IDENTIFY WELL-BORE STORAGE EFFECTS

The next step in validating test data is identification of well-bore storage effects. Well-bore storage is ALWAYS the first effect in the data being analysed. This is true because there is always a well-bore!

From PIE, select the PLOTS pull-down menu and then select the DERIVATIVE plot option. Choose one of the following cases that is closest to what your data looks like:

1. A nice unit-slope and a derivative "hump"...
   (the arrow points to the unit-slope)
   
   
   
2. A smooth curve and no "hump" present...
   
   
   
3. No initial upward slope of any sort...
   
   
   
4. Storage decreases with time (width of "hump" is less than 1 log-cycle)...
   
   
   
5. Starts off steeper than a unit slope...