BAKER HUGHES - Drilling Fluids Reference Manual

HYDRAULICS
4.
Calculate the Reynolds Number.
• Drillpipe
----------- ( 928) ( 10.45 )( 3.826) 15.3
Re ( )
p = -------------------------
928( Vp
) ( D p )ρ
= ------------------------------------------------------------------
1
- n p
( 62.45) 3 ( 0.70
- = 8465
3n ) + 1
4n --------------------------- 0.70
p +
μ ep
-----------------
p 40.70 ( )
• Drill collar
Re ( 928 )( 19.34) ( 2.8125) ( 15.3)
p = ---------------------------------------------------------------------
( 47.34) 30.70
= 15,192
--------------------------- ( ) + 1
0.70
4( 0.70)
• Annulus of drill collar and open hole
928V
Re = -------------------------------------------
a ( D 2 – D 1 )ρ ( 928) ( 3.40) ( 9.875 – 7.25) ( 15.3)
a = -------------------------------------------------------------------------------
---------------- n a
( 84.43) 20.5
= 1300
2n ------------------------ ( ) + 1
0.50
a + 1
μe a
3n a 3( 0.5)
• Annulus of drillpipe and open hole
Re ( 928 )( 1.98) ( 9.875 – 4.5) ( 15.3)
a = ----------------------------------------------------------------------------
( 158.31) 2 ( 0.5
= 827
------------------------ ) + 1
0.50
30.5 ( )
• Annulus of drillpipe and casing
Re ( 928 )( 1.12) ( 12.515 – 4.5) ( 15.3)
a = -------------------------------------------------------------------------------
( 257.03) 2 ( 0.5
= 429
------------------------ ) + 1
0.50
30.5 ( )
5. Find the flow regime in each section.
• Pipe
Variable Re Flow
Drill pipe 8465 Turbulent
Drill collar 15192 Turbulent
Drill collar – open hole 1300 Laminar
Drill pipe – open hole 827 L aminar
Drill pipe – casing 429 Laminar
Table 9 - 1 Reynolds Number Summary
Re c = 3470 – 1370( n p ) = 3470 – 1370(
0.70) = 2511
Re c = 4270 – 1370 ( n p ) = 4270 – 1370(
0.70 ) = 3311
• Annulus
Re c = 3470 – 1370( n a ) = 3470 – 1370( 0.50 ) = 2785
Re c = 4270 – 1370( n a ) = 4270 – 1370( 0.50) = 3585
BAKER HUGHES DRILLING FLUIDS
REFERENCE MANUAL
REVISION 2006 9-32