Drilling Fluid Additives Explained

Understanding drilling fluid additives is essential for anyone specifying, purchasing, or managing drilling fluid programs. This guide covers the main additive categories used in water based mud systems, explaining what each does, when to use it, and which Tiger Fluids products correspond to each function.

Viscosifiers

Viscosifiers increase the carrying capacity and gel strength of the drilling fluid. They are the foundation of any mud system, providing the hydraulic properties needed to transport cuttings from the bit to surface.

Bentonite

The most widely used viscosifier in Australian drilling. Tiger Gel and Tiger Ben are sodium bentonite products that hydrate in fresh water to form a thixotropic gel. Bentonite provides excellent gel strength for cuttings suspension at rest, and shear-thinning viscosity for efficient cuttings transport during circulation. Not suitable for salt water or high-hardness water without pre-treatment.

PHPA Polymers

Partially hydrolysed polyacrylamide (PHPA) polymers such as Tiger Drill provide viscosity through long-chain molecular structure rather than clay particle interaction. PHPA is used in inhibitive systems where clay addition is minimised, and in polymer-only systems for mineral exploration core drilling. PHPA also encapsulates drilled solids, preventing dispersion into the mud system.

Xanthan Gum

A biopolymer that provides excellent low-shear-rate viscosity (LSRV) and gel strength. Tiger XC (xanthan gum) is used in systems requiring suspension of heavy cuttings or weighted solids, and in horizontal drilling where low-shear-rate performance is critical for cuttings transport in the horizontal section.

Fluid Loss Control Additives

Fluid loss control (FLC) additives reduce the volume of filtrate that passes through the borehole wall into the formation. Excessive fluid loss can destabilise the borehole, cause clay swelling, and reduce mud volume in the active system.

Polyanionic Cellulose (PAC)

Tiger Super PAC R (regular grade) and Tiger Super PAC L (low viscosity grade) are the standard FLC additives for WBM. PAC polymers deposit onto the filter cake and reduce its permeability. Regular grade PAC also contributes to viscosity; low viscosity grade is used when viscosity is already adequate and only fluid loss reduction is needed.

Starch

Pre-gelatinised starch is used as a FLC additive in salt-saturated muds and high-temperature applications where PAC performance is reduced. Starch is also used in KCl systems and as a low-cost FLC in basic water well mud programs.

Lubricants

Lubricants reduce friction between the drill string and the borehole wall, lowering torque, drag, and risk of differential sticking. They are particularly important in deviated, extended reach, and HDD applications.

Tiger Slick

A concentrated liquid lubricant for addition to water based mud systems. Tiger Slick reduces the coefficient of friction between the drill string and filter cake, reducing torque and drag. Recommended addition rate is 2–5 L/m³ of active system, with higher rates used during HDD reaming and pullback operations.

Tiger Lube

A supplementary lubricant for use in high-friction applications or where Tiger Slick alone is insufficient. Tiger Lube can be used in combination with Tiger Slick for maximum lubricity benefit in demanding HDD or deep rotary drilling applications.

Foam Agents

Foam agents are used to generate drilling foam for air-foam drilling applications, including reverse circulation, aircore, and underbalanced drilling. Foam reduces hydrostatic head, assists cuttings transport in low-pressure formations, and suppresses dust in dry air drilling.

Tiger Foam

A concentrated foaming agent designed for injection into air drilling systems. Tiger Foam produces a stable, fine-bubble foam that transports cuttings efficiently. Typical injection rate is 0.5–2 L/min depending on formation and hole diameter. Tiger Foam is suitable for RC, RAB, and aircore drilling applications.

Lost Circulation Materials (LCM)

Lost circulation materials are used when drilling fluid is lost into the formation through fractures, vugs, or highly permeable zones. LCMs bridge across the openings and reduce or stop fluid loss.

Tiger Kwik Seal

A fine-ground fibrous and granular LCM blend designed to bridge fractures without plugging the bit nozzles or bit face. Tiger Kwik Seal is added to the active system at 5–20 kg/m³ depending on the severity of loss. For severe loss, a high-concentration slug may be pumped ahead of normal mud.

Tiger Swell

A swelling LCM designed for use in fractured or fissured formations where mechanical bridging alone is insufficient. Tiger Swell particles absorb water and swell to seal fractures. Particularly effective in formations with reactive clay content adjacent to the fracture.

Greases

Drilling greases provide boundary lubrication at metal-to-metal contact points, including drill pipe connections, stabilisers, and sub faces. They are distinct from fluid lubricants and are applied directly to the equipment rather than added to the mud system.

Tiger Grease

A high-performance drilling grease for thread protection and stabiliser lubrication. Tiger Grease provides excellent adhesion to metal surfaces, resists washing by drilling fluid, and protects connections in corrosive borehole environments. Applied by brush or dauber to all threaded connections before make-up.

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