Optimizing Detonating Cord Selection for Plug and Perforating Operations

Posted on by Crissa Fel Tawadan

In wireline and perforating operations, the selection of the correct detonating cord is crucial for ensuring consistent detonation transfer and safe perforation well execution. I recall a job where improper cord selection led to a misfire, forcing us to troubleshoot a failed wireline perforating gun. That experience reinforced the importance of understanding how different types of detonating cord behave under wellbore conditions.

Standard Detonating Cord for Plug and Perforating

For plug and perforating operations, the recommended detonating cord is FireLine 17/80 RDX. This oil field detonating cord provides reliable initiation, but under certain conditions—such as prolonged exposure to temperatures above 190°F for over an hour—it may experience shrinkage of up to 6%.

Shrinkage of the coreload can impact crimp-style (A-85) detonation transfer performance, but it does not affect 140S or 140F detonators, which utilize side detonation.

Alternative Detonating Cord Options

When selecting an alternative, it’s important to understand the specific conditions of the cased hole wireline job.

  • DETOTEC 80 RDX Nylon PERFACORD is a suitable alternative and exhibits the same shrinkage as FireLine.
  • Ensign-Bickford RDX 80 grain detonating cord is another approved option, offering reliable detonation transfer.

However, Low Shrink (LS) detonating cord is not recommended for plug and perforating due to its difficulty in side detonation when using 140S, 140F, or block detonation methods. The Kevlar jacket of LS cords makes initiation less reliable, increasing the chance of misfires. Additionally, LS cords are significantly more expensive without providing necessary benefits in typical plug and perf conditions.

When to Adjust Detonating Cord Selection

The 80 grain RDX cord is not always the ideal solution. Certain wireline services oil and gas jobs require alternative options depending on factors such as temperature, shot density, and gun system exposure.

  • Higher temperature conditions – If the wellbore experiences extended exposure to elevated temperatures, an alternative cord with higher thermal stability may be required.
  • Exposed gun systems – Requires a detonating cord that maintains integrity under open wellbore conditions.
  • Shot density of 6 shots per foot (SPF) or greater – It is recommended to use XHV (Extra High Velocity) detonating cord to ensure proper charge initiation across all perforations.

By matching the detonating cord to the specific wireline perforating application, misfires and costly remedial work can be avoided.

Conclusion: The Right Cord for the Right Job

In wireline well logging and cased hole logging, precision is key. The wrong choice of detonating cord can lead to misfires, increased operational costs, and unnecessary downhole pipe recovery efforts. By selecting the appropriate cord—whether FireLine 17/80 RDX, DETOTEC 80 RDX, or XHV for high-density perforating—we optimize wireline perforating gun performance, improve well integrity, and ensure seamless wireline services execution.

Attention to temperature exposure, shot density, and cord properties is essential for achieving complete wireline solutions in oil field wireline operations. As always, precision and proper planning lead to safer, more efficient perforation jobs.