Page 272 -

236 Appendices

6000
Minimum Required Air Injection Rate (scfm) 4000 Q =4 bbl/hour
5000

3000
w
Q =8 bbl/hour
w
Q =12 bbl/hour
2000
w
Q =16 bbl/hour
w
Q =20 bbl/hour
w
1000
Q =24 bbl/hour
w
For cuttings removal
0
0 2000 4000 6000 8000 10000 12000 14000 16000
Depth (ft)
Figure B.5 Calculated air injection requirements for drilling a 9⅞-in hole with a 5-in
drill pipe at an ROP of 120 ft/hr (water-air interfacial tension = 60 dynes/cm).

5000
Minimum Required Air Injection Rate (scfm) 3500 Q =4 bbl/hour
4500
4000

3000
2500
w
2000
Q =8 bbl/hour
w
Q =12 bbl/hour
1500
w
=16 bbl/hour
Q w
1000
w
Q =24 bbl/hour
w
500
For cuttings removal
0 Q =20 bbl/hour
0 2000 4000 6000 8000 10000 12000 14000 16000
Depth (ft)
Figure B.6 Calculated air injection requirements for drilling a 9⅞-in hole with a 5-in
drill pipe at an ROP of 60 ft/hr (water-air interfacial tension = 40 dynes/cm).