Pressure Testing Gone Wrong: A Wireline Engineer’s Hard Lesson in PWP Tools

Posted on by Crissa Fel Tawadan

One thing about wireline engineering—just when you think you’ve seen it all, the oilfield throws you a curveball.

This story takes place during a pressure test for a PWP tool, something that should have been routine. Instead, it turned into a lesson in bottom hole pressure (BHP) calculations, sensor calibration, and troubleshooting telemetry issues.

The Setup: Surface Testing Before Running In-Hole

We were preparing for a production logging job, and part of our checklist included pressure testing the Titan PWP tool before running it in the well.

The Titan PWP tool is designed to measure borehole pressure and temperature in real-time, making it a critical tool for formation evaluation. We had:

  • A Titan GPTBT telemetry tool, which included an external temperature sensor.
  • A hydraulic test pump rated to 10,000 psi, ensuring we could simulate bottom hole conditions.
  • Warrior software, which we relied on to display telemetry signals.

Before running in the hole, we needed to confirm pressure sensor accuracy.

The Warning Sign: No Pressure Response

We followed the standard pressure test procedure:

  • Removed pressure ports and installed a blanking port.
  • Connected the Titan PWP test adaptor to the hydraulic pump.
  • Pumped up to the calculated bottom hole pressure (around 4,900 psi).

Everything was going smoothly—except for one issue:

The tool wasn’t reading any pressure.

At first, I thought maybe it was a connection issue. We double-checked the monitor output, but nothing. Zero pressure response.

This wasn’t normal. Telemetry issues? Faulty calibration? Bad sensor?

Troubleshooting Under Pressure

Instead of panicking, we took a step back and went through our checklist:

  • Checked hydraulic connections—no leaks.
  • Manually verified pressure gauge on the pump—it was reading correctly.
  • Rebooted the Warrior software interface—still nothing.

Then, I remembered something from a previous job—a software glitch in Warrior that can cause telemetry lockups when switching tool serial numbers.

We followed this workaround:

  • Exited Warrior completely.
  • Powered off the interface.
  • Restarted Warrior and selected the PWP service again.

And just like that, the pressure reading popped up.

Had we not caught this, we might have assumed a faulty sensor and delayed the job unnecessarily.

Key Takeaways for Wireline Engineers

This experience reinforced several critical lessons for working with PWP tools and pressure sensors:

  • Always test pressure sensors before running in-hole.
    • Catching an issue at the surface saves hours of troubleshooting downhole.
  • Be aware of software glitches.
    • Some Warrior software versions lock up telemetry signals when switching tool serial numbers.
    • If telemetry disappears, restart the interface instead of rebooting the whole system.
  • Know how to calculate bottom hole pressure (BHP).
    • The formula: (DEPTH in feet) × (0.052) × (FLUID WEIGHT in lbs/gal) = BHP.
    • Understanding this ensures pressure testing accuracy.
  • Keep your ports clean.
    • The screened vent port can clog with debris—always inspect and replace O-rings when necessary.

Final Thoughts: The Importance of Pre-Job Testing

In wireline services, cased hole well logging, and production logging, nothing is more important than ensuring your tools are functioning before you go downhole.

That day, we avoided a major delay because we knew how to troubleshoot PWP telemetry issues. It’s a reminder that sometimes, the problem isn’t the tool—it’s the software.