Appeal No. 94-3973
Application 08/029,754
polymers with a base oil mud formulation, the improvement consisting essentially of:
first forming a solution of a low unsaturated polymer in a hydrocarbon oil in amounts to provide
from about 5 wt.% to about 20 wt.% of the polymer in the oil; and
adding a sulfonating agent to the solution of the polymer in the oil in an amount sufficient to
provide about 50 mmol to about 100 mmol of pendant sulfonate groups per 100 gm of polymer,
whereby a solution of sulfonated polymer in the oil is obtained and when the viscosification agent is a
neutralized sulfonated polymer adding a base to the solution of sulfonated polymer in an amount
sufficient to neutralize the polymer; and
thereafter combining the solution of the sulfonated polymer or neutralized sulfonated polymer
with the base oil mud formulation, whereby an oil-based drilling fluid composition is prepared.
The appealed claims as represented by claims 1 and 8.2 Claim 1 is drawn to drilling mud
additive concentrate compositions which consist essentially of a hydrocarbon oil and a sulfonated or
neutralized sulfonated polymer as a viscosification agent. Claim 8 is drawn to methods of preparing an
oil based drilling mud fluid wherein the improvement consists essentially of preparing a solution of a
sulfonated or neutralized sulfonated polymer viscosification agent in a hydrocarbon oil by adding a
sulfonating agent to a solution of a low unsaturated polymer in the hydrocarbon oil, optionally
neutralizing with a base, and thereafter combining the solution of the sulfonated or neutralized sulfonated
polymer in the hydrocarbon oil with a base oil mud formulation. According to appellants, the solution of
a sulfonated polymer or neutralized sulfonated polymer in a hydrocarbon oil is Areadily incorporated@
into oil based drilling mud fluids (specification, e.g., page 3).
The references relied on by the examiner are:
Thaler et al. (Thaler) 4,442,011 Apr. 10, 1984
Lundberg et al. (Lundberg) 4,447,338 May 8, 1984
Jachnik WO 83/02951 Sep. 1, 1983
(published World Intel. Prop. Org. Application)
T.W. Duke, P.R. Parrish, et al., AAcute Toxicity of Eight Laboratory-Prepared Generic Drilling Fluids
to Mysids,@ U.S. Environmental Protection Agency Report No. EPA-600/3-84-067. June 1984.
(Duke)
The examiner has rejected appealed claims 1 through 3, 8 and 9 under 35 U.S.C. ' 103 as
being unpatentable over Lundberg or Thaler and appealed claim 4 under 35 U.S.C. ' 103 as being
unpatentable over Lundberg or Thaler as previously applied, further in view of Duke and Jachnik. We
affirm the first ground of rejection with respect to appealed claims 1 through 3 but reverse this ground
2 Appellants have grouped claims 1 through 4 together and claims 8 and 9 together for purposes of
appeal (brief, page 2). Thus, we decide this appeal based on appealed claims 1 and 8. 37 CFR '
1.192(c)(5) and (6)(1993).
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