Digital Solution for Coiled Tubing Pipe Pull Test Automation and Placement Optimization

Abstract A new coiled tubing (CT) pipe pull test placement optimizer and automation solution is developed and integrated into an autonomous CT unit. This method provides consistency in strategic and automated pull test placement to extend the life of the pipe and consequently reduce total cost of ownership and greenhouse (GHG) emissions. A case study in the North Sea showcases the solution in real-time operations and simulated cases demonstrate the potential impact. Pull tests are a common means of mitigating stuck pipe in CT operations. Traditionally, they are executed at fixed intervals while the CT is run in hole. Risks associated with this rote approach include repeated pull tests at an already fatigued section, which accelerates fatigue of the CT pipe, and pull tests executed in wellbore sections with completion restrictions. The new solution addresses those risks by systematically combining the pipe's fatigue profile, weld points, and completion information to strategically adjust the pull test schedule, reducing the impact of those tests on pipe fatigue and the risks associated with drifting across downhole completion jewelry. The pull test automation and optimization are integrated into an automation-enabled CT unit in the North Sea. The automation eliminates the human factor and the risk of repeating pull tests at the same locations on each run; it also minimizes pull tests at the weakest points, which include the weld points where cycle fatigue is accelerated, and it eliminates pull tests at restrictions, reducing the risk of abrading or damaging completion jewelry. Finally, besides standardizing pull test placement, the combination of the pull test optimization and automation frees the CT operator to focus on other critical elements of the operation such as running and monitoring the unit and downhole tools, managing the crew, and engaging the customer representative. The performance of the pull test automation and optimization solution is tested in a simulated environment to quantify the impact on the CT pipe from new (0% fatigue) to end of life (EOL, 100% fatigue). The simulation uses a CT pipe with 1 3/4-in. outer diameter (OD) and a mission profile from a previous intervention campaign. CT of this OD is common in CT operations worldwide, making it an interesting test subject for the analysis. As compared to the traditional pull test approach, the optimized pull test placement redistributes the fatigue to less-fatigued sections of the pipe and extends the useful life of the pipe from 137 runs to EOL to 176 runs to EOL. Extending the useful life by 28% is equivalent to reducing the pipe's run-on-run cost and GHG manufacturing emission contributions by 22%.