Sharjah National Oil Company (SNOC) operates 3 fields Onshore Sharjah with 30+ years’ production history from over 50 gas condensate wells. The fields were produced historically under a blow down scheme resulting in significant condensate volumes being dropped. While these existing resources could be recovered through drilling additional wells apart from optimization opportunities in the current production regime, the most economical solution would be to verify if the existing well stock could be confirmed as having sufficient well integrity to safely allow the continued use of these wells thereby extending the field life through careful well and risk management.

The Sajaa and Moyeveid gas fields feature a series of challenging production issues. These include varying hydrogen sulphide levels upto 500 ppm, surface cemented annuli, sustained casing pressures, carbon steel tubulars, known corrosion issues greater than 0.5 mm per year, carbon dioxide and water production, all from multi-lateral wells at extremely low reservoir pressures. SNOC developed a comprehensive risk ranking process that categorized the wells into low, medium and high risk using a wide range of available production data, well age and corrosion inhibition data. Further investigation included corrosion logging data acquired from 2 wells in 2015 providing indicative well status and validation of electromagnetic corrosion measurement technology. Although, it did not provide a comprehensive and in depth review for a representative wider range of wells. In order to provide a more deterministic status of the well stock, and optimizing the risk ranking process, 10 wells were selected to be investigated with a campaign of corrosion logging in 2016. However, it was important that the intervention program would have minimal production impact with a small footprint slick-line intervention unit that would utilize state of the art magnetic imaging technology to record and measure the status of the well tubulars. Additionally, HSE impact was reduced by restricting the operations to daylight working hours and minimizing the numbers of personnel exposed to the well-site.

This paper summarizes the logging operations, analysis of the data collected, well tubular status & issues such as shallow surface corrosion and well correlation on a field basis. It also focuses on how this was integrated into the SNOC risk ranking model to allow continued production from the wells, while still maintaining the well integrity status that supported the company’s philosophy of managing risks ‘as low as reasonably practical’ (ALARP) maximizing recovery from a mature reservoir

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