Wattenbarger Typecurve Analysis

Boundary-Dominated Match

Transient Match

Wattenbarger typecurves are used for analyzing linear flow. They are particularly useful in the analysis of shale gas wells, which tend to exhibit long-term linear flow followed by a transition towards boundary-dominated flow.

Note:   For information on the Wattenbarger typecurve theory and equations, see Wattenbarger Typecurve Analysis Theory.

The Wattenbarger typecurve analysis method uses the following model: Fracture (rectangular).

Boundary-Dominated Match

To obtain information about reserves and drainage areas, we recommend that you focus on the boundary-dominated (depletion) stems of typecurves. These are located on the right-side of the plot, where each set of typecurve converges to a single line. The Wattenbarger typecurve analysis does not require hyperbolic exponent values. Instead, the data is matched on the single depletion stem. As the data is moved about the plot, the OGIP / OOIP is continuously updated on the Analysis tab. 

For gas reservoirs whose fluid properties are strongly a function of pressure, the data points appear to "stretch" and "contract", as they are moved around the screen. This is because of the pseudo-time effect. Harmony recalculates gas properties at average reservoir pressures based on the calculated OGIP from the typecurve match. As the match is modified, OGIP, average reservoir pressure, and material balance pseudo-time are automatically recalculated, and the data points are repositioned accordingly.

Transient Match

To obtain information about fracture half length, reservoir size, and well location in the reservoir, you should focus on the transient stems of typecurves. On the Wattenbarger typecurve plot, these appear on the left-side of the plot as different ye / yw values for the dimensionless channel model. You select the best fitting typecurve, which provides an associated ye / yw value.

From the selection and the permeability you define, Harmony calculates: