VERSACOAT Oil-Based Mud Emulsifier | SLB


Oil-based mud emulsifier and surfactant

Schlumberger Oilfield Services

Secondary benefits include improved thermal stability and high-pressure, high-temperature (HPHT) filtration control. The product is effective over a wide temperature range, in the presence of contaminants, and for reducing the adverse effects of water contamination.

Typical Physical Properties 
Typical Physical Properties Physical appearance   Dark amber, viscous liquid
Typical Physical Properties Specific gravity   0.85-0.95
Typical Physical Properties Flash point   83 degF [28 degC] (Pensky–Martens closed-cup test)
Typical Physical Properties Pour point   –20 degF [–28.9 degC]


VERSACOAT surfactant functions as a wetting agent and secondary emulsifier when used in conventional, low-fluid-loss, high-lime systems in combination with VERSAMUL versatile emulsifier package. In this application, the product oil-wets barite and drill solids to prevent water-wet solids; it improves thermal stability, rheological stability, filtration control and emulsion stability; and improves the fluid’s resistance to contamination. Concentrations for initial formulations range from 1 to 3 lbm/bbl [2.85 to 8.6 kg/m3] when used as a wetting agent, with occasional daily treatments.

VERSACOAT surfactant functions as the primary emulsifier when used in relaxed-fluid-loss, lower-lime systems, in combination with VERSAWET oil-based mud surfactant. In this application, the product forms a stable water-in-oil emulsion and provides a degree of oil-wetting. Concentrations for initial formulations range from 2 to 8 lbm/bbl [5.7 to 22.8 kg/m3] when used as the primary emulsifier, with occasional daily treatments. High temperature applications and some light mineral oils require higher concentrations of VERSACOAT surfactant.

VERSACOAT surfactant is a primary ingredient in all VERSA system formulations:


  • Wide application, including higher-lime, conventional and lower-lime, relaxed VERSA systems
  • Improves emulsion stability
  • Improves oil-wetting and prevents water-wet solids
  • Maintains stable water-in-oil emulsion and helps prevent water in HPHT filtrate
  • Improves thermal stability, rheological stability, filtration control and contamination-
  • Effective at counteracting the adverse effects of water contamination such as high viscosity, low-emulsion stability, and water-wet solids


  • Environmental restrictions concerning the use of oils and oil-base fluids should be considered since VERSACOAT is used in conjunction with oil.

Toxicity and handling

Bioassay information is available upon request. Handle as an industrial chemical, wearing protective equipment and observing the precautions described in the Material Safety Data Sheet (MSDS).

Packaging and storage

VERSACOAT surfactant is packaged in 55-galUS (208-L) drums. Store in a dry, well-ventilated area. Keep container closed. Keep away from heat, sparks, and flames. Store away from incompatibles. Follow safe warehousing practices regarding palletizing, banding, shrink-wrapping, and stacking.