BAKER HUGHES - Drilling Fluids Reference Manual

Chapter 4
Table of Contents
Contamination of Water Base Muds ..................................................................................................4-1
Contaminant Overview ..................................................................................................................4-1
Calcium / Magnesium Contamination........................................................................................4-2
Cement Contamination...............................................................................................................4-3
Anhydrite-Gypsum Contamination............................................................................................4-5
Salt Contamination.....................................................................................................................4-6
Carbonate / Bicarbonate Contamination ....................................................................................4-7
Estimation of Concentration of Carbonates / Bicarbonates ...................................................4-8
P f /M f Method..........................................................................................................................4-9
P1 – P2 Method for Hydroxyl/Carbonate/Bicarbonate Determination. .................................4-9
Garrett Gas Train Measurement (CO3= / HCO3¯)..............................................................4-10
pH / Pf Method.....................................................................................................................4-10
Equations..............................................................................................................................4-11
Special Procedure for Low pH Fluids..................................................................................4-12
Treatment of Carbonates ......................................................................................................4-12
Carbon Dioxide (CO2).........................................................................................................4-13
Hydrogen Sulfide (H2S) Contamination..................................................................................4-14
Temperature Flocculation / Deterioration ................................................................................4-14
Solids Contamination...............................................................................................................4-14
Oil / Gas Contamination...........................................................................................................4-14
List of Figures
Figure 4-1 Solution Species Present in Carbonate Systems as a Function of pH –
Calculated for K 1 =3.5 x 10 -7 and K 2 = 6.0 x 10 -11 .....................................................4-7
Figure 4-2
Ions Present at Various pH Levels...........................................................................4-8
List of Tables
Table 4-1 Comparisons of the Alkalinity Methods ..................................................................4-9
Table 4-2
P f /M f Alkalinity Ion Concentrations, mg/L..............................................................4-9
Baker Hughes Drilling Fluids
Revised 2006
Reference Manual
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