Post-Frac Production Analysis of Horizontal Completions in CANA Woodford Shale

The Oklahoma Woodford shale has produced hydrocarbon since the early 1950s. Recent horizontal development using multistage fracture stimulations of the CANA Woodford located in the Anadarko basin has resulted in high initial gas-flow rates, and substantial liquid production when in the gas-condensate window. Completion type and strategy have changed from methods used during the initial discovery phase in 2005 to the present development phase in 2011. This paper compares completion parameters used for a given time period to the individual production trend, using a linear flow transient model. Using the normalized reciprocal rate/pressure versus the square root of time plot, the stimulated reservoir volume (SRV), effective fracture half-lengths, reservoir-system permeability (km h), productivity index (PI), and overall stimulation effectiveness were determined. Ranking of fracture-stimulation effectiveness is made from production-derived bulk reservoir properties, including • The product of fracture-surface area and square root of the effective formation permeability (Ackm 1/2). • Apparent skin (s’) from the b’ intercept of the square root of time plot; an indication of skin. • Hydrocarbon pore volume (HCPV). The results are summarized in tables showing the effect of completion factors on the production outcome.