Rückgewinnbare Führungsankeranordnung und Verfahren zum Fräsen einer Bohrlochverrohrung

A tubular anchor assembly (22) coaxially and releasably securable in a subterranean well bore casing, comprising: a tubular inner mandrel (88); a tubular slip carrier (98,132) coaxially circumscribing the inner mandrel in a radially outwardly spaced relationship therewith, the slip carrier having a circumferentially spaced series of side wall slip windows (100, 102, 136, 138) therein and outwardly bounding an annular space between the inner mandrel and the slip carrier; a circumferentially spaced series of slips (40,42) carried in the annular space for radial movement through the slip windows between retracted and extended positions; and a circumferentially spaced series of arcuate, elongated spring members (108) disposed in the annular space and resiliently biasing the slips toward their retracted positions, the spring members being interdigitated with the slips and having longitudinally central portions secured to the slip carrier, with each slip being engaged by end portions of two spring members on circumferentially opposite sides thereof.