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226 Part III Underbalanced Drilling Systems

60
Q fx /Q l = 0 bbl/hr per gpm
Q /Q = 2 bbl/hr per gpm
fx
l
50 Q /Q = 4 bbl/hr per gpm
fx
l
GLR max without Backpressure Requirement (scf/gal) 40 Q /Q = 10 bbl/hr per gpm
Q /Q = 6 bbl/hr per gpm
l
fx
Q /Q = 8 bbl/hr per gpm
l
fx
fx
l
30
20

10

0
0.95 0.96 0.97 0.98 0.99
Γ max

Figure 10.13 Effect of reservoir fluid influx on the maximum allowable injection GLR.

70
Q /Q = 0 bbl/hr per gpm
l
fx
Q /Q = 1 bbl/hr per gpm
Minimum Required Backpressure (psia) 50 Q /Q = 4 bbl/hr per gpm
fx
l
60
Q /Q = 2 bbl/hr per gpm
l
fx
/Q = 3 bbl/hr per gpm
l
Q fx
l
fx
40
30
20
10

0
0 5 10 15 20
Injection GLR (scf/gal)
Figure 10.14 Effect of reservoir fluid influx on the minimum required backpressure.