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Dynamic Data Analysis – v5.12.01 - © KAPPA 1988-2017
Chapte
r 4 – R ate Transient Analysis (RTA)- p128/743
Most RTA software allows the scale to be set to the above and more. The regression of the
decline is non linear, i.e. it is possible to have the value of b determined from the regression
rather than assuming a value of b linked to the particular scale.
Fig. 4.B.1 – Arps
Once the decline parameters have been obtained, and since the analytical expression of the
rate and cumulative are known, it is possible, from a given abandonment rate, to calculate the
corresponding abandonment time, and hence the recovery at abandonment.
The abandonment rate is usually defined as either
q
a
or the ratio
q
q
a
i
.
The abandonment time is noted
t
a
and the recovery at abandonment
N t
p a
. The figure below
illustrates this extrapolation of the Arps plot.
Fig. 4.B.2 – Abandonment