Halliburton - get your perforated holes the same size
Thursday, May 17, 2012
Halliburton has developed a new "class" of perforating charges, for perforating oil and gas wells before hydraulic fracturing, which will make all of the holes the same size.
It is called MaxForce-FRAC charge.
It aims to make consistent perforation holes in the casing, whatever direction the gun is pointing in.
In trials, it has led to a 20 per cent improvement in flow efficiencies.
Getting a consistent hole size if very important, in order to ensure that each perforation tunnel contributes equally during the fracture treatment.
The fluid injection rates are proportional to the perforation hole size, and the required injection pressure is linked to the hole size.
If the fluid injection pressure becomes too high for the well equipment to handle, a 'screen-out' will occur, such as proppant getting blocked in the wellbore.
A big variation in entrance hole diameters can increase the near wellbore "tortuosity" (amount of twisting) in the fractured channel.
It can lead to many perforation holes not contributing to the stimulation.
The system was used in Martin County, Texas, with a 3-3/8-in 60 degree gun system, and the operator increased injectivity by 20 percent compared to the previous perforation.
In Reagan County, Texas, an operator evaluated the system over 15 separate frac stages, and found that it led to the required treating pressures being reduced by 8 to 10 per cent.