Page 576 - Petrophysics
P. 576
CHARACTERIZING NATURAL FRACTURES 543
Pressure derivative curve
Unit slope portion
storage and skin effect
Trough, a typical indication of
Presence of natural fractures
log(bt)
Figure 8.29. Eflect of natural fractures on pressure derivative on a log-log plot of
pressure and pressure derivative against time.
0.35
0.30 3.5688 6.5452
%tEHn= 2.9114----
0.25
0.20
0.15
0.10
0.05
0.00
0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00
Figure 8.30. Storage CoefJicientfiom the time coordinate of the minimum point of
the pressure derivative curve.
