CONOCOPHILLIPS COMPANY

Patent Trials and Appeals Board

Nov 2, 2021

2021004113 (P.T.A.B. Nov. 2, 2021)

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.
14/080,320 11/14/2013 Arelys Y. Salazar Hernandez 42067US01 3275
85937 7590 11/02/2021
Boulware & Valoir
Tamsen Valoir
2603 Augusta Drive
Suite 1350
Houston, TX 77057
EXAMINER
NOLD, CHARLES R
ART UNIT PAPER NUMBER
3674
NOTIFICATION DATE DELIVERY MODE
11/02/2021 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
mwhite@boulwarevaloir.com
nseigel@boulwarevaloir.com
patent@boulwarevaloir.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte ARELYS Y. SALAZAR HERNANDEZ and TAWFIK N. NASR
Appeal 2021-004113
Application 14/080,320
Technology Center 3600
Before JENNIFER D. BAHR, MICHELLE R. OSINSKI, and
CARL M. DEFRANCO, Administrative Patent Judges.
DEFRANCO, 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, 4–13, 17–20, and 22. A video
hearing was held on October 18, 2021. We have jurisdiction under
35 U.S.C. § 6(b). We reverse.

1 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R.
§ 1.42(a). Appellant identifies the real party in interest as ConocoPhillips
Company. Appeal Br. 3.
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CLAIMED SUBJECT MATTER
The claims are directed to hydrocarbon recovery using steam and
solvents, and, more specifically, to steam assisted gravity drainage (SAGD)
oil production that reduces solvent retention in the formation “by dictating
the timing and/or the solvent profile used in the process.” Spec. ¶¶ 1, 3. Of
the claims on appeal, claims 1 and 18 are independent. Claim 1, reproduced
below, is illustrative:
l. A method of producing heavy oil comprising:
a) providing an injection well and a production well in
fluid communication with said injection well;
b) initially injecting steam and a first light hydrocarbon
solvent into said injection well for a first period of time, said
first solvent consisting essentially of C1–C4:
c) subsequently injecting steam and a second heavier
hydrocarbon solvent instead of the first solvent into said
injection well for a second longer period of time after the first
period of time, said second solvent consisting essentially of
C5–C12; and
d) collecting a mobilized heavy oil and said first and
second solvents from said production well;
wherein said method improves recoveries of said first
and second solvents as compared to a steam and light solvent
co-injection alone or as compared to a steam and heavy solvent
co-injection followed by a steam and light solvent co-injection.

Resp. to Non-Compliant Appeal Br. (Appendix A).

REJECTIONS ON APPEAL
Claims 1, 2, 4–13, 17–20, and 22 stand rejected under 35 U.S.C.
§ 112, first paragraph, as lacking written description support. Final Act.
2–3.

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Claims 1, 2, 4–13, 17–20, and 22 stand rejected under 35 U.S.C.
§ 103(a) as being unpatentable over Edmunds (US 2010/0276140 A1,
published Nov. 4, 2010) and Applicant’s Admitted Prior Art (AAPA). Final
Act. 3–19.
ANALYSIS
A. Written Description
The Examiner asserts that the term “initially,” as used in claims 1 and
18, lacks adequate support in the Specification and, thus, is new matter. See
Final Act. 2–3. We disagree. The Specification expressly describes the
claimed method in terms of an “initial injection” of a light solvent (C4–) for
a first period of time followed by a subsequent injection of a heavier solvent
(C5+) for a second period of time. Spec. ¶ 70 (emphasis added). Likewise,
the Specification later states that “C4– was injected initially . . . followed by
a 1.5 year 95% C5+ sweep.” Id. ¶ 71 (emphasis added). Although the
Examiner acknowledges those descriptions, the Examiner concludes,
without explanation, that they “do[] not provide support for equating ‘first’
with ‘initial’.” Ans. 5. We fail to see the Examiner’s point, which conflicts
not only with the above descriptions but also with the following description
in the Specification: “Our study shows that injecting lighter solvent at the
beginning of solvent injection, decreasing its time of injection, and
following with a heavier solvent, sweeps out the lighter solvent, improving
the oil recovery and reducing the solvent retention in the reservoir.” Spec.
¶ 23 (emphasis added). In our view, those descriptions provide clear and
unambiguous support for the term “initially” as used in the context of
claims 1 and 18.
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The Examiner also asserts that the “wherein” clause of claims 1 and
18 fails to find adequate support in the Specification and, thus, is new
matter. Final Act. 3. Again, we disagree with the Examiner. The “wherein”
clause recites that the claimed method “improves recoveries of . . . solvents
as compared to a steam and light solvent co-injection alone or as compared
to a steam and heavy solvent co-injection followed by a steam and light
solvent co-injection.” In other words, the claimed method purports to
achieve better performance in terms of solvent recovery as compared to
known methods that similarly use a steam and solvent co-injection for oil
production. The Specification, in numerous places, describes that
comparison. See Appeal Br. 8–11 (citing Spec. ¶¶ 20, 23, 90–92, Fig. 2).
Indeed, Appellant’s Figure 2 illustrates the solvent retention characteristics
of the claimed method as compared to injecting a light solvent (C4–) alone
and as compared to injecting a heavy solvent (C5+) followed by a light
solvent. And, in describing Figure 2, the Specification states explicitly that
the claimed method “was still an improvement over the use of C4– alone”
and “[i]nterestingly, the reverse–C5+ [i.e., heavy solvent] followed by C4–
[i.e., light solvent] is also less effective than a short C4– sweep followed by
a longer C5+ sweep.” Spec. ¶¶ 71–72. Those descriptions, in our view,
provide ample support for the “wherein” clause of claims 1 and 18.
In sum, the two claim limitations noted by the Examiner find adequate
written description support in the Specification. Thus, for the above reasons,
we do not sustain the Examiner’s rejection of the claims under 35 U.S.C.
§ 112, first paragraph.
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B. Obviousness
We begin with claim 1. In rejecting claim 1, the Examiner finds that
Edmunds discloses all the steps of the claimed method except for the portion
of step (c) requiring that the second solvent “consist[s] essentially of C5–
C12.” Final Act. 4–5. According to the Examiner, although Edmunds
“continues to inject C4,” i.e., the light solvent, in conjunction with the step
of injecting C5+, the heavy solvent, Edmunds nonetheless teaches that “[t]he
heavy solvent is the key to this step” and omitting the light solvent would
have been obvious to one skilled in the art. Id. at 5–6 (citing Edmunds ¶ 40,
claim 1). More specifically, the Examiner concludes
[i]t would have been obvious . . . to modify Edmunds and omit
the light solvent injection when the heavy solvent is injected
with a reasonable expectation of success because this
modification is actually a removal of a component, a
component that costs a lot of money, has just been used, and
will be used again in the method, and the method teaches to
reduce the amount of light solvent; it is the heavy solvent that is
the change, . . .

Id. at 6.2
Appellant responds that the Examiner errs in several ways. See
Appeal Br. 14–19. Appellant argues, first, that the Examiner errs in finding
that Edmunds’s initial step of injecting a heavy solvent somehow equates to
the claimed first step of injecting a light solvent. See Appeal Br. 14.

2 The Examiner also acknowledges that Edmunds does not expressly
disclose step (d) of the claimed method, but, because “Applicant admits in
[0017] of the specification that this is common practice” in Expanding
Solvent-Steam-Assisted Gravity Drainage (ES-SAGD) methods for oil
production, the Examiner concludes that one skilled in the art would have
understood that Edmunds performs this step. Final Act. 8. Nowhere do we
discern that Appellant disputes that reasoning.
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Appellant notes that, in making that finding, the Examiner’s relies on
Edmunds’s characterization of the heavy solvent as having “a carbon chain
length of C4 or greater,” which, according to the Examiner, overlaps with
Appellant’s definition of a light solvent as having a length from C1–C4. See
Final Act. 4 (citing Spec. ¶¶ 33, 68–72); Ans. 7–8 (citing Edmunds ¶ 14).
We agree with Appellant that the Examiner misconstrues Edmunds’s
disclosure of the initial injection step. As Appellant correctly notes, the
Examiner’s finding conflicts with Edmunds’s express definition of a light
solvent as having a carbon chain length of C2–4. See Edmunds ¶ 27 (“As
used herein, the terms ‘light solvent’ or ‘light hydrocarbon’ will be
understood as comprising one or more alkane components preferably having
a length of C2 to C4.”). Although Edmunds explains that a heavy solvent
mixture may include some amount of C4, it makes clear that the heavy
solvent mixture of Edmunds’s method consists primarily of C5 or greater,
i.e., C5+. Id. ¶ 27 (“the heavy solvent may comprise a mixture of
hydrocarbons, each preferably having a length greater than C4 and wherein
the mixture has an average chain length of approximately C5.”). Moreover,
throughout, Edmunds repeatedly defines the heavy solvent in terms of C5 or
greater. See, e.g., Edmunds Abstract (“A method for producing
hydrocarbons . . . comprises a steam assisted gravity drainage (SAGD)
incorporating cyclic steam, heavy (e.g., greater than C4) solvent and light
(e.g., C2 to C4) solvent injection”); see also id. ¶¶ 33, 34, 37. Thus, while
C4 may be present in a heavy solvent, the heavy solvent being used in
Edmunds’s method has an average chain length of C5 or greater. And
because claim 1 requires that the first solvent “consist essentially of
C1–C4,” we fail to see a rational basis for the Examiner’s reading of the
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relatively small amount of C4 that might be present in the heavy solvent of
Edmunds’s first step as somehow meeting the claimed first solvent.
That notion aside, the Examiner nonetheless asserts that Edmunds
meets the claim language because the initial heavy solvent step (Phase I) of
Edmunds’s method may be omitted entirely and, instead, the method may
begin with the light solvent step (Phase II) before proceeding to the next step
(Phase III), which includes the injection of “both light and heavy solvents.”
See Final Act. 6 (citing Edmunds ¶ 40). According to the Examiner,
however, Edmunds’s Phase III may be modified to consist solely of a heavy
solvent injection because omitting the light solvent would be “economically
beneficial” and an “obvious design choice.” Id. at 6–7; see also Ans. 9
(“The Examiner’s rationale for the change is an economic one”).
Appellant argues error in the Examiner’s rationale for modifying
Phase III of Edmunds’s method. We agree. Nowhere do we discern from
Edmunds’s disclosure that the light solvent is optional in Phase III, be it for
economic reasons or otherwise. In fact, Edmunds emphasizes that only the
heavy solvent is optional in Phase III, not the light solvent, because it is the
heavy solvent that has an effect on cost. See Edmunds ¶ 40 (“[T]he amount
of the heavy solvent (e.g. pentane) will depend on certain cost and recovery
factors. Thus, in some cases, it may be found more economically efficient to
avoid using any heavy solvent in Phase III.”). Thus, the record evidence
does not support the Examiner’s cost-saving reasoning for omitting the light
solvent from Phase III of Edmunds’s method. See Appeal Br. 15–16, 21.
In the absence of any evidentiary support for the Examiner’s
modification of Edmunds, we agree with Appellant that Edmunds’s Phase III
can only be read as involving the injection of either light solvent alone or a
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mixture of light and heavy solvents, which fails to meet the claim language
of step (c) requiring the injection of a second heavy solvent that consists
essentially of C5 or greater “instead of the first solvent” that consists
essentially of C4 or lower. See Edmunds ¶ 51 (indicating Phase III as
including heavy solvent in the range of 0–10% and light solvent in the range
of 3–6%). Thus, without more, we do not sustain the Examiner’s rejection
of claim 1.3
Finally, Appellant also argues that the Examiner errs in finding that
Edmunds meets the claim language requiring that injection of the heavy
solvent be for a “longer period of time” than injection of the light solvent.
Appeal Br. 19–20. We disagree. Edmunds clearly contemplates that
the duration of each phase [may] vary based on various factors
such as the based on various factors such as the physical
characteristics of the reservoir and the bitumen contained
therein, the extraction efficiencies of the equipment, and the
number and spacing of the wells. In practice, each phase may
be conducted up till a desired recovery threshold of the Oil in
Place (OIP) is reached.

Edmunds ¶ 52. That disclosure provides clear support for the Examiner’s
finding that one skilled in the art would have understood to continue the
heavy solvent injection for a longer period of time than the light solvent
injection where doing so would result in a particular or maximum amount of

3 Appellant concedes that the claims do not cover a method where the initial
injection step involves injecting steam alone. See Appeal Br. 14 (arguing in
section 5.3 that “the initial injection [of] 100% steam” in Edmunds’s first
phase (Phase I) is different from the “co-injection” of steam and light
solvent in “the initial phase as required by the claims”); see also id. at 18–19
(conceding that “a steam only initial injection” does not meet the claim
language).
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oil recovery. See Final Act. 5. Thus, we reject the notion that Edmunds fails
to disclose the time durations of claim 1.
In the end, because Appellant persuades us of error in the Examiner’s
reading of Edmunds’s initial injection step and rationale for modifying
Edmunds, we do not sustain the rejection of claim 1 as being unpatentable
over Edmunds and AAPA. Claims 2, 4–13, and 17 depend from claim 1,
and thus, for the same reasons as claim 1, we do not sustain the rejection of
those dependent claims.
The Examiner also rejects independent claim 18 and dependent
claims 19, 20, and 22 on the same basis as claim 1. The Examiner relies on
the same unsupportable findings and reasoning to reject those claims as are
relied upon to reject claim 1. See Final Act. 13–19. As such, we do not
sustain the rejection of claims 18–20 and 22.
CONCLUSION
Claims
Rejected
35 U.S.C.
§
Basis Affirmed Reversed
1, 2, 4–13,
17–20, 22
112 ¶ 1 Written
Description
1, 2, 4–13,
17–20, 22
1, 2, 4–13,
17–20, 22
103(a) Edmunds,
Admitted Prior Art
1, 2, 4–13,
17–20, 22
Overall
Outcome
1, 2, 4–13,
17–20, 22
REVERSED