Heretofore, wellbore anchors have been employed in practice using full circle segmented slips which, when acted upon by a suitable drive member, fragment into a plurality of individual slip parts. Full circle (one piece) segmented slip tools work well when the interior diameter of the pipe or casing in which the tool is to be set is uniform. For example, when the wellbore pipe from the earth's surface to the point where the tool is to be set is 5 inch (20.3 pound per foot) casing the inside diameter is 4.184 inches. After fragmenting the full circle slip inside this 5 inch pipe, the slip parts need to move laterally towards the pipe from about 1/8 to 1/4 inch before they contact and bite into the pipe wall to fix the tool in place at that point.
When the inner diameter of the pipe in the well is not uniform, the full circle segmented slip tool is not as useful. For example, there are situations where there are two pipe strings in the same wellbore, one pipe string being of a smaller diameter than the other and concentric in the interior of the larger diameter pipe, and the smaller diameter pipe terminates somewhere along the length of the larger diameter pipe. In such a situation if the smaller diameter pipe is not removed from the well, a costly procedure, the wellbore tools have to first pass through the smaller diameter pipe and then after they leave the bottom end of the smaller diameter pipe, work within the larger area provided by the larger diameter pipe. The limited 1/4 inch lateral movement for the foregoing full circle segmented slip is inadequate for setting such a tool in the larger diameter pipe below the point where the small diameter pipe terminates. For example, if the foregoing 5 inch pipe was the smaller pipe and was set inside 7 inch (29 pound per foot) casing as the larger pipe, the 7 inch casing would have a 6.184 inch inside diameter. In such a case, the well tool would have to pass through the 4.184 inch inside diameter of the 5 inch pipe until it reached the end of that pipe and entered into the area where only the 7 inch pipe was present. In 7 inch pipe the tool would have to move its slips approximately 11/4 inches laterally before the slips would engage the 7 inch pipe. Regular full circle segmented slips are just not capable of this magnitude of lateral movement.