BAKER HUGHES - Drilling Fluids Reference Manual

Chapter 12
Table of Contents
PRESSURE PREDICTION AND CONTROL..................................................................................1
FORMATION PRESSURE.....................................................................................................................1
Normally Pressured Formations................................................................................................1
ABNORMAL FORMATION PRESSURES...............................................................................................2
HOW TO RECOGNIZE ABNORMAL PRESSURE ZONES......................................................................3
METHODS OF FORMATION PRESSURE PREDICTION .......................................................................4
Seismic..........................................................................................................................................4
Shallow Gas..............................................................................................................................4
Deeper Gas ..............................................................................................................................4
ELECTRIC LOG ANALYSIS..................................................................................................................5
Sonic Logs ....................................................................................................................................7
DRILLING PARAMETERS USED TO INDICATE AN ABNORMAL PRESSURE ZONE ...........................11
Increased Rate of Penetration.................................................................................................11
Rotary Torque ............................................................................................................................12
Changes in Drag on Connections ...........................................................................................12
Change in Pit Volume ...............................................................................................................12
The “d” Exponent .......................................................................................................................13
Gas Content of Drilling Fluid ....................................................................................................14
Changes in Cuttings ..................................................................................................................15
Shale Density .............................................................................................................................15
Flowline Temperature ...............................................................................................................15
Chloride Trends..........................................................................................................................16
Paleo Information.......................................................................................................................16
CONTROLLING FORMATION PRESSURE..........................................................................................16
Preplanning to Prevent or to Handle Kicks Safely................................................................16
Kick Recognition ........................................................................................................................17
Kicks While Drilling ....................................................................................................................17
Kicks While Tripping Out of the Hole......................................................................................19
Kicks While Tripping Into the Hole ..........................................................................................20
Behavior of Gas in the Wellbore..............................................................................................20
Rise of Gas without Expansion............................................................................................20
Rise of Gas with Uncontrolled Expansion..............................................................................21
Rise of Gas with Controlled Expansion..................................................................................21
Shut-In Drillpipe and Casing Pressures .................................................................................22
Fluid Weights and Pressures...................................................................................................23
Equivalent Circulating Density.................................................................................................24
U-Tube Concept.........................................................................................................................26
Closing Procedure .....................................................................................................................29
Procedure for Closing Well In While on Bottom................................................................29
Procedure for Closing Well In While Tripping....................................................................30
PRESSURE CONTROL METHODS ....................................................................................................31
The Wait and Weight Method of Well Control .......................................................................31
Baker Hughes DRILLING FLUIDS Well Control Kill Sheet .................................................33
SPECIAL PROBLEMS ........................................................................................................................34
Barite Plugs ................................................................................................................................35
Procedure to Set Barite Plugs .............................................................................................35
BAKER HUGHES DRILLING FLUIDS
REVISED 2004
TRAINING MANUAL
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