Improvements in or relating to well abandonment

摘要

A method for removing a section of well tubing involves: a) providing a work string with a hydraulic tensioning device 14 and a section mill 12 mounted below the hydraulic tensioning device; b) lowering the work string into tubing to be milled; c) pumping fluid through the work string to actuate the section mill and extend cutter blades; d) rotating the section mill 12 to mill the tubing with the cutter blades; e) pumping fluid through the work string to actuate the hydraulic 14 tensioning device to hydraulically pull a lower end of the hydraulic tensioning device upwards towards the work string thereby pulling the section mill 12 upwards while milling the tubing; f) raising the work string to extend the hydraulic tensioning device while milling the tubing; g) repeating steps (e) and (f) to remove a longitudinal section of the tubing. Also claimed is an apparatus for performing the method, the apparatus including a hydraulic tensioning device 14; a section mill 12 and an indicator (76, 2c) fig to provide first and second signals when the hydraulic tensioning device is towards the end of its stroke.