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GEOVIS ™

 is a trademark of CP Kelco U.S., Inc. and may be registered or applied for in other countries.   © 2002 CP Kelco U.S., Inc.The information contained herein is, to our best knowledge, true and accurate, but all recommendations or suggestions are made without guarantee, since we can neither

anticipate nor control the different conditions under which this information and our products are used. It is our policy, to assist our customers and to help in thesolution of particular problems which may arise in connection with application of our products.

Rev. 09/05

Kelco Oil Field Group   10920 W. Sam Houston Pkwy North, Ste 800   Houston, TX 77064   (713) 895-7575 

www.kofg.com

GEOVIS ™ XT    A High Viscosity, Thermally Stable Biopolymer

for Rheology ControlDescription GEOVIS XT  polymer is a high molecular weight polysaccharide used to enhance

the low shear rate viscosity of water based circulating systems.

Function The primary function of GEOVIS XT  is to optimize the rheological profile of drillingfluids by increasing viscosity at low shear rates (less than 5.1 sec

-1),

while maintaining plastic viscosity at a minimum value. In so doing, it improvessuspension and solids carrying capacity, especially under low flow rateconditions. GEOVIS XT  is functional in makeup waters ranging from fresh tolow salinity brines including seawater and <10% monovalent salt systems.

Features GEOVIS XT exhibits extended power law behavior in water base systems tooptimize hydraulic efficiency. Unlike other biopolymers, these properties areevident even at low concentrations of 0.75 to 1.0 lb/bbl. This allows fluids to beformulated with a relatively low concentration of biopolymer and reduces dailymaintenance treatments needed to maintain a specific LSRV. Due to its uniquemolecular structure, GEOVIS XT  retains a higher degree of low shear rateviscosity at elevated temperatures (300° - 310°F) when compared to othercommercial polysaccharides. GEOVIS XT  is more cement compatible thanother biopolymers, making it an ideal candidate in the formulation of cementspacer fluids.

Mixing For optimum hydration, GEOVIS XT  should be added through a conventional righopper at the rate of 10 minutes per 25 lb bag. Care should be exercised whenmixing under low shear conditions to avoid unhydrated polymer and eliminatewaste. Polymer can be slurried into a mineral oil, glycol or alcohol to improvedispersion and mixing efficiency.

Concentration For most applications, 0.75 to 1.25 lb/bbl should be adequate to maintain anLSRV >25,000 cP. As with other polysaccharides, pH should be maintained

in the range of 8.0 to 9.0 for maximum stability. In applications where BHT isabove 200°F, use of an oxygen scavenger will prolong polymer life.

Limitations Optimum performance is achieved in fresh water to low salinity monovalent brineswhere total salt content is <15%. Under higher salt concentrations, LSRV issuppressed, and may not fully develop even under prolonged mixing. Uppertemperature application range is approximately 310° - 325°F. In excess of thesetemperatures, viscosity recovery is limited, although the addition of commercialclays can improve overall fluid stability.

Toxicology and Safety GEOVIS XT is non-hazardous and can be used in environmentally sensitive areas.

General Information Chemical Name: PolysaccharideBulk Density: 40 – 50 lb/ft3

 Appearance: Cream colored dry powder, <40 meshDOT Classification: Non-hazardous, Non-toxic

Packaging: 25 lb or 25 Kg multi-ply, lined bags