This case study looked to identify a perforation design and a perforation charge that measurably increases Perforation Efficiency (PE) and reduces PE variability from stage to stage. Achieving these goals allows for more economic fracture surface area generation as well as more informed decisions toward frac design and full field development.
Primarily relying on industry-standard pre-fracture Step-Down Tests (SDT) to estimate number of perforation holes open, a variety of strategies and technologies were tested by altering perforation friction, orientation, entry hole diameter (EHD), perforations per cluster (PPC), and charge type. The trial was performed across multiple horizons in the Delaware Basin, consisting of over 4,500 stages from 193 wells across 13 horizons from the 1st Bone Spring Sand to the Wolfcamp C in Lea and Eddy Counties, New Mexico.
With the legacy perforation strategy and technology, the operator historically achieved a probability 50 (P50) using the cumulative distribution function (CDF) of 47% of perforations open pre-fracture. Utilizing eXtreme Limited Entry (XLE), 0 degree-oriented perforating, larger EHD, single perforation clusters, and a shaped charge which increases the reservoir contact area, the operator was able to increase the CDF P50 to 93% of perforations open pre-fracture.
This straightforward trial allowed the operator to meaningfully reduce the cost of operations while type curves were met or exceeded. Contributing to the success of this field trial was a clear and restricted design of the experiment in combination with a special shale-optimized perforating charge designed for greater near wellbore reservoir contact area.