Some lessons in the wireline world come quietly, buried in data logs or subtle tension fluctuations. 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 functioning, the wireline truck systems were solid, and our logging cable—only on its fourth run—was relatively new.
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 try every trick in the book—surging the well, cycling cable tension, even pulling hard and letting off. For those unfamiliar, these techniques are part of the broader suite of wireline and perforating troubleshooting. In most situations, they work.
But this time, nothing did.
We tried increasing tension gradually, monitoring real-time values through the wireline control systems. The idea was to hit 5,000 pounds while pumping—a maneuver meant to dislodge the gunstring or potentially shear 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 drop quietly to the floor—it backlashed, lashing upward into the windshield of the wireline truck.
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 This Happened—and How 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’s not just a theory—it’s now logged in every training module and wireline course we share with 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 every crew—covering risks, best practices, and wireline logging tools involved.
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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 lesson is now part of company-wide training—shared with all wireline units, from cased hole solutions to production logging services.
For the Wireline Companies Out There—Don’t Skip 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 walked away with only a few scratches—and a reinforced respect for the power stored in that logging cable.
Final Thoughts from the Truck
Wireline service companies are defined by how they respond to the unexpected. This experience changed how I approach every stuck string scenario—how I coach new hands, how I think about tension, and how I view every piece of wireline technology we touch.
So if you’re pulling hard and hoping for the best, stop. Call it in. Follow the process.
Because sometimes, the biggest lesson in well integrity isn’t downhole—it’s sitting just above the sheave, waiting to snap.