ASPHASOL SUPREME Sulfonated-Asphalt Shale Inhibitor | SLB


Sulfonated-asphalt shale inhibitor

Schlumberger Oilfield Services

ASPHASOL SUPREME sulfonated-asphalt shale inhibitor is used to aid in stabilizing shale sections, controlling solids dispersion, and improving filtercake characteristics. It is also used as a supplemental high-temperature fluid-loss additive for water-based drilling fluid systems.

ASPHASOL SUPREME inhibitor is a free-flowing powder and can be added directly to the mud system through the mixing hopper. It is not necessary to premix ASPHASOL SUPREME inhibitor with oil. It contains no surfactants.

Normal concentrations of this inhibitor range from 3 to 6 lbm/bbl [8.6 to 17.1 kg/m3] for shale stabilizing control and 6 lbm/bbl [17.1 kg/m3] for high-temperature fluid-loss control.

Typical Physical Properties  
Physical appearance Black-gray fine powder
Specific gravity 1.40–1.65
pH (2% solution) 7–10
Solubility in water 65% to 80% at 72 degF


  • Stabilize shales
  • Control solids dispersion
  • Improve wallcake characteristics


  • Improves borehole stability
  • Can be used in nonaqueous fluid (NAF) applications
  • Easy to handle and mix
  • Plugs microfractures and seals shales
  • Inhibits swelling and water-wetting of shales
  • Reduces HPHT fluid loss
  • Reduces torque and drag
  • Improves filtercake quality
  • Increases drilling fluid lubricity

Toxicity and handling

Bioassay information is available upon request. Handle as an industrial chemical, wearing protective equipment and observing the precautions described in the SDS.

Packaging and storage

ASPHASOL SUPREME inhibitor is available in 50-lbm [22.7-kg] multiwall sacks, with 50 sacks per shrink-wrapped pallet. Store in a dry, well-ventilated area. Keep container closed. Store away from incompatibles. Follow safe warehousing practices regarding palletizing, banding, shrink-wrapping, or stacking.


  • May impart high gel strengths when used in NAFs. The use of the product in such applications or systems must be preceded by pilot testing.