Drilling Fluids
WEL-GEL NT
™
WEL-GEL NT is a ground, premium-grade, untreated
Wyoming bentonite that complies with API Specification 13A.
Bentonite is an aluminum phyllosilicate from the smectite
family of minerals, consisting mainly of montmorillonite—
(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2·nH2O—and originating from
the weathering of volcanic ash.
Applications
Advantages
• Natural, environmentally benign, untreated
mineral
• Very effective, economical product
• Highly pseudoplastic viscosifier with
exceptional suspension character
• WEL-GEL NT hydrates, swells, and disperses in
fresh water to form a colloidal suspension with high,
pseudoplastic viscosity. In a deflocculated state, the
dispersed particles (platelets) pack tightly into a thin
filter cake to provide effective filtration control that also
contributes to wellbore stability.
• Dispersed suspensions provide efficient
filtration control
• Natural mineral that is environmentally benign
• Very high thermal stability
• Widely used throughout the drilling industry
• WEL-GEL NT provides the necessary viscosity and
thixotropy for hole cleaning and suspension of weight
materials. As an inorganic mineral, it is the most thermally
stable of all drilling-fluid viscosifiers/filtration controllers
and can be used as the backbone of high-temperature
systems up to 450°F (232°C). Powerful defocculants are
a necessary adjunct in high-temperature applications.
WEL-GEL NT is usually preferred over WEL-GEL™
viscosifier for high-temperature fluids.
Usage
WEL-GEL NT concentrations vary over a wide range: up to
35 lb/bbl (100 kg/m3). Using a Venturi hopper, the product
is added to fresh water that has been pretreated to remove
hardness. Subsequently, WEL-GEL NT suspensions are
usually diluted and then supplemented with a wide range
of products to flocculate, defocculate, and disperse to
achieve a variety of performance effects as required for
specific applications.
Typical Physical Properties
Appearance
Density
Tan powder
2.2 to 2.5 SG
Bulk density
56 lb/ft3
900 kg/m3
Solubility
Insoluble
Packaging
55-lb (25-kg), 110-lb (50-kg), and
100-lb (45.5-kg) sacks
2,205-lb (1,000-kg) bags
Bulk
WEL-GEL NT should be prehydrated in fresh water before
being introduced to other salt-bearing solutions. As with any
bentonite, it will not yield in seawater, and this should not be
attempted. The maximum limits for mix water are 2,000 mg/L
chloride and hardness greater than 100 mg/L.
Consult the MSDS, safety posters, and/or product label
before use, and use personal protective equipment
as advised.
weatherford.com
1
Issued March 2010
© 2010 Weatherford. All rights reserved.
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International Ltd. makes no guarantees or warranties, expressed or implied, with respect to its accuracy. Ensuring the completeness and accuracy of such information is the responsibility of the user of this product.
Always consult the Material Safety Data Sheet for this product before use. Weatherford products and services are subject to the Company’s standard terms and conditions, available on request or at weatherford.
com. For more information contact an authorized Weatherford representative. Unless noted otherwise, trademarks and service marks herein are the property of Weatherford. Specifications are subject to change
without notice.