How a Missing Port Plug, a Misread Depth, and a Dry Stroke Nearly Shut Down Our Wireline Day

Posted on by Crissa Fel Tawadan

In wireline, the real learning doesn’t happen behind a desk—it happens in the field. You figure it out while troubleshooting a short mid-run, assembling cased hole wireline toolstrings in the middle of a pump down job, with the pressure of a ticking clock and a client waiting on results. That’s where the true wireline training begins.

One job in particular reminded me how a few seemingly small oversights can turn into hours of troubleshooting, tool damage, or even a safety hazard. Here’s what happened—and what every wireline provider should be thinking about when prepping for any cased hole well services operation.

A Simple Plug That Cost Us a String

We’d just built a solid gunstring for a high-pressure perforation well. Detonators were verified, the wireline truck was calibrated, the weight bar and CCL were rebuilt and op-checked. Switch tests at surface looked good, so we equalized and started the run.

At 200 ft, a switch test showed a short. Pulled the string, and there it was: one port plug missing. In the confusion of troubleshooting a bad switch earlier, a third plug had been pulled and not replaced. The gun flooded. It was a preventable failure, but a powerful reminder.

From that day forward, I implemented a double-check protocol—no matter how rushed we are. Before any downhole tools go in:

  • Visually confirm all port plugs and seals

  • Rebuild and re-inspect every gun after troubleshooting

  • Physically check through wiring, shear screws, brass seats, and firing heads

  • Confirm gun count, phasing, and plug components match the shoot sheet

This isn’t just about wireline tools. It’s about the integrity of the entire wireline and perforating operation. Because a flooded gunstring can compromise more than just productivity—it can threaten well integrity.

The Crossed Armor That Didn’t Fool Me Twice

On another job, we had tension spikes going in hole, drops coming out. That kind of inconsistency is a red flag, especially in horizontal wireline where friction is amplified. After pulling out, we discovered a crossed armor strand above the grease head—probably caused during a poor rehead job.

That’s why every run now includes:

  • Feeling the line for high spots

  • Watching drum behavior for jumps or line bunching

  • Checking for tension inconsistencies during both RIH and POOH

Wireline control systems and grease head assemblies are only as good as the cable feeding through them. If you’re not managing your logging cable, you’re risking a fishing wire line operation—or worse.

The Grease Pump That Ran Dry

Ever had a grease pump start leaking mid-run? I have. It turns out the tank had been run nearly dry by the previous crew, and our crew stroked it a few times before catching it. That wiped out the packing, and next thing you know, we’re trying to hold pressure with compromised pressure control equipment.

From now on, the rule is simple:

  • Grease levels are checked after every run

  • In cold conditions, glycol hose wraps are used to maintain grease flow

  • If grease drops below minimum, the truck doesn’t spool another foot

In oil field wireline, especially when you’re handling wireline pressure control equipment at 10K, dry stroking a grease pump is one of those “quiet killers” of efficiency—and budget.

Depth Misread and the Surface Slam

One time, I came on shift, assumed the bump-up depth was negative 40 ft, and pulled out hard. Turns out, the actual bump-up was a positive 25 ft due to casing stretch. I hit the grease head with the string and tension spiked by 2000 lbs in less than half a second. Almost lost the tool.

We now:

  • Flag any abnormal bump-up values immediately

  • Make management aware of depth changes during correlation

  • Ensure surface alarms are functional and crew is briefed before every bump-up

Even the best wireline truck doesn’t save you if the depth system isn’t maintained and double-checked. Whether you’re setting plugs, logging a cement bond log (CBL log), or running a pipe caliper tool, depth verification is a non-negotiable.

Through-Wire Failures and Wrapping Reworks

Lastly, I’ve seen far too many through wires fail because tubing was bunched or not secured. One short due to insulation being peeled back mid-run taught me the value of proper gun building and tubing wrap.

Every shot tube now gets:

  • Primacord taped at each charge

  • Tubing candy-caned over the length of the gun

  • Inspection before every run to confirm through-wire integrity

This has reduced intermittent shorts and given us more confidence during wireline perforating, especially in complex perforating systems and high-shot count strings.

These aren’t just lessons—they’re the reason we still have successful, safe runs day after day. Whether you’re running production logging tools, cased hole logging, or just trying to stay competitive in the wireline services market, these habits matter.

That’s why I’ve built a full suite of wireline courses that teach these techniques—built by engineers, for engineers. Learn what is wireline in oil and gas, and more importantly, learn how to master it.

When the pressure’s on, it’s not the biggest tool that wins—it’s the sharpest crew.