Impact of Fluid Selection on High-Permeability Fracturing

Abstract

Summary High permeability fracturing has become a major well completion technique both for production rate increase and, especially, for pressure drawdown decrease. Today, this type of treatment is the main means of sand control in some petroleum regions. Several of these treatments which are characterized by short lengths and, often, disproportionate widths, have been reported to exhibit positive post-treatment skin effects. This can only be the result of fracture face damage. This paper indicates that if the extent of fracturing fluid invasion is minimized, the degree of damage (i.e., permeability impairment due to filter cake or polymer invasion) is of secondary importance. Thus, if the fluid leak-off penetration is small, even severe permeability impairments can be tolerated without exhibiting positive skin effects. While the first priority in designing fracture treatments should be to maximize the fracture conductivity, it is recommended that in high permeability fracturing, high polymer concentration cross-linked fracturing fluids with fluid loss additives and breakers should be used. Experimental work corroborates these contentions.