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Dynamic Data Analysis – v5.12.01 - © KAPPA 1988-2017
Chapte
r 4 – R ate Transient Analysis (RTA)- p134/743
Note: Periods of very low rates give artificially high values of
o
p
q
N
t
then the equation
t m b p
q
pss o
pss o
o
,
,
1
tends to
t mp
q
pss o
o
,
1
the points are found on the same -1 unit slope
straight line.
Based on this result, Palacio and Blasingame introduced type-curves that could be used for
variable flowing pressure conditions. In order to improve the type-curve analysis the Bourdet
derivative was also considered. However, due to the noise inherent to the production data, the
derivative was not applied to the normalized flow itself but to its integral. More precisely, the
Palacio-Blasingame type-curve plot shows the following:
Normalized rate:
PI t
q t
p p t
i
w
Normalized rate integral:
PI Int
t
PI d
t
q
p p
d
e
t
e
i
w
t
e
e
.
1
1
0
0
Normalized rate integral derivative:
e
Int
t
PI
Derivative
Int PI
ln
.
All three curves are plotted against
t
e
on a loglog scale:
Fig. 4.C.1 – Blasingame plot