Reasons Analysis on Pipe Sticking and Tubing and Casing Failure in One Well

An investigation on the pipe sticking accident during the process of repairing of one well was done and failure reasons for the tubing and casing were analyzed.By well logging,it was found that the 139.7 mm×9.17 mm casing string at depth of 3 355.0-3 356.5 m was severely corroded and deformed,and 177.8 mm×10.36 mm casing string at depth of 3 098.42-3 208.42 m was also corroded and deformed.It was considered that the pipe sticking at depth of 3 355.0-3 356.5 m during well repairing was caused by the casing deformation and damage by comparing the pipe sticking position with the casing damage location.It was considered that the tubing and casing failure was related to corrosion in accordance with the damage feature of the casing and tubing.Anti-corrosion tubings and casings were suggested to adopt.