Patent ID: 6761217
Filing Date: 2004-07-13
Classification: E21B

Abstract:
A downhole system for locating and fixing equipment at a required depth and orientation within a wellbore, the system comprising a portion of well bore casing having an inner surface in which a latch profile is defined; and downhole apparatus comprising a latch sub for locating equipment secured thereto at a required depth and orientation, and an anchor packer for releasably fixing the depth and orientation of said latch sub relative to a well bore, said equipment being secured to the latch sub by means of a first connection between said equipment and the anchor packer and a second connection between the anchor packer and the latch sub, wherein the first and second connections prevent relative movement between the connected components, the latch sub comprising a body and a latching member mounted on said body so as to be movable between a retracted position and an extended position, the latching member projecting a greater radial distance from said body when in the extended position than when in the retracted position, wherein the latching member is adapted to project into said latch profile provided in said portion of well bore casing when in the extended position during use and wherein a first portion of said latch profile is adapted to be engaged by the latching member in such a way that, when pressed against said profile portion, the latching member tends to slide along a well bore casing edge defining said profile portion so as to locate the latching member in abutment with a second profile portion and thereby prevent further movement of the latch sub in the direction of pressing, the latching member being further adapted to engage a third portion of said profile in such a way that, when pressed against said third profile portion, the latching member is moved towards the retracted position so as to permit movement of the downhole apparatus past said latch profile.