BAKER HUGHES - Drilling Fluids Reference Manual

Chapter 7
Table of Contents
BOREHOLE PROBLEMS...............................................................................................................7-1
HOLE STABILITY PROBLEMS ..........................................................................................................7-1
Introduction ................................................................................................................................7-1
The Mechanisms of Wellbore Instability – Mechanical Aspects........................................7-2
Preventative Action – Mechanical..........................................................................................7-4
Symptoms and Remedial Action ............................................................................................7-6
The Mechanisms of Wellbore Instability – Chemical Aspects ...........................................7-6
Preventative Action – Chemical..............................................................................................7-7
Symptoms and Remedial Action ............................................................................................7-8
Special Cases ...........................................................................................................................7-9
INHIBITIVE WATER BASED DRILLING FLUIDS...............................................................................7-11
Shale Hydration.......................................................................................................................7-11
Shale Hydration Inhibition......................................................................................................7-12
Pore Pressure Transmission.................................................................................................7-13
Pore Pressure Transmission Inhibition................................................................................7-14
Silicate Based Drilling Fluids.................................................................................................7-15
Cloud Point Glycols ................................................................................................................7-17
LOSS OF CIRCULATION.................................................................................................................7-21
Preventive Measures .............................................................................................................7-22
Seepage Loss .........................................................................................................................7-23
Partial Loss ..............................................................................................................................7-24
Severe (or Total) Loss of Returns........................................................................................7-26
Loss Circulation Prevention by “Stress Cage” Technique................................................7-32
DRILLSTRING STICKING ................................................................................................................7-34
Spotting Fluids.........................................................................................................................7-36
Remedial Procedures Using Spotting Fluids......................................................................7-37
Alternate Methods for Freeing Stuck Pipe ..........................................................................7-40
Other Causes of Drillpipe Sticking and Remedial Correction ..........................................7-42
LUBRICITY .....................................................................................................................................7-43
HIGH BOTTOMHOLE TEMPERATURES..........................................................................................7-45
Mechanisms of Thermal Degradation..................................................................................7-45
Temperature Limits.................................................................................................................7-46
Extending Temperature Limits..............................................................................................7-47
Drilling Fluid Properties..........................................................................................................7-47
Symptoms and Remedial Action ..........................................................................................7-49
Planning ...................................................................................................................................7-51
REFERENCES ................................................................................................................................7-52
BAKER HUGHESDRILLING FLUIDS
REVISION 2006 7-i
REFERENCE MANUAL