Page 625 - Air and Gas Drilling Manual

With the above, Equation 6-73 becomes
2
1 Chapter 11: Specialized Drilling Equipment 11-63
f
i5 0 234
.
.
2 log 114
0 00015
.
f i5 0 018
.
Equations 6-67 and 6-68 become, respectively,
10
.
a i5
.
53 36
.
a i5 0 019
and
0 018 53 36 2 (. 2
2 635)
.
.
b
i5 2
(
232 2 . ) 10 . 5
0 234)
(.
4
b i5 12 420
,
The pressure above the motor, P , is the approximate pressure at the bottom of the
am
inside of the drill string. Thus, Equation 6-72 becomes
05 .
2 0 019) ( 500)
(.
.
.
12 420) (
65 790)
(, 2 ( , 601 91) 2 e 601 91 1
P i4 2 0 019) ( 500)
(.
.
e 601 91
2
,
P i4 65 830 lb/ft abs
P i4
p i4
144
.
p i4 457 2 psia