Some lessons in the wireline world arrive softly, buried in data logs or minor tension swings. Others? They come crashing through the windshield.
It was a typical day on a cased hole logging job. We were already past the first perforation well depth and preparing to reposition for the second shot. The downhole tools were operational, the wireline truck systems were reliable, and our logging cable, only in its fourth journey— was relatively fresh.
Then, it happened. The gunstring became lodged in the well. What followed was a chain of decisions and mechanical stresses that I’ll never forget.
Stuck Guns and Surging Strategies
The client rep had us do everything, like surging the well, cycling the cable tension, and even pulling hard and letting go. For those unfamiliar, these techniques are part of the broader suite of wireline and perforating troubleshooting. In most circumstances, they work.
But this time, nothing did.
We tried increasing tension gradually, monitoring real-time values through the wireline control systems. The plan was to attain 5,000 pounds while pumping, which would dislodge the gunstring and maybe shred the weakpoint.
Instead, we crossed a different threshold entirely.
When the Cable Snapped
At 6,700 pounds, the logging cable parted just below the bottom sheave. And when it did, it didn’t just fall softly to the ground; it backlashed, shooting upward into the wireline truck’s windshield.
I was sitting in the cab.
Glass shattered everywhere. A jagged spray hit me across the face. Fortunately, I was wearing my safety glasses, as every oil field safety training course insists. The result was a few minor cuts and a major wake-up call.
Why Did This Happen and How Can We Fix It?
The root cause, according to the cable vendor and wireline tech analysis, was torque imbalance caused by repeated low-to-high tension cycling. The 9/32” quality wireline cable was rated for 10,000 lbs, but torque fatigue had weakened it significantly.
This torque imbalance occurs when wireline is rapidly shifted between low and high tension multiple times. The cable core begins to rotate unevenly under load, leading to stress fractures and early failure. That is not just a theory; it is currently documented in every training module and wireline course we provide to the field.
Wireline Services Action Plan
After this incident, new field-wide protocols were established across our wireline services operations:
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Never cycle cable more than three times when attempting to free stuck tools. From now on, pull and hold.
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Management must be contacted immediately before continuing operations on a stuck tool or gunstring.
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Stuck in hole procedures are now mandatory review topics for all crews, addressing dangers, best practices, and the wireline logging gear used.
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Safety glasses are mandatory during all high-tension operations at surface, especially around the rope socket and sheaves.
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This instruction is now part of company-wide training, taught to all wireline units, from cased hole solutions to production logging services.
The Wireline Companies: Don’t Ignore This Step
Whether you’re managing cement bond logs, perforating systems, pipe recovery, or horizontal wireline jobs, these moments are reminders that wireline equipment is both precise and unforgiving.
This incident had the potential for severe injury or worse. Thanks to field protocols and basic PPE, we left with only minor wounds and a renewed appreciation for the strength contained in that logging cable.
Final Thoughts from the Truck
Wireline service companies are defined by how they respond to the unexpected. This experience altered my perspective on every stuck string situation, including how I coach fresh hands, how I consider tension, and how I handle every piece of wireline equipment we come into contact with.
So if you’re pulling hard and hoping for the best, stop. Call it in. Follow the process.
Because the most important lesson in well integrity can occasionally be found sitting just above the sheave, waiting to break, rather than downhole.