Xcd Polymer

• Physical appearance-Cream-to-tanpowder specific
• Gravity- 1.5 Bulk
• Density- 50 Ib/ft3 (800 kg/m3)

The
primary function of FED ZAN D is to increase viscosity for cuttings
transport and suspension. FED ZAN D will perform effectively in all
water-base fluids,
from highly weighted to low-solids systems. This includes freshwater,
seawater, salt and heavy-brine systems. FED ZAN D works to provide an
optimized
rheological profile with elevated low-shear-rate viscosity 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. Shear thinning fluids have
low effective viscosities at the high shear rates encountered inside
the drillstring and at the bit This low effective viscosity for
minimal pressure losses and standpipe pressures allows optimized
hydraulics and maximized rats of penetrations. Conversely, at the low
shear rates experienced in the annulus, FED ZAN D enables the fluid
to have a high effective viscosity for adequately cleaning the well
and suspending cuttings. FED ZAN D should be added slowly
through
the hopper to prevent lumping and minimize waste. It should be added
at the rate of approximately one 25-lb sack every 7 minutes. The time
required
for the product to yield its ultimate viscosity depends on salinity,
temperature and shear. The amount of FED ZAN D required will depend
upon the
desired viscosity. Normal concentrations range from 0.25 to 2 lb/bbl
(0.71 to 5.7 kg/m3) for most mud systems. Special fluids and
difficult hole-cleaning conditions may require higher
concentrations-up to 4 lb/bbl (11.4 kg/m3). The addition of salt, an
antioxidant and thermal stabilizers will improve
temperature stability in fluids from 250 to >280^OF
(121 to 138^OC).
Specially formulated systems have been used at temperatures of 400^OF
(204^OC)
FED ZAN D is subject to bacterial degradation, and treatments with a
biocide are recommended to prevent fermentation

• Highly effective viscosifier; small treatments produce significant results
• Shear-thinning rheological profile for improved hydraulics
• Minimum frictional pressure losses for additional hydraulic horsepower at the bit and low, high-shear-rate viscosity for maximum penetration rates
• Viscous laminar flow in the annulus for improved wellbore stability with maximum hole-cleaning and suspension capacity
• Easy to mix

• Trivalent ions such as chromium and iron may cause biopolymer precipitation and loss of viscosity or crosslinking
• Not tolerant of high-pH or high calcium-ion conditions
• FED ZAN D systems should be pretreated with either sodium bicarbonate or SAPP and possibly citric acid prior to drilling cement
• Subject to bacterial degradation, a biocide should be used to prevent fermentation
• Slightly anionic nature of FED ZAN D required special mixing procedures when mixed with cationic materials