BAKER HUGHES - Drilling Fluids Reference Manual

Oil / Synthetic Fluids
CARBO-MUL ® / CARBO-MUL ® HT
CARBO-MUL ® is an oil-soluble, modified imidazoline (CARBO-MUL ® HT is a high-temperature
polyamide). Both are used as emulsifiers and wetting agents for the CARBO-DRILL family of oilbase
fluid systems.
CARBO-MUL is compatible with a wide range of internal phase salinities and can be used to emulsify
calcium chloride and sodium chloride brines, seawater, and freshwater in oil-base fluids. CARBO-
MUL is substantive (adsorbs on) to mineral surfaces, reducing interfacial surface energy and rendering
MIL-BAR, other weight materials, and drill solids oil-wet. CARBO-MUL, unlike soap surfactants,
does not require lime hydrate in order to function effectively and is an ideal surfactant for low-colloid,
relaxed inverts such as the CARBO-FAST oil-base fluid system.
CARBO-MUL is used as a combination emulsifier/wetting agent in the CARBO-FAST lowcolloid/relaxed-filtrate
oil-base fluid system, when only modest filtration control is required. No
filtration control additives, lime, or other surfactants are typically used in these high-penetration rate
systems.
CARBO-MUL is also used as the wetting agent/supplemental emulsifier in the CARBO-TEC
controlled-filtrate oil-base fluid system. CARBO-MUL is used in conjunction with CARBO-TEC,
lime, and filtration control additives in these more highly treated systems, and can be formulated to
withstand temperatures in excess of 400°F (204°C).
CARBO-FAST low-colloid/relaxed-filtrate oil-base fluid systems will require 0.4 to 0.75 gal/bbl (9.5
to 17.9 L/m 3 ) of CARBO-MUL (used as a primary emulsifier/wetting agent), depending on the
bottomhole temperatures, solids content, and type. CARBO-TEC controlled-filtrate oil-base fluid
systems will require 0.12 to 1.0 gal/bbl (2.9 to 23.8 L/m 3 ) of CARBO-MUL applied under similar
circumstances. Approximately 1.0 gal (3.8 L) of CARBO-MUL per 25 (100-lb) sacks of MIL-BAR is
normally sufficient when used as a wetting agent at weight-up.
Table 5-8 Typical Physical Properties – CARBO-MUL/CARBO-MUL HT
PROPERTY CARBO-MUL CARBO-MUL HT
Appearance Dark liquid Dark liquid
Flash Point 60°F (16°C) (ASTM D56) 170°F (77°C) (ASTM D56)
Pour Point 10°F ( 12°C) 23°F ( 5°C)
Density 7.7 lbm/gal (924 kg/m 3 ) 8.0 lbm/gal (952 kg/m 3 )
Baker Hughes Drilling Fluids
Reference Manual
5-32 Revised 2006