the drill string; and a rotating apparatus mounted with the body for moving the second end of the spring circumferentially around the drill string and anchoring the second end after the spring has gripped the drill string sufficiently tight to secure the body to the drill string while permitting the second end to be released when desired.

Abstract: A releasable stabilizer is provided for adjustable positioning along a drill string. The stabilizer includes a body positioned around the drill string with a threaded section on each end; a clamping wedge used at each end with an inwardly facing surface to grip the drill string; and a threaded end cap for forcing the wedge against the drill string by screwing the end cap onto the body to clamp the assembly onto the drill string.

Abstract: A tool is disclosed which fishes an object from a bore hole. The tool uses a tubular body having an upper and lower end, fingers are mounted within the body for moving between an opened position and a closed position and a spring is mounted within the body to use the fingers toward the lower end of the body. The movement of the fingers between the opened and closed positions is controlled by a camming mechanism slidably mounted within the body, which uses a sleeve forming a cam face defining a recycling "J" slot grooves and a pin extending from the body into the groove to cause the sleeve to rotate. Lugs are mounted with the sleeve for nesting within slots formed in the body to limit movement of the pin within the stems of the "J" slotted grooves.

Abstract: An apparatus adapted to be connected in a drill string is disclosed. It utilizes an axially located turbine which is driven by the mud flow through the drill string. The turbine is supported by a shaft and connected to an appropriate gear train. The gear train rotates an outer sleeve which has multiple turns of an external screw thereon. The screw or helix extends toward the wall of the drill bore. The helix lifts the column of mud in the annular space above the drill bit away from the drill bit thereby reducing the back pressure just above the drill bit. This improves the jetting action of the mud pumped through the drill bit and provides for a more rapid excavation of the immediate vicinity, thereby increasing the rate of penetration of the drill bit.