Working in wireline perforating is more than just running tools in and out of the well—it’s about safety, precision, and executing the job with absolute focus. When dealing with explosive devices, the margin for error is non-existent. Every step, from arming the perforating guns to safely disarming them in case of a misfire, must be executed with discipline.
Preparing for Arming and Disarming
The moment I step onto location, I know my role in ensuring wireline safety begins well before we start running tools downhole. Stray voltage checks must be completed, all grounding cables connected, and safety protocols reviewed. In pump-down perforating, activating the yellow strobe lights is a critical part of the procedure—it signals that the arming sequence is in progress.
- The safety key stays with me throughout the arming process.
- Before the device is lowered beyond 250 feet, the key is handed off to the lead operator standing outside.
- The key only returns to me after we reach the designated depth.
This ensures that at no time is the safety key inside the wireline unit during the arming process. This is just one of the many wireline control systems in place to mitigate risks in cased hole wireline operations.
The Arming Process
Arming a perforating gun isn’t just about making electrical connections—it’s about following a strict sequence that ensures everything functions as designed. The golden rule? Make the ballistic connection last—always electric before ballistic.
- Circuit Check – Using a blaster’s meter, I verify the gun circuit is functioning correctly.
- Cable Head Connection – I attach the CCL (Casing Collar Locator) and cable head to the gun.
- Detonator Handling – The detonator is kept inside a safety tube until the final step.
- Resistance Testing – Before attaching the detonator, I check its resistance.
- Shunting Wires – To prevent accidental discharge, the detonator leads remain shunted.
- Grounding Verification – The gun wire is checked against ground to ensure no stray voltage.
- Wiring the Detonator – First, the ground leg is connected, followed by the hot leg.
- Final Assembly – The detonator is attached to the prima cord, and the gun is fully sealed with a bullplug assembly.
With everything connected, the wireline perforating gun is now armed, and we’re ready to lower it into the well.
Disarming After a Misfire
If everything goes as planned, the guns fire and the perforation well is completed. But sometimes, we face a misfire. When that happens, disarming must follow the same precision as arming.
- Hold a Tailgate Safety Meeting – Before any action, the entire team must be briefed.
- Verify Key Position – The safety key stays with me, ensuring the process is controlled.
- Secure the Worksite – The line of fire is cleared, and unnecessary personnel step away.
- Gun Retrieval – The gun is carefully removed from the well and laid on stands.
- Breaking the Ballistic Connection First – Unlike arming, disarming is the opposite—ballistic before electric.
- Disassemble the Gun – The bullplug assembly is removed, and the prima cord is cut from the detonator.
- Safe Disposal of Detonator – The detonator is placed back in the safety tube, wires are shunted, and it is stored in the Type III magazine.
- Ensuring Safe Transport – If the perforating gun needs to be moved, all guns must either be disarmed or have an interrupter installed.
Why Precision Matters in Wireline Perforating
This is the reality of wireline and perforating—a world where well integrity depends on following the correct procedures every time. Whether it’s wireline well logging, cased hole logging, or full wireline perforating services, each step ensures that the perforating systems perform safely and effectively.
By following these best practices, we prevent accidents, ensure complete wireline solutions, and deliver high-quality oil field wireline services that keep operations running smoothly.
The key takeaway? Safety isn’t an option in wireline. It’s the job.