Page 22 - Fundamentals of Reservoir Engineering

CONTENTS XXII

Fig. 7.43 Russell afterflow analysis Exercise 7.9) 234

Fig. 7.44 Match between McKinley type curves and superimposed observed buildup
(Exercise 7.9). o − match for small ∆t (T/F = 2500) • − match for large ∆t (T/F =
5000) 235

Fig. 8.1 Radial numerical simulation model for real gas inflow 241

2
Fig. 8.2 Iterative calculation of p wf using the p formulation of the radial, semi-steady
state inflow equation, (8.5) 244

Fig. 8.3 Real gas pseudo pressure, as a function of the actual pressure, as derived in
table 8.1; (Gas gravity, 0.85; Temperature 200°F) 248

Fig. 8.4 2p/µZ as a function of pressure 248

Fig. 8.5 Calculation of p wf using the radial semi-steady state inflow equation expressed in
terms of real gas pseudo pressures, (equ. 8.15) 250

Fig. 8.6 p/µZ as a linear function of pressure 251

Fig. 8.7 Typical plot of p/µZ as a function of pressure 252

Fig. 8.8 Laboratory determined relationship between β and the absolute permeability A
relationship is usually derived of the form 256

Fig. 8.9 Gas well test analysis assuming semi-steady state conditions during each flow
period. Data; table 8.3 267

Fig. 8.10 Gas well test analysis assuming semi-steady state conditions and applying equ.
(8.47). Data; table 8.4 268
Fig. 8.11 MBH chart for the indicated 4:1 rectangular geometry for t DA < .01 (After
15
Earlougher, et.al ) 273
Fig. 8.12 Essis-Thomas analysis of a multi-rate gas well test under assumed transient flow
conditions. Data; table 8.6 274

Fig. 8.13 The effect of the length of the individual flow periods on the analysis of a multi-
rate gas well test; (a) 4×1 hr periods, (b) 4×2 hrs, (c) 4×4 hrs 277

Fig. 8.14 (a) Rate-time schedule, and (b) corresponding wellbore pressure response
during a pressure buildup test in a gas well 279

Fig. 8.15 Complete analysis of a pressure buildup test in a gas well: (a) buildup analysis
(table 8.12); (b) and (c) transient flow analyses of the first and second flow
periods, respectively (table 8.10) 284

Fig. 8.16 MBH plot for a well at the centre of a square, showing the deviation of m D(MBH)
from p D(MBH) for large values of the dimensionless flowing time t DA 287
10
Fig. 8.17 Iterative determination ofp in a gas well test analysis (Kazemi ) 288