BAKER HUGHES - Drilling Fluids Reference Manual

Chapter 1
Table of Contents
Fundamentals of Drilling Fluids ...............................................................................................................1-1
Functions of Fluids................................................................................................................................1-1
Promote Borehole Stability ...............................................................................................................1-1
Remove Drilled Cuttings from Borehole ..........................................................................................1-2
Cool and Lubricate Bit and Drillstring..............................................................................................1-2
Suspend Cuttings / Weight Material When Circulation Ceases........................................................1-3
Support Partial Weight of Drillstring or Casing................................................................................1-3
Minimize Adverse Effects on Productive Formations ......................................................................1-3
Transmit Hydraulic HP to Clean Bit and Bottom of Borehole .........................................................1-4
Release Undesirable Cuttings at the Surface.....................................................................................1-4
Ensure Maximum Information from Well ........................................................................................1-4
Limit Corrosion of Drillstring, Casing, and Tubular Goods .............................................................1-4
Minimize Environmental Impact ......................................................................................................1-4
Physical and Chemical Properties of Fluids..........................................................................................1-5
API Recommended Practices................................................................................................................1-5
Density ..............................................................................................................................................1-5
Rheology, Viscosity and Gel Strength Relationships .......................................................................1-5
Newtonian and Non-Newtonian Fluids.................................................................................................1-7
Viscosity............................................................................................................................................1-7
Flow Regimes....................................................................................................................................1-7
Determination of Flow Regime.......................................................................................................1-10
Continuity of Flow ..........................................................................................................................1-11
Mathematical Fluid Models ................................................................................................................1-11
Newtonian Fluid Model ..................................................................................................................1-12
Bingham Plastic Model ...................................................................................................................1-12
Determination of PV and YP ..........................................................................................................1-14
Power Law Model...............................................................................................................................1-16
Determination of n and K................................................................................................................1-18
Other Models.......................................................................................................................................1-20
Casson .............................................................................................................................................1-20
Robertson-Stiff................................................................................................................................1-20
Herschel-Bulkley.............................................................................................................................1-20
BAKER HUGHES DRILLING FLUIDS
REVISED 2006
REFERENCE MANUAL
I