DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 10 December 2025 has been entered.
Response to Amendment
The Amendment filed 20 November 2025 has been entered with the RCE submission filed 10 December 2025. Claims 1-11, 20, and 21 remain pending in the application. Claims 12-18 were previously withdrawn as being drawn to a non-elected Invention. Claim 19 is canceled. Applicant’s Amendments to the Claims in line with the Office’s suggestions have overcome the 112 Rejections previously set forth in the previous Office Action mailed 26 September 2025.
Applicant may see the note in the Conclusion below before considering the Prior Art rejections.
Claim Objections
Claims 1-11, 20 and 21 are objected to because of the following informalities:
Independent claim 1, line 18, should recite “triallyl amine and tetraallylammonium derivatives, divinyl ether” (correcting the typo by adding a comma; as in [0162]). The dependent claims are objected to by dependency.
Independent claim 1, at the new line starting with “(I) wherein”, should remove the comma after “selected from” (correcting the typo).
Independent claim 20, lines 17-18, should recite “triallyl amine and tetraallylammonium derivatives, divinyl ether” (correcting the typo by adding a comma; as in [0162]).
Independent claim 20, at the new line starting with “(I) wherein”, should remove the comma after “selected from” (correcting the typo).
Appropriate correction is required.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim 20 is rejected under 35 U.S.C. 103 as obvious over Showalter (2009/0264321) (cited previously) in view of Reichenbach-Klinke (2011/0237468) and Oates (2010/0300928).
Regarding independent claim 20, Showalter discloses A method of treating a portion of a subterranean formation (abstract “a composition comprising encapsulated expandable polymeric microparticles including expandable base microparticles encapsulated in a shell of at least one layer of a labile or degradable encapsulation material. … The invention is further directed to the use of the composition for modifying the permeability of subterranean formations”) comprising:
introducing a wellbore servicing composition into the subterranean formation (e.g., [0072] “the composition is added to injection water”), wherein the wellbore servicing composition comprises:
a base fluid (e.g., [0072] “injection water”); and
core-shell particles comprising a core and a shell (abstract “expandable base microparticles encapsulated in a shell” e.g. [0090] “one or more of labile crosslinks, a labile core, or a labile shell”), wherein the shell wholly or partially surrounds the core, and wherein:
(i) the core of each of the core-shell particles comprises silica, alumina, titania, barite, ilmenite, iron oxide, calcium carbonate, barium sulfate, manganese tetroxide, clays, cellulosics, carbon black, bitumen, fly ash, or combinations thereof ([0070] “In one aspect, the encapsulation material for the shell is selected from the group consisting of cross-linked polymers, emulsifiers, thermally responsive polymers, silicone elastomers, siloxanes, starches, gum gar, derivated cellulose sulfonated polysaccharides, silica, colloidal clays, a salt, and combinations thereof. In one aspect, the shell comprises at least two layers of encapsulation material”; when the silica or colloidal clay is the inner layer of two layers, it would be part of a “core”); and
(ii) the shell comprises a polymer that is a polymerization product of one or more monomers and optionally one or more cross-linkers ([0045] “Other suitable encapsulation materials or additives to the encapsulation materials include natural or synthetic cross-linked polymers, … ethylenically unsaturated monomers”), wherein the one or more monomers include a thermally stable monomer, the one or more cross-linkers include a thermally stable cross-linker, or wherein the one or more monomers include the thermally stable monomer and the one or more cross-linkers include the thermally stable cross-linker, wherein the thermally stable cross-linker is selected from pentaerythritol allyl ether (PAE), vinyl or allyl ethers of glycols, polyglycols or polyols, N, N'-divinylethyleneurea (DVEU), divinylbenzene, divinyltetrahydropyrimidin-2(1H)-one, dienes, triallyl amine and tetraallylammonium derivatives, divinyl ether, diallyl ether, N-vinyl-3(E)- ethylidene pyrrolidone, ethylidene bis(N-vinylpyrrolidone), or a combination thereof ([0042] “Representative non-labile cross linking monomers include methylene bisacrylamide, diallylamine, triallylamine, divinyl sulfone, diethyleneglycol diallyl ether, and the like”), and wherein the thermally stable monomer is selected from N-vinylpyrrolidone (NVP), vinylbenzenesulfonate, diallyldimethyl ammonium halide, 1-vinylimidazole, 4-vinylpyridine, or a combination thereof ([0027] “Preferred cationic monomers include dimethylaminoethylacrylate methyl chloride quaternary salt, dimethylaminoethylmethacrylate methyl chloride quaternary salt and diallyldimethyl ammonium chloride. Diallyldimethyl ammonium chloride is more preferred” and [0041] “Representative nonionic monomers include … N-vinyl pyrrolidone”) and
causing or allowing the wellbore servicing fluid to stabilize and/or reduce fluid loss into permeable areas of the subterranean formation ([0062]-[0063] “this invention is directed to a method of modifying the permeability to water of a subterranean formation an encapsulated polymeric microparticle composition comprising cross-linked expandable polymeric microparticles and a shell encapsulating the cross-linked expandable polymeric microparticles, the shell comprising at least one layer of a labile or degradable encapsulation material wherein the encapsulated microparticles have a smaller diameter than the pores of the subterranean formation and wherein the labile cross linkers break under the conditions of temperature and pH in the subterranean formation to form expanded microparticles. The composition then flows through a zone or zones of relatively high permeability in the subterranean formation under increasing temperature conditions, until the composition reaches a location where the temperature or pH is sufficiently high to promote expansion of the microparticles” and [0068] “The particle size of the polymer particles before release from the shell and expansion is selected based on the calculated pore size of the highest permeability thief zone”).
Regarding the (I) and (II), Showalter discloses “Representative non-labile cross linking monomers include methylene bisacrylamide, diallylamine, triallylamine, divinyl sulfone, diethyleneglycol diallyl ether, and the like” ([0042]), “Preferred cationic monomers include dimethylaminoethylacrylate methyl chloride quaternary salt, dimethylaminoethylmethacrylate methyl chloride quaternary salt and diallyldimethyl ammonium chloride. Diallyldimethyl ammonium chloride is more preferred” ([0027]), and “Representative nonionic monomers include … N-vinyl pyrrolidone” ([0041]).
However, Showalter fails to disclose including additional thermally stable monomers of vinylbenzenesulfonate, 1-vinylimidazole, or 4-vinylpyridine or additional thermally stable cross-linkers of pentaerythritol allyl ether (PAE), vinyl ethers of glycols, polyglycols or polyols, N,N'-divinylethyleneurea (DVEU), divinylbenzene, divinyltetrahydropyrimidin-2(1H)-one, dienes, … tetraallylammonium derivatives, divinyl ether, N-vinyl-3(E)-ethylidene pyrrolidone, or ethylidene bis(N-vinylpyrrolidone) i.e. in addition to the triallylamine cross linking monomer above.
Nevertheless, these appear to be well-known stable crosslinkers for expandable particles.
For example, Reichenbach-Klinke teaches “blocking underground formations in the extraction of fossil oil and/or gas, a first step involving introducing water-absorbing particles into liquid-bearing and porous rock formations, said particles being water-swellable, crosslinked and water-insoluble polymers” (abstract) wherein “a non-hydrolysable crosslinker shall be understood to mean a crosslinker which, incorporated in the network, maintains its crosslinking action at all pH values; this means that under the conditions of the application (time, temperature, pH) there is nearly no hydrolysis” ([0059]) and “the used crosslinker, that is not hydrolysable under the conditions of its application, was at least one representative from the group of N,N'-methylenebisacrylamide, N,N'-methylenebismethacrylamide or monomers having at least one maleimide group, preferably hexamethylenebismaleimide, monomers having more than one vinyl ether group, preferably ethylene glycol divinyl ether, triethylene glycol divinyl ether, cyclohexanediol divinyl ether, allylamino or allylammonium compounds having more than one allyl group, preferably triallylamine or a tetraallylammonium salt such as tetraallylammonium chloride, or allyl ethers having more than one allyl group, such as tetraallyloxyethane and pentaerythritol triallyl ether, or monomers having vinylaromatic groups, preferably divinylbenzene and triallyl isocyanurate, or diamines, triamines, tetramines or higher-functionality amines, preferably ethylenediamine and diethylenetriamine” ([0062]).
Similarly, Oates teaches “particles of a hydrophobic polymer” (abstract) wherein “The particles of the present disclosure, however, can include a non-labile cross-link. A non-labile cross-link included in the particles of the present disclosure is not hydrolyzed or otherwise degraded under conditions of temperature and/or pH that would cause labile cross-links to hydrolyze. … A non-labile cross-linking agent refers to a monomer that is incorporated into the particles of the hydrophobic polymer and results in a non-labile cross-link. Examples of such monomers can include di- and trifunctional monomers such as, for example, divinyl benzene, or diene functional monomers such as butadiene” ([0062]-[0063])
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified to include additional non-labile/non-hydrolyzable crosslinkers, such as divinyl ethers, a tetraallylammonium salt, pentaerythritol trialyl ether, divinylbenzene, or dienes, with a reasonable expectation of success, in order to use alternate known non-labile/non-hydrolyzable crosslinkers also suitable for forming expandable particles (thereby including:
“(I) wherein the one or more monomers include a thermally stable monomer selected from vinylbenzenesulfonate, 1-vinylimidazole, 4-vinylpyridine, or a combination thereof, and the one or more thermally stable cross-linkers, when also present, include a thermally stable cross-linker selected from pentaerythritol allyl ether (PAE), vinyl or allyl ethers of glycols, polyglycols or polyols, N, N'-divinylethyleneurea (DVEU), divinylbenzene, divinyltetrahydropyrimidin-2(1H)-one, dienes, triallyl amine and tetraallylammonium derivatives, divinyl ether, diallyl ether, N- vinyl-3(E)-ethylidene pyrrolidone, ethylidene bis(N-vinylpyrrolidone), or a combination thereof; or
(II) wherein the one or more cross-linkers include a thermally stable cross-linker selected from pentaerythritol allyl ether (PAE), vinyl ethers of glycols, polyglycols or polyols, N,N'-divinylethyleneurea (DVEU), divinylbenzene, divinyltetrahydropyrimidin-2(1H)-one, dienes, triallyl amine and tetraallylammonium derivatives, divinyl ether, N-vinyl-3(E)-ethylidene pyrrolidone, ethylidene bis(N-vinylpyrrolidone), or a combination thereof, and the one or more thermally stable monomers, when also present, include a thermally stable monomer selected from N-vinylpyrrolidone (NVP), vinylbenzenesulfonate, diallyldimethyl ammonium halide, 1- vinylimidazole, 4-vinylpyridine, or a combination thereof;”).
Second, this modification is obvious as no more than the simple substitution of a known element (known non-labile/non-hydrolyzable crosslinkers, such as divinyl ethers, a tetraallylammonium salt, pentaerythritol trialyl ether, divinylbenzene, or dienes) for another known element (known non-labile/non-hydrolyzable crosslinkers, such as triallylamine) within the capability of one of ordinary skill in the art at the time, in a manner that would have achieved predictable results (encapsulated expandable polymeric microparticles). KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007). See MPEP 2143 Examples of Basic Requirements of a Prima Facie Case of Obviousness.
Claims 1-11 and 21 are rejected under 35 U.S.C. 103 as obvious over Showalter in view of Reichenbach-Klinke and Oates, as evidenced by Schlumberger HPHT NPL (“HPHT Wells”; Schlumberger Oilfield Review; 2016) (cited previously).
Regarding independent claim 1 (and claims 3, 6, and 9), Showalter discloses A method of servicing a wellbore penetrating a subterranean formation (abstract “a composition comprising encapsulated expandable polymeric microparticles including expandable base microparticles encapsulated in a shell of at least one layer of a labile or degradable encapsulation material. … The invention is further directed to the use of the composition for modifying the permeability of subterranean formations”), the method comprising:
preparing a wellbore servicing composition (e.g., [0072] “the composition is added to injection water”) comprising:
(a) core-shell particles comprising a core and a shell (abstract “expandable base microparticles encapsulated in a shell” e.g. [0090] “one or more of labile crosslinks, a labile core, or a labile shell”), wherein the shell wholly or partially surrounds the core, and wherein:
(i) the core of each of the core-shell particles comprises a particle selected from silica, alumina, titania, barite, ilmenite, iron oxide, calcium carbonate, barium sulfate, manganese tetroxide, clays, cellulosics, carbon black, bitumen, fly ash, or combinations thereof ([0070] “In one aspect, the encapsulation material for the shell is selected from the group consisting of cross-linked polymers, emulsifiers, thermally responsive polymers, silicone elastomers, siloxanes, starches, gum gar, derivated cellulose sulfonated polysaccharides, silica, colloidal clays, a salt, and combinations thereof. In one aspect, the shell comprises at least two layers of encapsulation material”; when the silica or colloidal clay is the inner layer of two layers, it would be part of a “core”); and
(ii) the shell comprises a polymer that is a polymerization product of one or more monomers and optionally one or more cross-linkers ([0045] “Other suitable encapsulation materials or additives to the encapsulation materials include natural or synthetic cross-linked polymers, … ethylenically unsaturated monomers”), wherein the one or more monomers include a thermally stable monomer, the one or more cross-linkers include a thermally stable cross-linker, or wherein the one or more monomers include the thermally stable monomer and the one or more cross-linkers include the thermally stable cross-linker, wherein the thermally stable cross-linker is selected from pentaerythritol allyl ether (PAE), vinyl or allyl ethers of glycols, polyglycols or polyols, N, N'-divinylethyleneurea (DVEU), divinylbenzene, divinyltetrahydropyrimidin-2(1H)-one, dienes, triallyl amine and tetraallylammonium derivatives, divinyl ether, diallyl ether, N-vinyl-3(E)- ethylidene pyrrolidone, ethylidene bis(N-vinylpyrrolidone), or a combination thereof ([0042] “Representative non-labile cross linking monomers include methylene bisacrylamide, diallylamine, triallylamine, divinyl sulfone, diethyleneglycol diallyl ether, and the like”), and wherein the thermally stable monomer is selected from N-vinylpyrrolidone (NVP), vinylbenzenesulfonate, diallyldimethyl ammonium halide, 1-vinylimidazole, 4-vinylpyridine, or a combination thereof ([0027] “Preferred cationic monomers include dimethylaminoethylacrylate methyl chloride quaternary salt, dimethylaminoethylmethacrylate methyl chloride quaternary salt and diallyldimethyl ammonium chloride. Diallyldimethyl ammonium chloride is more preferred” and [0041] “Representative nonionic monomers include … N-vinyl pyrrolidone”); and
(b) a carrier fluid (e.g., [0072] “injection water”); and
placing the wellbore servicing composition into the wellbore, the subterranean formation or both ([0062]-[0063] “this invention is directed to a method of modifying the permeability to water of a subterranean formation an encapsulated polymeric microparticle composition comprising cross-linked expandable polymeric microparticles and a shell encapsulating the cross-linked expandable polymeric microparticles, the shell comprising at least one layer of a labile or degradable encapsulation material wherein the encapsulated microparticles have a smaller diameter than the pores of the subterranean formation and wherein the labile cross linkers break under the conditions of temperature and pH in the subterranean formation to form expanded microparticles. The composition then flows through a zone or zones of relatively high permeability in the subterranean formation under increasing temperature conditions, until the composition reaches a location where the temperature or pH is sufficiently high to promote expansion of the microparticles” and [0068] “The particle size of the polymer particles before release from the shell and expansion is selected based on the calculated pore size of the highest permeability thief zone”),
wherein thermally stable indicates that inclusion of the thermally stable monomer, the thermally stable cross-linker, or both the thermally stable monomer and the thermally stable cross-linker in the wellbore servicing composition provides for stability of the core-shell particles as indicated by maintenance of association of the core with the shell of the core-shell particles… (e.g., [0042] “"Non-labile cross linking monomer" means a cross linking monomer which is not degraded under the conditions of temperature and/or pH which would cause incorporated labile cross linking monomer to disintegrate” = thermally stable; note that including either the diallyldimethyl ammonium chloride cationic monomer or the N-vinyl pyrrolidone nonionic monomer would also necessarily provide stability, because these are defined as thermally stable monomers by Applicant).
Regarding the (I) and (II), Showalter discloses “Representative non-labile cross linking monomers include methylene bisacrylamide, diallylamine, triallylamine, divinyl sulfone, diethyleneglycol diallyl ether, and the like” ([0042]), “Preferred cationic monomers include dimethylaminoethylacrylate methyl chloride quaternary salt, dimethylaminoethylmethacrylate methyl chloride quaternary salt and diallyldimethyl ammonium chloride. Diallyldimethyl ammonium chloride is more preferred” ([0027]), and “Representative nonionic monomers include … N-vinyl pyrrolidone” ([0041]).
However, Showalter fails to disclose including additional thermally stable monomers of vinylbenzenesulfonate, 1-vinylimidazole, or 4-vinylpyridine or additional thermally stable cross-linkers of pentaerythritol allyl ether (PAE), vinyl ethers of glycols, polyglycols or polyols, N,N'-divinylethyleneurea (DVEU), divinylbenzene, divinyltetrahydropyrimidin-2(1H)-one, dienes, … tetraallylammonium derivatives, divinyl ether, N-vinyl-3(E)-ethylidene pyrrolidone, or ethylidene bis(N-vinylpyrrolidone) i.e. in addition to the triallylamine cross linking monomer above.
Nevertheless, these appear to be well-known stable crosslinkers for expandable particles.
For example, Reichenbach-Klinke teaches “blocking underground formations in the extraction of fossil oil and/or gas, a first step involving introducing water-absorbing particles into liquid-bearing and porous rock formations, said particles being water-swellable, crosslinked and water-insoluble polymers” (abstract) wherein “a non-hydrolysable crosslinker shall be understood to mean a crosslinker which, incorporated in the network, maintains its crosslinking action at all pH values; this means that under the conditions of the application (time, temperature, pH) there is nearly no hydrolysis” ([0059]) and “the used crosslinker, that is not hydrolysable under the conditions of its application, was at least one representative from the group of N,N'-methylenebisacrylamide, N,N'-methylenebismethacrylamide or monomers having at least one maleimide group, preferably hexamethylenebismaleimide, monomers having more than one vinyl ether group, preferably ethylene glycol divinyl ether, triethylene glycol divinyl ether, cyclohexanediol divinyl ether, allylamino or allylammonium compounds having more than one allyl group, preferably triallylamine or a tetraallylammonium salt such as tetraallylammonium chloride, or allyl ethers having more than one allyl group, such as tetraallyloxyethane and pentaerythritol triallyl ether, or monomers having vinylaromatic groups, preferably divinylbenzene and triallyl isocyanurate, or diamines, triamines, tetramines or higher-functionality amines, preferably ethylenediamine and diethylenetriamine” ([0062]).
Similarly, Oates teaches “particles of a hydrophobic polymer” (abstract) wherein “The particles of the present disclosure, however, can include a non-labile cross-link. A non-labile cross-link included in the particles of the present disclosure is not hydrolyzed or otherwise degraded under conditions of temperature and/or pH that would cause labile cross-links to hydrolyze. … A non-labile cross-linking agent refers to a monomer that is incorporated into the particles of the hydrophobic polymer and results in a non-labile cross-link. Examples of such monomers can include di- and trifunctional monomers such as, for example, divinyl benzene, or diene functional monomers such as butadiene” ([0062]-[0063])
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified to include additional non-labile/non-hydrolyzable crosslinkers, such as divinyl ethers, a tetraallylammonium salt, pentaerythritol trialyl ether, divinylbenzene, or dienes, with a reasonable expectation of success, in order to use alternate known non-labile/non-hydrolyzable crosslinkers also suitable for forming expandable particles (thereby including:
“(I) wherein the one or more monomers include a thermally stable monomer selected from vinylbenzenesulfonate, 1-vinylimidazole, 4-vinylpyridine, or a combination thereof, and the one or more thermally stable cross-linkers, when also present, include a thermally stable cross-linker selected from pentaerythritol allyl ether (PAE), vinyl or allyl ethers of glycols, polyglycols or polyols, N, N'-divinylethyleneurea (DVEU), divinylbenzene, divinyltetrahydropyrimidin-2(1H)-one, dienes, triallyl amine and tetraallylammonium derivatives, divinyl ether, diallyl ether, N- vinyl-3(E)-ethylidene pyrrolidone, ethylidene bis(N-vinylpyrrolidone), or a combination thereof; or
(II) wherein the one or more cross-linkers include a thermally stable cross-linker selected from pentaerythritol allyl ether (PAE), vinyl ethers of glycols, polyglycols or polyols, N,N'-divinylethyleneurea (DVEU), divinylbenzene, divinyltetrahydropyrimidin-2(1H)-one, dienes, triallyl amine and tetraallylammonium derivatives, divinyl ether, N-vinyl-3(E)-ethylidene pyrrolidone, ethylidene bis(N-vinylpyrrolidone), or a combination thereof, and the one or more thermally stable monomers, when also present, include a thermally stable monomer selected from N-vinylpyrrolidone (NVP), vinylbenzenesulfonate, diallyldimethyl ammonium halide, 1- vinylimidazole, 4-vinylpyridine, or a combination thereof;”).
Second, this modification is obvious as no more than the simple substitution of a known element (known non-labile/non-hydrolyzable crosslinkers, such as divinyl ethers, a tetraallylammonium salt, pentaerythritol trialyl ether, divinylbenzene, or dienes) for another known element (known non-labile/non-hydrolyzable crosslinkers, such as triallylamine) within the capability of one of ordinary skill in the art at the time, in a manner that would have achieved predictable results (encapsulated expandable polymeric microparticles). KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007). See MPEP 2143 Examples of Basic Requirements of a Prima Facie Case of Obviousness.
Regarding the stability at temperatures ≥300°F, Showalter discloses “The composition then flows through a zone or zones of relatively high permeability in the subterranean formation under increasing temperature conditions, until the composition reaches a location where the temperature … is sufficiently high to promote expansion of the microparticles” ([0063]) and provides an example ([0084]-[0088]) wherein “Heat activation of the microparticles of this invention is demonstrated in a bottle test” ([0085]) and “The bottles are placed in a constant temperature oven to age. Then, at a predetermined time, a bottle is removed from the oven and cooled to 75°F” ([0087]).
However, Showalter does not appear to specify what “sufficiently high” temperature is used, except that it is above 75°F.
Nevertheless, typical formation temperatures are well-known in the art to include high temperatures such as e.g. 300-350°F. For example, the Schlumberger HPHT NPL provides evidence of this, stating “a well that has temperatures above 350°F [177°C] is considered high temperature” (p.1) and depicting the Schlumberger HPHT classification system which delineates High Temperature as between 300-400°F (Figure 1).
Although silent to the exact ranges as instantly claimed, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Showalter to include:
“wherein thermally stable indicates that inclusion of the thermally stable monomer, the thermally stable cross-linker, or both the thermally stable monomer and the thermally stable cross-linker in the wellbore servicing composition provides for stability of the core-shell particles as indicated by maintenance of association of the core with the shell of the core-shell particles at temperatures of greater than or equal to at least about 300°F (148.9°C),”
with a reasonable expectation of success, in order to provide encapsulated expandable polymeric microparticles which will remain unexpanded until reaching the target zone where the temperature is sufficiently high to promote expansion of the microparticles and thus shutting off the thief zones. Applicant may note that, after KSR, the presence of a known result-effective variable would be one, but not the only, motivation for a person of ordinary skill in the art to experiment to reach another workable product or process. See also MPEP 2144.05 Obviousness of Similar and Overlapping Ranges, Amounts, and Proportions.
Regarding claims 2, 5, and 8, as in claim 1, Showalter states “"Non-labile cross linking monomer" means a cross linking monomer which is not degraded under the conditions of temperature and/or pH which would cause incorporated labile cross linking monomer to disintegrate” ([0042]). Thus, it appears that Showalter must provide:
(claim 2) wherein the one or more cross-linkers include the thermally stable cross-linker; and/or
(claim 5) wherein the one or more monomers include the thermally stable monomer; and further
(claim 8) wherein the one or more cross-linkers include the thermally stable cross-linker,
in order for the monomer to not be degraded under the temperature that would cause labile monomer to disintegrate.
Furthermore, it appears that Applicant has merely discovered a previously unappreciated property of a prior art composition or otherwise merely recognized another advantage which would flow naturally from following the suggestion of the prior art. Moreover, since Showalter provides the same composition as claimed, the polymer, if subjected to testing, would act in the same manner as claimed. For example, providing N-vinyl pyrrolidone would necessarily provide wherein ≥90% of covalent bonds in the N-vinyl pyrrolidone remain intact after exposure to temperatures up to 350°F in an aqueous environment for 16 hours.
Regarding claims 4 and 10, Showalter discloses encapsulation materials which include “natural or synthetic cross-linked polymers” and “ethylenically unsaturated monomers” ([0045]), which presumably includes the disclosed monomers, such as “"Labile cross linking monomer" means a cross linking monomer which can be degraded by certain conditions of heat and/or pH, after it has been incorporated into the polymer structure, to reduce the degree of crosslinking in the polymeric microparticle of this invention. The aforementioned conditions are such that they can cleave bonds in the "cross linking monomer" without substantially degrading the rest of the polymer backbone. Representative labile cross linking monomers include diacrylamides and methacrylamides of diamines such as the diacrylamide of piperazine, acrylate or methacrylate esters of di, tri, tetra hydroxy compounds including ethyleneglycol diacrylate, polyethyleneglycol diacrylate, trimethylopropane trimethacrylate, ethoxylated trimethylol triacrylate, ethoxylated pentaerythritol tetracrylate, and the like; divinyl or diallyl compounds separated by an azo such as the diallylamide of 2,2'-Azobis(isbutyric acid) and the vinyl or allyl esters of di or tri functional acids” ([0039]). Accordingly, Showalter discloses “wherein the cross-linker further includes a non-thermally stable cross-linker selected from acrylate or methacrylate diesters of diols, acrylate or methacrylate diesters, triesters, or higher functionality esters of polyols and sugars, bisacrylamide compounds, vinyl or allyl esters, 1,3,5-triallyl-1,3-5-triazine-2,4,6(1H,3H,5H)-trione, triallyl cyanurate, or a combination thereof.”
Even if it were somehow found that Showalter fails to disclose providing the combination of the cross linking monomers in the encapsulation materials per se, Showalter teaches “For example, characteristics of a microparticle for use in a particular reservoir are influenced by selection of the encapsulation material. For example, the choice may be made to use a particular backbone monomer or comonomer ratio in a labile polymer constituting the shell. Another way to influence the characteristics of the microparticle is the degree of reversible (labile) and irreversible crosslinking introduced … during manufacture of a labile polymer constituting the shell” ([0018]). Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Showalter to include, specifically, using the listed monomers, with a reasonable expectation of success, in order to select a particular encapsulation comonomers during manufacture of a labile polymer constituting the shell, for use in a particular reservoir.
Although not required to render obvious the claims, Showalter also discloses “Representative non-labile cross linking monomers include methylene bisacrylamide” ([0042]).
Regarding claims 7 and 11, Showalter discloses encapsulation materials which include “natural or synthetic cross-linked polymers” and “ethylenically unsaturated monomers” ([0045]), which presumably includes the disclosed monomers, such as “"Anionic monomer" means a monomer as defined herein which possesses an acidic functional group and the base addition salts thereof. Representative anionic monomers include acrylic acid, methacrylic acid, maleic acid, itaconic acid, 2-propenoic acid, 2-methyl-2-propenoic acid, 2-acrylamido-2-methyl propane sulfonic acid, sulfopropyl acrylic acid and other water-soluble forms of these or other polymerizable carboxylic or sulphonic acids, sulphomethylated acrylamide, allyl sulphonic acid, vinyl sulphonic acid, the quaternary salts of acrylic acid and methacrylic acid such as ammonium acrylate and ammonium methacrylate, and the like” ([0023]); “"Cationic Monomer" means a monomer unit as defined herein which possesses a net positive charge. Representative cationic monomers include the quaternary or acid salts of dialkylaminoalkyl acrylates and methacrylates such as dimethylaminoethylacrylate methyl chloride quaternary salt (DMAEA.MCQ), dimethylaminoethylmethacrylate methyl chloride quaternary salt (DMAEM.MCQ), dimethylaminoethylacrylate hydrochloric acid salt, dimethylaminoethylacrylate sulfuric acid salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt (DMAEA.BCQ) and dimethylaminoethylacrylate methyl sulfate quaternary salt; the quaternary or acid salts of dialkylaminoalkylacrylamides and methacrylamides such as dimethylaminopropyl acrylamide hydrochloric acid salt, dimethylaminopropyl acrylamide sulfuric acid salt, dimethylaminopropyl methacrylamide hydrochloric acid salt and dimethylaminopropyl methacrylamide sulfuric acid salt, methacrylamidopropyl trimethyl ammonium chloride and acrylamidopropyl trimethyl ammonium chloride; and N,N-diallyldialkyl ammonium halides such as diallyldimethyl ammonium chloride (DADMAC)” ([0027]); and “"Nonionic monomer" means a monomer as defined herein which is electrically neutral. Representative nonionic monomers include N-isopropylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, dimethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide, acryloyl morpholine, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, dimethylaminoethylacrylate (DMAEA), dimethylaminoethyl methacrylate (DMAEM), maleic anhydride, N-vinyl pyrrolidone, vinyl acetate and N-vinyl formamide. Preferred nonionic monomers include acrylamide, N-methylacrylamide, N,N-dimethylacrylamide and methacrylamide” ([0041]). Accordingly, Showalter discloses “the polymer further comprising a monomer that is not thermally stable, wherein the not thermally stable monomer is selected from acrylamide, methacrylamide, N,N-dimethylacrylamide, N-isopropylacrylamide, acrylic acid and salts thereof, 2-acryloylamino-2-methylpropane-1-sulfonic acid (AMPSA) and salts thereof, dimethylaminopropyl methacrylamide (DMAPMA), methacrylamido propyltrimethylammonium chloride (MAPTAC), [3-(acryloylamino)propyl]trimethyl ammonium chloride (APTAC), 2-acryloyloxyethyltrimethyl ammonium chloride (AETAC), 2-methacryloyloxyethyltrimethyl ammonium chloride (METAC), acryloyloxyethyldimethylbenzyl ammonium chloride (AEDBAC), methacryloyloxyethyldimethylbenzyl ammonium chloride (MEDBAC), or a combination thereof.”
Even if it were somehow found that Showalter fails to disclose providing the combination of the listed monomers in the encapsulation materials per se, Showalter teaches “For example, characteristics of a microparticle for use in a particular reservoir are influenced by selection of the encapsulation material. For example, the choice may be made to use a particular backbone monomer or comonomer ratio in a labile polymer constituting the shell. Another way to influence the characteristics of the microparticle is the degree of reversible (labile) and irreversible crosslinking introduced … during manufacture of a labile polymer constituting the shell” ([0018]). Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Showalter to include, specifically, using the listed monomers, with a reasonable expectation of success, in order to select a particular encapsulation comonomers during manufacture of a labile polymer constituting the shell, for use in a particular reservoir.
Regarding claim 21, Showalter states “"Non-labile cross linking monomer" means a cross linking monomer which is not degraded under the conditions of temperature and/or pH which would cause incorporated labile cross linking monomer to disintegrate” ([0042]). Thus, it appears that Showalter must provide “wherein greater than or equal to 90% of covalent bonds in the thermally stable cross-linker and the thermally stable monomer remain intact after exposure to temperatures up to 350 °F in an aqueous environment for 16 hours,” in order for the monomer to not be degraded under the temperature that would cause labile monomer to disintegrate.
Furthermore, Applicant should note that "the discovery of a previously unappreciated property of a prior art composition, or of a scientific explanation for the prior art’s functioning, does not render the old composition patentably new to the discoverer." See MPEP 2112. Also, mere recognition of latent properties in the prior art does not render nonobvious an otherwise known invention, and "[t]he fact that appellant has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious." See MPEP 2145.
In this case, it appears that Applicant has merely discovered a previously unappreciated property of a prior art composition or otherwise merely recognized another advantage which would flow naturally from following the suggestion of the prior art. Moreover, since Showalter provides the same composition as claimed, the polymer, if subjected to testing, would act in the same manner as claimed, i.e., it would be capable of demonstrating “wherein the thermally stable cross-linker is selected from cross-linkers for which greater than or equal to 90% of covalent bonds therein remain intact after exposure to temperatures up to 350 °F in an aqueous environment for 16 hours, and wherein the thermally stable monomer is selected from monomers for which greater than or equal to 90% of covalent bonds therein remain intact after exposure to temperatures up to 350 °F in an aqueous environment for 16 hours.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties Applicant discloses and/or claims are necessarily present. Alternatively, if there is any difference between the composition and that of the instant claims, the difference would have been minor and obvious insofar as because it has been held "Products of identical chemical composition cannot have mutually exclusive properties." See MPEP 2112.
Response to Arguments
Applicant’s arguments with respect to claims rejected under 35 USC § 102 over Showalter have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, based on Applicant’s Amendment to the claims, a new ground(s) of rejection is made under 35 USC § 103 over Showalter in view of Oates, and the arguments do not apply to the combination being used in the current rejection.
Conclusion
The Office observes that Applicant discloses “In embodiments, the shell of the composite includes, consists essentially of, or consists of an organic water soluble polymer, or a crosslinked polymer that would be water soluble if not crosslinked. … In embodiments, the core-shell composites may not substantially swell in water and, thus, may not cause significant viscosification or gelation of the treatment fluid” ([0048]; note that “substantially” is defined in [0013]). The vast majority of Prior Art (such as Showalter, Reichenbach-Klinke, and Oates) particularly intend the crosslinked particles to swell in water upon hydrolysis of certain crosslinking monomers, with the non-labile crosslinking monomers retained so that the expanded/swollen particle does not entirely dissolve. Accordingly, Applicant may consider incorporating this feature into the claims (e.g., “wherein the core-shell particles do not substantially swell in water”) to overcome the cited Prior Art.
As always, Applicant may consider contacting the Examiner for an Interview or the like, in the case further explanation or guidance is desired.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
The reference to Herth (2011/0015301) teaches a copolymer (B) (abstract) used as “water-absorbing particles, which comprise copolymer (B), are introduced into liquid-bearing and porous rock formations, and wherein the particles in the water-bearing rock formation, by absorbing water, prevent liquid flow through the rock layer(s)” ([0207]) wherein “Possible hydrolysis-stable crosslinkers are N,N'-methylenebis(meth)acrylamide and monomers having more than one maleimide group per molecule, such as hexamethylenebismaleimide; monomers having more than one vinyl ether group per molecule, such as ethylene glycol divinyl ether, triethylene glycol divinyl ether and/or cyclohexanediol divinyl ether, for example cyclohexane-1,4-diol divinyl ether. It is also possible to use allylamino or allylammonium compounds with more than one allyl group, such as triallylamine and/or tetraallylammonium salts. The hydrolysis-stable crosslinkers also include the allyl ethers, such as tetraallyloxyethane and pentaerythrityl triallyl ether” ([0069]). However, this reference only recognizes these as “A hydrolysis-stable crosslinker shall be understood to mean a crosslinker which--incorporated in the network--maintains its crosslinking action in a pH-independent manner. The linkage points of the network thus cannot be broken up by a pH change of the swelling medium. These contrast with hydrolysis-labile crosslinkers which--incorporated in the network--can lose their crosslinking action through a change in the pH” ([0068]) and does not teach use of these as thermally-stable crosslinking monomers.
The reference to Deville (2021/0062064) teaches “In certain embodiments, divinyl ether, diallyl ether, vinyl or allyl ethers of polyglycols or polyols, divinylbenzene, 1,3-divinylimidazolidin-2-one (also known as 1,3-divinylethyleneurea or divinylimidazolidone), divinyltetrahydropyrimidin-2(1H)-one, dienes (such as 1,7-octadiene and 1,9-decadiene), allyl amines (such as triallylamine and tetraallylethylene diamine), N-vinyl-3(E)-ethylidene pyrrolidone, and ethylidene bis(N-vinylpyrrolidone) may serve as thermally stable crosslinkers, and may not hydrolyze at higher temperatures” ([0020]). However, this reference only teaches these thermally stable crosslinkers used as viscosifiers or for fluid loss control agents, and does not disclose or teach a core for a core-shell particle,
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/ANDREW SUE-AKO/Primary Examiner, Art Unit 3674