Published: 09/20/2010
Published: 09/20/2010
In moderate- and high-permeability wells the lack of adequate fracture conductivity is a limiting factor for production potential; in tight gas reservoirs the limiting factor is often effective fracture half-length, although adequate conductivity is also important for efficient recovery of fracturing fluid.
Traditionally, efforts to enhance conductivity have been directed toward improving flow through a porous proppant pack. Significant efforts to increase proppant-pack permeability include development of less damaging carrier fluids, high-strength man-made proppants, efficient fracturing fluid breakers, and so on. Despite these advances, well tests frequently indicate disappointingly shorter or less conductive fractures than designed. Multiple studies indicate proppant-pack retained permeability is often a small fraction of the maximum expected value.
A new hydraulic fracturing technique enables a step-change approach to increasing fracture conductivity. The technique is based on the creation of a network of open channels inside the fracture. Modeling and experimental work indicate the technique delivers conductivities more than 10 times those obtained from conventional fracture treatments. Extensive laboratory-, yard- and field-scale experiments, combined with theoretical work, enabled creation of a framework to describe the physical processes occurring during application of this new technique.
By providing significantly higher fracture conductivity, this new approach delivers consequential benefits: better fracture cleanup; lower pressure loss within the fracture; and longer effective fracture half-lengths, all of which contribute to improved short- and long-term production.
A 15-well field study demonstrates post-treatment results with significant gains in well production and expected ultimate recovery with respect to offset wells treated with conventional fracturing methods.