There are jobs you never forget in the wireline business—and this was one of them. Not because of a misfire or a lost run, but because it reminded us just how fast things can go sideways when you’re dealing with live wireline tools and thousands of pounds of tension.

We were halfway through a pump down perforating job on a horizontal well, prepping to shoot the second stage. Everything seemed normal until the gunstring got stuck in the hole. Not a full hang-up—just tight. The kind of thing that usually works itself out with a little finesse and pressure cycling.

But this time, finesse wasn’t going to cut it. And the choices we made over the next ten minutes nearly turned a simple cased hole wireline job into a serious safety incident.

When the Cable Snapped, So Did the Illusion of Control

The well was pressurized, the logging cable under tension, and I was working every trick I knew. We surged the well. We tried cable cycling. We even pumped fluid to free the string from what we thought might be a ledge.

When none of that worked, the call was made: part the weakpoint and recover what we could. But instead of breaking off clean, the wireline snapped at surface—right at the bottom sheave—under 6700 pounds of tension.

What followed was chaos. The cable backlashed through the wireline truck, smashed the windshield of the logging cab, and peppered the engineer’s face with glass. Luckily, they were wearing safety glasses—one of the few things that kept this from turning critical.

What Caused It: Torque Imbalance from Over-Cycling

Here’s the part most people miss—this wasn’t a weak cable. It was a 9/32” wireline cable, barely broken in with just three prior runs. It should’ve held up to at least 10,000 pounds of tension. Instead, it failed at 6,700.

The post-incident analysis showed what really happened: repeated cable cycling from low to high tension had caused a torque imbalance. According to our wireline equipment vendor, this kind of stress disrupts the internal geometry of the cable. Eventually, it starts to fail far below its rated breaking strength.

And it was completely avoidable.

The Fix: Updated SOP for Handling Stuck Toolstrings

We went back to the drawing board and rewrote our process for dealing with stuck guns and cased hole wireline hardware. Now, every team follows a strict stuck string SOP—one that limits cycling and emphasizes safe tensioning methods.

Stuck Gun SOP for Horizontal Wireline Operations

1. No More Than Three Cable Cycles

• If the string doesn’t free within three up-down cycles, stop immediately.

• Cycling beyond this increases the risk of internal torque imbalance and premature failure.

2. Pull and Hold—Don’t Oscillate

• Apply tension and hold steady. Oscillating from low to high tension is what damages the cable.

• Let the pressure control equipment and well conditions do the work—not your sheaves.

3. Immediate Escalation to Management

• If the string remains stuck after limited attempts, call management before proceeding.

• Don’t improvise. Escalation ensures decisions are made with full awareness of risk.

4. Safety Glasses Mandatory During Tension Pullout

• Every crew member involved in recovery or tension operations must wear eye protection.

• This is now non-negotiable. Cable snapback is unpredictable.

5. Review Cable History Before Applying Load

• Know how many runs the cable has made, and inspect for visible torque signs.

• If in doubt, back out and rebuild the string—never guess under load.

Why This Is a Must in the Wireline Services Market

In today’s high-pressure wireline services oil and gas environment, the pressure to perform is constant. But safety and reliability have to come first—especially in jobs involving wireline perforating, perforation services, and production logging.

Misjudging cable limits can lead to:

• Catastrophic equipment failure

• Risk to wireline crew safety

• Tool loss requiring fishing wire line or pipe recovery

• Complete NPT on critical perforation well schedules

• Client dissatisfaction in a competitive wireline services market

What We Teach Now in Our Wireline Courses

We now include this scenario in our wireline courses, complete with real tension graphs, damage photos, and decision trees. New engineers and trainees learn:

• What torque imbalance looks like in early signs

• How to spot rising risk from over-cycling

• When to escalate and stop tensioning

• What to log and communicate to supervisors when a string gets stuck

They also review historical misruns just like this one, reinforcing the mindset that not every solution lies in brute force.

Applying the Lesson to Real-World Wireline Logging

We now use this best practice across all services, including:

• Cased hole logging and formation evaluation

• Long-string wireline perforating guns

• Sensitive downhole camera jobs

• Post-frac cement bond log (CBL log) operations

• Deep wireline well logging where slack-off weight and tension fluctuations are common

Whether it’s plug and abandon, pressure control, or tight-window wireline and perforating runs, the same principle applies: cycle less, observe more, escalate sooner.

Final Thoughts – Pull Smart, Not Hard

That cable didn’t fail because it was weak. It failed because we ignored what we couldn’t see—internal stress caused by repeated force. We tried to solve the problem with muscle when what we needed was process.

And that’s the biggest takeaway for any wireline provider, wireline company, or engineer working in the field today.