Page 450 - Air and Gas Drilling Manual

9-54 Air and Gas Drilling Manual
The inside diameter of the drill pipe body lumped geometry in this openhole section
is
.
d 7 3 826 inches
d 7
D 7
12
.
D 7 0 319 ft
The total length of the lumped drill pipe tool joints geometry increment, H 2, in
the cased section is
H 2 350 ft

The inside diameter of the drill pipe tool joints lumped geometry in this cased
section is

D 0 292 ft
.
6
The total length of the lumped drill pipe body geometry increment, H 1, in the
cased section is
,
H 1 6 650 ft
The inside diameter of the drill pipe body lumped geometry in this cased section is

.
D 7 0 319 ft
Inside the Drill String (10,000 ft to 7,000 ft)
The fifth drill string section increment is denoted by the length H 5. The
temperature at the bottom of the drill collars (bottomhole temperature) in the
openhole section is

T 604 41.˚R
5
The average temperature of the drill collar length H 5 and, thus, the temperature of the
aerated fluid flow inside the drill collars is
T av5 601 91.˚R

In order to obtain the approximate value of the Fanning friction factor for
Equation 6-82, it is necessary to estimate the Reynolds number and, thus, the flow
conditions inside the drill collars along H 5. This is accomplished by determining
the Reynolds number at the entrance end of the inside of the drill collar section and