BAKER HUGHES - Drilling Fluids Reference Manual

Chapter 9
Table of Contents
HYDRAULICS ..................................................................................................................................9-1
INTRODUCTION ................................................................................................................................9-1
RHEOLOGY.......................................................................................................................................9-1
Rheological Terms.......................................................................................................................9-1
Generalized Flow Curves............................................................................................................9-2
Rheological Models.....................................................................................................................9-3
DRILL STRING AND ANNULAR HYDRAULICS ...................................................................................9-9
Fluid Velocity ..............................................................................................................................9-9
Power Law Constants, n and K .................................................................................................9-11
Effective Viscosity......................................................................................................................9-11
Reynolds Number ......................................................................................................................9-12
Flow Regime and Critical Reynolds Number............................................................................9-13
Critical Flow Rate .....................................................................................................................9-13
Fanning Friction Factor............................................................................................................9-14
Friction-Loss Pressure Gradient...............................................................................................9-15
Equivalent Circulating Density .................................................................................................9-16
BIT HYDRAULICS...........................................................................................................................9-16
Nozzle Velocity ..........................................................................................................................9-17
Pressure-Drop Across Bit..........................................................................................................9-17
Hydraulic Horsepower and Impact Force.................................................................................9-18
Jet Selection...............................................................................................................................9-19
SWAB AND SURGE .........................................................................................................................9-20
Equivalent Fluid Velocity..........................................................................................................9-21
Flow Regime..............................................................................................................................9-22
Surge or Swab Pressure ............................................................................................................9-22
Equivalent Fluid Weight............................................................................................................9-22
Gel-Breaking Pressure ..............................................................................................................9-23
CUTTINGS TRANSPORT ..................................................................................................................9-23
Laminar Flow Condition ...........................................................................................................9-25
Turbulent Flow Condition .........................................................................................................9-26
Cuttings Transport ....................................................................................................................9-26
Transport Efficiency ..................................................................................................................9-26
Cuttings Concentration .............................................................................................................9-27
SUMMARY......................................................................................................................................9-28
HYDRAULICS EXAMPLE.................................................................................................................9-29
Bit Hydraulics............................................................................................................................9-34
Swab and Surge.........................................................................................................................9-36
Cuttings Transport ....................................................................................................................9-36
Cuttings Concentration .............................................................................................................9-37
NOMENCLATURE ...........................................................................................................................9-38
REFERENCES..................................................................................................................................9-40
BAKER HUGHES DRILLING FLUIDS
REERENCE MANUAL
REVISIOIN 2006 9-i