Platform conductor integrity management in life extension of ageing offshore wells

Abstract

The increase in ageing offshore wells in most of the oilfields in the South China Sea, with their assets exceeding their design life is a challenge faced by operators worldwide. Severe corrosions on the metallic structures of oil wells consisting of the conductor and casings can result in catastrophic events leading to structural collapse. This paper describes the engineering methodology involved in the integrity assessments for platform conductor evaluation using analytical methods to assess the present condition of the conductor/casing assembly based on corrosion inspection data and existing cement elevations. In cases where a physical repair is not possible, recommendations would be made for inspecting the anomaly for signs of worsening, conductor buckling and material degradation. A rehabilitation flow-chart is developed in the repair or replace the decision-making process, hence prolonging the well operating life. It is mainly to provide understanding and guideline for conductor integrity management.