SWA EH Wetting Agent | SLB


Invert-emulsion wetting agent

Schlumberger Oilfield Services

SWA EH invert-emulsion wetting agent is a specialized surfactant to preferentially oil-wet solids in the VERSA oil-based drilling fluid systems.

SWA EH additive complements the systems’ normal wetting agents to assist in preventing water-wetting of solids. In certain situations, SWA EH additive has the ability to reverse water-wetting of solids that might occur.

Typical Physical Properties  
Physical appearance Brown liquid
Specific gravity 1.1
pH 4.5–5.0 (10% water)
Flash point 167 degF [75 degC]


SWA EH wetting agent can be added to reverse a water-wet solids problem, allowing the surface area of the solids to return to an oil-wet environment. SWA EH agent will prevent water wetting of all weight material, including FER-OX hematite weighting agent.

SWA EH wetting agent may be added to a drilling fluid as a pretreatment before displacement or cementing jobs are initiated to eliminate any occurrence of water-wetting or used to condition a fluid that has encountered a water-wet problem. In general, for pretreatment, concentrations of 1 lbm/bbl [2.8 kg/m3] are suggested, however if a large amount of open hole is exposed, larger treatments should be considered, but should be limited to no more than 2 lbm/bbl [5.6 kg/m3].

Recommended treatment levels for water-wet solids contamination, such as water flows, and CO2 intrusions, are from 1 to 2 lbm/bbl [2.8 to 5.7 kg/m3]. Begin treatment as soon as wetting characteristics are observed (graininess, barite settling, flocculation, etc.).

During all treatments, normal concentrations of emulsifiers and other additives should be maintained. In all situations, pilot testing should be done before adding SWA EH wetting agent to insure that overtreatment is avoided.


  • Prevents water-wet solids
  • Reverses water-wetting of solids


  • Overtreatment may cause low rheology

Toxicity and handling

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

Packaging and storage

SWA EH wetting agent is packaged in 5-galUS [18.9-L] cans and 55-galUS [208-L] drums. Store in a dry location away from sources of heat or ignition, and minimize dust.