Deepwater milling completed two days faster with real-time CT data

An operator successfully dressed and baited a stuck CT fish in a deepwater well using the ACTive Xtreme™ CT real-time rugged downhole measurement tool. The operation was completed two days faster than conventional methods, with improved precision and reduced risk. Real-time data enabled better depth control and minimized operational uncertainty.

An operator faced a complex challenge in the US Gulf: a 3,914-ft CT fish was stuck at 24,020-ft MD, severely limiting communication with the perforated zone and reducing well injectivity. The fish’s geometry—oval cross section, outward-facing burs, and residual bend—complicated dressing and baiting operations.

Additional challenges, because of vessel heave and CT string elasticity, included depth-control issues, high buckling loads, and the risk of milling-induced damage. The operation required precise control and monitoring to avoid motor stalls and ensure safe engagement with the fish.

A custom BHA featuring a cut lip shoe milling tool was selected through yard testing and modeling. A downhole camera inspection provided critical visual data to guide the dressing strategy. The telemetry system allowed dynamic monitoring, helping detect motor stalls and confirm proper engagement with the fish.

The operation achieved the following:

• Successful dressing and baiting in a single run each.
• Reduced milling time by 2 days and baiting time by 12 hours.
• Minimized motor stalls and improved torque and WOB application.
• Enhanced depth control through real-time feedback.
• Validated tubing force models, improving planning confidence.

This integration of advanced telemetry and conventional techniques improved decision making, reduced troubleshooting time, and eliminated the need for additional trips.

For more information, read SPE-209001-MS.