The physical characteristics of the 3-A-2
reservoir are described in figure to the
right:
a) Calculate the percentage of recovery,
assuming this reservoir could be
produced at a constant cumulative
gas oil ratio (GOR) of 1100 SCF/STB,
when the reservoir pressure falls to
3550, 2800, 2000, 1200 and 800 psia.
Plot the percentage recovery versus
reservoir pressure.
Formation volume factor, bbl/STB
1.65
1.60
1.55
1.50
1.45
1.40
1.35
1.30
800 1200 1600
rmation
oil ratio
acto
Deviation factor
2000 2400
2800
Pressure, psia
0.96
0.94
0.92
0.90
0.88
0.86
3200 3600 4000 4400
Gas deviation factor
1100
1000
900
700
600
500
400
300
Solution gas-oil ratio, SCF/STB/n6.2
Problem 5 (Continued)
b) Recalculate recoveries assuming the that cumulative produced GOR is 3300
SCF/STB, to demonstrate the effect of increased GOR on recovery. Plot the
percentage of recovery versus pressure on the same graph used in part (a).
c) How is the percentage of recovery affected, if the produced GOR is tripled?
d) Will shut-in of high GOR producers improve recovery in a reservoir? Explain.
Fig: 1
Fig: 2