Well Integrity and Corrosion Analysis Techniques Applied to Tubular Design and Remaining Life Extension of Gas Production Wells

One of the most critical challenges comprising well integrity assurance is the compromise between tubular productive performance, fitness for service and overall risk. For some time, Pan American Energy has been involved in the development of a combined integrity-corrosion analysis technique, specifically conceived to ensure compatibility between high level corporative targets (such as productive and regulatory compliance demands) and integrity assurance programs.

In the last 2 years, a team integrated by corrosion and integrity engineers implemented the integrity-corrosion assessment method on high pressure gas wells, with the following objectives:

• To estimate and project metal loss rates on critical components (tubing – well head – flow line), affected by active damage mechanisms.
• To assess fitness for service, in order to estimate and, if necessary extend, residual life.

As a result of this approach, it became possible to increase production rates without sensible risk increment due to corrosion and erosion-corrosion damage, restructuring existing programs to compensate for metal loss evolution and eventual fitness for service compromise, in order to maintain residual life. The current Well Integrity Program was upgraded, including new prediction and mitigation methods, with focus on ensuring continuous fitness for service, safe operation, risk management and periodic performance evaluation.

Key Words: Corrosion – Erosion – Gas – Risk – Well - Integrity.