DOWNHOLE APPARATUS RECOVERY

摘要

A sub for connection into a drill string. The sub comprises an upper body and a lower body, and is configured so that torque can be transferred from the upper body to the lower body. The upper and lower bodies are axially coupled by means of an axial coupling that is arranged to fracture when placed under a predetermined tension. Once fractured, the upper body can be separated from the lower body. The axial coupling is substantially isolated from said torque.