Baker Hughes Incorporated

Patent Trials and Appeals Board

May 1, 2020

14665977 - (D) (P.T.A.B. May. 1, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
14/665,977 03/23/2015 Angela Anh Doan 020569-30900-
CIP (CM4-547
8296
71762 7590 05/01/2020
JONES DELFLACHE LLP
1333 HEIGHTS BOULEVARD
SUITE 300
HOUSTON, TX 77008
EXAMINER
SUE-AKO, ANDREW B.
ART UNIT PAPER NUMBER
3674
MAIL DATE DELIVERY MODE
05/01/2020 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte ANGELA ANH DOAN, GUIDO GUSTAVO NARVAEZ, and
MATTHEW GRADY KELLUM
Appeal 2019-004773
Application 14/665,977
Technology Center 3600
Before JENNIFER D. BAHR, JAMES P. CALVE, and
JILL D. HILL, Administrative Patent Judges.
BAHR, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1, 2, 6, 7, 9, 18, 19, 21–24, and 26.2
We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM IN PART.

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. Appellant identifies the real party in interest as Baker
Hughes, a GE company, LLC. Appeal Br. 1.
2 On December 21, 2018, Appellant canceled claims 4, 5, 11–14, 16, and 25.
See Advisory Act. 1 (entering the Amendment).
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CLAIMED SUBJECT MATTER
Appellant’s invention is directed to “a method of delaying
viscosification of a cementitious slurry in a well by including in the slurry
hydratable particulates having a minimum of 90% retention on a 20 mesh
screen,” wherein “[t]he presence of the hydratable particulates in the slurry
enhances the stability of the slurry by minimizing settling of the cement.”
Spec. ¶ 1. Claim 1, reproduced below, is illustrative of the claimed subject
matter.
1. A method of delaying viscosification of a cement slurry
during the cementing of a well and after pumping the cement
slurry into the well, the method comprising:
(a) pumping into the well a cement slurry, the slurry
comprising cement and a hydratable polymeric viscosifying
agent selected from the group consisting of underivatized guar,
hydroxypropyl guar, carboxymethyl hydroxypropyl guar,
xanthan, hydroxyethyl cellulose, methylhydroxyethyl cellulose,
carboxymethyl cellulose, carboxymethylhydroxy cellulose,
carboxymethyl hydroxyethyl cellulose, hydroxyethylmethyl
cellulose, ethylhydroxyethyl cellulose,
ethylmethylhydroxyethyl cellulose, hydroxypropyl cellulose,
hydroxyethylpropyl cellulose, dialkyl carboxymethyl cellulose,
polyvinyl alcohol, xanthan, phosphomannans, scleroglucan,
dextran, starch, locust bean gum, welan gum, karaya gum,
diutan, an ammonium or alkali metal salt of an
acrylamidomethylpropanesulfonic acid and mixtures thereof
wherein the particle size of the hydratable polymeric
viscosifying agent is such that a minimum of 90% of the
hydratable polymeric viscosifying agent is retained on a 20
mesh screen;
(b) delaying viscosification of the cement slurry; and
(c) cementing the pipe or casing in the well with the
cement slurry containing the hydratable polymeric viscosifying
agent to form a sheath wherein viscosification of the cement
slurry is more delayed than when a substantially similar cement
slurry is pumped into the well, the substantially similar cement
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slurry containing a hydratable polymeric viscosifying agent
having a particle size such that less than 90% of the hydratable
polymeric viscosifying agent is retained on a 20 mesh screen
and further wherein the substantially similar cement slurry only
differs by the particle size of the hydratable polymeric
viscosifying agent.
EVIDENCE
The prior art relied upon by the Examiner is:
Name Reference Date
Chang US 6,165,947 Dec. 26, 2000
Creel US 2006/0213662 A1 Sept. 28, 2006
Reddy US 2012/0090841 A1 Apr. 19, 2012
Gunnar DeBruijn et al., High-Pressure, High-Temperature
Technologies, Oilfield Review 46, 46–60 (Autumn 2008) (hereinafter
DeBruijn).

REJECTIONS
I. Claims 18, 21, and 24 stand rejected under 35 U.S.C. § 112(b) as
indefinite.
II. Claims 1, 2, and 26 stand rejected under 35 U.S.C. § 103 as
unpatentable over Reddy and Chang.
III. Claims 21 and 23 stand rejected under 35 U.S.C. § 103 as
unpatentable over Reddy.
IV. Claim 18 stands rejected under 35 U.S.C. § 103 as unpatentable
over Reddy, as applied to claim 21, and Chang.
V. Claim 24 stands rejected under 35 U.S.C. § 103 as unpatentable
over Reddy and Creel.
VI. Claim 22 stands rejected under 35 U.S.C. § 103 as unpatentable
over Reddy, Chang, and Creel.
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VII. Claims 6 and 9 stand rejected under 35 U.S.C. § 103 as
unpatentable over Reddy and DeBruijn.
VIII. Claims 7 and 19 stand rejected under 35 U.S.C. § 103 as
unpatentable over Reddy, DeBruijn, and Chang.
OPINION
Rejection I—Indefiniteness
The Examiner rejects claim 21, as well as claims 18 and 24, which
depend from claim 21, as indefinite because, according to the Examiner,
“one of ordinary skill in the art would not be reasonably apprised of the
scope of [‘water-insoluble adsorbent’] in terms of what materials are and are
not necessarily encompassed by [this term].” Final Act. 3 (underlining
omitted). In explaining the basis of the rejection, the Examiner states that
“‘water-insoluble adsorbent’ is a functional limitation and also not a typical
name of any established grouping/class in the art, especially one comprising
the range of disclosed materials, which don’t appear to necessarily share a
clear common structure or property.” Id. at 2–3 (referring to the “[s]uitable
water-insoluble adsorbents” listed in paragraph 44 of Appellant’s
Specification). The Examiner adds that “the disclosure only relates to these
‘water-insoluble adsorbents’ to which the ‘polymeric hydratable viscosifying
agent may be adsorbed.’” Id.
Appellant takes issue with the Examiner’s characterization of the
phrase “water-insoluble adsorbent” as functional language. Appeal Br. 6.
Appellant submits that “the phrase ‘water-insoluble adsorbent’ refers to a
structure of a component onto which is adsorbed the claimed hydratable
polymeric viscosifying agent.” Id. According to Appellant,
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The common meaning of the word “adsorbent” is a solid
substance that adsorbs another substance. The phrase “water-
insoluble” modifies the adsorbent, i.e., it limits the adsorbent to
those which are water-insoluble. Thus, the phrase “water-
insoluble adsorbent” references an adsorbent which is water-
insoluble. As used in the claims of Appellant, the adsorbent is
the substance onto which the hydratable polymeric viscosifying
agent is adsorbed.
Id. at 7. Appellant argues that the “[t]he issue is whether the phrase ‘water-
insoluble adsorbent’ provides enough certainty to one of skill in the art when
read in the context of the invention.” Id. (citing Interval Licensing LLC v.
AOL Inc., 766 F.3d 1364, 1370 (Fed. Cir. 2014)). In this case, Appellant
contends that “Appellant has provided a standard for assessing a
‘water-insoluble adsorbent’ based on the common usages of the word
‘adsorbent’ and ‘water-insoluble’ coupled with the description in the
specification, e.g., the adsorbent is the surface onto which the polymeric
viscosifying agent is adsorbed.” Id.
In response, the Examiner states that the term “adsorbent” is
functional language because it describes the structure by what it does (i.e.,
“describing that which is capable of adsorbing (or collecting and holding)”),
not what it is. Ans. 5. The Examiner finds that “Appellant’s disclosure has
provided no clear standard for ascertaining what are ‘adsorbents’ vs. what
are not ‘adsorbents.’” Id. The Examiner queries, “[f]or example, at what
capability of collecting and holding does a solid become an adsorbent?” Id.
Appellant correctly characterizes the issue as “whether one of skill in
the art would be apprised of the meaning of the phrase ‘water-insoluble
adsorbent’ (using the standard dictionary [definition] of ‘adsorbent’ or
‘adsorb’) when the claims are read in light of the Specification and in light
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of the person skilled in the art.” Reply Br. 3–4. Claims, when read in light
of the specification, must “reasonably apprise those skilled in the art both of
the utilization and scope of the invention” using language “as precise as the
subject matter permits.” In re Packard, 751 F.3d 1307, 1313 (Fed. Cir.
2014). In determining whether a claim is definite under 35 U.S.C. § 112(b),
“[t]he USPTO, in examining an application, is obliged to test the claims for
reasonable precision according to [this principle].” Id. An examiner can
properly reject a claim as failing to meet the statutory requirements of
§ 112(b) by identifying “ways in which language in a claim is ambiguous,
vague, incoherent, opaque, or otherwise unclear in describing and defining
the claimed invention.” Id. at 1311. Appellant submits that “[t]he Examiner
does not state and has provided no evidence that one of skill in the art would
not understand the meaning of ‘adsorbent’, ‘water-insoluble’ or ‘water-
insoluble adsorbent’.” Reply Br. 4. According to Appellant “[t]he
Examiner’s position is premised on his perception that one of skill in the art
would have been unable to recognize a material which is adsorbent versus
non-adsorbent.” Id. Appellant adds that “[t]he claimed terminology . . . is
not complicated and no reason is provided as to why one of skill in the art
would be unable to recognize an adsorbent from a non-adsorbent.” Id.
Appellant also acknowledges that a myriad of different components
are used in the oilfield art for different purposes, but points out that “the
Examiner does not state cements, calcium carbonate[,] and crosslinked
polymers are known adsorbents in oilfield chemistry.” Reply Br. 5
(emphasis added). Appellant also notes that “the Specification (para. 00044)
provides exemplary water-insoluble adsorbents onto which the claimed
polymeric hydratable viscosifying agent may be absorbed” and contends that
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“[t]here is no requirement that Appellant provide an exhaustive list of
species of adsorbents and the fact a large number of substances may be
within the phrase ‘water-insoluble adsorbent’ does not render the claims
indefinite.” Id. Appellant further contends that Appellant “has provided a
standard for measuring the ‘degree’ of the claimed phrase by providing the
weight ratio of the viscosifying agent to the water-insoluble adsorbent as
well as the amount of viscosifying polymer in the cementitious slurry
(Specification, paras. 00044-00045).” Id. at 8.
Even taking into account the Examiner’s point, which is not without
merit, that different materials may have different degrees of adsorbency and,
thus, to some extent, the term “adsorbent” is a term of degree, the Examiner
does not set forth sufficient evidentiary findings or technical explanation to
establish a reason to believe that a person of ordinary skill in the art would
not be reasonably apprised of the scope of the claimed subject matter
(particularly, the scope of “a viscosifying agent adsorbed onto a water-
insoluble adsorbent”) when the language in question is read in light of the
Specification and in the context of the claim as a whole. In particular, given
the common meanings of “water-insoluble” and “adsorbent,” as Appellant
submits, “the phrase ‘water-insoluble adsorbent’ references an adsorbent
which is water-insoluble.” Appeal Br. 7. “As used in the claims of
Appellant, the adsorbent is the substance onto which the polymeric
viscosifying agent is adsorbed.” Id. Further, Appellant’s Specification
provides a non-exhaustive list of materials considered to be suitable water-
insoluble adsorbents within the context of Appellant’s invention, as well as a
range of typical weight ratios of polymeric hydratable viscosifying agent to
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water-insoluble adsorbent and a preferred range of the amount (in pounds) of
viscosifying polymer. Spec. ¶¶ 44–45.
Appellant’s Specification does not expressly enumerate all materials
that are suitable “water-insoluble adsorbents,” but the aforementioned
disclosure of paragraphs 44 and 45 of the Specification does provide
guidance as to what is meant by this terminology, and the Examiner does not
specifically explain why this guidance would not be sufficient to apprise one
of ordinary skill in the art of the metes and bounds of this claim language.
“As the statutory language of ‘particular[ity]’ and ‘distinct[ness]’ indicates,
claims are required to be cast in clear—as opposed to ambiguous, vague,
indefinite —terms.” In re Packard, 751 F.3d at 1313 (citation omitted).
At the same time, this requirement is not a demand for
unreasonable precision. The requirement, applied to the real
world of modern technology, does not contemplate in every
case a verbal precision of the kind found in mathematics. Nor
could it do so in a patent system that actually works, in practice,
to provide effective protection for modern-day inventions.
Rather, how much clarity is required necessarily invokes some
standard of reasonable precision in the use of language in the
context of the circumstances.
Id.
For the above reasons, we do not sustain the rejection of claim 21, or
claims 18 and 24 depending from claim 21, as indefinite.

Rejection II—Obviousness: Reddy/Chang (Claims 1, 2, and 26)
The Examiner finds that Reddy discloses a method substantially as
recited in claim 1, wherein the hydratable polymeric viscosifying agent is a
“modified biopolymer additive (MBA),” including the biopolymer
hydroxyethyl cellulose (HEC). Final Act. 9–10. The Examiner finds,
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however, that “Reddy only discloses these biopolymers that are modified
with carbonate to be MBA’s ([0011]), wherein ‘the MBAC may form a mass
that plugs the zone at elevated temperatures, such as those found at higher
depths within a wellbore’ ([0045]).” Id. at 10. The Examiner “observes that
hydroxyethylcellulose (HEC) and acrylamidomethylpropanesulfonic acid
(AMPS), among many other polymers and salts thereof, are all considered
obvious variants of swellable polymers for viscosification, in the art.” Id.
For example, the Examiner finds that
Chang teaches a dry crosslinked polymer particulate system
(Col. 13, line 50-Col. 15, line 6; also Col. 23, line 42-Col. 24,
line 44), which when added to a treatment fluid “do not hydrate
and thicken the water immediately, hence low friction pressure
is observed while pumping” (Col. 14, lines 22-24) (i.e., they act
as a delayed viscosification system) and “the material behaves
as a solid fluid loss control material, such as the often used
carbonate pill, but the particles form a tighter network on the
face of the rock once they start to hydrate and expand” (Col. 14,
lines 24-28), comprising “hydroxyethylcellulose (HEC)” (Col.
14, lines 1-13 and lines 35-36) which are “ground into fine
particles or granules having a size of from about 10 to about
200 meshes on the U.S. Sieve Series” (Col. 14, lines 19-21).
Id.
The Examiner determines it would have been obvious to modify
Reddy “to include swelling agents comprising ‘hydroxyethylcellulose’
polymer of ~10 mesh size, as in Chang, in order to ‘form a mass’ that ‘plugs
the zone’ and ‘behaves as a solid fluid loss control material.’” Final Act. 10.
According to the Examiner, “the inclusion of 10 mesh size hydratable
polymeric viscosifying agent (present in both Reddy and Chang) necessarily
provides the viscosification delay as claimed,” namely, the viscosification of
the slurry being more delayed than when a substantially similar cement,
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differing from the claimed cement slurry only by the particle size of the
hydratable polymeric viscosifying agent, is pumped into the well. Id. at 11.
Appellant argues that Reddy does not disclose the claimed polymeric
viscosifying agent, or the claimed particle size of the hydratable viscosifying
agent. Appeal Br. 8–9. In particular, Appellant submits that Reddy
discloses using a cement slurry containing a modified biopolymer additive
(MBA) composed of the reaction product of the biopolymer (HEC) having a
mesh size from about 10 to about 190 and an organic carbonate. Id. at 10–
11. In other words, Appellant submits, the mesh size that Reddy discloses in
paragraph 16 refers to the mesh size of the HEC, which is a reactant, along
with carbonate, reacted to form the MBA, which is incorporated into the
MBA-containing cement composition (MBAC). Id. at 11. Appellant points
out that paragraph 16 of Reddy does not address the particle size of the
MBA, which is the material that is introduced into the well and must meet
the claimed particle size of the hydratable polymeric viscosifying agent. Id.
These arguments are unavailing because they attack Reddy
individually, rather than in combination with Chang as set forth in the
rejection. “Non-obviousness cannot be established by attacking references
individually where the rejection is based upon the teachings of a
combination of references.” In re Merck & Co., 800 F.2d 1091, 1097 (Fed.
Cir. 1986) (citing In re Keller, 642 F.2d 413, 425 (CCPA 1981)). As the
Examiner points out on page 7 of the Answer, the rejection relies on Chang,
not Reddy, for the HEC of ~10 mesh size. See Final Act. 10.
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Appellant argues that Chang teaches grinding the polymer “into
particles having a broad size from 10 to 200 meshes”3 and “does not recite
the particulates as having a minimum of 90% retention on a 20-mesh
screen.” Appeal Br. 15. Appellant adds that “Chang fails to specify that
particle sizing is a known mechanism by which viscosification is delayed.”
Id.
Appellant’s argument that Chang does not teach particulates having a
minimum of 90% retention on a 20-mesh screen is not responsive to the
rejection set forth by the Examiner. The Examiner, as discussed above,
correctly finds that Chang teaches grinding the HEC “into fine particles or
granules having a size of from about 10 to about 200 meshes on the U.S.
Sieve Series.” Final Act. 10 (citing Chang 14:19–21). The Examiner
reasons that, in view of this teaching, it would have been obvious to modify
Reddy’s cement slurry to include an HEC polymer “of ~10 mesh size” and
that polymeric viscosifying agent of ~10 mesh particle size “is such that a
minimum of 90% of the . . . polymeric viscosifying agent is retained on a 20
mesh screen.” Id. at 10–11; see also id. at 9 (stating that “10 mesh would
have about 100% of particles retained on a 20 mesh screen”). This accords
with the general rule that claimed ranges that overlap the prior art create a
prima facie case of obviousness that must be rebutted by the applicant. See
In re Woodruff, 919 F.2d 1575, 1578 (Fed. Cir. 1990). Here, Appellant does
not present any evidence or technical reasoning to suggest that a person
having ordinary skill in the art would not have had a reasonable expectation
of success in selecting a particle size of about 10 mesh from within the range

3 Appellant cites Chang, column 5, lines 53–56, in support of this statement,
but this portion of Chang does not mention particle size.
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taught by Chang or that the claimed range provides unexpected results
compared to the range disclosed in Chang.
Further, Appellant’s contention that Chang fails to specify particle
sizing as a known mechanism for delaying viscosification is unsound. After
disclosing the particle size into which the HEC is ground, Chang states that
these fine particles, which “can be added to a blender tank on location[,] . . .
do not hydrate and thicken the water immediately, hence low friction
pressure is observed while pumping.” Chang 14:19–24.
Appellant also argues that Reddy does not disclose delaying
viscosification during the cementing of a well. Appeal Br. 13 (contending
that the Examiner’s reliance on paragraph 45 of Reddy is misplaced). For
the reasons that follow, Appellant’s argument is not persuasive.
The Examiner points out that “MBAC in Reddy is defined as ‘an
MBA-containing cement composition’ ([0034]), and Reddy discloses ‘The
compositions disclosed herein may be used as wellbore cementing fluids to
cement a well penetrating a subterranean formation’ ([0041]).” Ans. 9.
Additionally, Reddy expressly discloses “wellbore cementing compositions
comprising modified biopolymers and methods of using same” and, further,
discloses placing the cement slurry composition “into an annulus of the
wellbore and [allowing it] to set such that it isolates the subterranean
formation from a different portion of the wellbore.” Reddy ¶¶ 1, 42. This
type of process is known as “primary cementing,” in which “a cement slurry
is placed in the annulus [located between the pipe or casing and the walls of
the wellbore] and permitted to set into a hard mass (i.e., sheath) to thereby
attach the string of pipe to the walls of the wellbore and seal the annulus.”
Id. ¶ 2. Further, Reddy discloses delaying viscosification of the product
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until it has reached a desired depth within the wellbore, where it may
harden/thicken and plug the zone. Reddy ¶¶ 5, 36, 42, 45, 46 (disclosing
that, in various embodiments, the MBACs “may provide desirable
rheological and/or operational properties” and “[t]he delayed viscosity of the
MBAC may enable the use of lower pump pressures and higher pump
rates”). Thus, Reddy discloses delayed viscosification during cementing.
Chang, likewise, discloses delaying viscosification of the product until it has
reached a desired depth within the wellbore, where it may harden/thicken
and plug the zone. Chang 14:22–24, 65–67; 23:48–51; 24:6–8.
Appellant argues that Chang “does not reference cementing, much
less the cementing of a pipe or casing in a wellbore to form a cement
sheath.” Appeal Br. 15. Appellant elaborates that “[t]he Examiner has not
provided any reason to conclude that the HEC of Chang could be used with
a cement.” Reply Br. 11 (italics omitted). Appellant contends, moreover,
that “the combination of Reddy and Chang would not suggest use of the
HEC of Chang in place of the MBA of Reddy. . . . At best, the combination
of Reddy and Chang would suggest use of the HEC of Chang for reaction
with the organic carbonate to produce the MBA.” Id. at 12 (italics omitted).
In other words, according to Appellant,
The combination of Reddy and Chang would not render a
MBAC containing the HEC of Chang (in place of the MBA
reaction product) with a cement. Rather, the combination of
Reddy and Chang would only suggest a MBAC containing a
cementitious slurry containing a MBA prepared by reacting the
HEC of Chang with an organic carbonate.
Id. (italics omitted).
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Appellant’s argument that Chang does not disclose cementing a well
is unavailing because, as the Examiner points out (Ans. 9), the Examiner
relies on Reddy, and not Chang, for the cementing. Moreover, although
Chang does not explicitly mention “cement” or “cementing,” Chang teaches
that the dry crosslinked polymer particulate system disclosed therein may be
used during “completion” operations, which persons of ordinary skill in the
art would understand include both primary and secondary cementing
operations. Chang 1:10–12; 4:30–33; 6:60–61; see Reddy ¶¶ 42, 43
(discussing primary and secondary cementing operations in well completion
operations); id. ¶ 2 (discussing primary cementing “whereby a cement slurry
is placed in the annulus and permitted to set into a hard mass (i.e., sheath) to
thereby attach the string of pipe to the walls of the wellbore and seal the
annulus”); Creel ¶ 36 (explaining that well completion operations comprise
primary and secondary cementing operations); Spec. ¶ 29 (describing “a
typical cementing operation” in which “the cement slurry is pumped down
the inside of the pipe or casing and back up the outside of the pipe or casing
through the annular space” to seal the subterranean zones in the formation
and support the casing). Even if Chang does not expressly mention
cementing, Chang at least suggests compatibility of the disclosed dry
polymer particulate system with cementing operations, and Appellant does
not assert, much less present persuasive evidence or technical reasoning to
suggest, to the contrary.
Appellant argues that “Chang provides no indication that the viscosity
of a cement slurry may be delayed by use of the crosslinked polymer” and
that Reddy’s teachings regarding viscosification delay relate to drilling
rather than cementing. Appeal Br. 15–16. Appellant contends that Reddy
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refers in paragraph 45 “to a drilling operation, not a cementing operation.”
Id. at 17. In sum, according to Appellant, “[n]othing in Chang suggests use
of a hydratable polymeric viscosifying agent of the claimed particle size to
delay viscosification during a cementing operation,” and “[n]othing in
Reddy suggests use of the MBA, much less the biopolymer, to delay
viscosification.” Id. (italics omitted). This line of argument is not
persuasive.
Reddy expressly discloses “[a] method of cementing a wellbore
comprising preparing a wellbore cementing composition comprising a
cementitious materials and a modified biopolymer additive”; placing the
cementing composition having an initial viscosity into the wellbore;
allowing the cementing composition to reach a desired depth in a
subterranean formation, wherein the cementing composition has a
transitional viscosity during placement in the formation and final viscosity,
greater than the transitional viscosity, at the desired depth; “and allowing the
wellbore cementing composition to set.” Reddy, Abstract; ¶¶ 4–5. Reddy
discusses primary cementing, wherein “a cement slurry is placed in the
annulus and permitted to set into a hard mass (i.e., sheath) to thereby attach
the string of pipe to the walls of the wellbore and seal the annulus.” Id. ¶ 2;
see also id. ¶ 42 (disclosing placing the MBAC into an annulus of the
wellbore and allowing it to set such that it isolates the subterranean
formation from a different portion of the wellbore). This primary cementing
process disclosed by Reddy appears to be the type of “typical cementing
operation” for sealing subterranean zones in the formation and supporting
the casing that Appellant discloses. See Spec. ¶ 29. Reddy discloses that
wellbore cementing compositions comprising an MBA “may display
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desirable characteristics such as reduced particle settling, reduced fluid loss,
and improved rheology” to facilitate and improve such cementing processes.
Id. ¶¶ 3, 11. In paragraph 45, Reddy discusses delaying viscosification for
deeper penetration into the voids so that, for example, “the MBAC may form
a mass [(i.e., sheath)] that plugs the zone at elevated temperatures, such as
those found at higher depths within a wellbore.” Thus, paragraph 45 appears
to discuss delaying viscosification in the type of cementing operation called
for in claim 1. Moreover, Reddy further discloses that, “[i]n various
embodiments, MBACs of this disclosure may provide desirable rheological
and/or operational properties when compared to otherwise similar
composition lacking a biopolymer that has been modified as described
herein (i.e., an MBA).” Id. ¶ 46. Thus, Reddy attributes the desirable
rheological properties (i.e., delayed viscosification) to the inclusion of the
MBA.
Similarly, Chang, which at least suggests compatibility of the
disclosed dry polymer particulate system with cementing operations, as
discussed above, also teaches delaying the viscosification of the product
until it has reached a desired depth within the wellbore, where it may
harden/thicken and plug the zone. Chang 14:22–24 (stating that the fine
HEC particles “do not hydrate and thicken the water immediately, hence low
friction pressure is observed while pumping”), 14:65–67; 23:48–51; 24:6–8
(discussing that the fine particles of HEC “do not hydrate and thicken the
water immediately”).
Appellant also asserts that there would be no reasonable expectation
of success in combining the references, and that the Examiner’s rationale for
the combination constitutes hindsight because it misinterprets and takes out
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of context “isolated snippets” from Reddy. See Appeal Br. 18–19. These
assertions are unpersuasive because they are premised on the purported
deficiencies of Reddy and Chang discussed above.
For the above reasons, Appellant does not apprise us of error in the
rejection of claim 1 as unpatentable over Reddy and Chang. Accordingly, we
sustain the rejection of claim 1, as well as claims 2, and 26, which depend
from claim 1 and for which Appellant does not present any separate
arguments (see Appeal Br. 8–20), as unpatentable over Reddy and Chang.

Rejections III and IV—Reddy and Reddy/Chang (Claim 18)
Claim 21 recites “pumping into the well a cement slurry containing a
viscosifying agent adsorbed onto a water-insoluble adsorbent,” and claims
18 and 23 depend from claim 21. Claims App. Both the rejection of claims
21 and 23 and the rejection of claim 18 are predicated, in pertinent part, on
the Examiner’s determination that it would have been obvious, in view of
Reddy’s teachings in paragraphs 37 and 38, to modify Reddy “to include a
viscosifying agent adsorbed onto a water-insoluble adsorbent (that is
encapsulating the basic material) . . . in order to [allow] ‘even further
viscosification of the composition’ ‘after it has reached a desired wellbore
depth and/or has been placed into a desired area of the formation.’” Final
Act. 18–19. This determination stems from the Examiner’s observation that
“[i]t would clearly be advantageous for the encapsulated basic material to be
packaged together with the MBA, so it can readily contact the MBA upon
release from the encapsulation and lead to further viscosification.” Id. at 19.
Appellant points out that Reddy does not disclose or imply that the
MBA is adsorbed onto the solid porous material. Appeal Br. 22. Rather, as
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Appellant points out, Reddy discloses the basic material being absorbed into
the solid porous material and then being released by diffusion through the
porous material to contact the MBA. Id.; see Reddy ¶¶ 37, 38.
Reddy mentions nothing about adsorbing the MBA, or any reactant
used to form the MBA, onto the encapsulated basic material to permit
contact with the basic material. Reddy only discloses absorbing the aqueous
solution (basic material) such that it slowly diffuses through the particulate
solid material to eventually contact the MBA to further adjust the viscosity
of the MBA after it has reached the desired wellbore depth or area of the
formation. Reddy ¶¶ 37–38. In other words, Reddy does not appear to be
suggesting use of the encapsulated basic material to hasten the contact of the
basic material with the MBA. In fact, Reddy suggests that it may be
desirable “[t]o delay the reaction even longer” by placing on the porous solid
material “an external coating of a polymeric material through which an
aqueous solution slowly diffuses.” Reddy ¶ 38. Thus, Reddy does not
appear to contemplate adsorbing the MBA onto the porous solid material
(with the basic material encased therein), and it is not clear why a person
having ordinary skill in the art would have been prompted to do so.
Accordingly, we do not sustain the rejection of claims 21 and 23 as
unpatentable over Reddy or the rejection of claim 18 as unpatentable over
Reddy and Chang.
Rejections V and VI—Obviousness: Reddy/Creel and
Reddy/Chang/Creel
The deficiency in the rejection of claim 21 also pervades the rejection
of claim 24, which depends from claim 21. For this reason, and for the
additional reason set forth below, we do not sustain the rejection of claim 24.
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Claims 22 and 24 recite that “the hydratable polymeric viscosifying
agent is an ammonium or alkali metal salt of an
acrylamidomethylpropanesulfonic acid and mixtures thereof.” Claims App.
The Examiner relies on Creel for teaching
acrylamidomethylpropanesulfonic acid (hereinafter AMPS) sized as dry
particles of 2 mm (10 mesh) as a swelling agent that hydrates downhole to
produce high viscosity. See Final Act. 12, 21 (citing Creel ¶¶ 16–18, 36).
The Examiner determines it would have been obvious to modify Reddy to
include AMPS sized as dry particles of 2 mm (10 mesh) as taught by Creel
as the hydratable viscosifying agent “in order to ‘form a mass’ or ‘barrier’
that ‘plugs the zone’ and ‘prevents fluids in that subterranean formation
from migrating into other subterranean formations.’” Id. According to the
Examiner, “the modification is obvious as no more than the use of familiar
elements (swellable polymers of ~10 mesh size as in Chang/Creel and
Reddy) according to known techniques (cementing as in Reddy) in a manner
that achieves predictable results (cementing with plugging of voids to reduce
fluid loss).” Id. at 12 (citing KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398,
415–421 (2007)).
Appellant argues that, although Creel discloses using AMPS as a
swellable polymer, Creel does not teach using “AMPS in a cementitious
slurry for forming a cement sheath.” Appeal Br. 20. Appellant further
elaborates that paragraph 36 of Creel, cited by the Examiner, references
neither a slurry containing the swellable polymer nor pumping a slurry
containing the polymer into a wellbore, but instead places the swellable
polymer in a closed container and then releases the swelling agent from the
container to isolate the formation. Id.; see also Reply Br. 13–14 (asserting
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that Creel’s “swellable polymer is not used in admixture with a cement” and
suggesting that a person having ordinary skill in the art would not have a
reasonable expectation of success in making the combination).
The Examiner responds by dismissing Appellant’s arguments as
attacking the references individually. Ans. 11. The Examiner explains that
“Reddy provides the delayed viscosification in cementing, not Creel, and
Creel provides the claimed particulates.” Id.
Here, Appellant’s argument amounts to more than merely an attack on
Creel individually. Creel teaches that Creel’s disclosed swelling agent (e.g.,
AMPS) may be used in primary cementing (which is usually performed by
pumping a cement slurry down through a string pipe and into the annulus to
allow the cement slurry to set into a cement column). Creel ¶¶ 5, 36.
However, Creel does not teach including the swelling agent in the cement
slurry and introducing the cementitious slurry into the wellbore. Rather,
Creel teaches placing the swelling agent into a container, closing the
container, placing the container into the wellbore, and releasing the swelling
agent from the container at the position of interest, where the swelling agent
is allowed to set such that it isolates the subterranean formation from a
different portion of the wellbore. Id. ¶ 36. Further, Creel teaches that in
embodiments in which the swelling agent is closed within a container, the
swelling agent is placed in the wellbore by dry transport, which means it is
not exposed to reactive mediums such as water. Id. ¶ 13. The container is
sufficiently closed to prevent exposure of the swelling agent to fluids in the
wellbore, which might cause the swelling agent to swell before such
swelling is desired. Id. ¶ 32.
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A person having ordinary skill in the art, having read the teachings of
Creel, would not have a reasonable expectation of success in including
Creel’s swelling agent in a cementitious slurry and then introducing the
cementitious slurry into the wellbore. Rather, Creel’s teachings imply that
Creel’s swelling agent, if exposed to reactive media, such as water or other
ingredients in the cementitious slurry, might expand prematurely, prior to
arriving at the desired location in the wellbore. See Reddy ¶ 34 (disclosing
that, in addition to the MBA, the cementing composition comprises
cementitious material, water, and optional additives). Thus, a person having
ordinary skill in the art would not have been prompted to include Creel’s
swelling agent in Reddy’s cementitious slurry in Reddy’s method.
Accordingly, we do not sustain the rejection of claim 24 as
unpatentable over Reddy and Creel, or the rejection of claim 22 as
unpatentable over Reddy, Chang, and Creel.

Rejection VII—Obviousness: Reddy/DeBruijn
In rejecting claim 6, the Examiner finds that Reddy discloses pumping
into a well a cement slurry comprising cement and a hydratable polymeric
viscosifying agent of particles having a mesh size of about 10, which,
according to the Examiner, is “such that a minimum of 90% of the
hydratable viscosifying agent particles is retained on a 20 mesh screen.”
Final Act. 13 (boldface omitted) (citing Reddy ¶ 16). The Examiner
explains that “10 mesh would have about 100% of particles retained on a 20
mesh screen.” Id.
Incorporating arguments asserted against the rejection of claim 1
(Appeal Br. 22), Appellant argues that Reddy does not disclose a cement
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slurry including the claimed sized particulates. Appeal Br. 11. Appellant
submits that paragraph 16 of Reddy relates to a reactant (HEC) used to make
the MBA, and Reddy’s cement slurry contains the MBA, and not the HEC.
Id. at 10–12. Appellant adds that Reddy’s modified biopolymer, “i.e., the
MBA, is the reaction product of the biopolymer and an organic carbonate.”
Id. at 12 (citing Reddy ¶ 11).
The Examiner’s only response to this argument is that Appellant is
attacking the references individually. Ans. 12. The Examiner explains that
“Chang provides the 10 mesh HEC, not Reddy.” Id. This response, while
pertinent to the rejection of claims 7 and 19 as unpatentable over Reddy,
DeBruijn, and Chang, is unavailing for the rejection of claims 6 and 9 as
unpatentable over Reddy and DeBruijn. The Examiner does not rely on
DeBruijn for particle size. See Final Act. 12–14.
Reddy discloses that “the wellbore cementing composition comprises
a cementitious material and a modified biopolymer additive (MBA),” and
that “the MBA is a reaction product of a polymer and an organic carbonate.”
Reddy ¶ 11. According to Reddy, in one embodiment, “a reaction mixture
for the preparation of an MBA comprises . . . a biopolymer,” such as
“derivatized polysaccharides such as hydroxyethyl cellulose (HEC).” Id.
¶ 12. Reddy discloses that “a biopolymer suitable for use in this disclosure
is in the solid form (e.g., as granules) and may have a mesh size of from
about . . . 10 to about 190.” Id. ¶ 16. “[A] method of preparing an MBA . . .
comprises contacting [the] biopolymer . . . (e.g., HEC) and an organic
carbonate . . . to form a reaction mixture.” Id. ¶ 22. “[T]he reaction is
carried out as a solid-state reaction such that the product (i.e., MBA) is a
material in the solid state.” Id. ¶ 27; see also id. ¶¶ 25–26 (disclosing use of
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a non-aqueous solvent and a solid organic carbonate, followed by removal of
the non-aqueous solvent, followed by introduction of the reaction mixture
into a roller oven to expose it to reaction temperatures). Reddy theorizes
that the MBAs produced “may be the product of an intra- and/or inter-
molecular complex transesterification mechanism and not the product of a
hydroxyalkylation reaction” and that “[t]he increased product viscosities for
some MBAs may suggest the MBA has a molecular weight that is greater
than that of the biopolymer starting reagent.” Id. ¶ 28.
As Appellant correctly points out on page 11 of the Appeal Brief,
paragraph 16 of Reddy discusses the mesh size of the biopolymer (e.g.,
HEC) that is reacted with an organic carbonate to form the MBA, and not
the mesh size of the resulting MBA, which is used in the cementitious slurry.
Reddy does not specifically disclose the particle size of the MBA.
Thus, Reddy does not support, by a preponderance of the evidence,
the Examiner’s finding that Reddy discloses pumping into the wellbore a
cement slurry comprising particulates of hydratable viscosifying agent
having a particle size such that a minimum of 90% of the viscosifying agent
is retained on a 20 mesh screen. Accordingly, we do not sustain the
rejection of claim 6, or claim 9, which depends from claim 6, as
unpatentable over Reddy and DeBruijn.

Rejection VIII—Reddy/DeBruijn/Chang
Appellant’s arguments in contesting the rejection of claims 7 and 19
essentially reiterate arguments asserted against the rejection of claim 1,
which, for the reasons discussed above, fail to apprise us of error in the
rejection of claim 1 and, likewise, fail to apprise us of error in the rejection
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of claims 7 and 19. See Appeal Br. 22–23. Accordingly, we sustain the
rejection of claims 7 and 19 as unpatentable over Reddy, DeBruijn, and
Chang.
CONCLUSION
In summary:
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
18, 21, 24 112(b) Indefiniteness 18, 21, 24
1, 2, 26 103 Reddy, Chang 1, 2, 26
21, 23 103 Reddy 21, 23
18 103 Reddy, Chang 18
24 103 Reddy, Creel 24
22 103 Reddy, Chang, Creel 22
6, 9 103 Reddy, DeBruijn 6, 9
7, 19 103 Reddy, DeBruijn,
Chang
7, 19
Overall
Outcome
1, 2, 7, 19,
26
6, 9, 18,
21–24

TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(1)(iv).
AFFIRMED IN PART