Preselected casing tensioning system

摘要

A well assembly utilizes a casing tensioning system that allows a preselected amount of stretch to be applied in the casing. The assembly includes a tubular mandrel that secures to the upper end of the string of casing. A load ring has internal grooves that mate with exterior grooves on the mandrel, the load ring being of a ratcheting type. A retainer will latch the load ring in the wellhead housing. A positioning ring mounts to an upper portion of the mandrel to position the load ring at a desired distance above a stop shoulder on the lower portion of the mandrel and the load ring. During tensioning, the load ring remains stationary in the wellhead housing as the mandrel is pulled upward until the stop shoulder contacts the load ring.