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Gas and Liquid Injection Rates 193

Additional data are given as follows. Calculate the pressure profile along
the annulus.
Total measured depth: 8,045 ft
Hole roughness: 0.0018 in
Liquid injection rate: 191 gpm
Gas injection rate: 301 scf/min
Oil influx rate: 1 bbl/hour
Weight of injected liquid: 8.4 ppg
Gas specific gravity: 0.7
Oil gravity: 35°API
Liquid‒gas interfacial tension: 60
Liquid viscosity: 2 cp
Oil viscosity: 1 cp
Surface temperature: 60°F
Flowing bottom hole temperature: 140°F
Surface choke pressure: 14.7 psia
Length of heavy drill pipe below collar: 425 ft
Heavy drill pipe OD: 5 in
Drill collar length: 500 ft
Drill collar OD: 5.75 in
Drill pipe OD: 4.5 in

Solution
This problem can be solved with computer program Hagedorn-Brown Annular
Pressure.xls. The results are shown in Figure 9.12.

Pressure (psia)
0 1000 2000 3000 4000 5000 6000
0
1000
2000
3000
Depth (ft) 4000
5000
6000
7000
8000
9000

Figure 9.12 Calculated pressure profile in the annulus.