Multi-finger calipers have provided an excellent overview of internal tubing condition for the past fifty years. However, understanding the fine details of pipe condition over short intervals required familiarity and training in interpreting the raw curves produced by these tools. The development of digital caliper data and 3D visualization software has dramatically altered pipe condition evaluation at Prudhoe Bay, Alaska.

3D visualization software allows the average engineer to quickly and accurately understand the details of localized tubing damage. Additionally, computer processing of digital caliper data supports quick correlation of tubing damage to wellbore geometry, other leak detection logs, previous caliper data of the same well interval, and cross-correlation of data from different wells. This has resulted in dramatic improvements to recent wellwork decisions, allowing surgical placement of patches, plugs, and whipstocks. Caliper logs have been used to assess scale buildup prior to coiled tubing scale removal operations and have been run after removal to evaluate job effectiveness. Additionally, areal corrosion trends and velocity effects have been identified, resulting in recommendations to deter damage.

This paper presents several examples of how 3D visualization software has led to improved wellwork operations based on a study of approximately 500 calipers run in the Eastern Operating Area of Prudhoe Bay, Alaska.

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