As a wireline engineer, I’ve always found that the smallest mistakes can lead to significant challenges, especially when working with advanced equipment and technology. Recently, I encountered a situation that underscored just how critical attention to detail and proper tool usage is in wireline operations. This particular incident involved a new piece of equipment: an offset PCE (Pressure Control Equipment) sheave hanger. What seemed like a routine task ended up being a valuable learning experience for our team, and I’d like to share this story to highlight some of the key lessons learned.
The Incident: Lost Time and Twisted Wireline
The day began with the usual setup for wireline logging operations, but things quickly took an unexpected turn when we were working with the new offset sheave hanger. The task was to set the pack-off at the plug set depth, but as we attempted to press the “Meter Reset” button on the Benchmark panel, a simple mistake occurred. Instead of resetting the meter, the “Tension Zero” button was pressed, which inadvertently set the hanging weight to zero.
This caused the wireline to twist around itself multiple times while the pack-off was set, creating a tangled mess. Initially, we thought the situation could be easily remedied by applying the pack-off, slackening the line to release the tension, and resetting the true zero. The plan seemed simple enough, but it quickly became evident that the offset sheave hanger wasn’t behaving as expected.
With traditional, non-offset sheave hangers, the sheave’s cables would stop its rotation, making it difficult for the line to twist. However, the offset sheave hanger lacked this feature, allowing the cable to rotate freely around itself, which compounded the issue. This led to a significant amount of lost time as the crew worked to untangle the wireline and restore it to a usable state.
To make matters worse, we soon realized that the aerial lift on location was not tall enough to reach the top of the pressure control equipment, further delaying the operation. Eventually, we were able to apply enough reverse torque to the wireline to untwist it, but it had taken much longer than expected, resulting in a costly delay.
The Root Cause: A Simple Mistake
Looking back on the incident, it’s clear that a simple mistake with the “Tension Zero” button had a domino effect. However, the main issue wasn’t just the pressing of the wrong button; it was the lack of proper precautions and equipment to prevent the wireline from twisting freely when tension was released. The use of an offset sheave hanger, without the additional safeguards in place, made it possible for the wireline to become tangled, causing both confusion and downtime.
Action Items: New Procedures for Future Operations
After the incident, we immediately implemented several changes to prevent this from happening again. Here are the key steps we’ve taken to ensure a smoother and more efficient operation in the future:
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Use of the Wireline Clamp:
We’ve decided that in the future, when slackening the cable under tension, the wireline clamp should always be used on top of the greasehead, in addition to the pack-off. This added precautionary measure ensures that the wireline remains in place and doesn’t twist when releasing tension. -
Implementation of a Chain Device for Offset Sheave Hangers:
A chain device has been designed to address the specific issues with the offset sheave hanger. This device allows the sheave to rotate freely during normal operations but prevents it from making a full revolution, thus eliminating the risk of twisting the wireline. -
Better Calibration of Tension:
To avoid future confusion with the “Tension Zero” button, we’ve developed a procedure for recalibrating the system. If the button is accidentally pressed, the winch operator can press it again to restore the weight to normal levels. Although this procedure didn’t work as expected with the Benchmark 051 panel, we’ve found that removing the measuring head, placing a cut piece of cable in the head, and recalibrating zero works until we can return to the surface. -
Inspection of Aerial Lifts:
As part of our pre-job checks, we now inspect the aerial lift on location to ensure it can reach the desired height. If it cannot, we immediately inform the client and avoid unnecessary responsibility for fixing potential upper pressure control equipment issues.
The Bigger Picture: The Importance of Preparation in Wireline Operations
While this incident revolved around a specific piece of equipment, it serves as a reminder of the larger importance of preparation and attention to detail in wireline services. Whether you’re performing wireline well logging, cased hole logging, or any other wireline-related task, ensuring that all equipment is properly calibrated and that the correct procedures are followed can prevent costly delays and safety issues.
Tools like wireline control systems, logging cables, and pipe caliper tools are essential in every well operation. Yet, without proper checks and balances, even the most sophisticated tools can become a hindrance rather than a help. This experience reinforced the importance of thorough training and continuous improvement, as well as the need to stay up-to-date with the latest wireline technologies and best practices.
Conclusion: Continuous Improvement in Wireline Services
In the end, the offset sheave hanger incident was a humbling experience, but one that provided valuable lessons for the entire team. By incorporating new procedures, improving our equipment, and ensuring proper checks are in place, we’re better prepared to handle the challenges that come with complex wireline operations.
Wireline services, including perforating systems, wireline perforating guns, and downhole camera tools, are critical in the oil and gas industry. As wireline companies, we have a responsibility to ensure that every operation is carried out with precision, safety, and efficiency. Whether it’s through better training, better equipment, or better planning, we must always strive for continuous improvement to deliver complete wireline solutions that meet the needs of our clients and ensure the integrity of the well operations.
This experience served as a reminder that even the smallest issues can have a significant impact, but by learning from our mistakes and refining our processes, we continue to improve the quality and safety of our wireline services.