Abstract: A retrievable anchor assembly for use in well bores and the like includes a unitary mandrel arranged to be directly attached to the tubing, and at its lower end to additional tubing or to well apparatus such as a well pump. An upper expander is threaded onto the mandrel and a lower expander is attached to the mandrel by shear pins. A plurality of slips are disposed in curcumferentially spaced relationship about the mandrel and held in place thereon by a plurality of garter springs which extend through the slips. A cage encircles the upper and lower expanders and the slips and includes openings through which the slips project for engagement with the well bore wall. The cage also includes slots through which drag springs that are attached to the upper expander extend for engagement with the well bore wall whereby relative rotation can be accomplished between the mandrel and upper expander to move the slips between set and retracted positions.

Abstract: An improved slip and slip assembly for use with well tools such as anchors. The slip assemblies include a plurality of slips having ends formed by segments of circles, having a concave outer surface including teeth arranged to hold in both the upwardly and outwardly directions, and concave expander surfaces arranged to mate with the tapered surfaces of expanders on a well tool to move the slips into engagement with the well bore wall. The slips are held in the assembled relationship by a plurality of garter springs that extend through arcuate holes that extend through the sidewalls of the slips.

Abstract: An isolation valve that may be inserted in the casing of a subterranean well at a position above a production formation and operated to a closed position upon the withdrawal of the mandrel and wash tube commonly employed for effecting the gravel packing of the screen and production formation. The valve has a frangible flapper piercable by mechanical means or by increased pressure after removal of the wash tube.

Abstract: A hydraulically actuated running and setting tool includes a stationary setting tool mandrel that is connected to the packer by releaseable collets. Variable volume chambers are provided in the tool that are arranged so that no downward movement of the components relative to the space in the well bore below the packer is necessary. Setting is accomplished by hydraulic pressure and testing of the packer can occur prior to release of the setting tool from the packer. Release of the setting tool from the packer occurs by pulling upwardly on the setting tool with equalization of the pressure above and below the packer or applying additional hydraulic pressure as in setting until sufficient force is developed to part a shear member.