Atoka Sands (Pregnant Shale or Davis Sand) Play
Production Decline Curves
Figure 1 is a decline curve from an average Pregnant Shale/Davis Sand well. Note the hyperbolic (ski-slope) nature and long life of the well. This serves as a good model for economic runs of a typical well, except it is important to know that this well has not had the benefit of a LSF (light sand frac). The production performance could be enhanced from this style of stimulation, and even this well could respond to a new LSF treatment.
The economic models used in this report do not project the effects of a LSF; but fortunately, the well that was cored in the Barnett (Sims #1) shows how one of the key analogy wells has responded to LSF treatment (see Photo 3, Barnett Shale core). A decline curve history for the Sims #1 (Figure 2) demonstrates how this well was stimulated with a new LSF treatment, adding new reserves and increasing the rate of production to original levels of Initial Potential.
Based on interviews with many operators and service companies in the area, no company has yet attempted a LSF treatment in the Pregnant Shale.