Investigation and Analysis of the Catastrophic Failure of an Offshore Water Injector Well

Abstract

The catastrophic failure of an offshore water injector well is presented in this paper. The failure mode was determined from the final collapsed state of the conductor pipe which resulted in the surface Xmas tree and wellhead to drop vertically down onto the platform deck. Various inspections and assessments are carried out to determine the integrity of the well structure and compared against the original drilling records. Stability evaluations of the casing is also carried out to account for the loss of annular cement which resulted in loss of centralisation. The analyses conclude that various sequence of events have contributed towards the failure of this well. The lack of intermediate inspections and monitoring have resulted in uninhibited corrosion and pitting on the conductor pipe. Some considerations on the necessity of an effective inspections strategy and rationalisations of a robust integrity screening are also drawn.