DUO‐VIS L

Biopolymer viscioifier for water-based muds

DUO‐VIS L biopolymer viscosifier is a high yield, non‐clarified xanthan gum that is pre‐dispersed in a water‐miscible, oil‐free and clay‐free carrier fluid. DUO‐VIS L is effective in most water‐base fluids from low‐solids to highly weighted systems. This includes fresh water, salt, and some heavy‐brine systems.

The high‐molecular‐weight DUO‐VIS L xanthan gum biopolymer is the primary economical shear‐thinning viscosifier for displacement spacers to provide solids transport, solids suspension, friction reduction, and improved displacement efficiency.

DUO‐VIS L viscosifier produces elevated low‐shear‐rate viscosity (LSRV) and high, but fragile, gel strengths. These properties provide superior hole cleaning and suspension, improved hydraulics, reduced torque and drag, and assist in minimizing filtrate invasion. The water‐miscible carrier fluid of DUO‐VIS L additive assists in dispersion and helps prevent lumps or “fisheyes” so the polymer rapidly and smoothly viscosifies without the need for high shear.

Applications

DUO‐VIS L viscosifier is primarily used for displacement spacers where the biopolymer will not be in contact with the formation. Because the non‐clarified xanthan gum is pre‐dispersed in a water‐miscible carrier fluid, it provides the unique rheology profile much more readily than dry material. This is especially critical when the proper mixing equipment is not available.

DUO‐VIS L additive works to provide an optimized rheological profile with elevated LSRV and highly shear‐thinning characteristics with low “n” values. These characteristics frequently result in fluids with inverted flow properties, i.e., the yield point being greater than the plastic viscosity. Due to the low‐shear rates experienced in the annulus, DUO‐VIS L agent enables the fluid to have a high effective viscosity for adequate cleaning of the wellbore and suspending solids.

Advantages

• Easily dispersible with rapid viscosity development without high shear; small treatments produce significant results
• Shear‐thinning rheological profile for improved hydraulics
• Minimum frictional pressure losses for additional hydraulic horsepower
• Reduces torque and drag
• Assists in minimizing filtrate invasion
• Viscous laminar flow in the annulus for improved wellbore stability with maximum hole‐ cleaning and suspension capacity
• Lower toxicity product and more environmentally acceptable than oil‐base carrier fluids
• Easy to mix