CMC, a technical grade sodium carboxymethyl
– cellulose, is a long chain organic colloid that increases viscosity and
reduce filtration properties of water base muds. CMC includes three grades:
low, high and extra high viscosity.
Application
CMC is
effective as a filtration control agent, protective colloid and viscosifier for
low solid, water base muds. CMC is stable at temperatures in excess of 1200C
( 250 0F). CMC is relatively stable to bacterial fermentation. It is
effective in fluids containing up to approximately 50,000mg/l sodium chloride.
CMC is more effective when concentration of calcium are less than 500 mg/l.
Recommended treatment
CMC – EHV is
recommended for use in low solids water base muds when a significant increase
in viscosity is needed. A concentration of 0,3 to 2,85kg / m3(0,1 to
1,0 lb/bbl) is normal adequate obtain satisfactory properties. CMC- HV
concentration level are 1,4 to 11,4 kg/m3( 0,5 to 4,0 lb/bbl),
however, actual concentration will depend on the type mud system, wellboretemperatures, filtrate value, and viscosity
required.CMC – LV concentration level are 2,85 to 11,4 kg/ m3( 1,0
to 4,0 lb/bbl), but actual concentration will depend as the same CMC- HV.
Typical physical properties
Appearance…………………White powder
Bulk density…………………752kg/m3(47lb/ft3)
Hygroscopic……………………..Slightly
PH in H2O………………………Neutral
Safe handling recommendations
Utilize normal precaution for employee
protection when handling chemical products.
Use of appropriate respirator gloves,
goggles and apron is recommended for employee comfort and protection.
Shipping
CMC does not have a restricted
classification for transportation by the international or domestic regulatory
agencies.
