The Time a Sign Saved the String: Tagging Out the Wellhead During Stage Frac Ops

Posted on by Crissa Fel Tawadan

It was a fast-paced stage frac operation—high pressure, tight turnarounds, and everyone moving in sync. We were working a long lateral in a cased hole wireline job, running back-to-back stages with little room for error.

The crew was sharp. The wireline truck was live. Our logging cable was 12,000 feet deep. We had just finished setting the plug and were pulling up to reposition for the next perforation well depth.

Then the wellhead valves started to shift.

Someone unfamiliar with our operation mistook an open valve for an oversight—and began closing it.

If that sign hadn’t been there—bold, bright, and stating “WIRELINE CABLE IN THE WELL. DO NOT CLOSE. EXCEPT IN CASE OF EMERGENCY”—we would’ve had a severed cable, a full fishing wire line operation, and a delayed frac.

That sign? It saved the job.

Why Tagging Out the Wellhead Is More Than Just Policy

In the wireline services oil and gas space, especially on horizontal wireline frac pads, it’s not uncommon for multiple vendors to be working in close proximity. One mistake at the wellhead control panel can result in:

  • Severed wirelines
  • Damaged perforating guns
  • Costly downhole pipe recovery
  • Crew safety risks
  • Lost time and revenue

That’s why our team implemented a rigid tag-out procedure anytime wireline is in the hole.

The Tag-Out Process in Action

Before starting any wireline and perforating operation, our team does the following:

  • Places a clearly visible warning sign on the wellhead valves
  • Communicates the meaning of the sign in every safety meeting
  • Assigns a designated supervisor to place and remove the sign
  • Reviews responsibilities with the company representative each shift

The rule is simple: wireline operations do not start without the sign in place.

When pulling out of hole, we monitor for these indicators:

  • Tool trap closes at 1,000 feet—first cue that tools are approaching surface
  • Radio silence enforced from 250 feet to surface
  • Green light ON – Safety key is in safe position
  • Yellow strobe + horn at 250 feet – Radio silence confirmed

Red light? That’s full fire mode and should not be on during retrieval.

We don’t touch the wellhead valves until:

  • The tool trap is confirmed closed
  • Green and yellow lights are on
  • The engineer verbally confirms “tools are bumped up and above trap”

Only then can the designated supervisor remove the tag and close the wellhead valves.

Lessons From the Field

I’ve worked enough cased hole well services to know how easy it is for the small steps to get overlooked in the rush. But tagging out the wellhead isn’t just a checkbox. It’s one of the most important wireline control system safeguards we have in high-pressure multi-vendor operations.

Whether you’re working production logging, wireline perforating, or prepping for formation evaluation, this procedure ensures both well integrity and crew safety.

What I Teach Every Wireline Tech and Trainee

If you’re enrolled in one of my wireline courses, this is something I emphasize again and again:

  • Tag it out before you run in
  • Communicate the process in the safety meeting
  • Assign accountability—don’t leave it to chance
  • Follow the signal protocol strictly—green and yellow, not red
  • Only close the wellhead valves once the engineer confirms it’s safe

This is how you build a reputation in the wireline business for being both fast and safe.

Final Thought

As the wireline services market continues to push for faster cycle times and higher stage counts, small details like this become your biggest assets.

Tagging out the wellhead isn’t about slowing the job—it’s about ensuring it finishes without a hitch.