Page 248 - Fundamentals of Reservoir Engineering
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OILWELL TESTING 186
∆ p wf (psi)
50
40
30
20
10
10 20 30 40 50 TIME (hrs)
0
-10
-20
-30
2 4
= = = 1 x = 1
Fig. 7.17 Plots of ∆ ∆∆ ∆p wf (calculated minus observed) wellbore flowing pressure as a
function of the flowing time, for various geometrical configurations
(Exercise 7.5)
To facilitate the calculation of dimensionless pressure functions, as illustrated in
exercise 7.5, the MBH dimensionless plots of p D(MBH) versus t DA can be expressed in
digitised form and used as a data bank in a simple computer program to evaluate p D
functions by applying equ. (7.46) (which can always be reduced to the form of
equ. (7.47)). In fact such a program could be written for the range of small desk
calculators which have sufficient memory storage capacity. Digitised MBH functions
10
have already been presented by Earlougher et al for all the rectangular geometrical
configurations considered by Matthews, Brons and Hazebroek.
