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Exercise 9: Derivative Smoothing

NOTE: Derivative Analysis tools are only available in the AquiferTest Pro edition.

This exercise will demonstrate how to use derivative analysis tool to help in identifying aquifer conditions and type curve matching. The AquiferTest project have already been created for you. the exercise assumes that you are familiar with the AquiferTest interface. If not, please review Exercise 1.

[1] Start AquiferTest and click on the (Open other project...) button, or if AquiferTest was already started then select File/Open from the main menu.

[2] Browse to the folder: "C:\Users\Public\Documents\AquiferTest Pro\Exercises\", and select the project: Moench Fracture Skin.HYT

[3] Click the [Open] button

This pumping test consists of a fully penetrating pumping well and an observation well located 110 meters away.

[4] Once the project has loaded, select Analysis > Create a New Analysis from the main menu

[5] From the Data from list, uncheck the UE-25b#1 (Pumping Well) so that only the UE-25a#1 is selected

[6] Select the Diagnostic Graph tab to view the drawdown over time in log-log format. The diagnostic graph should look like the image below:

As you can see this diagnostic plot does not really give a clear indication of conditions of the aquifer system. In other words, it cannot be easily matched to one of the diagnostic plot templates. To help determine the appropriate aquifer conditions, you will apply derivative smoothing to the curve.

[7] From the main menu, select Analysis > Derivative... . The Derivative Settings dialog will appear on your screen,

[8] Select the Set each dataset separately option

[9] From the Method combo box, select the Bourdet Derviate (BOURDET 1989) method. The Derivative Settings window should look like the image below:

[10] Click the [Ok] button to apply the settings. The derivative data was not improved significantly. As you can see from the image below, there has been little to no change in the diagnostic graph:

The graph can be further enhanced by increasing the L-Spacing of the derivative method.

[11] Select Analysis > Derivative from the main menu. Alternatively you can click the button to open the Derivative Settings window.

[12] Change the L-Spacing value to 0.5

[13] Click the Ok button

With the additional smoothing, the diagnostic graph clearly reveals double porosity aquifer conditions, which is highlighted in the image above.

This completes the derivative smoothing exercise. The next exercise will demonstrate how to analyze pumping test data from horizontal wells. You have the choice of exiting AquiferTest or continuing on to the next exercise.

 

 

 


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