Integrity Management; Piloting of Gas-lift System in a Super Giant Field is building an accurate block in the development of effective strategy for well integrity management

Abstract

Abstract In a super-giant field onshore Abu Dhabi; the production strategy is to maintain the sustainable capacity but due to increase in water production the need of artificial lift is mandatory to maintain the production plateau. However, accurate well integrity management in such field is critical due to fluid characterization, souring environment and field extension (35 X 20 Km).The selection of the artificial lift technique plays an important role in improving the ultimate recovery. However managing the integrity of the artificial lift wells is more challenging under the presence of H2S, CO2 and high P & T. The loss of production caused by integrity related issues and the need to determine specifications and accurate future integrity management plan lead to need for a gas lift pilot. For the future it is envisaged that integrity assurance plans needs to be an integral part of the field-development planning, ensuring that asset value is maximized. More challenges will exist when dealing with Gas Lift as it is a long term artificial lift technique affecting well design for long life completion. Therefore, Gas lift was piloted to better understand real integrity challenges and measure corrosion trends with time to gain operational and technical experience and to compare them with initial theories. The pilot was monitored closely with intensive program. An optimization process was followed, assisted by modelling. Although the initial thought that the corrosion might affect the top part of the completions because of the injected gas specification, but the time-laps corrosion logs gave a completely different and unexpected picture. The pilot results enabled the overall project to be concluded; the lessons learnt from the pilot were captured and used as building block for the full-field development options. The paper describes the pilot results, the integrity challenges and the contoured problems, the philosophy of monitoring the corrosion evolution, the findings and how it was different from the initial expectation. Finally the clear impact on the integrity management process to ensure proper long-life well design and completion strategy.