BAKER HUGHES - Drilling Fluids Reference Manual

MECHANICAL SOLIDS CONTROL
G = the gravitational constant, cm/sec 2
d = the diameter of the particle, cm
D S = density of the particle, S.G.
D M = density of the fluid, S. G.
µ = viscosity of the fluid, centipoise
In general,
• The smaller of two particles of the same specific gravity has a lower settling velocity.
• The heavier of two particles of equal diameter will settle faster.
• The higher the fluid density, the lower the settling velocity.
• The higher the viscosity, the lower the settlin g velocity.
For example, it can be calculated that a barite particle (4.2 specific gravity and 4-microns in
diameter) will settle at approximately the same rate as a low-gravity particle (2.6 specific gravity)
having a diameter of 6 microns.
Hydrocyclones
Hydrocyclones are used for desanding, desilting and salvaging barite. Figure 10-4 is a crosssectional
view illustrating the operating principle of a hydrocyclones.
BAKER HUGHES DRILLING FLUIDS
REVISION 2006 10-11
REFERENCE MANUAL