Baker Hughes IncorporatedDownload PDFPatent Trials and Appeals BoardMay 1, 202014665977 - (D) (P.T.A.B. May. 1, 2020) Copy Citation 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). Appeal 2019-004773 Application 14/665,977 2 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 Appeal 2019-004773 Application 14/665,977 3 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. Appeal 2019-004773 Application 14/665,977 4 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, Appeal 2019-004773 Application 14/665,977 5 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 Appeal 2019-004773 Application 14/665,977 6 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 Appeal 2019-004773 Application 14/665,977 7 “[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 Appeal 2019-004773 Application 14/665,977 8 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, Appeal 2019-004773 Application 14/665,977 9 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, Appeal 2019-004773 Application 14/665,977 10 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. Appeal 2019-004773 Application 14/665,977 11 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. Appeal 2019-004773 Application 14/665,977 12 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 Appeal 2019-004773 Application 14/665,977 13 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). Appeal 2019-004773 Application 14/665,977 14 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 Appeal 2019-004773 Application 14/665,977 15 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 Appeal 2019-004773 Application 14/665,977 16 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 Appeal 2019-004773 Application 14/665,977 17 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 Appeal 2019-004773 Application 14/665,977 18 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. Appeal 2019-004773 Application 14/665,977 19 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 Appeal 2019-004773 Application 14/665,977 20 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. Appeal 2019-004773 Application 14/665,977 21 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 Appeal 2019-004773 Application 14/665,977 22 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 Appeal 2019-004773 Application 14/665,977 23 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 Appeal 2019-004773 Application 14/665,977 24 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 Copy with citationCopy as parenthetical citation