ABSTRACT
When perforating for hydraulic fracturing treatments, there are several questions that need to be answered.
What Is the Hole Size and How Much Penetration Is Needed?
The guideline for minimum perforation size is to shoot so that the diameter of the perforation is six times the largest particle diameter. Figure 12.1 proved a chart developed from experimental work done on a 10 ft long, 7 in. diameter Lucite casing that was žtted with 4 ft perforated zone containing 30 perforations (Gruesbeck and Collins, 1978). As the žgure shows, a perforation diameter to average particle diameter of 6 will handle any concentration of sand. This same work showed that the minimum frac width required to accept the proppant is three times the largest particle diameter. If nearwellbore effects are expected, then the perforation length should be at least 2½ times the borehole diameter to try and minimize the stress cage effects.
