Hydraulic Fracturing Consultants

Proppant Distribution in Hydraulic Fractures

An introduction to this significant technology for maximizing fracture stimulation quality can be found in IPT's landmark technical paper, SPE 56725: Lateral Proppant Distribution: The Good, the Bad and the Ugly of Putting Frac Jobs Away. Proppant induced friction can negatively affect the lateral and vertical proppant distribution adjacent to the target interval, thereby reducing the production response and reserve recovery from gas and oil wells.  Proppant induced friction also ties to polymer dehydration and the potential for damage.

The concept is as follows: If proppant enters the fracture and changes the pressure character, then it is building proppant-induced friction. Premature proppant-induced friction can easily divert slurry injection away from the pay interval and there may be minimal indication of this on the observed treating pressure response. When this happens, fracture models can not predict the myriad of slurry diversion scenarios that can occur. At IPT, we design the fracture treatment to minimize proppant-induced friction from the beginning, noting of course that some reservoirs need to be packed for conductivity and/or consolidation purposes.

Proppant distribution is a key aspect typically ignored by most practitioners of this craft and it is a primary reason why most fracture stimulation treatments achieve less than expected results. The most significant damage mechanism in hydraulic fracturing with polymer based systems also ties directly to the dehydration effects that result when this is occurring.  If simply "putting a job in the ground" continues to be the measure of a successful stimulation treatment, then the industry will continue to evolve in the direction of water fracs because a slick water treatment will produce similar or better than a poorly designed and implemented crosslinked gel job. A proppant distribution design is intended to minimize proppant induced friction and place proppant adjacent to the pay interval beyond the capabilities of most water frac type applications, thereby achieving an improved effective fracture stimulation and production response.