You don’t really think about the collector—until it becomes the reason your job grinds to a halt. It’s one of those wireline components you trust will work, tucked neatly into the drum housing, doing its job as the wireline spins in and out of the well. That is, until it doesn’t.

We were midway through a multi-stage cased hole logging operation. Typical horizontal wireline setup—logging cable, pressure control equipment, a string of perforating guns, and a full run of downhole tools ready to go. Just before arming, we did a routine rehead and followed up with an insulation test using the megohmmeter.

That’s when the number hit me: 10 MΩ.

Now, anyone who’s been through the right wireline courses knows what this means. For 1000V testing, the expected value should be over 100 MΩ. Less than that and you’ve got possible insulation leakage somewhere in your wireline system. At that moment, every second counted. A decision had to be made—keep moving forward or investigate deeper?

We megged again, same result. So I cut the head and even trimmed 400 feet of wireline, just to rule out contamination or conductor issues. But the number didn’t change. That’s when I realized the issue wasn’t with the wireline—it was the collector itself.

I removed it from the circuit and tested it alone. Sure enough, out of spec. We were in the middle of a tight frac schedule, trying to stay ahead of operations, and suddenly we were staring down unexpected downtime due to a faulty wireline collector.

The backup collector was right there in the unit, but as luck would have it, the leads were too short to feed through the side of the drum. That detail cost us valuable time—and it could’ve been avoided with a proper pre-job loadout inspection.

This is the side of wireline services that doesn’t get talked about enough. Everyone sees the perf gun fire or the cased hole solutions we provide downhole, but the real work starts at surface. It’s the meg checks, the cable resistance readings, the collector inspections that ensure the wireline control systems and wireline equipment hold up when it matters most.

We eventually installed a third collector—tested, insulated, and within spec—and got the job done. The wireline and perforating stage ran clean after that. The logging cable delivered every signal, every pulse. But it stuck with me—how close we came to losing that window.

Whether you’re offering production logging services, formation evaluation, or working as a wireline provider in the oilfield services company space, this job demands detail. From the conductor to the caliper log, every piece matters. And in this wireline business, it’s often the small parts—the overlooked ones—that carry the biggest risk.

So now, during every job loadout, we check the backup collectors—lead length, conductor wiring, and insulation resistance. Because next time, it might not be just 10 MΩ slowing us down—it might be a complete shutdown of your wireline unit.

That’s the nature of working in the wireline services oil and gas market: fast, high stakes, and full of variables. But with the right preparation and mindset, even something as small as a collector won’t stand in your way.