Page 442 - Air and Gas Drilling Manual

9-46 Air and Gas Drilling Manual
.
13 95 lb/ft
ga4
Using Equation 1-2, the density of the gas as it exits this annulus section,
.
13 95 3 ga4 , is
ga4
32 2
.
lb sec 2
0 433
.
ga4 4
ft
From Equation 9-7, the kinematic viscosity of the gas at this location, ga4 , is
.
0 000000251
ga4
0 433
.
ft 2
.
0 000000579
ga4
sec
The average kinematic viscosity of the mixture as it exits this annulus section,
, is
ava4
.
.
.
( 1 282)( 0 000000579) ( 31 92)( 0 0002691)
.
ava4
.
1 282 31 92
.
2
0 000259 ft /sec
.
ava4
The approximate average velocity of the aerated drilling fluid as it exits this
annulus section, V a4, is
.
.
,
1 826 6 598 79
(. 0 426
19 47)
.
445 579 519 67
,
.
V a4 % 2 2 &
.
0 656)
4 (. 0 552
V a4 524 ft/sec
.
Using Equation 6-75, the Reynolds number of the aerated drilling fluid as it
exits this annulus section, N Ra4, is
0
(.24 ) ( .656 . 0 552 )
5
N
Ra4
. 0 000259