There are two kinds of days in wireline services oil and gas—the ones where everything goes smoothly, and the ones that remind you why pressure control is critical.
This story takes place on one of those second kind of days.
The job was simple: run a cased hole logging operation to assess casing integrity before well perforation. The well had pressure, so we had to rig up wireline pressure control equipment—grease injection systems, BOPs (blowout preventers), and wireline rams. We double-checked the logging cable, confirmed our equipment was rated for the expected well pressure, and ran through our pressure control safety checklist.
Everything looked good.
Then, as we started wireline well logging, things took an unexpected turn.
The Moment Everything Changed
As the logging tool was running downhole, the pressure readings on our control system spiked. At first, we thought it was a minor fluctuation—until the grease seal on the control head failed.
In the world of wireline well logging, losing a grease seal mid-operation is like driving down the highway and suddenly realizing your brakes aren’t working.
Line speed slowed immediately. We engaged the hydraulic pack-off and started troubleshooting.
Solving the Problem Under Pressure
When dealing with a loss of grease seal, every second counts. The procedure drilled into us during safety training kicked in:
- Reduce wireline speed but don’t stop the line.
- Slowly engage the hydraulic pack-off to contain the pressure.
- Check grease injector pressure—it must stay at least 1,500 PSI over well pressure.
- If the seal isn’t regained, close the wireline BOPs.
We went through these steps methodically, but something still wasn’t right.
Identifying the Root Cause
- At this point, we had three possibilities:
- Worn or improperly sized flow tubes
- A pressure hose leak
- Contaminated grease causing pump failure
We suspected the third. Without the right grease viscosity, the system can’t maintain pressure.
I checked the grease reservoir—sure enough, contamination was visible. It was thickened, likely due to temperature fluctuations. Cold weather conditions can cause grease to harden, leading to loss of lubrication in pressure control systems.
Our fix? Replace the grease, re-pressurize, and continue operations.
We bled down the grease injector system, flushed it, and refilled with the correct viscosity grease for the temperature. Within minutes, the pressure stabilized, and we regained the grease seal.
Crisis averted.
Lessons Every Wireline Engineer Must Remember
That night, as we packed up our wireline truck, I thought about how pressure control isn’t just about equipment—it’s about training, quick thinking, and teamwork.
Here’s what I took away from that job:
- Know your pressure ratings. The lowest-rated piece of equipment dictates the entire system’s safety threshold.
- Never rush pre-job equipment checks. Proper wellsite testing before starting operations prevents surprises.
- Temperature matters. Cold weather affects grease viscosity, impacting pressure control systems.
- Training is everything. The reason we handled this safely was because we had drilled these procedures countless times.
Final Thoughts
In the wireline service market, no two jobs are the same. Pressure control procedures exist for a reason, and when things go sideways, it’s those procedures that keep us safe.
So next time you’re on location, take that extra minute to double-check your wireline control systems, wellhead connections, and lubricator setup. Because in this business, staying ahead of pressure isn’t just a job—it’s survival.
What’s your most memorable pressure control experience? Let’s talk in the comments.