Mr. Erik Milito - The House Committee on Natural Resources ...

WATER MANAGEMENT ASSOCIATED WITH HYDRAULIC FRACTURING 11
Source: Advanced Resources International, Inc. (2009)
Figure 5—Control Room Monitoring a Hydraulic Fracture Stimulation
Understanding the in-situ reservoir conditions is critical to successful stimulations, and in the design of the fracture
treatment and fluid used. Hydraulic fracturing designs are continually refined, both during the fracture stimulation
itself, as well as over time as more about fracturing the target formation is learned from experience. Thus, while the
concepts and general practices are similar, the details of a specific fracture operation can vary substantially from
resource to resource, from area to area, from operator to operator, and even from well to well.
<strong>The</strong> ideal properties of a fracturing fluid relate to its compatibility with the formation rock; its compatibility with the
formation fluids; its ability to transfer enough pressure throughout the entire fracture to create a wide fracture, and be
able to transport the proppant into the fracture, while breaking back down to a low viscosity fluid for cleanup after the
treatment. Finally, and most importantly, the fracture treatment must meet necessary performance specifications.
5.3.2 Factors Influencing Fracturing Fluid Composition
As described in 4.4, there are a wide variety of additives that could be included in the fracturing fluid mix to achieve
successful fracturing. <strong>The</strong>se could include proppants, gel and foaming agents, salts, acids, and other fluid additives.
Today, operators and service companies are working to maximize the utilization of environmentally benign additives
and minimize the amount of additives required.
<strong>The</strong> characteristics of the resource target determine the required fracture fluid composition. For example, gas shale’s
may contain various naturally occurring trace metals and compounds that are leached from rocks by acidic water,
oxidation, and the action of ions found in brines. Numerous compounds have been formed naturally in the shale, and
a stimulation fluid pumped into a well may require various chemicals to counteract any negative effects these
compounds may have in the well or the reservoir. Iron compounds found within the Fayetteville shale require an iron