Page 587 - Air and Gas Drilling Manual

The inside surface of the drill pipe body has the surface roughness of commercial
steel. Therefore, over this lumped drill pipe body length the surface roughness is
e p 0 00015 ft Chapter 11: Specialized Drilling Equipment 11-25
.
With the above, Equation 6-73 becomes
2
1
f i3 0 319
.
.
2 log 114
0 00015
.
.
f i3 0 016
Equations 6-67 and 6-68 become, respectively,
10
.
a i3
53 36
.
.
a i3 0 019
and
0 016 53 36 2 (. 2
.
.
2 635)
b
i3 2
(
232 2 . ) 10 . 5
(.
0 319)
4
b i3 2 486
,
Equation 6-72 becomes
05 .
(.
2 0 019) ( ,
2 375)
2 2
.
( 50 860) ( , 586 29) e 586 29 1
2 486) (
.
,
P
i2
2 375)
(.
2 0 019) ( ,
.
e 586 29
2
P 48 402 lb/ft abs
,
i2