LINER DRILLING SYSTEM WITH RETRIEVABLE BOTTOM HOLE ASSEMBLY

摘要

A liner drilling system employs a bottom hole assembly that may be retrieved before reaching the total liner depth. The system includes an outer string made up of a liner and a profile nipple. An inner string including a running tool, drill pipe, and a drill lock tool are lowered into the outer string and rotationally and axially locked to the outer string. Drilling may be performed by rotating the inner string, which also rotates the outer string. The operator may retrieve the inner string by pulling the inner string and the liner upward until the upper end of the liner is located at the drilling rig floor. While supporting the liner at the drilling rig floor, the operator retrieves the inner string, then re-runs it back into the outer string.