Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
DETAILED ACTION
Election/Restrictions
Applicant’s election without traverse of the Species of “an isolated silanol group” silanol group; “crystalline” silica; “dimethyl diethoxy silane (DMDES)” functionalization; “cetyltrimethyl ammonium bromide” surfactant, drawn to claims 1 and 3-11, in the reply filed on 22 June 2026 is acknowledged.
Claim 2 is withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Species, there being no allowable generic or linking claim.
Specification
The disclosure is objected to because of the following informalities:
[0069] should recite “sodium dodecyl sulfate” and “alkyl polyglucoside” (correcting the typos; as in [0034]).
[0078] should recite “That is, the applicable variables determined in Example 1.1 remained constant, but the concentration of CTAB was varied at 0.5 mM, 0.6 mM, 0.7 mM, and [[0.5]] 0.8 mM in water” (correcting the typo).
Appropriate correction is required.
Claim Objections
Claims 1 and 3-11 are objected to because of the following informalities:
Every occurrence of “CO2” should recite “CO2” (correcting the typos by correcting the subscript). The dependent claims are objected to by dependency.
Independent claim 1 should recite “a plurality of functionalized silanol[[-]]group silica nanoparticles, the silanol group selected from” (correcting the typos by removing the hyphen and adding a comma).
Claim 8 should recite “sodium dodecyl sulfate” and “alkyl polyglucoside” (correcting the typos; as in [0034]).
Appropriate correction is required.
Allowable Subject Matter
Claim 11 is objected to as being dependent upon a rejected base claim and including informalities as above, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims and correcting the informalities.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1 and 3-10 are rejected under 35 U.S.C. 103 as obvious over Hiraoka (2023/0002669) in view of Morales (2023/0108336), as evidenced by the NPL reference to De Vylder (“A comprehensive model for the role of water and silanols in the amine catalyzed aldol reaction”; Chem. Eng. Journal; Vol. 404, 2021, p.1-13) and the NPL reference to Alfa Chemistry (“HLB Value and Calculation”; Alfa Chemistry; <https://surfactant.alfa-chemistry.com/hlb-value-and-calculation.html>; accessed 8 January 2025) (all cited previously in parent 18/318,223).
Regarding independent claim 1, Hiraoka discloses A CO2 foam treatment fluid (abstract “An aqueous sol used in CO2 foam flooding … The aqueous sol for increasing stability of froth or emulsion in a mixture containing carbon dioxide, water, and oil in CO2 foam flooding of EOR, the sol including silica particles having an average particle diameter of 1 to 100 nm as measured by dynamic light scattering and having surfaces at least partially coated with a silane compound having a hydrolyzable group, the silica particles serving as a dispersoid and dispersed in an aqueous solvent having a pH of 1.0 to 6.0 serving as a dispersion medium” and e.g., [0124] “injecting the aqueous sol of the present invention, water, and carbon dioxide … simultaneously into the subsurface oil reservoir” i.e. as a “CO2 foam”) comprising:
a plurality of functionalized silanol group silica nanoparticles ([0103] “Examples of the silane compound having an amino group (and a hydrolyzable group) include … 3-aminopropyltriethoxysilane” and [0104] “the silane compound used for the surface treatment of the aforementioned aqueous silica sol may further contain a second silane compound” and [0106] “Examples of the silane having the aforementioned hydrolyzable group and having a C1-40 alkyl group include alkoxysilanes, such as methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, and n-decyltrimethoxysilane. These silane compounds may be used alone or in combination of two or more species”; note [0118] “The phrase “silica particles coated with a silane compound” encompasses the case where hydrolyzable groups are completely hydrolyzed” = the groups are all silanols) …;
…; and
a surfactant ([0130] “In the step (a), the aqueous sol or water may contain an optional component used for crude oil recovery. Examples of the optional component include, but are not limited to, a surfactant”)... .
Regarding the silanol groups, Hiraoka discloses “The amount of surface treatment (coating) with the silane compound having a hydrolyzable group; i.e., the number of silane compound molecules bonded to the silica particle surface is preferably, for example, 0.01 to 5 or 1 to 5 per nm2 of the silica particle surface” ([0119]).
However, Hiraoka does not specify if this forms isolated silanol groups, vicinal silanol groups, or geminaol silanol groups.
Nevertheless, these are the only three possible types of silanol groups that can be formed, especially at Hiraoka’s disclosed density of 0.01-5 groups/nm2. For example, the NPL reference to De Vylder provides evidence of this, stating “Silanol groups on a silica surface can occur either in an isolated, geminal and vicinal position with respect to each other [45]. A silanol group is denoted as “isolated” when the distance to the closest other silanol groups is such that they cannot be involved in mutual hydrogen- bond interactions. This is typically at least 3.3 Å. Vicinal silanol groups are within 3 Å from each other but not on the same silicon atom, and form a hydrogen-bond with each other that facilitates a proton transfer between both groups. Geminal silanol groups are linked to the same surface silicon atom and are too close to each other to form a hydrogen bond [46]” (p.7-8). Applicant may note that 1 nm = 10 Å and thus a density of e.g. 1 group/nm2 would provide at least an isolated silanol group.
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 Hiraoka to include isolated silanol groups, vicinal silanol groups, and/or geminaol silanol groups, with a reasonable expectation of success, in order to provide the desired density of silane compounds coating the nanoparticle surface (thereby providing:
“a plurality of functionalized silanol group silica nanoparticles, the silanol group selected from the group consisting of an isolated silanol group, a vicinal silanol group, a geminaol silanol group, and any combination thereof;”). For example, the Office observes that Applicant has disclosed no criticality to providing any particular type of silanol group.
Regarding the crystalline silica, Hiraoka discloses “The aqueous silica sol (unmodified silica sol), which forms the aqueous sol of the present invention, is an aqueous silica sol containing colloidal silica as a dispersoid, and can be produced by any known method using water glass (aqueous sodium silicate solution) as a raw material” ([0087]).
However, Hiraoka fails to specify whether the colloidal silica is produced as crystalline silica.
Nevertheless, there are the only two possibilities of types of silica to use (crystalline vs. non-crystalline or amorphous), and Hiraoka plainly contemplates that silica produced by “any known method” (and thus either type) would be suitable.
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 Hiraoka to include crystalline silica specifically, with a reasonable expectation of success, in order to provide colloidal silica “produced by any known method” for use as the nanoparticles (thereby providing:
“wherein the plurality of functionalized silanol group silica nanoparticles comprise crystalline silica;”).
Second, the modification would have been obvious as no more than being "Obvious to try" – choosing from a finite number of identified, predictable solutions (either i) crystalline silica or ii) amorphous silica, produced by any known method, for use as the nanoparticles), with a reasonable expectation of success. 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.
For example, although not necessary to render the claims obvious, Applicant may see the NPL reference to Nabil (“Preparation of crystalline silica (quartz, cristobalite, and tridymite) and amorphous silica powder (one step)”; Journal of Physics and Chemistry of Solids; Vol. 121, 2018; p.22-26) in the Conclusion previously which describes such standard production methods for silica nanoparticles.
Furthermore, the Office observes that Applicant fails to provide any criticality to using crystalline silica vs. non-crystalline silica (amorphous silica) for the nanoparticles. Rather, Applicant appears to disclose that these are equivalents for the current Invention.
Regarding the surfactant, Hiraoka discloses optionally including surfactant ([0130]) for a fluid with increased foam stability (abstract) with functionalized silica nanoparticles having a negative zeta potential i.e. a negative surface charge ([0155]).
However, Hiraoka fails to specify the HLB value of the surfactant, such as 8-18.
Morales teaches “a foam formulation … where the foam has volumetric and time stability” (abstract) wherein the State of the Art teaches that “The particle concentration in solutions used to generate foams ranges between 0.5 and 2% (m/V). The particles used can have a spherical or lamellar shape and dimensions between 12 nm and 770 nm. Silica, alumina, polymer or latex particles are usually used and are associated with ionic surfactants such as sodium dodecyl sulfate (SDS) when they gave a positive surface charge, or cetyltrimethylammonium bromide (CTAB), when they have a negative surface charge, according to what is taught in the article by Hinnant et al. (Hinnant, K. M., Conroy, M. W. & Ananth, R. Influence of fuel on foam degradation for fluorinated and fluorine-free foams. Colloids Surfaces A Physicochem. Eng. Asp. 522, 1-17, 2017)” ([0010]).
The NPL reference to Alfa Chemistry provides evidence that CTAB has a HLB of 10-12 (p.2).
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 Hiraoka to include, specifically, CTAB surfactant, with a reasonable expectation of success, in order to generate a foam with the silica particles and a corresponding known surfactant for when the silica particles have a negative surface charge (thereby including:
“a surfactant having a hydrophilic-lipophilic balance (HLB) value of 8 to 18”).
Regarding claims 3-5, Hiraoka discloses “Examples of the silane compound having an amino group (and a hydrolyzable group) include … 3-aminopropyltriethoxysilane” ([0103]) and “the silane compound used for the surface treatment of the aforementioned aqueous silica sol may further contain a second silane compound” ([0104]) wherein “Examples of the silane having the aforementioned hydrolyzable group and having a C1-40 alkyl group include alkoxysilanes, such as methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, and n-decyltrimethoxysilane. These silane compounds may be used alone or in combination of two or more species” ([0106]). Accordingly, Hiraoka discloses:
(claim 3) wherein the silanol group is functionalized with a silane; and/or
(claim 4) wherein the silanol group is functionalized with a silane containing one or more of a propyl group, a methyl group, or an octyl group; and/or
(claim 5) wherein the silanol group is functionalized with a silane selected from the group consisting of dimethyl diethoxy silane, 3-aminopropyl triethoxy silane, methyl poly(ethylene glycol) silane, ethoxy trimethyl silane, dimethoxy dimethyl silane, propyl triethoxy silane, trimethoxy propyl silane, octyl triethoxy silane, and any combination thereof.
Regarding claim 6, Hiraoka discloses optionally including surfactant ([0130]).
The only possible types of surfactants are anionic, cationic, non-ionic, and zwitterionic. Accordingly, even if it were somehow found that Hiraoka fails to disclose including a particular type of surfactant, 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 Hiraoka to include at least one of an anionic surfactant, a cationic surfactant, a non-ionic surfactant, or a zwitterionic surfactant, with a reasonable expectation of success, in order to realize the known benefits of combining the functionalized silica nanoparticles and known surfactants (thereby providing “wherein the surfactant is selected from the group consisting of an anionic surfactant, a cationic surfactant, an non-ionic surfactant, a zwitterionic surfactant, and any combination thereof”).
Regarding claims 7 and 8, as in claim 1, 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 Hiraoka to include, specifically, CTAB as the surfactant, with a reasonable expectation of success, in order to generate a foam with the silica particles and a corresponding known surfactant for when the silica particles have a negative surface charge (thereby including:
(claim 7) wherein the surfactant is selected from the group consisting of sodium dodecyl sulfate, cetyltrimethyl ammonium bromide, alkyl polyglucoside, ethoxylated coco amine, and any combination thereof; and/or
(claim 8) wherein the surfactant is cetyltrimethyl ammonium bromide).
Regarding claim 9, Hiraoka discloses wherein the plurality of functionalized silanol group silica nanoparticles have an average diameter in the range of about 1 nanometer to about 100 nanometers ([0075] “In the present invention, the surface-treated silica particles contained in the aqueous sol may have an average particle diameter (DLS particle diameter) of 1 to 100 nm, or 1 to 50 nm, or 3 to 30 nm, or 5 to 15 nm”).
Regarding claim 10, Hiraoka discloses “the aqueous sol, water, and carbon dioxide are injected into the formation rock so that the zeta potentials of the silica particles in the aqueous sol and the formation rock are negative or positive each other. This can prevent aggregation of the silica particles in rock pores, which is preferable for the formation and maintenance of stable CO2 foam and an improvement in crude oil recovery efficiency on the basis thereof” ([0132]) and “FIG. 1 shows the results of measurement of the zeta potentials of the aqueous sols (aqueous silica sols subjected to surface treatment with a silane compound) prepared in Examples 1 and 2 at different pH values from pH 2 or more to pH 10 or less” ([0154]) and depicts in Fig. 1 that Example 1 has an absolute zeta potential of 35 mV at pH 9.
Although silent to the exact absolute zeta potential range 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 Hiraoka to include “wherein the CO2 foam treatment fluid has an absolute value zeta potential in the range of about 30 millivolts to about 40 millivolts,” with a reasonable expectation of success, in order to provide suitable zeta potentials which “can prevent aggregation of the silica particles in rock pores.” 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.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
The reference to Baran (7,033,975) (cited by Applicant) discloses “the use of surface-modified nanoparticles” (abstract) such as “silica” nanoparticles (6:7) modified with “silanes” (4:55-5:22) that “provides foams that are stable under pressure” (1:45-49) such as wherein “surface-modified nanoparticles are used in combination with surfactant in such fluids” (2:10-11) and includes physical foaming agent such as “carbon dioxide” (8:19-20). However, this reference does not specify the HLB of the fluorinated surfactants and fails to disclose or teach use with proppant such as in fracturing, instead being directed to mobility control such as by blocking permeable areas with the foam.
The reference to Southwell (10,934,478) discloses “methods of increasing production from a hydrocarbon containing formation by adding a proppant to the formation, wherein a treatment fluid comprising a colloidal silica nanoparticle is added to the formation … during … the time the proppant is added to the formation” (abstract) wherein the silica nanoparticle is “used to create a surface treated colloidal silica” (8:35) using silanes such as “Propyltrimethoxysilane” = trimethoxy propyl silane and “Octyltriethoxysilane” (9:30-35) and may be prepared with “an anionic surfactant sodium dodecyl sulfate” (27:43-44) and “polyoxyethylene nonylphenyl ether (reagent Tergitol® NP-9 manufactured by Sigma-Aldrich Corporation) with HLB=13.0 was charged as a nonionic surfactant” (27:49-51) which may be used in a “foam” fracturing fluid (1:19). However, this reference particularly uses “colloidal silica,” which is well-known to be an amorphous/non-crystalline silica, not a crystalline silica, and thus it would not be obvious to modify this reference to instead use a crystalline silica nanoparticle base.
The reference to Karadkar (12,492,332) is also parent Application 18/318,223. However, this reference fails to raise Double Patenting considerations because all patented claims are directed to Group I while all current claims are directed to non-elected Group II of the Restriction/Election Requirement between Groups I and II as mailed 25 January 2024 and maintained in the Notice of Allowability mailed 20 August 2025.
The reference to Holcomb (2010/0096139) discloses nanoparticles added to a fluid containing a wetting agent (abstract) which can be a CO2 foamed fluid ([0019]) with silica nanoparticles with an anionic surfactant ([0022]). However, this reference fails to disclose or teach functionalization with silanes.
The reference to Li (2017/0240800) (cited in parent), which discloses an inorganic fine particle reinforced foam system comprising carbon dioxide (abstract) with foaming agent surfactant ([0016]) and fine particles which presumably may include modified silicon dioxide nano-particles used for a similar foam ([0006]), for use in “displacement of reservoir oil, fracturing, profile control and water shutoff” ([0031]). However, the modified silicon dioxide nano-particles as in CN102746841A (cited in parent) are modified with siloxanes and do not appear to have silanol groups.
The reference to Khamatnurova (2021/0207021) discloses a foamed treatment fluid comprising surfactants, natural gas, and nanoparticles (abstract) along with “carbon dioxide” gas ([0024]) and “proppant” ([0020]), wherein the nanoparticles may be “silica” ([0015]) that has the surface modified with surface modifying agents to render the nanoparticles hydrophobic, hydrophilic, or hydro-neutral ([0017]) and wherein the surfactants may include zwitterionic or cationic surfactants to stabilize the foam ([0026]). However, this reference fails to disclose or teach modifying the silica nanoparticles with silanes i.e. such that there are silanol groups, nor using surfactants of HLB 8-18.
The reference to Watts (2023/0068743) discloses a gas and nanoparticle fluid (abstract) comprising CO2 ([0065]) as a foam of surfactants in combination with colloidal silica nanoparticles ([0035]) which are surface treated with silanes ([0043]). However, not only is colloidal silica an amorphous/non-crystalline silica, but also this reference fails to disclose or teach use with proppants such as in fracturing, instead being directed to mitigating fracturing hits by reducing fracture driven interference.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANDREW SUE-AKO whose telephone number is (571)272-9455. The examiner can normally be reached M-F 9AM-5PM EST.
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/ANDREW SUE-AKO/Primary Examiner, Art Unit 3674
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