PO.DCA.Diag.Bourdet
Description
Calculates the Bourdet (smoothed) derivative at point t. Used for flow regime identification and production diagnostics.
Syntax
=PO.DCA.Diag.Bourdet(x_values, y_values, t, L)Parameters
| Parameter | Description |
|---|---|
| x_values | Sample points, strictly increasing. The result is dy/dx on the abscissa you pass. For the semilog derivative well-test analysis wants, use PO.DCA.Diag.Bourdet.SemiLog instead. |
| y_values | Sample values (rate, pressure, or cumulative production). |
| t | One of x_values: the sample point at which to calculate the derivative. |
| L | Smoothing window in natural-log cycles of x: the least separation in ln(x) a neighbour must have from t to be used. L=0 uses adjacent points. Typical: 0.1-0.5. It only engages where the data is sampled finer than L. Requires x>0. |