## 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:

- A nice unit-slope and a derivative "hump"...

(the arrow points to the unit-slope)

- A smooth curve and no "hump" present...

- No initial upward slope of any sort...

- Storage decreases with time (width of "hump" is less than 1 log-cycle)...

- Starts off steeper than a unit slope...