Emulsifiers, Wetting Agents & Dispersants

Across the various invert emulsion systems, AES Drilling Fluids provides robust emulsifiers, wetting agents, and dispersants to address drilling challenges while controlling cost. Through our expertise developing many of our own products, our options provide optimal drilling fluid properties under the most difficult drilling conditions. 

Emulsifiers and wetting agents are essential additives for any invert emulsion (oil-or-synthetic based) drilling fluid system. Emulsifiers typically offer some oil-wetting characteristics while wetting agents provide some emulsification properties. Dispersants provide additional oil-wetting.

Emulsifiers, wetting agents, and dispersants are all based upon surfactant chemistry, but they have distinct differences depending upon performance objectives. For example, our AES MUL X is optimized for AES VERT, which utilizes diesel or distillate as the base fluid while ENERMUL and ENERMUL II are designed for the rheological profile desired using EnerREACH. Similarly, AES WA X and ENERWET have structures to reflect performance targets at optimal price. Our entire portfolio balances various performance and environmental targets with the most cost effective solution for a given system.

A surfactant features a “water-loving” hydrophilic end and an “oil-loving” lipophilic end. The ratio of hydrophilic and lipophilic portions of a surfactant molecule is referred to as the HLB number (Hydrophile-Lipophile Balance). The HLB value indicates whether or not the surfactant is soluble in oil or water, and it’s ability to generate invert emulsions and oil-wetting capabilities. 

An emulsifier generates the water droplets of the internal phase while a wetting agent oil-wets solids

General surfactant composition


Emulsifiers are critical to establishing and maintaining strong emulsions in oil-and-synthetic based drilling fluid systems.  This key product provides some important functions in order to maintain a stable fluid system throughout a broad range of challenging drilling conditions. As more water/brine is introduced, more emulsifier is consumed. Secondary emulsifiers can further strengthen emulsions and boost ES values.

An emulsifier:

  • Forms a stable film around the water/brine to form a droplet
  • Maintains the water/brine droplet in the internal phase
  • Enhances filtration control, filtercake quality and emulsion stability

Wetting Agents

Wetting agents serve as critical components to maintaining the integrity of any invert emulsion drilling fluid. Wetting agents are designed specifically for invert emulsions (oil or synthetic-based) and oil-wet drill solids as well as commercial solids, such as barite. If a solid particle is not sufficiently oil-wet, it will agglomerate and fall out of the drilling fluid, compromising fluid stability.

Wetting agent is consumed as it coats water-wet solids, requiring continuous addition as drilling progresses and regular treatment when adding commercial solids.

Functionally, wetting agents:

  • Reduce the surface tension between the oil-liquid phase and solids
  • Oil-wet the water-wet drill solids while drilling
  • Essential when adding barite, lost circulation material, or other water-wet materials
  • Wetting agents get consumed as it coats more solids, requiring additional material as drilling progresses


As low gravity solids accumulate, it is more challenging to maintain an oil-wet, dispersed fluid system. At these extremes, a supplemental dispersant provides a thinning effect to control undesirable drilling fluid properties through stronger oil-wetting characteristics. The effects of these additives should be tested by pilot testing to minimize the risk of over-treatment.

Our Emulsifiers, Wetting Agents & Dispersants: A Hands-On Approach

At AES Drilling Fluids, we manufacture and sell many of our own emulsifiers and wetting agents through the CES Energy Solutions family.  This  allows us to optimize products for our customers’ specific needs – ensuring these chemistries are truly fit-for-purpose.  This also leads to increased quality and reliability throughout the manufacturing process. 

Learn more about the CES Energy Solutions family

Emulsifiers, Wetting Agents & Dispersants from AES Drilling Fluids

Our extensive product line covers a broad range of performance requirements for invert emulsion systems, from conventional oil-based muds to chloride-free synthetic muds. Contact your AES Drilling Fluids Account Manager to review product details for your application.

ProductDescriptionProduct Data SheetAssociated Fluid System(s)
ABS MULEmulsifierABS MUL Product BulletinABS 40
ABS MUL HTHigh Temperature EmulsifierABS MUL HT Product BulletinABS 40
AES MUL IISecondary EmulsifierAES MUL II Product BulletinABS 40
AES MUL XEmulsifierAES MUL X Product BulletinAES VERT
AES WA IIWetting Agent AES WA II Product BulletinABS 40
AES WA XWetting AgentAES WA X Product BulletinAES VERT
AES SPERSEDispersant/ThinnerAES SPERSE Product BulletinABS 40
ENERMULPrimary EmulsifierENERMUL Product BulletinEnerREACH
ENERMUL IISecondary EmulsifierENERMUL II Product BulletinEnerREACH
ENERSPERSEDispersant/Thinner ENERSPERSE Product BulletinEnerREACH
ENERWETWetting Agent ENERWET Product BulletinEnerREACH
FLOMULSpecialized EmulsifierFLOMUL Product BulletinN/A
STARMULSecondary EmulsifierN/APURESTAR

Emulsifier Case Histories

FLOMUL restores fluid properties of a water-flow contaminated OBM