Page 274 - Practical Well Planning and Drilling Manual

Section 2 revised 11/00/bc 1/17/01 12:04 PM Page 250

[ ] Well Programming
2.5.13

CMC and PAC polymers are supplied in pure grade (which is just
what that implies) or in technical grade (which is where sodium chlo-
ride, a by-product in the manufacturing process, is not removed from
the final product). Pure grade polymers should be specified in your
tenders with the exception of using CMC in a sodium chloride brine or
in seawater and it should be made clear to the vendors that tech grade
PACs will not be accepted.
XCD polymer should be xanthan gum, coated for dispersion.
No polymer blends are acceptable (such as guar gum and urea).
This can be spot checked. Any substitute should be detailed and
quoted separately.
PAC, regular, and low vis. No technical grade polyanionic cellu-
lose should be accepted. This can be spot checked. Vendor should
state the degree of substitution for both PAC regular and low vis-
cosity submitted.
Nonfermenting starch. State biocide and percentage present. If the
vendor does not quote a bacterially stabilized starch, the percentage of
the biocide to stabilize the starch should be quoted.
Guar gum viscosifier. Tenderer should quote a guar gum variant to
provide viscosity. The type of variant should be stated (e.g., hydroxy
propyl guar.)
Sulfonated asphalt. Quote a known trade name, e.g., Soltex.
Otherwise, specifications should be provided.
Amine corrosion inhibitor. This should be a film-forming amine and
if possible should have biostat properties. A brief description and spec-
ification should be provided.
Basic zinc carbonate. This must be a zinc carbonate and zinc oxide
blend. The stoichiometric ratio should be provided.
Glycols provide useful inhibitive and lubricating properties. The
use of glycols in drilling fluids has recently become popular. The
required glycol is a polypropylene glycol, which has been manufac-
tured specifically for use in drilling muds. Industrial waste products
from a “glycol stream” should not be accepted. Vendors should state
the suppliers trademark name of the glycol supplied. In the event that
the vendor is not prepared to supply this information, the generic
chemical name, the percentage, and the content of impurities must be
supplied. Glycol can be spot-checked against a “finger print” of a ref-

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