As a wireline engineer, you’re often faced with challenges that demand quick decision-making and a solid understanding of both the equipment and the well conditions. During a recent job, we encountered a situation that pushed us to the limits of troubleshooting and problem-solving. The incident, involving a Probe Shooting Panel CCL (Casing Collar Locator) failure, gave us a deeper understanding of the crucial role wireline logging plays in ensuring smooth and precise operations.
The Situation
It all started during a routine wireline run at around 9,000 feet. The CCL signal, essential for logging collar depths in the wellbore, became weak and eventually disappeared entirely on our logging system. At that point, we made the decision to pull out of the hole to investigate. The main suspects for the failure included the CCL tool itself, a leaking cablehead, or the Probe shooting panel. After assessing the situation, we found ourselves stuck in non-productive time, estimated to be around four hours.
Troubleshooting the Issue
Our first course of action was to check the CCL calibration and thresholds, ensuring the equipment was functioning correctly. We also performed several successful switch tests on the Multitronic shooting software, but the CCL signal remained intermittent or entirely gone. As we continued troubleshooting, we eventually pulled out of the hole to replace the CCL tool and found a small leak in the slip rings, which we promptly changed out.
Despite these efforts, the CCL signal remained weak. This was when the backup Probe panel arrived, and once it was swapped in, the signal returned to normal. That’s when we realized the cause of the issue: the failure stemmed not from the downhole equipment, but from the Probe panel, which had developed a small leak that hindered the signal.
Action Items and Prevention
One of the key takeaways from this experience is the importance of understanding the signal routing within the wireline logging system. We realized that the Multitronic software, which provides real-time monitoring and diagnostics, could have tipped us off to the issue earlier. The lack of initial current changes on the downhole equipment should have signaled to us that the problem was likely with the Probe panel, not the CCL tool itself.
In hindsight, the leak in the slip rings, with a resistance of 195Mohms (compared to the acceptable value of >100Mohms), could have been a clue to avoid unnecessary part replacements. This is a vital learning moment for all engineers working with wireline logging systems, especially when dealing with the nuances of Cased Hole Logging and well perforation.
Preventive Measures
To prevent this situation from happening again, we’ve implemented a few key procedures to streamline troubleshooting and enhance system reliability. Here’s what we’ve put into place:
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Enhanced Signal Routing: When working with the Multitronic panel, we’ve modified the system to ensure the CCL signal is properly routed, allowing for better tracking during both logging and perforating. This modification involves connecting the CCL cable from the back of the Probe panel to the “logging system” port on the Multitronic panel. This allows engineers to gain up the CCL signal and confirm collar detection before perforating.
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Switching Back to ‘LOG’ Mode: When in the “PERF” mode, the Multitronic panel does not display movement on the onboard CCL meter. Therefore, we’ve implemented a practice of switching back to “LOG” mode to confirm the CCL response before proceeding with perforation operations. This ensures we never miss a step in the process and prevents costly mistakes.
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Using Backup Equipment: In the event that the primary Probe panel fails, having a backup ready and tested ensures that operations continue without significant delays. This is especially critical when working with wireline perforating systems, where time is of the essence.
The Importance of Communication and Preparation
This experience reinforced the need for clear communication between the wireline engineer and the team on the ground. In situations where well conditions are complex and the equipment is intricate, every small detail counts. Having a strong understanding of wireline services and tools such as wireline pressure control equipment, perforating systems, and wireline service providers helps ensure smooth operations even in unexpected circumstances.
By learning from this failure, we’re able to refine our approach to well integrity, Cased Hole Wireline operations, and wireline logging techniques. The focus on wireline perforating and production logging services can’t be overstated, as every step in the logging process helps create a clearer picture of the well’s condition.
Conclusion: Continuous Improvement in Wireline Services
Wireline logging is an essential part of modern well operations. Whether you’re running cased hole logging or performing downhole pipe recovery, the importance of understanding your tools, knowing the systems inside and out, and anticipating potential failures is crucial. With tools like the wireline truck, logging cable, and wireline control systems, wireline engineers are equipped to handle even the most challenging of situations. However, it’s the lessons learned from failures like these that truly shape our approach and improve our practices moving forward.
We continuously strive to enhance our wireline services, incorporate better wireline technologies, and provide complete wireline solutions to our clients. With the right training and expertise in downhole tools, engineers can avoid critical failures and ensure that every well operation is executed with precision and efficiency.