BAKER HUGHES INCORPORATED

Patent Trials and Appeals Board

May 1, 2020

14029520 - (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.
14/029,520 09/17/2013 Andreas Brandl 020569-30900 (54711-US) 1106
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 ANDREAS BRANDL, CHRISTINA MAGELKY,
ANGELA ANH DOAN, and WINDAL SCOTT BRAY
Appeal 2019-004760
Application 14/029,520
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 1–4, 24, 26, 31, 33, 34, 38, and 40–47.2
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 Incorporated, a GE company, LLC.” Appeal Br. 1.
2 Appellant canceled claims 14, 29, 30, 32, 36, 37, and 39 subsequent to the
Final Action. See Advisory Act. (Jan. 15, 2019).
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CLAIMED SUBJECT MATTER
Appellant’s invention is directed to “a method of delaying
viscosification of a well treatment fluid by use of particulates having a
minimum of 40% retention on a 60 mesh screen and a minimum of 1%
retention on a 20 mesh screen.” Spec. ¶ 1. Claims 1, 38, and 40 are
independent. Appeal Br. 17–19 (Claims App.). Claim 1, reproduced below,
is illustrative of the claimed subject matter.
1. A method of delaying viscosification of a cementitious
slurry during the cementing of a pipe or casing in a wellbore,
the method comprising including in the cementitious slurry 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 alcohols,
acrylamidomethylpropane sulfonic acid and salts thereof, the
hydratable polymeric viscosifying g agent comprising
particulates having a minimum of 40% retention on a 60 mesh
screen and a minimum of 1% retention on a 20 mesh screen,
introducing the cementitious slurry containing the hydratable
polymeric viscosifying agent into the wellbore and cementing
the pipe or casing in the wellbore with the cementitious slurry
to form a cement sheath.
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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 43, 45, and 46 stand rejected under 35 U.S.C. § 112(b) as
indefinite.
II. Claims 38, 42, and 47 stand rejected under 35 U.S.C. § 102(a)(1)
as anticipated by Reddy.
III. Claims 33, 34, and 43–45 stand rejected under 35 U.S.C. § 103 as
unpatentable over Reddy.
IV. Claims 1, 2, 4, 24, 26, and 31 stand rejected under 35 U.S.C. § 103
as unpatentable over Reddy and Chang.
V. Claims 40 and 41 stand rejected under 35 U.S.C. § 103 as
unpatentable over Reddy, DeBruijn, and Chang.3
VI. Claim 3 stands rejected under 35 U.S.C. § 103 as unpatentable
over Reddy, Chang, and Creel.

3 We interpret the Examiner’s reference to “Reddy as in claim 32” in the
statement of the rejection of claims 40 and 41 to mean Reddy in view of
DeBruijn because claim 32 (prior to its cancellation and re-writing of its
dependent claim 40 in independent form) was rejected based on Reddy in
view of DeBruijn. See Final Act. 4, 7; see also Appeal Br. 14 n.1 (noting
that the Examiner included DeBruijn in rejecting claim 32).
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VII. Claim 46 stands rejected under 35 U.S.C. § 103 as unpatentable
over Reddy and Creel.
OPINION
Rejection I—Indefiniteness
The Examiner rejects claim 43, as well as claims 45 and 46, which
depend from claim 43, 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. 2 (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. (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. 5.
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. at 5–6. According to Appellant,
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
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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 6. 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. at 6–7.
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. 4. The Examiner finds that “Appellant’s disclosure has
provided no clear standard for ascertaining what are ‘adsorbents’ vs. what
are not ‘adsorbents.’” Id. at 5. 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
of the person skilled in the art.” Reply Br. 4. Claims, when read in light of
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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. 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. 5–6
(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
“[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. at 6. Appellant further contends that Appellant “has
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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 “the hydratable polymeric viscosifying agent
[being] 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. 6.
“As used in the claims of Appellant, the adsorbent is the substance onto
which the hydratable 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 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
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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 43, or
claims 45 and 46 depending from claim 43, as indefinite.

Rejection II—Anticipation: Reddy
The Examiner finds that Reddy discloses the method of claim 38. See
Final Act. 3–4. The Examiner cites Reddy’s disclosure in paragraph 16 of
using a biopolymer in solid form, as granules, having a mesh size within one
of three enumerated ranges, to support the finding that Reddy discloses the
particulate size requirement of claim 38. See id. at 3. In particular, the
Examiner focuses on “a mesh size of […] about 10” and finds that “10 mesh
would have about 100% of particles retained on a 20 mesh screen.” Id.
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In contesting the rejection, Appellant points out, correctly, that Reddy
discloses introducing into the wellbore “a cement composition containing
the modified additive” (MBA), not the biopolymer (hydroxyethyl cellulose
(HEC)) itself. Appeal Br. 8. Indeed, the Examiner recognizes that Reddy
discloses introducing into the wellbore a “cementing composition
compris[ing] a cementitious material, water, an MBA[,] and optional
additives.” Final Act. 3 (citing Reddy ¶ 34).
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
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
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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 8 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.
In response, the Examiner posits:
A solid-state reaction reacting a solid with another solid
would necessarily produce a solid product the same size or
larger than the solid reactants, based on mass conservation.
This is supported by Reddy’s observation about the MBA
molecular weight being greater than the HEC biopolymer
molecular weight.
Therefore, it is a reasonable conclusion that Reddy’s
starting HEC biopolymer of 10-190 mesh at least implies that
the resultant MBA also has a mesh size of about 10-190 mesh.
In other words, if the intermediate product is retained on the
claimed mesh size, and mass is only added to form the final
product, then the final product would also be retained on the
claimed mesh size.
Ans. 7.
The Examiner does not cite any authority for the principle that “[a]
solid-state reaction reacting a solid with another solid would necessarily
produce a solid product the same size or larger than the solid reactants,
based on mass conservation” (Ans. 7), much less provide any evidence or
persuasive technical reasoning to support the conclusion that the particle
size of one of the particulate reactants would be retained or increased in the
resultant product. As Appellant points out, “an increase in molecular weight
is not synonymous with an increase in particle size of the reaction product.”
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Reply Br. 10. Appellant asserts that “it is well known that solid state
reactions are dependent on the area of contact between the reactant solids
which is dependent on the total surface area of the reactants,” and, thus,
“solid state reactions are typically conducted by grinding the reactants in the
reaction vessel, i.e., during the reaction stage,” thereby reducing the particle
size. Id. Appellant does not direct our attention to any reliable source to
substantiate this assertion about how solid state reactions are typically
conducted, much less present any evidence that the solid state reaction
producing the MBA in Reddy necessarily is carried out by grinding.
Nevertheless, Appellant’s recognition that an increase in molecular weight is
not synonymous with an increase in particle size and observations about how
the solid state reaction may be carried out sufficiently highlight that the
Examiner’s finding regarding the particle size of the MBA lacks the
requisite evidentiary underpinning to establish anticipation.
Accordingly, we do not sustain the rejection of claim 38, or claims 42
and 47, which depend from claim 38, as anticipated by Reddy.

Rejection III—Obviousness: Reddy
Claims 33 and 34:
The aforementioned deficiency in the rejection of claim 38 as
anticipated by Reddy also pervades the rejection of claims 33 and 34, which
depend from claim 38. See Final Act. 14. The Examiner’s additional
findings and reasoning regarding the consistency of the slurry do not make
up for the shortcomings discussed above. See id. Accordingly, we do not
sustain the rejection of claims 33 and 34 as unpatentable over Reddy.
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Claims 43–45:
Claim 43 depends from claim 38 and further recites that “the
hydratable polymeric viscosifying agent is adsorbed onto a water-insoluble
adsorbent.” Appeal Br. 20 (Claims App.). In rejecting claim 43, as well as
claims 44 and 45, which depend from claim 43, the Examiner finds that
Reddy teaches adjusting the viscosity of the MBA-containing cement
composition (MBAC) using one or more encapsulated basic materials,
which are designed to be released from encapsulation and contact the
MBAC after it reaches a desired wellbore depth or area of the formation.
Final Act. 14 (citing Reddy ¶ 37); see also Reddy ¶ 34 (explaining what is
meant by MBAC). The Examiner also finds that Reddy teaches that the
basic material comprises an aqueous solution and is encapsulated in a
particulate solid material that remains dry and free flowing after adsorbing
the basic material, and the basic material slowly diffuses through the
particulate solid material. Final Act. 14 (citing Reddy ¶ 37). The Examiner
notes, in particular, that Reddy discloses that examples of suitable
particulate solid materials include “diatomaceous earth, zeolites, silica,
alumina, metal salts of alumino-silicates, [and] clays.” Id. (underlining
omitted) (citing Reddy ¶ 38).
The Examiner determines that, in view of the aforementioned
teachings of Reddy in paragraphs 37 and 38, “[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.” Final Act. 15. Thus,
according to the Examiner, it would have been obvious to adsorb the
hydratable viscosifying agent “onto a water-soluble adsorbent (that is
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encapsulating the basic material), wherein the water-insoluble material is
selected from the group consisting of . . . silica, particulates, precipitated
silicas, silica, alumina, silica-alumina, . . . zeolites, diatomaceous earth, . . .
and clays and mixtures thereof,” 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.” Id.
Appellant points out that Reddy does not disclose or imply that the
MBA is adsorbed onto the solid porous material. Appeal Br. 11. Rather, as
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.
The Examiner’s obviousness rejection of claims 43–45 based on
Reddy suffers from the same shortcoming as the rejection of claim 38 as
anticipated by Reddy, namely, with respect to the unsupported finding
regarding the retention of particulates of the hydratable polymeric
viscosifying agent in the cementitious slurry (i.e., the MBAC). Reddy’s
teachings regarding use of an encapsulated basic material to increase
viscosification are directed to the basic material contacting the MBA (the
reaction product), not contacting the biopolymer (e.g., HEC) used to form
the MBA. As discussed above, the Examiner’s finding regarding the particle
size (and, thus, retention percentage on a 60 mesh or 20 mesh screen) of the
MBA lacks the requisite evidentiary underpinning.
Moreover, 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
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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 43–45 as
unpatentable over Reddy.

Rejections IV and V—Obviousness: Reddy/Chang and
Reddy/Debruijn/Chang
Independent claims 1 and 40 specify that the hydratable polymeric
viscosifying agent is “selected from the group consisting of” an enumerated
list including, among others, “hydroxyethyl cellulose.” Appeal Br. 17, 19
(Claims App.). The Examiner finds that Reddy only discloses the
biopolymers disclosed in paragraph 12 (which include HEC) “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]).” Final Act. 7, 9.
However, the Examiner “observes that hydroxyethylcellulose (HEC) and
acrylamidomethylpropanesulfonic acid (AMPS), among many other
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polymers and salts thereof, are all considered obvious variants of swellable
polymers for viscosification, in the art.” Final Act. 8, 9. 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 about10 to about 200
meshes on the U.S. Sieve Series” (Col. 14, lines 19-21 ).
Final Act. 8–10.
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. 8, 10. The Examiner reasons that “the modification is obvious as no
more than the use of familiar elements (swellable polymers of ~10 mesh size
as in Chang 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. (citing KSR Int’l Co. v. Teleflex
Inc., 550 U.S. 398, 415–421 (2007).
Appellant reiterates the deficiency of Reddy, discussed above, in
regard to the claimed particulate size. Appeal Br. 13. Appellant also argues
that Chang is not drawn to a method of cementing a well and does not even
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mention cementing of a well, much less forming a cement sheath. Id.
Appellant elaborates that “[t]he Examiner has not sufficiently articulated a
reason with a rational evidentiary underpinning to explain why, given the
teachings of Reddy and Chang, one of skill in the art would have been
prompted to modify the teachings of Reddy with the teachings of Chang,”
and, further, “has not provided any reason to conclude that the HEC of
Chang would be used with a cement.” Reply Br. 14 (italics omitted).
Appellant contends, moreover, that “the combination of Reddy and Chang
would not suggest use of the HEC of Chang as the MBA. 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. (italics
omitted). In other words, according to Appellant,
The combination of Reddy and Chang would not render a
MBAC containing the HEC of Chang with a cementitious
slurry. Rather, the combination of Reddy and Chang would
only suggest a MBAC containing a cementitious slurry and a
MBA prepared by reacting the HEC of Chang with an organic
carbonate.
Id. (italics omitted).
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
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(discussing primary and secondary cementing operations in well completion
operations); id. ¶ 2 (discussing primary cementing “whereby 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. ¶ 28 (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 correctly notes that Chang teaches using its dry polymer
particulate system to minimize “fluid loss during completion of a well by
forming a filter cake on the surface of the formation” and that “the
particulate system bridges the formation face and rehydrate[s] in situ to form
a filter-cake.” Appeal Br. 13–14 (citing Chang 1:12–14; 4:36–38).
However, Appellant argues that Chang forms a viscous plug in the formation
that “is broken for clean-up,” and Chang does not disclose using “sized
particulates to delay the set time of a cement downhole.” Id. at 14
(submitting that Appellant’s claims “recite the delay in viscosification of the
slurry during the cementing process wherein the slurry forms the cement
sheath”).
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This line of argument does not apprise of error because, as the
Examiner points out (see Ans. 9), claims 1 and 40 do not recite delaying the
set time of the cement. Rather, claim 1 recites a method of delaying
viscosification of a cement slurry (Appeal Br. 17 (Claims App.)), and claim
40 recites a step of delaying hydration of the cementitious slurry until the
slurry is placed into the targeted location or reaches a downhole temperature
of 500oF or higher.4 Moreover, and perhaps more importantly, both Reddy
and Chang disclose 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. Reddy, Abstract; id. ¶¶ 5, 36, 37, 42, 45; Chang 14:22–
24, 65–67; id. 23:48–51; id. 24:6–8. In this sense, the objectives of both
Reddy and Chang are the same.
Appellant’s argument that, at best, the combination of Reddy and
Chang would suggest use of Chang’s HEC for reaction with the organic
carbonate to produce the MBA, but not the use of Chang’s HEC itself in
Reddy’s cementitious slurry (Reply Br. 14) is not correct. Chang discusses
the disadvantages of conventional fluid loss additives containing carbonates
(Chang 2:13–50), as well as the cost and complexity of using modified HEC

4 The Examiner relies on DeBruijn as “evidence that it is well-known in the
art that temperatures on the order of 500-600oF are encountered downhole”
and determines that, thus, it would have been obvious to modify Reddy to
form a mass to plug the zone at such elevated temperatures. Final Act. 5
(italics omitted); see Reddy ¶ 45 (disclosing that “the MBA may form a
mass that plugs the zone at elevated temperatures, such as those found at
higher depths with a wellbore”). “Appellant does not dispute the existence
of such downhole temperatures,” nor does Appellant specifically dispute the
Examiner’s determination that it would have been obvious to modify Reddy
to form a mass to plug a zone at such elevated temperatures. Appeal Br. 14
n.1.
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(id. 3:10–4:25). Thus, Chang teaches that it is desirable to use “unmodified
HEC” to avoid such cost and complexity. Id. 4:17–25. Along these same
lines, Chang teaches that an advantage of the disclosed dry particulate
system (i.e., Chang’s HEC) “is that 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,” and, further, “[t]here is no solid invasion and permanent formation
damage like that usually associated with calcium carbonate pills.” Id. 4:58–
65; see also id. 14:24–28 (cited by the Examiner (Final Act. 8, 10) for this
teaching). Further, Chang teaches that “[t]he fine particles can be added to a
blender tank on location” and “do not hydrate and thicken the water
immediately, hence low friction pressure is observed while pumping,”
suggesting that Chang’s dry particulate HEC would be suitable for Reddy’s
cementitious slurry. Chang 4:56–59; see Reddy ¶ 3 (discussing an interest
in developing wellbore cement slurries that increase in viscosity only after
passing deeper into the wellbore to avoid the need for high pump pressures
and/or low pump rates), ¶ 11 (Reddy disclosing “a pumpable cementitious
slurry”). We, therefore discern no error in the Examiner’s determination that
the combined teachings of Reddy and Chang render obvious a method
comprising introducing a cementitious slurry including cement and Chang’s
HEC into a wellbore and delaying hydration and viscosification of the slurry
until it reaches a targeted location, and cementing a pipe or casing in the
wellbore with the cementitious slurry to form a cement sheath.
For the above reasons, Appellant does not apprise us of error in the
rejection of claim 1 as unpatentable over Reddy and Chang, or the rejection
of claim 40 as unpatentable over Reddy, DeBruijn, and Chang.
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Accordingly, we sustain the rejection of claim 1, as well as claims 2, 4, 24,
26, and 31, which depend from claim 1 and for which Appellant does not
present any separate arguments (Appeal Br. 12–14), as unpatentable over
Reddy and Chang. We also sustain the rejection of claim 40, as well as
claim 41, which depends from claim 405 and for which Appellant does not
present any separate arguments (id.), as unpatentable over Reddy, DeBruijn,
and Chang.
Rejections VI and VII—Reddy/Chang/Creel and Reddy/Creel
Claim 3 depends from claim 1, and further recites that “the hydratable
polymeric viscosifying agent is selected from the group consisting of a
polyvinyl alcohol or an ammonium or alkali metal salt of an
acrylamidomethylpropanesulfonic acid and mixtures thereof.” Appeal
Br. 17 (Claims App.). Claim 46 depends from claim 38, via claim 43, and
further recites that “the hydratable polymeric viscosifying agent is an
ammonium or alkali metal salt of an acrylamidomethylpropanesulfonic
acid.” Id. at 20.
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, 16 (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

5 The Claims Appendix (Appeal Br. 19) contains an error in reproducing
claim 41. See Amendment filed Feb. 11, 2019 (presenting claim 41
depending from claim 40); Advisory Act. dated Feb. 26, 2019 (entering the
Amendment).
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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. at 12, 16.
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 12–13 (citing KSR, 550 U.S.
at 415–421); see id. at 16–17.
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. 15. 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. 15 (asserting 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. 9; see In re Merck & Co., 800
F.2d 1091, 1097 (Fed. Cir. 1986) (citing In re Keller, 642 F.2d 413, 425
(CCPA 1981)) (stating, “Non-obviousness cannot be established by
attacking references individually where the rejection is based upon the
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teachings of a combination of references.”). The Examiner explains that
“Reddy provides the cementing, not Creel.” Ans. 10.
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.
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
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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 3 as
unpatentable over Reddy, Chang, and Creel, or the rejection of claim 46 as
unpatentable over Reddy and Creel.
CONCLUSION
In summary:
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
43, 45, 46 112(b)

43, 45, 46
38, 42, 47 102(a)(1) Reddy 38, 42, 47
33, 34, 43–
45
103 Reddy 33, 34, 43–
45
1, 2, 4, 24,
26, 31
103 Reddy, Chang 1, 2, 4, 24,
26, 31

40, 41 103 Reddy, DeBruijn,
Chang
40, 41
3 103 Reddy, Chang, Creel 3
46 103 Reddy, Creel 46
Overall
Outcome
1, 2, 4, 24,
26, 31, 40,
41
3, 33, 34,
38, 42–47

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).
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AFFIRMED IN PART