Page 361 - Air and Gas Drilling Manual

8-44 Air and Gas Drilling Manual
=
o
T
.
586 29 R
av3
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
With the above, Equation 6-73 becomes
  2
 
f =  1 
  0 319  
i3
.
114
 2 log 0 00015  + . 
  . 
.
f = 0 016
i3
Equations 6-67 and 6-68 become, respectively,
a i3 = 10 .
53 36
.
a = 0 019
.
i3
and
.
2 635)
.
b i3 = 0 016   53 36  2 (. 2
π
2
.
(
232 2 . ) 10    5
0 319)
 4  (.
,
b = 2 486
i3
Equation 6-72 becomes
  2 0 019) ( , 2 375)   05 .
(.
 (, 2 + ( , 586 29) 2 e  586 29 − 1 
.
2 486) (
33 050)
.
    

P =  
i2  2 0 019) ( , 
2 375)
(.
 586 29 
.
 e 
 
2
P i2 = 32 540 lb/ft abs
,