Ensuring Safety in Wireline Perforating with Check Fire Procedures

Posted on by Crissa Fel Tawadan

One misstep in handling perforating guns, downhole tools, or firing circuits can lead to costly failures or dangerous situations. Over time, I’ve learned that one of the most critical safety procedures in wireline perforating is the check fire process—a step that confirms the firing system is functioning properly before arming the perforating guns.

There was a time when a cased hole wireline job almost went sideways due to an overlooked check fire step. The operation involved pump down perforating in a horizontal well, and everything appeared ready to go. But just before arming the perforation well charges, a last-minute check fire verification revealed an issue with the firing circuit. Had we ignored it, the consequences could have been severe.

Why Check Fire Procedures Matter in Wireline Perforating

The check fire procedure is essential for verifying that the wireline control system, logging cable, and firing mechanism are all working correctly before detonation. This process helps:

  • Prevent misfires that could lead to stuck perforating guns or pipe recovery operations
  • Confirm that the firing system can generate the required 0.8 amps DC for detonation
  • Eliminate the risk of accidental surface or downhole detonations
  • Ensure clear communication between the Field Engineer and Operator

For wireline service providers, following a strict check fire protocol reduces operational risks and ensures that wireline perforating operations go smoothly.

How to Perform a Check Fire Procedure in Wireline Perforating

A check fire must be conducted using a resistorized detonator and a test fixture with a 120-ohm resistor to simulate a firing load. The test verifies the system’s ability to deliver an all-fire current of 0.8 amps DC in both positive and negative polarities before proceeding with arming the charges.

Equipment Needed:

  • Blasters Multimeter set to the 2-amp DC range
  • 120-ohm resistor fixture for firing circuit testing
  • Wireline truck shooting panel
  • Collar locator (CCL) and firing head attached to the cable

Check Fire Procedure Steps:

  • Field Engineer inspects the rigging area and confirms that all personnel are ready
  • Field Engineer announces, “Stand by to check fire”
  • Operator ensures no one is in contact with the wireline or firing head and acknowledges readiness
  • Engineer commands, “Check fire open”
  • Operator verifies that the logging cable is an open circuit and confirms with “Open”
  • Engineer applies firing power to the cable and verifies an open circuit on the shooting panel
  • Engineer commands, “Short it positive”
  • Operator connects the test fixture and verifies positive polarity by reading a minimum of 0.8 amps DC
  • Operator confirms with “Fire OK Positive”
  • Engineer commands, “Short it negative”
  • Operator switches to negative polarity and verifies a minimum reading of -0.8 amps DC
  • Operator confirms with “Fire OK Negative”
  • Engineer switches to the CCL monitor position and commands, “Check collars”
  • Operator verifies collar locator functionality using a metal object to simulate a casing collar

If no issues arise, the Engineer:

  • Places the firing system in the SAFE position
  • Removes the safety key and wears it on an armband or lanyard
  • Exits the wireline unit and announces, “Fire OK, Collars OK, Cable is shorted”

If any issue is detected, the entire process must be restarted from the beginning to ensure the system is safe.

Applying Best Practices in Wireline Services

In wireline perforating operations, skipping a check fire procedure could result in:

  • Failed perforation charges requiring a fishing wire line job
  • Damage to wireline pressure control equipment
  • Accidental detonation of a perforating gun oil and gas charge
  • Increased downtime in the cased hole logging service market

By ensuring a strict check fire protocol, wireline companies improve operational safety, reduce downtime, and prevent unplanned pipe recovery efforts.

Lessons Learned in Wireline Well Logging and Perforating Operations

Since enforcing a standardized check fire process, results have shown:

  • Fewer misfires and failed perforating services
  • Improved logging cable performance and wireline gun safety
  • Stronger compliance with oilfield services company safety protocols

For any wireline service provider, ensuring that firing heads, perforating guns, and pressure control equipment are operating correctly before arming explosives is essential.

In the wireline oilfield, safety isn’t just a box to check—it’s the foundation of every successful operation.