As the offshore oil and gas industry matures, the application of through-tubing operations has increased. To reduce operational risks and improve efficiency, a plugging and abandonment (P&A) strategy has become more appealing; however, it brings challenges that are inherent to the techniques normally employed for the A-annulus cement job.

The conventional tubing puncher gun used to establish communication between the inside of the tubing with the A-annulus is known for potential cement displacement issues that can lead to channeling of the cement sheath or slurry contamination. The potential issues are related to the nature of the existing devices, which demands that the entire gun carrier is in direct contact with the pipe wall, creating the optimum standoff that allows the perforating charge, and that the charges are all aligned in a single phase to penetrate the tubing without damaging the casing behind it.

To mitigate the potential displacement issues, a new puncher system with a phased distribution of the perforating charges was developed. This new technology enables an even distribution of cement slurry across the entire cross section of the annulus and creates a higher flow area, favoring a much better cement sheath quality. This improved cement quality was verified by running a cement evaluation log with an acoustic map of cement distribution behind tubing. This paper describes the development of this novel puncher system.