Unlike conventional and unconventional perforating technologies on the market, Areco’s CoFrac™ System combines a propellant cap and a shaped charge into a single unit to create the next generation completion technology.
Propellants have been utilized in a number of methods to create a delayed pressure pulse to break-up the crushed zone around perforation tunnels. Propellants have been added as solid sleeves over guns, solid sticks ignited across open sets of perforations and propellant discs within gun bodies. With each of these techniques, the propellant is located within the wellbore when it burns, thus the pressure pulse builds within the casing and then flows into perforation tunnels. As the pressure pulse moves into perforations, it can disrupt the tunnel crushed zone and create fractures. The net effect is lower skin and improved perforation efficiency. Unfortunately, by burning propellant within the casing, the efficiency of the pressure pulse is reduced.
To tackle the challenges above, ARECO’s CoFrac™ System places propellant in a molded cap that attaches to the face of individual shaped charges. This results in jets produced by shaped charges dragging the propellant material behind the high-velocity jet as it penetrates casing, cement annulus, and formation. As a result, most of the propellant burns sequentially within the perforation tunnel, thus delivering direct continuum pressure pulse to the perforating event. The propellant provides a secondary stream of energy, enlarging the perforation tunnel diameter, cleaning up the perforation tunnel and giving impetus to the shaped charge jet, resulting in deeper penetration. The result is very effective and efficient in disrupting crushed zones and creating fractures around the perforation tunnel.