BAKER HUGHES - Drilling Fluids Reference Manual

Baker Hughes Drilling Fluids
Figure 3-22
Viscosity Increases with NEW-DRILL Additions
AQUA-COL, AQUA-COL D, and AQUA-COL S – These are low molecular weight water
soluble polyols. The concentration is proportional to the level of inhibition. Addition of polyol to
improve inhibition must be viewed against the increased cost of the fluid. The optimum
concentration for clay inhibition in North Sea wells is in the range 3% to 5% by volume. The
GLYKIT test can be used for measuring AQUA-COL concentration in the drilling mud system.
In order to allow for (theoretical) depletion, the product concentration is usually allowed to
increase by 0.5% to 1.0% through the interval. At high AQUA-COL concentrations (> 7.0%),
there have been some flocculating effects in laboratory fluids. Consultation with BHDF is
required before considering raising the active concentration above 7.0% by volume AQUA-COL.
Caustic Soda – Caustic Soda, is used primarily for pH and alkalinity control. It minimizes the
solubility of calcium as well as magnesium contaminants in water-base drilling fluids. Caustic
Soda is always added to solubilize and activate LIGCO and UNI-CAL. Do not mix it through the
fluid hopper. Dissolve it in water in a chemical barrel. One sack should be added very slowly with
careful agitation to 189 liters (50 gal) of water in the chemical barrel. Caustic soda is a corrosive
material and should be handled with extreme caution.
MIL-BAR - Barium sulfate (BaSO 4 ), commonly known as barite is used to increase the density
of all types of drilling fluids. MIL-BAR is chemically inert to all drilling fluid additives
Selected Well Summaries
Table 3-25 AQUA-DRILL Applications in the North Sea provides an overview of six AQUA-
DRILL mud wells drilled in the North Sea. Data from each well was from the 17 ½” hole
section.
Baker Hughes Drilling Fluids
Reference Manual
Revised 2006 3-85