Page 353 - Air and Gas Drilling Manual

8-36 Air and Gas Drilling Manual
0 950  
10  
.
53 36 
2 635 
.
 .
=
.
a a a4 =   0 025   1 +  .  
a4
and 2 2
2 635)
.
.
b a4 = 0 076  53 36  2 (.
0 656 −
π
2 32 2) ( . 0 552  ) 10    [ 2 2 ] 2
(
.
.
.
0 656)
0 552)
 4  (. − (.
,
b a4 = 22 870
Equation 6-57 becomes
 2 0 025) ( 125)  05 .
(.
[
2 

.
,
)
(
P a4 =  ( , 2 + 22 870 598 79) 2 ] e 598 79 − 22 870 598 79 
,
(
.
.
16 030)
 


2
,
P a4 = 18 643 lb/ft abs
P a4
p a4 =
144
.
p = 129 5 psia
a4
The fifth annulus seciton increment is denoted by the length H 5. The
temperature at the bottom of the length H 5 in the openhole annulus section (bottom
of the drill collar geometry), T 5, is
T = T + 001 ( H + H + H + H + H )
.
5 r 1 2 3 4 5
T = T + 0 01 10 000)
(
.
,
5
r
T = 604 41 R
o
.
5
The average temperature of drill collar length H 5 is
T + T
T av5 = 4 5
2
o
.
T av5 = 601 91 R