There are some jobs in the wireline oilfield that burn into your memory—literally.

It was a high-pressure horizontal wireline job, and we were prepping for a multi-stage perforation well operation. I had the full pressure control equipment rigged up: grease head, wireline BOP, tool trap, and lubricator. The crew was solid, the logging cable had passed inspection, and we had a full string of perforating guns ready to go. Everything looked good—until we equalized.

That’s when it happened.

The lubricator hadn’t been properly filled. We cracked open the well master valve while it was only partially full. Within seconds, I heard a sharp hiss and watched smoke curl out from the grease head. We stopped everything. When we pulled the cable, it had literally melted. The wireline had been severed—cooked by rapid compression and heat.

It was a painful, expensive lesson—but it changed the way I approach equalizing lubricators forever.

Equalization seems like a small part of the process, but it’s critical. In cased hole logging and other wireline services, especially when pressure is involved, one misstep during equalization can compromise the entire operation. And in the worst cases, it damages tools, ruins the wireline logging run, and creates serious well integrity issues.

Now, I teach this step with extra emphasis in all my wireline courses.

There are two proper ways to equalize: either through a pressure-rated hose connected to the wing valve, or using a low-pressure centrifugal pump to fill the lubricator. Never—never—use a frac pressure pump. Those things are built for brute force, not finesse, and they can easily over-pressurize the wireline equipment.

When I’m equalizing with a hose, I:

• Make sure gauges are on both the wellhead and lubricator
  
• Connect the hose from the wing valve to the pump-in sub
  
• Keep the grease pressure at zero and don’t apply packoff yet
  
• Slowly open the wing valve, then slowly open the pump-in sub valve
  
• Wait for water to fill the lubricator and spill from the grease head
  
• Then apply grease pressure and monitor both gauges until they match

That’s when I know the well and lubricator are truly equalized—and only then do we proceed with opening the master valve.

And when we’re using a pump to fill the lubricator, we use the centrifugal pump from the blender, not the frac pump. Its high-volume, low-pressure output is perfect for quickly and safely filling the lubricator. Once the fluid hits the top and spills, we apply grease pressure, confirm equalization, and go in hole.

Equalizing properly not only protects your logging cable, but also ensures safe entry and exit of your downhole tools and perforating guns. Whether you’re working in cased hole wireline, pump down perforating, or production logging services, your success relies on strict pressure control.

The wireline control systems we use today are sophisticated, and wireline technologies continue to evolve. But even the most advanced wireline truck, pressure control equipment, or downhole camera can’t save a job if basic practices like equalizing are rushed or done wrong.

That one melted cable taught me that safety isn’t about speed—it’s about understanding the system and doing things right. Whether you’re running caliper logs, cement bond logs, or managing complex wireline and perforating strings, slow is smooth, and smooth is fast.

So, to every wireline tech out there—from rookies to veterans—never cut corners during pressure ops. The wireline services oil and gas sector demands more than just knowledge of what is wireline in oil and gas. It demands execution. Precision. Awareness.

Equalize with care, or you’ll be dealing with more than just downtime.