Viscosifiers – Water-Based Muds

Water-based muds require viscosifiers compatible with the base fluid and tolerant to drilling conditions. AES Drilling Fluids has a range of options from basic gel additives to enhanced grades of xanthan gum, such as ENERZAN.

ENERZAN L liquid xanthan gum

Viscosifier Options

There are several kinds of viscosifiers used in water-based muds in order to provide quality hole cleaning and solid-suspension characteristics. Viscosifiers work in concert with all of the mud components, meaning there is a wide range of options for the numerous water-based drilling fluids available.

Clay-Based Viscosifiers

Bentonite, a name given for commercially mined sodium montmorillonite (a form of smectite clay) is the most common clay additive used in both oil and water based drilling fluids.  When a bentonite clay particle is hydrated, the interlayers expand as water is absorbed.  This expansion is what creates viscosity in a clay-based drilling fluid system.  The distance at which the particle expands is related to the type and amount of cations present

Another type of commercial clay often used is Attapulgite, a needle-shaped non-swelling particle primarily used in saltwater muds.  The inherit shape of this material is responsible for the clay’s behavior and ability to build viscosity.  Because of its non-swelling and crystalline structure, Attapulgite alone does not provide sufficient filtration control.

Polymer Viscosifiers

Polymers, defined as large molecules comprised of small, identical recurring units, are widely used in water-based muds. Their structures can usually be classified as linear, branched, or cross-linked.  However, polymers can also be categorized by their origin:  natural, modified, or synthetic.

One of the most often used natural polymers is known as xanthan gum. When hydrated, xanthan gum arranges itself as a long branching structure with weak hydrogen bonding – this provides it’s viscosifying characteristics.

The effectiveness of polymers/starch additives rely on many factors including the concentration of the material and the fluids inherent pH/hardness/salinity. Starch additives, typically added for filtration control, also can provide viscosity as a secondary function.

Common polymers used in water-based drilling fluids:

  • Xanthan Gum – Shear thinning polymer with excellent suspension characteristics
  • PHPA (Partially Hydrolyzed Polyacrylamide) – Provides shale inhibition properties and drilled solids encapsulation, along with an inherent viscosity
  • HEC (Hydroxyethylcellulose) – Modified cellulose polymer used widely in completion and workover fluids for viscosity and fluid loss control due to its relatively clean, acid soluble characteristics. HEC structure is such that it does not suspend solids effectively.
  • High Temperature Synthetic Polymers – Chemically synthesized and tailor made to fit a specific application, often ultra-high temperature conditions.
  • PAC (Polyanionic Cellulose) – Polyanionic modified polymer which reduces fluid loss and increases viscosity
  • CMC (Carboxymethycellulose) – Modified anionic polymer which reduces fluid loss and increases viscosity

Viscosity Concepts

Our expertise insures our drilling fluid systems are maintained at maximize performance at with cost. Our TechTips series seeks to educate customers with some of this knowledge related to key drilling fluid concepts.

Select Viscosifier Additives for Water-Based Mud from AES Drilling Fluids

Filtration control additives vary by performance requirements to minimize cost for an application. Contact your AES Drilling Fluids Account Manager to review product details for your application.

ProductDescriptionProduct Data SheetAssociated Mud System(s)
ENERZANHigh purity dispersible xanthan gum biopolymer used for rheology control in fresh water, seawater, brine and saturated salt environmentsENERZAN Product BulletinGeneral WBM
ENERZAN LA premium grade xanthan gum
dispersed in light mineral oil for ease of use
ENERZAN L Product BulletinGeneral WBM
ES-VISPremium bentonite for the EnerSEAL systemES-VIS Product BulletinGeneral WBM
SURE SWEEPWBM viscosifier for high viscosity sweepsSURE SWEEP Product BulletinGeneral WBM
XG-VISA dispersible xanthan gum biopolymer used for rheology modifications, hole cleaning and solids suspension in all
types of water based mud systems
XG-VIS Product BulletinGeneral WBM

Water-Based Mud Additives

Corrosion Inhibitors & Scavengers
Filtration Control
Shale Inhibitors
Loss Prevention & Treatment

Invert Emulsion Additives

Emulsifiers, wetting agents & dispersants
filtration control
loss prevention & treatment