The success of the Barnett Shale has many operators in search of similar producing formations. One such formation is the Woodford Shale which stretches from Kansas to west Texas. The Woodford is an ultra-low permeability reservoir that must be effectively fracture stimulated in order to obtain commerical production. Once a formation that was drilled through on the way to deeper horizons, this shale play now dominates drilling activity in southeast Oklahoma. Like the Barnett, initial testing of the Woodford Shale was from existing vertical wells that penetrated deeper horizons. Currently, the main exploitation of the Woodford Shale is from long horizontal wells with some lateral lengths exceeding 4000 ft. The wells are stimulated in stages with large hydraulic fracture treatments. Successful shale plays have demonstrated that production is directly related to the size of the stimulated reservoir volume. Techniques to optimize hydraulic fracturing effectiveness have been evolving in the area the last few years. Over 100 frac stages have been mapped in the Woodford Shale using surface tiltmeters, offset-well microseismic and treatment-well microseismic mapping techniques. This paper will examine the effect of lateral azimuth, formation dip and its influence on asymmetric fracture growth; the effect of existing faults and its interaction with the fracture stimulation. Additionally, stimulation size, number of stages, perforation clusters and fracture initiation problems will be discussed. Finally, a comparison to Barnett Shale type fracture networks will be made. Understanding fracture growth in the Woodford Shale willl enhance the development of the play by helping operators optimize fracture completion and well placement strategies. Overview of the Woodford Shale The Woodford Shale is of Devonian age and extends from southern Kansas, through Oklahoma and into west Texas. It is found within the black shale belt as show in Figure 1. It is easily identified by a very high gamma ray streak and is 50–300 ft thick as shown in Figure 2. Completions have been made from depths of 900 ft in northeast Oklahoma to 13,000 ft in west Texas. A typical core contains: 35–50% quartz, 0–20% calcite/dolomite, 0–20% pyrite, and 10–50% total clay. Porosity ranges from 3–9% and permeability ranges from 0.000001 md to 0.001 md. Water saturation varies from 30% to 45%. The formation is slight underpressured with pressure gradients in the 0.35 to 0.44 psi/ft range. The Woodford Shale was first produce in 1939 in southeast Oklahoma. Drilling activity that targeted the Woodford Shale as the primary objective was slow to grow. By late 2004 there were only 22 Woodford shale completions. By the end of 2006 there were 143 Woodford Shale completions.[1,2] Through mid year 2007, there had been an additional 176 wells drilled with an estimated total of 350 wells for the year (see Figure 3).