Duong Decline

The Duong method was developed specifically for unconventional reservoirs with very low permeability. The shape of the curve is suited for wells that exhibit long periods of transient flow. The Duong method will reach a finite EUR Expected Ultimate Recovery, and tends to be more conservative than traditional Arps declines with b > 1.

The Duong Production Decline Model
q =		Rate expression as a function of time
Q =		Cumulative production as a function of time
EUR =		EUR in terms of model parameters

Note:   Reference SPE Society of Petroleum Engineers paper 137748.

Creating a Duong Decline Analysis

1. Launch an entity for analysis.

2. Click the Decline thumbnail; then select the type of worksheet you want to create.

The worksheet opens in the main pane, displaying a plot of the selected well's production data:

3. Add the Duong analysis to the worksheet. See Adding an Analysis for additional information.

4. Best fit the analysis to the data by doing one of the following:

• selecting data points
• editing parameters

Note:   This method is extremely sensitive to noise in the data. Therefore, we recommend you manually select the appropriate data for curve fitting.