OFFICE ACTION
This application has been assigned or remains assigned to Technology Center 1700, Art Unit 1774 and the following will apply for this application:
Please direct all written correspondence with the correct application serial number for this application to Art Unit 1774.
Telephone inquiries regarding this application should be directed to the Electronic Business Center (EBC) at http://www.uspto.gov/ebc/index.html or 1-866-217-9197 or to the Examiner at (571) 272-1139. All official facsimiles should be transmitted to the centralized fax receiving number (571)-273-8300.
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 .
Responses to Restriction Arguments
Claims 19-24 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 2 OCT 2025. Method claims 1-18 are treated on the merits below.
Applicant's election with traverse of Group I - claims 1-18 in said reply is acknowledged. The traversal is on the grounds that claims 1-24 are not properly restrictable, the typical there would not be a serious burden on the Examiner to examine the claims of both groups together, employing a multifaceted search strategy covering different fields, classes, and subject matter cannot be considered a "serious" burden but instead is part of the normal burden of examining a patent application, the subject matter of Groups I and II are believed to be sufficiently related that a thorough search of the subject matter of one claim Group would encompass a search of the subject matter of both claim groups, and to avoid duplicative examination by the Patent Office and unnecessary delay and expense to Applicant, Applicant respectfully requests examination on the merits of the claims of Groups I and II together. The request is DENIED.
Applicants have failed to show that a search is the only criteria for determining "serious burden" on the part of the examiner. Nevertheless, it should be noted that the search for and examination, including consideration of and responses to arguments, of multiple inventions in the same application creates a serious burden on the examiner. Moreover, this is not found persuasive because with regard to apparatus claims versus method claims, in apparatus claims the material or article worked upon does not limit apparatus claims and is not a major consideration when determining the patentability of said apparatus claims (MPEP 2115). “Expressions relating the apparatus to contents thereof during an intended operation are of no significance in determining patentability of the apparatus claim.” Ex parte Thibault, 164 USPQ 666, 667 (Bd. App. 1969). Furthermore, “[i]nclusion of material or article worked upon by a structure being claimed does not impart patentability to the claims.” In re Young, 75 F.2d 966, 25 USPQ 69 (CCPA 1935) (as restated in In re Otto, 312 F.2d 937, 136 USPQ 458, 459 (CCPA 1963)). In stark contrast thereto, in method claims the materials on which a process is carried out must be accorded weight in determining the patentability of a process. Ex parte Leonard, 187 USPQ 122 (Bd. App. 1974) and see MPEP 2116. Accordingly, unlike the elected method claims, patentable weight will not be given to the claimed materials set forth in the pending nonelected apparatus claims which significantly alters the search strategy and amplifies the searching required which leads to a burden on the PTO.
Curiously, Applicant has not set forth any compelling reasons why the groups are not distinct from each other as set forth by the examiner in the restriction requirement and merely concludes that claims 1-24 are not properly restrictable for the above reasons. Accordingly, if Applicant continues to assert that the restriction requirement is in error, Applicant is respectfully urged to promptly petition the requirement pursuant to 37 CFR 1.44 since the requirement is still deemed proper and is therefore made FINAL.
Priority
Acknowledgment is made of applicant's claim for domestic priority under 35 U.S.C. § 119(e).
Information Disclosure Statement
Note the attached PTO-1449 form) submitted with the Information Disclosure Statements.
Drawings
The drawings are objected to under 37 CFR § 1.83(a) since the drawings must show every feature of the invention specified in the claims. Therefore, the following features must be shown or the features canceled from the claims. No new matter should be entered.
The subject matter of claim 17 (the tank, elongated conduit, and subterranean reservoir)
The subject matter of claim 18 (the tank, elongated conduit, and secondary mixing device).
Per Rule 84, the drawings are further objected to because suitable descriptive and concise text legends should be provided to label the blank boxes in Figure 1 such as the source of emulsion 20, metering device 14, process liquid source 18, fluid pressurization device 12, and flow restrictor 16 for understanding of the drawings (37 CFR 1.84(o)). Suggested formats for labeling the elements of the invention via text legends can be found in US Patent No. 11745388 and 8591098. Note the elements/boxes are clearly labeled with such text legends for improved and rapid understanding of the drawings. Blank boxes in a drawing Figure even if presented with a refence character fail to express what elements are being depicted in said Figure. Looking to the specification to determine what elements are being depicted by uninformative blank boxes in a Figure during a typical search is a time consuming and aggravating diversion, a departure from the drawings to the written specification that would not be required if the drawing Figures comply with 37 CFR 1.84(o).
INFORMATION ON HOW TO EFFECT DRAWING CHANGES
Replacement Drawing Sheets
Drawing changes must be made by presenting replacement figures which incorporate the desired changes and which comply with 37 CFR 1.84. An explanation of the changes made must be presented either in the drawing amendments, or remarks, section of the amendment. Any replacement drawing sheet must be identified in the top margin as “Replacement Sheet” (37 CFR 1.121(d)) and include all of the figures appearing on the immediate prior version of the sheet, even though only one figure may be amended. The figure or figure number of the amended drawing(s) must not be labeled as “amended.” If the changes to the drawing figure(s) are not accepted by the examiner, applicant will be notified of any required corrective action in the next Office action. No further drawing submission will be required, unless applicant is notified.
Identifying indicia, if provided, should include the title of the invention, inventor’s name, and application number, or docket number (if any) if an application number has not been assigned to the application. If this information is provided, it must be placed on the front of each sheet and centered within the top margin.
Annotated Drawing Sheets
A marked-up copy of any amended drawing figure, including annotations indicating the changes made, may be submitted or required by the examiner. The annotated drawing sheets must be clearly labeled as “Annotated Marked-up Drawings” and accompany the replacement sheets.
Timing of Corrections
Applicant is required to submit acceptable corrected drawings within the time period set in the Office action. See 37 CFR 1.85(a). Failure to take corrective action within the set period will result in ABANDONMENT of the application.
If corrected drawings are required in a Notice of Allowability (PTOL-37), the new drawings MUST be filed within the THREE MONTH shortened statutory period set for reply in the “Notice of Allowability.” Extensions of time may NOT be obtained under the provisions of 37 CFR 1.136 for filing the corrected drawings after the mailing of a Notice of Allowability.
Specification
The specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant's cooperation is requested in correcting any errors of which applicant may become aware in the specification.
The abstract is acceptable.
The title is acceptable.
Claim Rejections - 35 U.S.C. § 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
The inquiry during examination is patentability of the invention as the inventor or a joint inventor regards such invention. If the claims do not particularly point out and distinctly claim that which the inventor or a joint inventor regards as his or her invention, the appropriate action by the examiner is to reject the claims under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. In re Zletz, 893 F.2d 319, 13 USPQ2d 1320 (Fed. Cir. 1989).
Claims 7 and 14-15 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or joint inventor regards as the invention.
Claim 7: does the “at least one channel” have any relationship to the plurality of channels set forth in claim 1?
Claim 14, line 4: does “pressurization” have any relationship to the “pressurizing step” of claim 1.
Claim 15, line 4: does the “discharging the pressurized dilute emulsion” occur from the fluid pressurization device of claim 1.
Claim Rejections - 35 USC § 102
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 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 terms used in this respect are given their broadest reasonable interpretation in their ordinary usage in context as they would be understood by one of ordinary skill in the art, in light of the written description in the specification, including the drawings, without reading into the claim any disclosed limitation or particular embodiment. See, e.g., In re Am. Acad. of Sci. Tech. Ctr., 367 F.3d 1359, 1364 (Fed. Cir. 2004); In re Hyatt, 211 F.3d 1367, 1372 (Fed. Cir. 2000); In re Morris, 127 F.3d 1048, 1054-55 (Fed. Cir. 1997); In re Zletz, 893 F.2d 319, 321-22 (Fed. Cir. 1989).
The Examiner interprets claims as broadly as reasonable in view of the specification, but does not read limitations from the specification into a claim. Elekta Instr. S.A.v.O.U.R. Sci. Int'l, Inc., 214 F.3d 1302, 1307 (Fed. Cir. 2000). "A claim is anticipated only if each and every element as set forth in the claim is found, either expressly or inherently described, in a single prior art reference." Verdegaal Bros. Inc. v. Union Oil Co. of California, 814 F.2d 628, 631 (Fed. Cir. 1987).
The express, implicit, and inherent disclosures of a prior art reference may be relied upon in the rejection of claims under 35 U.S.C. 102 or 103. "The inherent teaching of a prior art reference, a question of fact, arises both in the context of anticipation and obviousness." In re Napier, 55 F.3d 610, 613, 34 USPQ2d 1782, 1784 (Fed. Cir. 1995) (affirmed a 35 U.S.C. 103 rejection based in part on inherent disclosure in one of the references). See also In re Grasselli, 713 F.2d 731, 739, 218 USPQ 769, 775 (Fed. Cir. 1983). See MPEP 2112.
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.
Claims 1-14 and 16 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by HOCH et al. (US 6103786).
The patent to HOCH et al. ‘786 discloses in at least Figures 2 and 5 and via the underlined/emphasized language below, a method of inverting an emulsion, the method comprising: introducing an emulsion from source 1 or 2 comprising a continuous phase and a discontinuous phase containing a polymer into a process liquid from the other or source 1 or 2 in which the polymer is soluble and the continuous phase is immiscible, wherein introducing the emulsion into the process liquid comprises introducing the emulsion into the process liquid upstream of a fluid pressurization device (pump 3) to form a dilute emulsion and pressurizing the dilute emulsion with the fluid pressurization device 3 to form a pressurized dilute emulsion; and passing the pressurized dilute emulsion through a flow restrictor 2, 3, 4 (Figures 2 and 5) comprising a plurality of channels 2, 3 (Figure 5) that divides the pressurized dilute emulsion between the plurality of channels, thereby generating a shear force for dispersing and inverting the emulsion in the process liquid;
wherein the flow restrictor exhibits a pressure drop of at least 3 bar (col. 9, lines 61-63; col. 10, lines 43-45);
wherein the plurality of channels comprises a plurality of tubes 2 extending parallel to each other (Figure 5 and col. 6, lines 19-30);
wherein the plurality of tubes 2 are contained within a housing 1 and are surrounded with a filler material 4 - Figure 5;
wherein passing the pressurized dilute emulsion through the flow restrictor 2, 3, 4 comprises conveying the pressurized dilute emulsion from the fluid pressurization device 3 though an upstream pipe 1 having an open cross-sectional area to the flow restrictor, the flow restrictor defines an open cross-sectional area at 2 and/or 3, and a ratio of the open cross-sectional area of the flow restrictor divided by the open cross- sectional area of the upstream pipe ranges from 0.01 to 0.3 (Figure 5 and col. 6, lines 19-30);
wherein a velocity of the pressurized dilute emulsion through the flow restrictor channels is at least 5 times greater than a velocity of the dilute emulsion entering the fluid pressurization device via the pressures described at col. 4, lines 38-44; col. 6, lines 46-50; col. 7, lines 34-36; col. 9, lines 5-8 and 39-41;
wherein the flow restrictor defines at least one channel having a length ranging from 0.1 mm to 1 meter and an inner diameter ranging from 5 micrometers to 5 millimeters (col. 6, lines 22-30);
wherein a residence time of the pressurized dilute emulsion within the flow restrictor is less than 5 seconds via the pressures described at col. 4, lines 38-44; col. 6, lines 46-50; col. 7, lines 34-36; col. 9, lines 5-8 and 39-41;
wherein the flow restrictor 2, 3, 4 is devoid of mixing elements - Figure 5;
wherein the emulsion is a water-in-oil latex with the continuous phase comprising a hydrocarbon and the discontinuous phase comprising a water-soluble polymer, and the process liquid is a water source (col. 1, lines 48-50 and the underlined language seen below);
wherein the water-in-oil latex comprises about 10 wt% to about 80 wt% of the water-soluble polymer and about 0.5 wt% to 10 wt% of an inversion surfactant (see TABLE 1 - wt% column; col. 4, lines 12-22; col. 5, lines 1-4);
wherein the emulsion is an oil-in-water emulsion with the continuous phase comprising water, the discontinuous phase comprising an oil-soluble polymer, and the process liquid is a hydrocarbon source (col. 3, lines 32-35 and lines 48-53 and the underlined language seen below);
wherein pressurizing the dilute polymer emulsion with the fluid pressurization device comprises pressurizing the dilute polymer emulsion with the fluid pressurization device to a pressure of at least 3 bar via the pressures described at col. 4, lines 38-44; ol. 6, lines 46-50; col. 7, lines 34-36; col. 9, lines 5-8 and 39-41;
wherein introducing the emulsion into the process liquid comprises drawing the process liquid as a side-stream from a conduit, and further comprising reinjecting the process liquid into the conduit after introduction of the emulsion into the process liquid, pressurization, and passage through the flow restrictor as seen in Figure 2 via the recirculation loop downstream of 4 and leading back to source 1;
and wherein introducing the emulsion into the process liquid comprises introducing an amount of the emulsion into an amount of the process liquid effective to form the dilute emulsion having from about 100 ppm to 50,000 ppm of the polymer (see TABLE 1 - wt% column; col. 4, lines 12-22; col. 5, lines 1-4).
More specifically, HOCH et al. discloses a method including forming stable polymer dispersions with polymer particle sizes of 0.1 to 10 μm that are prepared by dissolving a water-in-oil emulsion, comprising a polymer dissolved in an organic solvent which is immiscible with water (organic phase) and an aqueous phase, wherein the viscosity of the organic phase is 1.0 to 20,000 mPas (measured at 25 degrees C., the surface tension between organic and aqueous phase is 0.01 to 30 mN/m, the particle size of the water emulsified in the organic phase is 0.2 to 50 μm and the ratio by volume of organic phase to aqueous phase is in the range 80:20 to 20:80, subjecting this emulsion to a shear process at a shear power wherein the water-in-oil emulsion is inverted and converted into an oil-in-water emulsion.
The present invention relates to a process for preparing stable, finely divided polymer dispersions and the use of polymer dispersions prepared by the process according to the invention for producing dipped articles, coated articles and adhesives.
It is known that a polymer dispersion or emulsion is conventionally prepared in such a way that a polymer solution as organic phase is placed in contact with an aqueous phase while using high shear power. Emulsifiers or emulsifier mixtures are usually added with further auxiliary agents either in the aqueous phase only or in both phases, in order to improve the emulsifying effect. A wide variety of different units are used for the shear-induced dispersion of the organic polymer-containing phase in the aqueous phase (oil-in-water emulsion), such as high-pressure (gap) homogenisers, ultrasonic dispersers, Ultra-Terrax, Kotthoff mixing sirens, dissolver discs, colloid mills and a wide variety of designs of various nozzles. In the known process, the solvent is removed by stripping, pressure reduction (flashing) or by some other distillative process. Furthermore, the relatively low concentration emulsions (thin latex) may be brought up to the final concentration required by distilling, centrifuging or by creaming.
The process according to the invention ensures that stable polymer dispersions which have specific, defined polymer particle diameters are always obtained. The invention therefore provides a process for preparing stable polymer dispersions with polymer particle sizes of 0.1 to 10 μm, which is characterized in that a water-in-oil emulsion, comprising a polymer dissolved in an organic solvent which is immiscible with water (organic phase) and an aqueous phase, wherein the viscosity of the organic phase is 1.0 to 20,000 mPas (measured at 25 degrees C.), the surface tension between organic and aqueous phase is 0.01 to 30 mN/m, the particle size of the water emulsified in the organic phase is 0.2 to 50 μm and the ratio by volume of organic phase to aqueous phase is in the range 80:20 to 20:80, is subjected to a shear process at a shear power, wherein the water-in-oil emulsion is inverted and converted into an oil-in-water emulsion. The stable polymer dispersions prepared by the process according to the invention preferably have a polymer particle size of 0.1 to 50 μm.
The viscosity of the organic phase in the water-in-oil emulsion is preferably 10 to 20,000 mPas, in particular 100 to 5000 mPas. The surface tension between organic and aqueous phase is preferably in the range 0.5 to 30, in particular 0.5 to 5 mN/m. The particle size of the water emulsified in the organic phase is preferably 1 to 25 μm, in particular 1 to 10 μm and the ratio by volume of organic phase to aqueous phase is preferably in the range 70:30 to 30:70, in particular 60:40 to 40:60.
The water-in-oil emulsion to be subjected to shear by the process according to the invention may be prepared in a conventional manner, for instance by initially introducing the polymer-containing phase into a stirred container. The aqueous phase, optionally containing emulsifier, is then introduced and the mixture is emulsified in such a way that the ranges specified above for viscosity, surface tension and particle size in the water-in-oil emulsion are achieved.
The phase inversion from water-in-oil emulsion to oil-in-water emulsion is performed by passage through a suitable homogenising machine such as high-pressure homogenisers, colloid mills and toothed rim dispersers.
The water-in-oil emulsion to be subjected to shear by the process according to the invention is particularly preferably prepared by initially introducing the organic phase into a container and circulating this via a homogenising nozzle and adding the aqueous phase in a specific material stream upstream of a homogenising nozzle and thus subdividing the aqueous phase as finely as possible. During this stage enough aqueous phase is added to achieve phase inversion (batchwise process).
During continuous dispersion by the process according to the invention, dispersion is performed in such a way that the aqueous phase is added in several emulsifying steps in sequence, defined by the organic phase.
Polymers which are suitable for use in the process according to the invention are either thermoplastic polymers or elastic polymers (rubbers). The following polymers may be mentioned by way of example: polyolefins such as polyethylene, polypropylene, ethylene/.alpha.-olefin copolymers such as ethylene/propene copolymers, ethylene/butene copolymers, ethylene/pentene copolymers, ethylene/hexene copolymers, ethylene/heptene copolymers and ethylene/octene copolymers. Obviously, the corresponding isomers may also be used as parent materials for the polyolefins. Polyisobutylenes and their secondary products such as halogenated polyisobutylene and copolymers of isobutylene and methylstyrene, isoprene and chlorinated polyethylene (CM) or chlorosulphonated polyethylene (CSM) are particularly preferably mentioned as polyolefins. In addition the following may be used as polymers: copolymers of ethylene with polar monomers such as vinyl acetate, vinyl esters, acrylates, methacrylates, maleic acid, maleic anhydride, (meth)acrylic acid, fumaric acid and their esters. The following polymers are also suitable: diene polymers such as polybutadiene, polyisoprene, polydimethylbutadiene and their copolymers with each other or with styrene or styrene derivatives, such as .alpha.-methylstyrene with acrylonitrile, methacrylonitrile with acrylates or methacrylates. The diene polymers mentioned above may also be present in the form of terpolymers or multiple copolymers. Furthermore, the following are suitable as polymers: natural rubber and its derivatives, polychloroprene and polydichlorobutadiene and their copolymers, and also styrene/butadiene block copolymers. In addition, post-treated polymers may also be used such as hydrogenated nitrile rubbers and hydrogenated styrene/butadiene block copolymers. In addition the following may be used as polymers: polyurethanes, polyesters, polyesteramides, polyethers, polycarbonates and modifications thereof. The following are preferably used as polymers in the process according to the invention: polyisobutylenes and copolymers of isobutene and isoprene, ethylene/propylene copolymers, ethylene/propylene/diene copolymers, SBR, NBR and HNBR as well as polycarbonates and polyurethanes, in particular copolymers of isobutylene and isoprene, and their halogenated analogues (butyl rubber, halogenated butyl rubber).
The following may be mentioned as water-immiscible organic solvents in which the previously mentioned polymers are dissolved: aliphatic, aromatic, araliphatic and/or cycloaliphatic hydrocarbons.
Emulsifiers which may be used for the process according to the invention are those which are known from and conventionally used in the field of polymer dispersion. The emulsifiers are generally added to the aqueous phase. The following may be used, for example, as emulsifiers in the process according to the invention: aliphatic and/or aromatic hydrocarbons with 8 to 30 carbon atoms which have a hydrophilic terminal group such as a sulphonate, sulphate, carboxylate, phosphate or ammonium terminal group. Furthermore, non-ionic surfactants with functional groups, such as polyalcohols, polyethers and/or polyesters are suitable as emulsifiers.
In principle, any conventional industrial emulsifiers and surfactants which are suitable for stabilising oil and polymer dispersions in water may be used. The following are preferably used as emulsifiers: fatty acids salts such as the sodium and/or potassium salts of oleic acid, the corresponding salts of alkylaryl sulphonic acids, naphthyl sulphonic acid and their condensation products with, for instance, formaldehyde, and the corresponding salts of alkylsuccinic acids and alkylsulphosuccinic acids. Obviously, it is also possible to use the emulsifiers in any mixture with each other. Choosing the appropriate, emulsifier depends in particular on the polymers to be emulsified, the solvents used and the end properties required for the dispersions prepared according to the invention.
The amount of emulsifier used again depends on the criteria mentioned above and can readily be determined in an appropriate preliminary test. In this case, obviously, the amount of emulsifier used is only that which is absolutely necessary for successful performance of the process according to the invention. The amount of emulsifier is conventionally 20 to 0.1 parts by wt., in particular 10 to 0.5 parts by wt., with reference to the polymer used. Obviously, the emulsifiers may be used, as mentioned above, on their own or in a mixture with each other. The best mixing ratio again has to be determined in an appropriate preliminary test.
When the water-in-oil dispersion has been subjected to an appropriate shear process, the water-in-oil emulsion is inverted and converted into an oil-in-water emulsion. This can be recognized, inter alia, by the emulsion, which is virtually clear prior to the shear process, turning into a milky/cloudy emulsion. In addition, it is important, in the process according to the invention, that a stable water-in-oil emulsion is present, even if for only a short time, before phase inversion due to the application of a shear force.
The jet disperser preferably used herein is a pressure reduction nozzle which has a much higher degree of efficiency than high-pressure homogenisers. When using a homogenising pressure of only 50 bar, emulsions with the same particle size are obtained as when using a high-pressure homogeniser at 200 bar. The aqueous, polymer-deficient phase may be recycled to the process, as the aqueous phase, optionally after adding fresh emulsifier.
Stable dispersions prepared by the process according to the invention have a polymer concentration of 10 to 70, preferably 40 to 60 wt. % (determined as proportion of solids in the dispersion). Elevated pressure during the process according to the invention is required only in order to feed the phases to be homogenised through the jet disperser. Homogenisation and phase inversion take place in the shear field in the nozzle.
Stable polymer dispersions with a specific polymer size range, prepared by the process according to the invention, contain only small amounts of the emulsifier used (in the range 0.1 to 10 parts by wt.) and are therefore particularly suitable for preparing high-quality dipped articles, laminates, adhesive dispersions and fabric coatings.
Selecting the actual shear unit to use when performing the claimed process depends, in principle, on the practical situation. Here, a jet disperser was used as the dispersing device because finely divided dispersions can advantageously be prepared, either continuously or batchwise. A characteristic feature of a jet disperser is that relatively well-defined shear conditions are produced. Since the process claimed here has to be performed with specific regulation of the process parameters mentioned above, the use of a jet disperser for this process is especially beneficial.
A pre-emulsion 1 was pumped through nozzle holes 2 in tubular piece 4 of the jet disperser Figure 5), and thus finely divided. The emulsion 3, homogenised in this way, was discharged from the jet disperser at atmospheric pressure including a nozzle which had a nozzle body with orifices of cross-section 0.5 mm and length 0.75 mm. The number of orifices was 6. A nozzle can be used which had 60 orifices, each with a diameter of 0.75 mm and a length of 1.1 mm.
In one example (1), the emulsifier solution is initially introduced into the stirred loop container 1. The rubber solution is passed from container 2 with stirring into container 1 so that a fairly coarsely divided O/W emulsion was produced. Then this pre-emulsion was circulated via jet disperser 4 by means of pressure-increasing pump 3 in order to achieve a sufficiently finely divided dispersion. The pressure across the nozzle was adjusted to 10 bar. The number of cycles was 5. The geometry of the nozzle is given in FIG. 5.
The same procedure was used as in example 1, but the pressure across the nozzle was increased to 50 bar (see Table 1). The number of cycles was 5.
In Example 3 the same solutions were prepared as in example 1 (see also Table 1). The rubber solution was initially introduced into loop container 1 and circulated through pressure-increasing pump 3 and jet disperser 4. At the same time, the emulsifier solution was removed from container 2 under suction in the approximate ratio of 1:5 (aqueous:organic) and finely homogenised. A finely divided W/O emulsion was produced first which then inverted to give an O/W emulsion at a concentration of about 30 wt. % of aqueous phase. When phase inversion has been achieved, emulsion production can, in principle, be terminated. The O/W emulsion has a milky/white appearance after phase inversion.
The O/W dispersion obtained in this way had a particle size of 1-4 μm. Before inversion, the W/O emulsion had a particle size of 1-5 μm. Particle sizes within this range were also found in all the examples according to the invention. The particle size of this emulsion was then 1.9 μm.
Examples 4 to 6 according to the invention. The same procedure was used as described in example 3, but different pressures were used across the dispersing nozzle (see Table 1). In all cases, a stable dispersion was obtained, from which the solvent could be removed and which could be concentrated by creaming. Examples 7 to 9 according to the invention The same procedure was used as described in examples 4-6, but larger amounts of emulsifier were used (see Table 1). In all cases, a stable dispersion was obtained, from which the solvent could be removed and which could be concentrated by creaming. The particles sizes in these dispersions were smaller than those in examples 4-6.
Examples 10 to 13 according to the invention. The same procedure was used as described in example 9, but a pressure of 10 bar was used for dispersion and the type of emulsifier was varied (see Table 1). In example 13, a butyl rubber dispersion was prepared. In all cases, a stable dispersion was obtained, from which the solvent could be removed and which could be concentrated by creaming. Very finely divided dispersions were obtained.
Examples 14 to 15 according to the invention. The same procedure was used as described in example 13, but a mixture of two different emulsifiers was used (see Table 1). In all cases, a stable dispersion was obtained, from which the solvent could be removed and which could be concentrated by creaming. Particularly finely divided dispersions were obtained.
Example 16: Emulsifier solution and rubber solution were withdrawn continuously and separately from storage containers 1 and 2. The increase in pressure and metering of the emulsifier solution were achieved using pumps 3 and 4. The O/W emulsion was produced in mixer 5 and this was homogenised in jet disperser 6. An unstable dispersion was obtained which separated into two phases again within a short time of storing.
Example 17: the same procedure was used as described in example 16, but the pressure across the dispersing nozzle was increased to 60 bar. Nevertheless, stable dispersions could not be obtained.
Example 18: preparation of a bromobutyl dispersion by means of a continuous phase inversion process (process 3, see FIG. 3). Emulsifier solution and rubber solution were withdrawn from storage containers 1 and 2, continuously and separately (see labels on FIG. 3). Increasing the pressure and metering the rubber solution were achieved using pump 6 in mixer 7.1, increasing the pressure and metering the emulsifier solution, divided into three substreams, into mixers 7.1, 7.2 and 7.3 was achieved with pumps 5, 4 and 3. The mixture is homogenised in mixer 7.2 by means of a jet disperser 8.1, and the mixture is homogenised in mixer 7.3 by a jet disperser 8.2. A finely divided O/W emulsion was specifically produced by using this step-wise procedure. The partial amounts of emulsifier solution were adjusted so that phase inversion took place only in jet disperser 8.3. Three nozzles of the same structural type were used in series, wherein the pressure drop across all the nozzles was 24 bar. A stable dispersion was obtained.
The process used here shows that careful adjustment of the time of phase inversion enables the production of stable dispersions. During a continuous process, the physical location of the phase inversion process is important as well as the timing. Furthermore, metered addition of the phases has to be arranged in such a way that premature phase inversion, possibly due to too rapid addition of the aqueous phase, does not take place.
Example 19: The same procedure was used as described in example 18, but butyl rubber was dispersed. A stable dispersion was again obtained.
Examples 20 to 36: Preparation of a butyl rubber dispersion by means of a batchwise phase inversion process: Emulsifier solution: 1.76 kg of potassium oleate 144.94 kg of fully demineralised water Rubber solution: 76.8 kg of polymer solution, 19.1% in hexane 21 kg of n-hexane to obtain a concentration of 15%. From a 400 l container, the rubber solution was circulated so that a pressure drop of 10 or 20 bar was recorded in the nozzle. The emulsifier solution is metered from the storage container into the rubber solution, wherein a ratio by volume of 1:10 (aqueous to organic phase) was maintained. After completion of the addition procedure, the emulsifier solution was circulated in the system for another 1 hour. The emulsifying process was then complete.
Polymer used for trials: Polysar bromobutyl 2030-1, solution in hexane, from Antwerp, concentration 18%, ML 1+8, 125.degree. C.=34; Polysar bromobutyl 2030-1, solution in hexane, from Antwerp, concentration 18%, ML 1+8, 125.degree. C.=32 ME; Polysar bromobutyl .times.2, in bales from Antwerp, ML 1+8, 125.degree. C.=46 ME; Basic polymer prior to halogenation to give bromobutyl 2030, solution in hexane, from Antwerp, concentration about 18%, ML 1+8, 125.degree. C.=39 ME
This mode of operation involving recycling the serum to the dispersion stage also meant that only enough emulsifier had to be used in the process as had been entrained in the final product.
Examples 37 to 40: Preparing a bromobutyl dispersion by means of a discontinuous phase inversion process, varying the dispersing pressure. The same procedure was used as is described in example 3, but the pressure across the dispersing nozzle was varied (see Table 3).
Claim Rejections - 35 USC § 103
The terms used in this respect are given their broadest reasonable interpretation in their ordinary usage in context as they would be understood by one of ordinary skill in the art, in light of the written description in the specification, including the drawings, without reading into the claim any disclosed limitation or particular embodiment. See, e.g., In re Am. Acad. of Sci. Tech. Ctr., 367 F.3d 1359, 1364 (Fed. Cir. 2004); In re Hyatt, 211 F.3d 1367, 1372 (Fed. Cir. 2000); In re Morris, 127 F.3d 1048, 1054-55 (Fed. Cir. 1997); In re Zletz, 893 F.2d 319, 321-22 (Fed. Cir. 1989). The Examiner interprets claims as broadly as reasonable in view of the specification, but does not read limitations from the specification into a claim. Elekta Instr. S.A.v.O.U.R. Sci. Int'l, Inc., 214 F.3d 1302, 1307 (Fed. Cir. 2000).
To determine whether subject matter would have been obvious, "the scope and content of the prior art are to be determined; differences between the prior art and the claims at issue are to be ascertained; and the level of ordinary skill in the pertinent art resolved .... Such secondary considerations as commercial success, long felt but unsolved needs, failure of others, etc., might be utilized to give light to the circumstances surrounding the origin of the subject matter sought to be patented." Graham v. John Deere Co. of Kansas City, 383 U.S. 1, 17-18 (1966).
The Supreme Court has noted:
Often, it will be necessary for a court to look to interrelated teachings of multiple patents; the effects of demands known to the design community or present in the marketplace; and the background knowledge possessed by a person having ordinary skill in the art, all in order to determine whether there was an apparent reason to combine the known elements in the fashion claimed by the patent at issue.
KSR Int'l Co. v. Teleflex Inc., 127 S.Ct. 1727, 1740-41 (2007). "Under the correct analysis, any need or problem known in the field of endeavor at the time of invention and addressed by the patent can provide a reason for combining the elements in the manner claimed." (Id. at 1742).
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 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 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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
The instant office action conforms to the policies articulated in the Federal Register notice titled “Updated Guidance for Making a Proper Determination of Obviousness” at 89 Fed. Reg. 14449, February 27, 2024, wherein the Supreme Court’s directive to employ a flexible approach to understanding the scope of prior art is reflected in the frequently quoted sentence, ‘‘A person of ordinary skill is also a person of ordinary creativity, not an automaton.’’ Id. at 421, 127 S. Ct. at 1742. In this section of the KSR decision, the Supreme Court instructed the Federal Circuit that persons having ordinary skill in the art (PHOSITAs) also have common sense, which may be used to glean suggestions from the prior art that go beyond the primary purpose for which that prior art was produced. Id. at 421–22, 127 S. Ct. at 1742. Thus, the Supreme Court taught that a proper understanding of the prior art extends to all that the art reasonably suggests, and is not limited to its articulated teachings regarding how to solve the particular technological problem with which the art was primarily concerned. Id. at 418, 127 S. Ct. at 1741 (‘‘As our precedents make clear, however, the analysis need not seek out precise teachings directed to the specific subject matter of the challenged claim, for a court can take account of the inferences and creative steps that a person of ordinary skill in the art would employ.’’). ‘‘The obviousness analysis cannot be confined . . . by overemphasis on the importance of published articles and the explicit content of issued patents.’’ Id. at 419, 127 S. Ct. at 1741. Federal Circuit case law since KSR follows the mandate of the Supreme Court to understand the prior art— including combinations of the prior art—in a flexible manner that credits the common sense and common knowledge of a PHOSITA. The Federal Circuit has made it clear that a narrow or rigid reading of prior art that does not recognize reasonable inferences that a PHOSITA would have drawn is inappropriate. An argument that the prior art lacks a specific teaching will not be sufficient to overcome an obviousness rejection when the allegedly missing teaching would have been understood by a PHOSITA—by way of common sense, common knowledge generally, or common knowledge in the relevant art. For example, in Randall Mfg. v. Rea, 733 F.3d 1355 (Fed. Cir. 2013), the Federal Circuit vacated a determination of nonobviousness by the Patent Trial and Appeal Board (PTAB or Board) because it had not properly considered a PHOSITA’s perspective on the prior art. Id. at 1364. The Randall court recalled KSR’s criticism of an overly rigid approach to obviousness that has ‘‘little recourse to the knowledge, creativity, and common sense that an ordinarily skilled artisan would have brought to bear when considering combinations or modifications.’’ Id. at 1362, citing KSR, 550 U.S. at 415–22, 127 S. Ct. at 1727. In reaching its decision to vacate, the Federal Circuit stated that by ignoring evidence showing ‘‘the knowledge and perspective of one of ordinary skill in the art, the Board failed to account for critical background information that could easily explain why an ordinarily skilled artisan would have been motivated to combine or modify the cited references to arrive at the claimed inventions.’’ Id.
From Norgren Inc. v. Int’l Trade Comm’n, 699 F.3d 1317, 1322 (Fed. Cir. 2012) (‘‘A flexible teaching, suggestion, or motivation test can be useful to prevent hindsight when determining whether a combination of elements known in the art would have been obvious.’’); Outdry Techs. Corp. v. Geox S.p.A., 859 F.3d 1364, 1370–71 (Fed. Cir. 2017) (‘‘Any motivation to combine references, whether articulated in the references themselves or supported by evidence of the knowledge of a skilled artisan, is sufficient to combine those references to arrive at the claimed process.’’). In keeping with this flexible approach to providing a rationale for obviousness, the Federal Circuit has echoed KSR in identifying numerous possible sources that may, either implicitly or explicitly, provide reasons to combine or modify the prior art to determine that a claimed invention would have been obvious. These include ‘‘market forces; design incentives; the ‘interrelated teachings of multiple patents’; ‘any need or problem known in the field of endeavor at the time of invention and addressed by the patent’; and the background knowledge, creativity, and common sense of the person of ordinary skill.’’ Plantronics, Inc. v. Aliph, Inc., 724 F.3d 1343, 1354 (Fed. Cir. 2013), quoting KSR, 550 U.S. at 418–21, 127 S. Ct. at 1741–42.
The Federal Circuit has also clarified that a proposed reason to combine the teachings of prior art disclosures may be proper, even when the problem addressed by the combination might have been more advantageously addressed in another way. PAR Pharm., Inc. v. TWI Pharms., Inc., 773 F.3d 1186, 1197–98 (Fed. Cir. 2014) (‘‘Our precedent, however, does not require that the motivation be the best option, only that it be a suitable option from which the prior art did not teach away.’’) (emphasis in original). One aspect of the flexible approach to explaining a reason to modify the prior art is demonstrated in the Federal Circuit’s decision in Intel Corp. v. Qualcomm Inc., 21 F.4th 784, 796 (Fed. Cir. 2021), which confirms that a proposed reason is not insufficient simply because it has broad applicability. Patent challenger Intel had argued in an inter partes review before the Board that some of Qualcomm’s claims were unpatentable because a PHOSITA would have been able to modify the prior art, with a reasonable expectation of success, for the purpose of increasing energy efficiency. Id. at 796–97. The Federal Circuit explained that ‘‘[s]uch a rationale is not inherently suspect merely because it’s generic in the sense of having broad applicability or appeal.’’ Id. The Federal Circuit further pointed out its pre-KSR holding ‘‘that because such improvements are ‘technology independent,’ ‘universal,’ and ‘even common-sensical,’ ‘there exists in these situations a motivation to combine prior art references even absent any hint of suggestion in the references themselves.’ ’’ Id., quoting DyStar Textilfarben GmbH v. C.H. Patrick Co., 464 F.3d 1356, 1368 (Fed. Cir. 2006) (emphasis added by the Federal Circuit in Intel). When formulating an obviousness rejection, the PTO may use any clearly articulated line of reasoning that would have allowed a PHOSITA to draw the conclusion that a claimed invention would have been obvious in view of the facts. MPEP 2143, subsection I, and MPEP 2144. Acknowledging that, in view of KSR, there are ‘‘many potential rationales that could make a modification or combination of prior art references obvious to a skilled artisan,’’ the Federal Circuit has also pointed to MPEP 2143, which provides several examples of rationales gleaned from KSR. Unwired Planet, 841 F.3d at 1003.
When considering the prior art in its entirety, note Allied Erecting v. Genesis Attachments, 825 F.3d 1373, 1381, 119 USPQ2d 1132, 1138 (Fed. Cir. 2016) ("Although modification of the movable blades may impede the quick change functionality disclosed by Caterpillar, ‘[a] given course of action often has simultaneous advantages and disadvantages, and this does not necessarily obviate motivation to combine.’" (quoting Medichem, S.A. v. Rolabo, S.L., 437 F.3d 1157, 1165, 77 USPQ2d 1865, 1870 (Fed Cir. 2006) (citation omitted))). However, "the prior art’s mere disclosure of more than one alternative does not constitute a teaching away from any of these alternatives because such disclosure does not criticize, discredit, or otherwise discourage the solution claimed…." In re Fulton, 391 F.3d 1195, 1201, 73 USPQ2d 1141, 1146 (Fed. Cir. 2004).
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over HOCH et al. in view of KUROSAWA (US 7448793 B2).
HOCH et al. does not disclose the heater. KUROSAWA discloses an emulsion production apparatus comprises a first rotor 9 which is fixed to a rotary hollow shaft 7 to atomize mixture liquid supplied from a mixture liquid pipe 2 at a portion below the mixture liquid pipe 2, an intermediate support body 15 which is disposed above the first rotor 9 and compresses the mixture liquid which has passed through the first rotor 9, and a second rotor 18 which is fixed to the hollow shaft 7 so as to further atomize the liquid which has passed through long holes 16 disposed in the support body 15.
As depicted in FIG. 1, a basic configuration of the emulsion production apparatus is provided with a mixture liquid pipe 2 which is vertically extended and mixes an oil (such as a light oil, a heating oil, an A heavy oil) with water to transfer the mixture along with a center shaft of a cylindrical vessel 1. The upper part of the liquid pipe 2 is branched in the form of a character Y to pipes 2a and 2b, to each of which an oil tank 3 and a water tank 4 are respectively connected. Namely, the liquid pipe 2 is made of stainless-steel, and the branch pipes 2a and 2b are provided with a flow regulation valve 4a and 4b , respectively. One ends of the branch pipes 2a and 2b are piped to the bottom part of the oil tank 3 and the bottom part of the water tank 4 through the flow regulation valves 4a and 4b, respectively. Both the oil tank source 3 and the water tank source 4 are made of stainless-steel, and the insides of the oil and water tank sources 3 and 4 have heaters 5 and 6 built-in so as to keep liquid temperatures of the liquid (water or oil) stored therein at prescribed temperatures, respectively.
A rotary hollow shaft 7 is concentrically disposed outside the liquid pipe 2 and is rotating at high speed around the liquid pipe 2. The upper part of the hollow shaft 7 is supported by a fixed plate 8 via a first bearing 8a so as to be freely rotatable, and the lower part of the hollow shaft 7 is fixed to a cylindrical first rotating body 10 of a first rotor 9 [pressurization device]. The first rotor 9 is made of stainless-steel and is provided with twelve plate-like first paddles 11, which are radially fixed on the lower face 10a of the first rotating body 10 as the plane view is shown in FIG. 2. A conical bottom plate 12 which is integrally formed with the first rotor 9 is disposed below the first rotor 9. The bottom plate 12 has a conical upper face 12a and a plane bottom face 12b. The top portion 12c of the conical upper face 12a is disposed facing the lower end of the liquid pipe 2, and the top angle is formed almost 60 degrees. A first chamber 13 is formed between the lower face 10a of the first rotating body 10 of the first rotor 9 and the conical upper face 12a of the conical bottom plate 12, and the periphery of the chamber 13 is radially divided by the twelve first paddles 11. The upper sides 11a of the first paddles 11 are planted on the lower face 10a of the first rotating body 10 and the lower sides 11b of the first paddles 11 are planted on the inclined upper face 12a of the conical bottom plate 12. The first rotor 9 [pressurization device] is composed of the first rotating body 10, the twelve first paddles 11 and the conical bottom plate 12. A gap g is formed as a flow path between the periphery of the first rotor 9 and the side wall of the cylindrical vessel 1. The conical bottom plate 12 is directly connected to a rotary shaft 14a of a motor 14 installed at the lower part on the outside of the cylindrical vessel 1. The liquid temperature of the liquid (e.g., a light oil and water) stored in the oil tank 3 and the water tank 4 is maintained at about 55 degrees C by means of the heater 6. Each liquid in the tanks 3 and 4 passes through the flow regulation valves 4a and 4b from the branch pipes 2a and 2b, respectively, and flows into the liquid pipe 2, turning into the mixture liquid of the water and the oil in the liquid pipe 2, and the mixture liquid freely drops along the liquid pipe 2.
Thus, one or more heaters 5, 6 are disposed inline prior to the location of the downstream pressurization device 9. Accordingly, it would have been obvious to one skilled in the art before the effective filing date of the invention to have provided HOCH et al. with an inline heater as taught by KUROSAWA for the purposes of keeping liquid temperatures of the liquid (water or oil) stored in the respective liquid sources at prescribed temperatures (col. 4, lines 36-40).
Claims 2, 8-13, and 16-18 are rejected under 35 U.S.C. 103 as being unpatentable over HOCH et al. in view of LOGAN et al. (US 2016/0333253 A1).
HOCH et al. does not disclose the subject matter of claims 17-18 and assuming, arguendo, that HOCH et al. does not teach or suggest the subject matter of claims 2, 8-13, and 16, LOGAN et al. discloses inversion systems and methods of diluting w/o lattices including about 10 wt % to 80 wt % of a water soluble polymer. Using the inversion systems and methods described herein, dilution of w/o lattices is carried out in a single step to form dilute lattices having 10,000 ppm or less polymer; the dilute lattices form polymer solutions with no further addition of mixing force or water. The solution viscosities of the polymer solutions obtained using the systems and methods of the invention are at least about 80% of solution viscosity expected in the absence of shear.
The invention relates to apparatuses and methods for rapid inversion of water-in-oil polymer lattices to form polymer flooding solutions for enhanced oil recovery. Crude oil development and production can include up to three distinct phases: primary, secondary, and tertiary (or enhanced) recovery. During primary recovery, the natural pressure of the reservoir or gravity drives oil into the wellbore, combined with artificial lift techniques (such as pumps) which bring the oil to the surface. But only about 10 percent of a reservoir's original oil in place is typically produced during primary recovery. Secondary recovery techniques extend a field's productive life generally by injecting water or a gas to displace oil and drive it to a production wellbore, resulting in the recovery of 20 to 40 percent of the original oil in place.
Enhanced oil recovery, or EOR, is a generic term encompassing techniques for increasing the amount of crude oil that can be extracted from a subterranean formation such as an oil field. EOR techniques offer prospects for ultimately producing 30% to 60% or more of the reservoir's original oil in place. Of these techniques, polymer flooding is particularly favored. Polymer flooding is generally accomplished by dissolving the selected polymer in water, and injecting the polymer solution into the reservoir.
However, since the target concentration of polymer in the solutions is typically about 10,000 ppm (1 wt %) or less, transport at the target concentration is not economically efficient. Transporting the dried polymers, while economically efficient, is sometimes not favorable for field use due to difficulties in fully hydrating the dry polymers in the field. To address these issues, various formulations have been developed to allow economically feasible transportation and storage. Specialized methods have also been developed to convert the formulations to use concentrations of fully hydrated polymers in the field.
Organic polymers traditionally used in EOR include water soluble polymers such as polyacrylamides, polyacrylates, copolymers thereof and copolymers of these with acrylamidomethylpropane sulfonic acid, ammonium functional monomers such as DADMAC (N,N′-diallyl-N,N′-dimethylammonium chloride), as well as hydrophobically modified versions of these, also called associative polymers or associative thickeners. Associative thickeners typically include about 1 mole % or less of a hydrophobic monomer such as a C.sub.8-C.sub.16 linear or branched ester of acrylic acid or N-alkyl adduct of acrylamide. The most commonly employed polymer for EOR is a copolymer of 70 mole % acrylamide and 30 mole % acrylic acid.
The EOR polymers are deliverable as powder, as a concentrate such as a 20 wt % polyacrylamide gel, or in the water phase of a water-in-oil (w/o) latex. Of these formats, water-in-oil lattices have the advantage of being deliverable in a liquid format that is easily handled in the field because the latex viscosity is lower than that of a water solution of comparable wt % polymer. Typically, such lattices include about 10 wt % to 80 wt % polymer solids, yet have a latex viscosity of less than about 2000 cP. Latex polymers are favored for use in offshore applications and other relatively isolated operations due to the ease of use and relatively simple equipment requirements.
Commercial w/o lattices are formulated for EOR by dissolving monomer in a high-solids aqueous solution to form a water phase, mixing a hydrocarbon solvent and a surfactant having a hydrophilic-lipophilic balance (HLB) of about 2 to 8 to form an oil phase, mixing the two phases using techniques that result in a water-in-oil emulsion or latex, and polymerizing the monomer via a free-radical azo or redox mechanisms. After polymerization is complete, a higher HLB surfactant (HLB>8) is often added as a destabilizer to facilitate latex inversion when water is added. “Inversion” is a term of art in EOR to describe the dilution of w/o lattices with a water source, causing destabilization of the latex and subsequent dissolution of the concentrated polymer particles to full hydrodynamic volume and maximum solution viscosity.
In EOR applications, it is a goal of field operators to achieve continuous inversion and hydration of w/o lattices to reach the target polymer solution concentration before the injection mixture reaches the reservoir rockface. In offshore EOR applications, the transit time between the topside mixing of the polymer with the injection water and the injection into the reservoir rock can range from about 5 minutes to about 180 minutes. In such applications, the final target concentration of the polymer solution is about 500 to 10,000 ppm (0.05 wt % to 1 wt %) in a pipe in line. However, inversion of conventional lattices at concentrations below 1 wt % is problematic. There exists a concentration effect in which w/o latex polymers invert more efficiently at target concentrations of about 1 wt % polymer or more. This is especially true in high temperature condition, high total dissolved solids conditions, or in both such conditions. When a typical anionic latex polymer is inverted at 1000 ppm in tapwater, for example, full solution viscosity cannot be reached even after several hours of stirring in the laboratory. Actual industrial conditions are much less favorable for reaching target concentrations of 1 wt % or less of fully inverted and hydrated polymer solutions in a 5-180 minute time frame.
Further, there is increasingly the need to address polymer flooding in challenging conditions encountered in reservoirs wherein ambient or produced water source contacted by the polymer includes high total dissolved solids, such as total dissolved solids of up to about 30 wt %. Another need is to address reservoirs where the available water source is present at an elevated temperature, such as 60° C. to 200° C. In some cases, the ambient or produced water source is both high total solids and is present at a high temperature. Field operators strongly prefer to use ambient or produced water sources rather than purified water sources. However, use of such water sources lead to difficulties in dispersing the high molecular weight polymers to use concentrations. Inversion of w/o lattices in such water sources can result in slow inversion times and/or require multistage dilution and mixing procedures; it can also result in coagulation, precipitation, or gross phase separation of polymer upon or after contact of the latex with the diluted water environment. The products of such instability cause plugged equipment in the field and failure to accomplish mobility control within the reservoir. These problems remain largely unaddressed by conventional methods and equipment developed for inversion of w/o lattices in the field. Thus there is a need to address inversion of w/o lattices in field conditions where the use water source has high total dissolved solids, is present at high temperature, or both.
As used herein, the term “water source” means a source of water comprising, consisting essentially of, or consisting of fresh water, deionized water, distilled water, produced water, municipal water, waste water such as runoff water or municipal waste water, treated or partially treated waste water, well water, brackish water, “gray water”, sea water, or a combination of two or more such water sources as determined by context. In some embodiments, a water source includes one or more salts, ions, buffers, acids, bases, surfactants, or other dissolved, dispersed, or emulsified compounds, materials, components, or combinations thereof. In some embodiments, a water source includes about 0 wt % to 30 wt % total dissolved non-polymeric solids. The terms “aqueous”, “waterbased”, or “water solution” generally refer to a composition including a water source listed herein. Generally and as determined by context, the term “water source” includes high total dissolved solids water sources, high temperature water sources, and water sources that are both high total dissolved solids and high temperature water sources.
As used herein, the term “high total dissolved solids” refers to a water source having at least 0.5 wt % non-polymeric solids dissolved therein, and in embodiments up to about 30 wt % non-polymeric solids dissolved therein. In general, “saline” or “salinity” refers to a water source wherein a portion, in some embodiments a substantial portion, the total dissolved solids are salts, as determined by context.
As used herein, the term “mixing element” means baffle elements within a static mixer, such as plates, helices, vanes, paddes, or blades, intended to disrupt laminar flow and cause mixing within the static mixer; or vanes, paddles, blades, screw elements, or other elements of dynamic mixers such as rotating or corotating screw mixers, planetary and double planetary mixers, cell disruptors, impellers, and the like.
As used herein, the terms “latex”, including “water-in-oil latex”, “polymer latex”, “w/o latex”, or “inverse emulsion polymer” and related terms mean a discontinuous internal water phase within a continuous oil phase, wherein the water phase includes at least one water soluble polymer present at about 10 wt % to 80 wt % of the latex. Water soluble polymers are characterized as having a majority, that is more than 50 mole %, of repeat units derived from one or more water soluble monomers such as acrylamide, acrylic acid or a salt thereof, 2-acrylamido-2-methylpropane sulfonic acid or a salt thereof, a diallyldimethylammonium halide, or another water soluble monomer. In some embodiments the water soluble polymer further includes a minor amount, such as less than about 10 wt %, of repeat units derived from one or more water insoluble monomers. In some embodiments, a latex is an invertible latex.
As used herein, the term “invertible latex” means a w/o latex wherein a surfactant having an HLB of about 14 or greater is further added to the polymer latex to facilitate inversion. In some embodiments, an invertible latex includes about 2.5 wt % to 5 wt %, based on the weight of the latex, of the surfactant having an HLB of about 14 or greater.
As used herein, the term “inversion time” or related terms means the time between contact of a water source with a w/o latex, and subsequent formation of a dilute latex.
As used herein, the term “dilute latex” or related terms means a w/o latex that is completely dispersed in a water source in the form of fine droplets in an amount that provides about 10,000 ppm (1 wt %) or less of water soluble polymer.
As used herein, the verbs “dilute” or “invert” mean to add a sufficient amount of a water source to a latex to provide a dilute latex.
As used herein, the term “hydration” refers to a process that includes the sequestration of the dilute latex oil phase into micelles with the aid of surfactants, the release of the polymer particles into the water, the swelling of the polymer to form hydrogel particles, and the disentangling of the hydrogel into individual polymer chains.
As used herein, the term “hydration period” refers to the period of time between forming a dilute latex and achieving a polymer solution. In some embodiments, the hydration period is characterized by the absence of mixing operations.
As used herein, the term “polymer solution” means a dilute latex wherein the Filter Ratio (FR) test gives a value of about 1.5 or less when measured using industry standard methods for filtration of a dilute latex or polymer solution having 1000 ppm polymer through a filter having a 5 μm pore size. In some embodiments, a polymer solution is characterized as a having achieved its maximum viscosity. In some embodiments, a polymer solution is achieved by contacting the latex with the water source to form a dilute latex and allowing the dilute latex to remain contacted for a hydration period.
The inversion systems of the invention comprise a single inversion device. In some such embodiments, the inversion device is a static mixer designed and adapted to provide a pressure drop of about 2 psi to 150 psi between the inlet and outlet of the static mixer. It will be understood by one of skill that the parameters of diameter, length, mixing element number and configuration is designed and adapted to provide the targeted pressure drop when contacted with a water source and a water-in-oil latex at a selected flow rate.
In some embodiments, the inversion systems of the invention comprise a single inversion device. In some such embodiments, the inversion device is a mixing pump designed and adapted to provide a pressure drop of about 2 psi to 150 psi between the inlet and outlet of the pump. Pumping devices useful in conjunction with the present inversion systems include centrifugal pumps and positive displacement pumps. Such mixing pumps are designed to provide low shear to the materials applied thereto.
The inversion systems of the invention can comprise a single inversion device. In some embodiments, the inversion device is characterized by the absence of mixing elements. Inversion devices characterized by the absence of mixing elements are usefully designed and adapted to provide a pressure drop of about 2 psi to 150 psi between the inlet for the water source and the outlet where the dilute latex exits the device. FIGS. 1-7 show exemplary inversion devices characterized by the absence of mixing elements; FIGS. 8-9 show exemplary inversion systems employing the devices of FIGS. 1-7.
As shown in FIGS. 1-7, an inversion device (12) employed in the inversion systems and in conjunction with the inversion methods of the present invention comprises four primary components: a first conduit (1); a second conduit (4); and a chamber (7). Optionally, the device includes an adaptor (8) useful for fluidly connecting the device to one or more pipes, tubes, and the like. The dimensions and geometries of each component of the inversion device are selected by one of skill depending upon the rate of flow of the water source and w/o latex that is fed into the inversion device, as well other factors, such as localized temperatures or the construction of the pipeline into which diluted w/o lattices are dispensed.
As shown in FIGS. 1-7, the first conduit (1) of device (12) has one or more inlets (2) and one or more outlets (3). In some embodiments, the conduit has both a head portion (10) and a cylindrical portion extending into a cylinder portion (11). In some embodiments, cylinder portion (11) is cylindrical in shape; in other embodiments cylinder portion (11) has a frustoconical shape. The second conduit (4) has one or more inlets (5) and outlets (6). The second conduit (4) secures to the first conduit's head portion (10) by any fastening means that would be appreciated by one of ordinary skill in the art, for example, the head portion (10) of the first conduit and the second conduit (4) may have one or more openings so that a screw can secure one conduit to another.
As shown in FIGS. 1-7, chamber (7) of device (12) has one or more inlets (17) and outlets (18) that are in communication with the outlets of both the first conduit (1) and the second conduit (4). In some embodiments, chamber (7) and second conduit (4) are formed from physically separate articles. In other embodiments, chamber (7) and second conduit (4) are geometrically distinct areas of a single article. In embodiments where chamber (7) and second conduit (4) are formed from physically separate articles, chamber (7) is secured to second conduit (4). The chamber (7) is secured to the second conduit (4) by any fastening means that would be appreciated by one of ordinary skill in the art. For example, both the second conduit (4) and the chamber (7) may have one or more openings so that a screw can secure the second conduit to the chamber, or the outer surface of the chamber (7) can fuse to the outer surface of the second conduit (4). The conduits inlets, outlets, and chamber of the inversion device are characterized by the absence of mixing elements.
As shown in FIGS. 1-7, adaptor (8) of device (12) secures to chamber (7) and is communication with the outlets of the chamber (7). The adaptor (8) may secure to the chamber (7) by any fastening means that would be appreciated by one of ordinary skill in the art, for example, a portion of the chamber (7) may insert into the adaptor (8).
As shown in FIGS. 6A-6C, the inlets (5) of said second conduit (4) of device (12) are situated substantially perpendicular to said second conduit (4). Further as shown in FIGS. 6A-6C, inlets (5) of said second conduit (4) are perpendicular to first conduit (1). As shown in FIGS. 6A and 6C, at least a portion of chamber (7) comprises a frustoconical shape. As shown in FIG. 6B, the second conduit (4) is perpendicular to, but offset from first conduit (1). As shown in FIGS. 6B and 6C, the axial center lines of first conduit (1) and an inlet (5) are perpendicular to each other but do not intersect. In such embodiments, the offset of first conduit (1) causes a flow pattern within the device wherein the center line of flow incoming through inlet (5) does not intersect with the center line of flow incoming through inlet (2).
In the embodiment of device (12) shown in FIG. 7, conduit (1) is coaxial with chamber (7) and outlet (18). In other embodiments, the center axis of flow through conduit (1) is offset from the center axis of flow through chamber (7) and outlet (18).
In some embodiments of device (12) as shown in FIGS. 1-7, the first conduit (1) has a head portion (10) that does not traverse said second conduit (4) and a portion that traverses said second conduit (4). During use of the device (12), first conduit (1) is in fluid communication with chamber (7). Outlets (3) of said first conduit (1) are proximal to inlet (17) of chamber (7). In some such embodiments, outlets (3) of said first conduit (1) are contiguous to inlet (17) of chamber (7). In other such embodiments, outlets (3) of said first conduit (1) or lie within inlet (17) of chamber (7). In still other such embodiments, outlets (3) of said first conduit (1) or lie within chamber (7).
The inversion device characterized by the absence of mixing elements provides reduced shear on the latex being diluted within the device when compared to conventional dynamic or even static mixers. Since the polymers employed in EOR applications are desirably very high molecular weight materials and they are susceptible to shearing forces that can lead to substantial amounts of polymer chain scission. Substantial chain scission leads to a loss in observed viscosity of the resulting diluted polymer solution, forcing the user to employ higher concentrations of the latex feed in the dilution to achieve the targeted polymer solution viscosity. Thus it is highly advantageous to avoid shearing the polymers during dilution. By substantially reducing the shear force applied to the polymers during the dilution, as compared to use of conventional static and dynamic mixers, the inversion devices achieve greater efficiency during inversion: that is, a selected polymer solution concentration achieves a greater viscosity when subjected to less shear.
The inversion devices of the present invention are formed from materials suitable for handling materials used in EOR applications, including those carried out using high temperature and/or high total dissolved solids water sources, water soluble polymers, polymer solutions, polymer concentrates, w/o lattices, and chemicals such as scale inhibitors, biocides, foam inhibitors, surfactants, and the like that are known to those of skill in EOR operations. Suitable materials include those recognized by one of skill as useful to manufacture the inversion devices or various components thereof, further wherein the materials possessing physical characteristics suitable for exposure to the materials, pressures, and temperatures selected by the user. Examples of such materials include stainless steel, high nickel steel alloys, ceramics, thermoplastic or thermoset polymers, or polymer composites including particles, fibers, woven or nonwoven fabrics, and the like.
The inversion devices are designed and adapted to provide a pressure differential (or pressure drop) of about 2 psi to 150 psi between at least one inlet of the inversion device, and the outlet where the dilute latex exits the inversion device. Thus, for example, the minimum pressure differential is about 2 psi to 150 psi, or about 2 psi to 125 psi, or about 2 psi to 100 psi, or about 2 psi to 75 psi, or about 2 psi to 50 psi, or about 2 psi to 40 psi, or about 2 psi to 30 psi, or about 2 psi to 20 psi, or about 2 psi to 15 psi, or about 5 psi to 150 psi, or about 10 psi to 150 psi, or about 5 psi to 100 psi, or about 5 psi to 50 psi, or about 5 psi to 30 psi, or about 5 psi to 20 psi, or about 10 psi to 100 psi, or about 10 psi to 50 psi, or about 10 psi to 30 psi between the inlets and outlets of the inversion device, that is, between the points of entry of materials and exit of the dilute latex from the inversion device. The pressure within the inversion device is limited in some embodiments solely to avoid the mechanical degradation of the polymers present within the devices during inversion. However, it is a feature of the methods and devices of the invention that low pressure drop, for example as low as 2 psi pressure differential, is sufficient to provide rapid and complete inversion of lattices including 10 wt % to 80 wt % polymer to result in polymer solutions including 1 wt % or less polymer.
In some embodiments, the inversion devices are designed and adapted to invert w/o lattices comprising about 10 wt % to 80 wt % of one or more water soluble polymers having a weight-average molecular weight of about 1,000,000 to 100,000,000 g/mole to result in polymer solutions having less than about 20% loss of polymer average molecular weight based on the starting latex, by employing a single step inversion using the inversion devices of the invention. In embodiments, the weight average molecular weight of the water soluble polymer is about 1,000,000 g/mol to 100,000,000 g/mol, or about 2,000,000 to 100,000,000 g/mole, or about 3,000,000 to 100,000,000 g/mole, or about 5,000,000 to 100,000,000 g/mole, or about 7,000,000 to 100,000,000 g/mole, or about 1,000,000 to 80,000,000 g/mole, or about 1,000,000 to 60,000,000 g/mole, or about 5,000,000 to 90,000,000 g/mole, or about 5,000,000 to 80,000,000 g/mole, or about 5,000,000 to 70,000,000 g/mole, or about 5,000,000 to 60,000,000 g/mole, or about 5,000,000 to 50,000,000 g/mole, or about 5,000,000 to 40,000,000 g/mole or about 5,000,000 to 30,000,000 g/mole, or about 5,000,000 to 20,000,000 g/mole, or about 5,000,000 to 15,000,000 g/mole, or about 5,000,000 to 10,000,000 g/mole. In some embodiments, the loss of polymer average molecular weight of the polymer solution based on the polymer average molecular weight of the starting latex is 0% to about 20%, or about 2% to 20%, or about 4% to 20%, or about 6% to 20%, or about 8% to 20%, or about 10% to 20%, or 0% to about 18%, or 0 to about 16%, or 0 to about 14%, or 0 to about 12%, or 0 to about 10%, or about 5% to 15%, or about 5% to 10% loss of polymer average molecular weight based on the starting latex.
In some embodiments, the inversion devices are designed and adapted to invert w/o lattices comprising about 10 wt % to 80 wt % of one or more water soluble polymers having a weight-average molecular weight of about 1,000,000 to 100,000,000 g/mole to result in polymer solutions having less than about 20% loss of polymer average solution viscosity based on the theoretical polymer solution viscosity (that is, the expected solution viscosity for the polymer when fully inverted and hydrated in the absence of substantial shear), for example 0% to about 20%, or about 2% to 20%, or about 4% to 20%, or about 6% to 20%, or about 8% to 20%, or about 10% to 20%, or 0% to about 18%, or 0 to about 16%, or 0 to about 14%, or 0 to about 12%, or 0 to about 10%, or about 5% to 15%, or about 5% to 10% loss of polymer average solution viscosity based on the theoretical polymer solution viscosity.
The inversion devices are further characterized in that their use within the inversion systems of the invention results in inversion time of about 5 minutes or less, for example about 1 to 5 minutes, or about 2 to 5 minutes, or about 3 to 5 minutes, or about 4 to 5 minutes, or about 1 to 4 minutes, or about 1 to 3 minutes, or about 1 to 2 minutes. The inversion time is defined as the time between contact of the water source with the w/o latex, and formation of a dilute latex—that is, where the water source and the latex are fully mixed. In some embodiments, the inversion time is the residence time of the mixing components within the inversion device of the invention; that is, a water source and a w/o latex are applied to the inversion device and a dilute latex exits the device. In other embodiments, the dilute latex forms after exiting the inversion device. The inversion devices are characterized in that their use within the inversion systems of the invention results in formation of dilute lattices in a single step. The dilute lattices are formed in 5 minutes or less. The dilute lattices are polymer solutions, or subsequently become polymer solutions within about 180 minutes of formation of the dilute latex and without carrying out any further mixing operations other than the mixing that occurs during transport in a pipe, for example an injection pipe.
The polymer solutions are characterized by the lack of observable coagulation, precipitation, or gross phase separation of the polymer from the water source. The polymer solutions are further characterized by a Filter Ratio (FR) of 1.5 or less when measured using industry standard methods of filtration of a polymer solution or dilute latex having 1000 ppm polymer through a filter having a 5 μm pore size, for example about 1.0 to 1.5, 1.0 to 1.4, or about 1.0 to 1.3, or about 1.0 to 1.2, or about 1.0 to 1.1, or about 1.0 when measured using industry standard methods of filtration of a polymer solution or dilute latex having 1000 ppm polymer through a filter having a 5 μm pore size.
The inversion device is characterized by the absence of mixing elements, further as shown in FIGS. 1-7, the length of the first conduit of the inversion device is adjusted to minimize the inversion time. The spacing between introduction of the latex and the water source within the inversion device is suitably adjusted by adjusting the relative lengths of the first and second conduits. Optimal spacing is achieved depending on the rate of feed of the water source and the latex, overall dimensions of the system and overall dimensions of the inversion device relative to the rate of flow. In some embodiments, the first conduit includes a single outlet. In some such embodiments, the single outlet is positioned to direct the latex flow in a substantially linear fashion through the first conduit and through the outlet of the first conduit. In some such embodiments, the first conduit provides for injection of the latex directly into the chamber inlets of the inversion device or even directly into the chamber.
The relative sizes of the various features of the inversion devices characterized by the absence of mixing elements—such as conduit lengths, conduit inner diameters, inlet and outlet sizes, and the like—are adjusted to provide proper flow and pressure drop within the device. An exemplary inversion device is shown in FIG. 7, which is similar to the device of FIG. 6A wherein letter labels A to I correspond to the following exemplary, non-limiting measurements and flow rates useful in diluting a latex having about 10 wt % to 80 wt % polymer content to form a dilute latex having 10,000 ppm (1 wt %) polymer content, further accounting for rates of water source flow commonly encountered by those practicing the art of tertiary oil recovery by diluting a w/o latex with a water source.
All parameters and flow rates are approximate and can vary ±20% for each parameter or flow rate depending on the selection by one of skill. The recited parameters are scalable at scale factors of about 0.25 to 10, or 1 to 5. In some embodiments, the flow rate of the water source is about 3 m3/hr to 5000 m3/hr and the flow rate of the latex source is about 0.1 m3/hr to 500 m3/hr.
The inversion devices are characterized in that their use within the inversion systems of the invention results in formation of dilute lattices in a single step. The dilute lattices are formed in 5 minutes or less. The dilute lattices are polymer solutions, or subsequently become polymer solutions within about 180 minutes of formation of the dilute latex without carrying out any further mixing operations. The polymer solutions are characterized by the lack of observable coagulation, precipitation, or gross phase separation of the polymer from the water source. The polymer solutions are further characterized by a Filter Ratio (FR) of about 1.5 or less when measured using industry standard methods of filtration of a polymer solution or dilute latex having 1000 ppm polymer through a filter having a 5 μm pore size.
The inversion systems of the invention comprise at least one inversion device as described above. In some embodiments, the inversion system is characterized as having a single inversion device and no additional mixing devices. In other embodiments, the inversion system further comprises one or more mixing devices situated downstream from the inversion device, wherein the one or more mixing devices are selected from static mixers and pumps. In all such embodiments, the inversion device is situated in fluid communication with a water source. In some embodiments, the inversion device is disposed in-line with a water source such that the entire flow of the water source passes through the inversion device. In all such embodiments, the inversion device is situated in fluid communication with a latex source.
The inversion systems of the invention include an inversion device, a latex source fluidly connected to the first conduit of the inversion device, a water source fluidly connected to the second conduit of the inversion device, and a pipeline connected to the outlet of the inversion device and situated to receive a dilute latex and/or a polymer solution for use in one or more EOR applications.
The inversion devices are advantageously used in one or more methods of the invention to dilute, or “make down” conventional w/o lattices for EOR in a single dilution step. No additional mixing or diluting is required. In conventional dilution methods, the tradeoff of high shear mixing, leading to loss of viscosity, for loss of mixing efficiency is well understood by those of skill. However, by employing inversion devices characterized as providing low shear, such as static mixers or mixing pumps, or by employing devices characterized by the absence of mixing elements, we have realized sufficiently high mixing efficiency to achieve dilution of conventional w/o lattices in a single dilution step to reach a polymer concentration of about 10,000 ppm or less. The molecular weight of the diluted polymer is reduced by 20% or less, compared to the expected molecular weight of the polymer in the absence of shear. The viscosity of the polymer solution is reduced by 20% or less, as a relative measure of molecular weight after inversion compared to the expected viscosity of a polymer solution of the same concentration of polymer formed in the absence of shear. The dilution takes about 5 minutes or less. Optionally, after dilution, a dilute latex is subjected to one or more pumping or static mixing steps to accelerate formation of the polymer solution.
The inversion devices and systems of the invention provide a method of diluting one or more w/o lattices into a process stream, the process stream comprising a water source. As shown in FIGS. 8-9, an inversion system (100) includes inversion device (12), adaptor (8), alone or as part of an apparatus for feeding, attached to an opening (16) in a pipeline (9) wherein the adaptor (8) is secured to the pipeline (9) by any means that would be appreciated by one of ordinary skill in the art. After this setup is established, one or more w/o lattices and a water source are introduced into the inversion device (12), mixed in the chamber (7), and fed into the pipeline (9). In some embodiments the water source is diverted from the pipeline (9) at a point upstream from adaptor (8). In some embodiments, pipeline (9) contents comprise, consist essentially of, or consist of produced water or sea water resulting from one or more subterranean hydrocarbon recovery processes.
One will recognize many vehicles suitable for introducing w/o latex sources and water sources into the inversion device; such vehicles include tanks, pressure sources, pumps, valves, regulators, pipes, measuring devices, and computerized process measurement and control means. Such conventional chemical metering and fluid control equipment is suitably optimized for use in the inversion systems of the invention.
In some embodiments, the inversion systems of the invention further include one or more mixing devices situated downstream in the flow toward the subterranean reservoir from the inversion device. For example, in some embodiments, the mixing device is a static mixer, a pump, or a combination of two or more of either of these. In an advantageous embodiment, the inversion device is a static mixers similar to or such as those sold by Sulzer Ltd. of Winterthur. Switzerland under the trade names SMX and SMV and described in document EP 1437173, incorporated by reference in its entirety herein. Other static mixers suitably employed in the inversion systems include those sold by Koflo Corporation of Cary, Ill. Preferably, the static mixers contain at least 10 mixing elements, for example about Useful static mixers employed in the inversion systems of the invention comprise at least about 5 static mixer elements; for example about 5 to 100 static mixer elements, for example about 5 to 90, or about 5 to 80, or about 5 to 70, or about 5 to 60, or about 5 to 50, or about 5 to 40, or about 5 to 30, or about 5 to 20, or about 7 to 100, or about 10 to 100, or about 12 to 100, or about 14 to 100, or about 16 to 100, or about 18 to 100, or about 20 to 100, or about 22 to 100, or about 24 to 100, or about 26 to 100, or about 28 to 100, or about 10 to 50 static mixer elements.
In some embodiments, the inversion systems of the invention further include one or more pumping devices situated downstream in the flow toward the subterranean reservoir from the inversion device. Pumping devices useful in conjunction with the present inversion systems include centrifugal pumps and positive displacement pumps.
One of skill will appreciate that the dimensions of the one or more inversion devices are suitably optimized to provide a rate of throughput and a pressure differential according to the previously discussed parameters by applying conventional engineering principles.
Optionally, in some embodiments a first inversion device is situated in line with a bypass flow and a second inversion device is situated in line with the main water source flow. Optionally, a first and second inversion device are situated in line with the main water source flow.
In an exemplary embodiment, FIG. 8 shows inversion system (100) including inversion device (12), characterized by the absence of mixing elements and disposed in-line with one or more water sources (13) flowing through a pipeline (9) toward one or more subterranean reservoirs. Water source (13) is introduced into inversion device (12) via inlet (15). A latex source (20) is introduced into inlet (2) of conduit (1). The water source (13) and latex source (20) are mixed in chamber (7) to form a dilute latex, which is dispensed via outlet (18) into pipeline (9′). The dilute latex forms a polymer solution between chamber (7) and the subterranean reservoir, about 0.1 second to 150 minutes after entering chamber (7).
In another exemplary embodiment, FIG. 9 shows another inversion system (101) wherein bypass flow (15) is taken from water source (13) flowing through pipeline (9) at a point (9′) upstream from inversion device (12). Bypass flow (15) is introduced into conduit (4) via inlet (5). A latex source (20) is introduced via pipeline (19) into inlet (2) of conduit (1). Water source (13) and latex source (20) are mixed in chamber (7) to form a dilute latex, which is dispensed via outlet (18) into pipeline (9′). The dilute latex combines with water source (13) to form combined flow (13′). Combined flow (13′) forms a polymer solution between outlet (18) and the subterranean reservoir, about 0.1 second to 150 minutes after entering chamber (7). In such embodiments, the dilution of the w/o latex is partially carried out within the inversion device, such that the polymer solids content of the dilute latex is about 1 wt % or less; additional dilution is then completed as the bypass flow joins the main water source flow.
In either of the embodiments shown in FIGS. 8-9, it is a feature of the invention that inversion systems of the invention comprise a single inversion device. Only one inversion device is required in the inversion systems of the invention in order to transform a w/o latex to a dilute latex that becomes a polymer solution without further mixing or dilution steps. However, optionally one or more static mixers, pumps, or both are employed in-line and downstream from the inversion device. Such mixers and pumps include mixing elements and are employed to facilitate improved mixing of the dilute latex or polymer solution components. However, no additional dilution is carried out after formation of the dilute latex; that is, two or more separate additions of a water source to the w/o lattices or dilute lattices are not required when employing the inversion systems of the invention.
As shown in FIGS. 8-9, the co-feeding of different liquid compositions into a process stream (13) can be achieved by the following steps: introducing several different compositions into the inversion device (12), allowing a mixture of the different compositions to form, and dispensing the mixture into a process stream (13). Compositions including the w/o lattices are added to the system in any order prescribed by a person of ordinary skill in the art. For example, the w/o lattices, the water source, and one or more additives suitably added to a latex, dilute latex, or polymer solution, such as stabilizers, surfactants, and the like maybe added sequentially, simultaneously or in pre-programmed order and blended in a single step.
In some embodiments the activity of the sources fed into inversion device (12) is controlled by adjusting the flow rate of the sources introduced into the device, adjusting the internal dimensions of the inversion device (12), or both. One or more pumps that are in communication with the inversion device may be suitably employed to adjust the flow rates. Staged mixing can be achieved in chamber (7) by controlling flow rates of sources fed into the chamber. In yet another embodiment, the rate of mixing of the latex and the water source prior to their introduction into said process stream is controlled by adjusting the flow rate of said latex and water source, which are introduced into the mixing chamber.
The inversion systems of the invention include various additional elements and devices, without limitation, to regulate, support, and augment mixing of the water source with a w/o latex. These additional devices include, for example, tanks, sensors, flow regulators, pressure gauges, injection ports, sampling ports, and the like; they are connected within the inversion system via pipes, valves, wires, connectors, and the like commonly employed in the industry, as will be appreciated by one of skill. The one or more additional elements and devices do not substantially modify the ability of the inversion device to accomplish the mixing necessary to form a polymer solution, but instead are positioned within the inversion system to provide or regulate or measure one or more materials or values such as water source flow rate, temperature, the rate of addition of the w/o latex to the inversion device, and the like.
Examples of suitable additional devices include a screen, such as a filter basket or a Y-strainer basket situated upstream from the inversion device; one or more quill type injectors incorporated within or disposed upstream from the inversion device for introducing fluids into the water source; and one or more additional devices or device elements used to provide further mixing, to develop a pressure drop, or both. Such additional devices include multiple orifice series or arrays, in-line diffusers, pipeline mixers, valves, nozzles, orifice plates, tee mixers, jet mixers, static plate mixers, inline vortex mixers, rotor stator mixers, and pipeline mechanical mixers.
One will appreciate that the dimensions and particular arrangement of the inversion device in the inversion system, and the rate of addition of the latex source to the inversion device are selected and optimized by one of skill based on conditions encountered in the individual subterranean reservoir, including water source flow rate and available infrastructure for the inversion system.
Described herein is a method of inverting a water-in-oil latex, the method comprising: (a) applying a water-in-oil latex source to an inversion device, the latex comprising about 10 wt % to 80 wt % of a water soluble polymer and about 2 wt % to 5 wt % of a surfactant having an HLB of 14 or greater, (c) applying a water source to the inversion device, (d) contacting the latex with the water source within the inversion device to form a dilute polymer latex; and (e) dispensing the dilute latex from the inversion device, the dilute polymer latex or polymer solution comprising about 10,000 ppm or less of the water soluble polymer.
The invertible lattices useful in conjunction with the present invention are characterized in some embodiments as a conventional water-in-oil (w/o) latex that further includes an inversion surfactant. Conventional w/o lattices are formed by dissolving monomer(s) including acrylamide in a high-solids aqueous solution to form a water phase, mixing a hydrocarbon solvent and a surfactant having an HLB of about 2 to 8 to form an oil phase, mixing the two phases using techniques that result in a water-in-oil emulsion or latex, and polymerizing the monomer via a free-radical azo or redox mechanisms to result in a water soluble polymer. After polymerization is complete, a higher HLB surfactant (HLB>8) is often added as a destabilizer to facilitate latex inversion when water is added. We have found that by employing about 2 wt % to 5 wt % of an inversion surfactant having an HLB of greater than 14, single step inversion using the devices and systems described herein is possible. Thus, “invertible lattices” described herein are defined as conventional w/o lattices comprising about 10 wt % to 80 wt % of a water soluble polymer and about 2 wt % to 5 wt % of a surfactant having an HLB of about 14 or greater.
Single step inversion of the invertible lattices is advantageously carried out using using any of the water sources available in the field for EOR applications. By “single step” it is meant that after an invertible latex and a water source are applied to an inversion device disposed within an inversion system of the invention to form a dilute latex, no subsequent addition of water sources or mixing force is required in order for the dilute latex to form a polymer solution. In some embodiments, additional mixing of the dilute latex occurs within the fluid flow in one or more pipes or tubes that are part of the inversion system of the invention; however, for the purposes of this disclosure such fluid flow is already present within the inversion system and thus is not added. It is an advantage of the methods of the invention that even high temperature water sources, high total dissolved water sources, and high temperature/high total dissolved water sources are easily applied to an inversion device together with an invertible latex to provide a single step inversion that results in a polymer solution having 10,000 ppm or less of polymer solids and a Filter Ratio (FR) of about 1.5 or less when measured using industry standard methods of filtration of a polymer solution or dilute latex having 1000 ppm polymer through a filter having a 5 μm pore size.
Inversion surfactants useful in the w/o lattices comprise, consist essentially of, or consist of surfactants or blends thereof having an HLB of about 14 to 30. In some embodiments, the inversion surfactant is nonionic and includes one or more compounds comprising one or more ethoxy groups, propoxy groups, or a combination thereof. In some embodiments, the inversion surfactant is ionic and includes one or more carboxylate, sulfonate, phosphate, phosphonate, or ammonium moieties. In some embodiments, the inversion surfactant includes a linear or branched C.sub.8-C.sub.20 hydrocarbyl moiety. In some such embodiments, the inversion surfactant is an alkoxylated alcohol such as an ethoxylated, propoxylated, or ethoxylated/propoxylated alcohol, wherein the alcohol includes a linear or branched C.sub.8-C.sub.20 hydrocarbyl moiety. In some such embodiments, the inversion surfactant includes about 10 and 40 ethylene oxide repeat units and 0 to about 10 propylene oxide repeat units. In some embodiments, the inversion surfactant includes a sorbitan moiety. In some embodiments, the inversion surfactant is a block copolymer. In some such embodiments, the block copolymer is linear, branched, or hyperbranched.
In some embodiments, the dispensing is about 5 minutes or less after the introducing. In some embodiments, the water source is a high temperature water source, a high total dissolved solids water source, or a high temperature/high total dissolved solids water source. In some embodiments, the methods further comprise mixing the dilute latex or a polymer solution after the dispensing, the mixing comprising static mixing or pumping.
The inversion device is employed in an inversion system of the invention to form a dilute latex from an invertible latex using the methods of the invention. The dilute latex forms a polymer solution after a hydration period. In embodiments, the hydration period is concurrent with and extends to a point in time after the dilution. The hydration period ends when the polymer achieves full hydrodynamic volume within the diluted aqueous environment. Thus, the end of the hydration period is manifested as maximum solution viscosity of the polymer in the dilute aqueous environment. In some such embodiments, the dilute latex becomes a polymer solution prior to the time it exits the inversion device. In other embodiments, the dilute latex flows from inversion device and subsequently forms a polymer solution. In such embodiments, the hydration period is about 0.1 seconds (s) to 180 minutes (min) after contact of the latex with the water source.
Employing the inversion methods of the invention, an invertible latex is inverted to form a dilute latex that results in a polymer solution having less than about 10,000 ppm polymer solids based on the weight of the polymer solution, for example about 100 ppm to 10,000 ppm, or about 300 ppm to 10,000 ppm, or about 500 ppm to 10,000 ppm, or about 1000 ppm to 10,000 ppm, or about 2000 ppm to 10,000 ppm, or about 3000 ppm to 10,000 ppm, or about 4000 ppm to 10,000 ppm, or about 5000 ppm to 10,000 ppm, or about 100 ppm to 9000 ppm, or about 100 ppm to 8000 ppm, or about 100 ppm to 7000 ppm, or about 100 ppm to 6000 ppm, or about 100 ppm to 5000 ppm, or about 100 ppm to 4000 ppm, or about 100 ppm to 3000 ppm, or about 100 ppm to 2000 ppm, or about 100 ppm to 1000 ppm, or about 500 ppm to 7000 ppm, or about 300 ppm to 3000 ppm, or about 200 ppm to 2000 ppm, or about 200 ppm to 3000 ppm polymer solids based on the weight of the polymer solution. In some embodiments, the w/o latex is an invertible latex.
In embodiments, the time between the contact of the water source with the invertible latex and formation of a dilute latex is about 5 minutes (min) or less, for example about 5 seconds (s) to 5 min, or about 30 s to 5 min, or about 1 min to 5 min, or about 3 min to 5 min, or about 5 s to 4 min, or about 5 s to 3 min, or about 5 s to 2 min, or about 5 s to 1 min.
In some embodiments, the method comprises, consists essentially of, or consists of a single inversion (dilution) step employing an inversion system of the invention, wherein the inversion system includes a single inversion device. In some such embodiments, the invertible lattices employed in conjunction with the methods of the invention comprise about 10 wt % to 80 wt % of a water soluble polymer and about 2 wt % to 5 wt % of a surfactant having an HLB of about 14 or greater.
In some embodiments, a hydration period within an the injection line after formation of the dilute latex provides sufficient time to allow the dilute latex to form a polymer solution that achieves adequate injectivity
In some embodiments, the flow rate of the liquid within the inversion systems of the invention are between 3 m3/h and 5000 m3/h and the injection pressure is between 40 and 200 bars. Injection pressure is governed by the field pressure. Similarly, the latex flow rate into the inversion device is between 0.1 m3/h and 500 m3/h, according to the type of borehole (vertical, horizontal, multiple, etc).
For one example 14, the dilute latex was collected immediately after the inversion device and the 1 to 3 dilution was performed with a residence time of less than 30 seconds. For another example 15, the dilute latex was collected after passing through an additional four feet of 4″ static mixer and 150 feet of 2″ diameter hose. The 1 to 3 dilution was performed with a residence time of about 60 seconds.
Accordingly, it would have been obvious to one skilled in the art before the effective filing date of the invention to have provided the method of HOCH et al. with the underlined features above as taught by LOGAN et al for the purposes of providing methods used for enhanced oil recovery applications wherein w/o latex inversion is carried out under conditions of restricted space and/or equipment weight allowances; to provide methods for accomplishing w/o latex inversion in a single step; for inversion equipment capable of enabling continuous inversion and hydration, in a total time of 180 minutes or less; to accomplish a single-step inversion process under harsh conditions such as use of water sources having high temperature, high total dissolved solids, or both; with the methods achieved via inversion systems that include an in-line or bypass-mounted inversion device that is designed and adapted to provide a pressure differential (or pressure drop) of at about 2 psi to 150 psi between the inlet and outlet of the device wherein the inversion device is a static mixer or mixing pump or the inversion devices can be characterized by the absence of mixing elements such as blades, vanes, paddles and the like, such as those required for operability of conventional dynamic or static mixers whereby the methods are accomplished via at least one inversion device that includes a single inversion device and no further mixing devices or the inversion system comprises a single inversion device characterized by the absence of mixing elements and one or more additional mixing devices selected from static mixers and pumps.
Claims 3-7 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over HOCH et al. in view of KUROSAWA (US 7448793 B2).
Assuming, arguendo, that HOCH et al. does not teach or suggest the subject matter of claims 3-7 and 9, the patent to WALDRON et al. that discloses a mixing device and methods for manufacturing an aqueous fuel, and more particularly to a specially designed mixing device that creates a superior aqueous fuel emulsion from a hydrocarbon fuel, water, and an aqueous fuel emulsifier package.
In the case of an oil-phased emulsion, the emulsifier supply would be first mixed with the hydrocarbon source before it is mixed with the discontinuous phase of water. Conversely, in a water-phased emulsion the emulsifier supply would be first mixed with the water source (or portions thereof) before it is mixed with the discontinuous phase of hydrocarbon fuel (or portions thereof). In the case where portions are premixed, the balance is introduced at a subsequent point as the aqueous fuel emulsion is manufactured.
While there can be several mixing stations during the emulsification process, a high-shear mixing stage is usually required when a water source is mixed with a hydrocarbon fuel source. Prior to the high-shear mixing, the various stages can be mixed with less intense mixing devices, such as in-line mixers or other common liquid agitators, because the chemicals being mixed have relatively compatible chemical properties. Because of the very different chemical properties of water and oil, significant amounts of mechanical energy are required to reduce the discontinuous phase to sizes where they can contribute to a stable aqueous fuel emulsion.
A mixing unit in incorporated into a blending system and method for producing aqueous fuel emulsions with consistently uniform dispersed phase particle sizes with a relatively inexpensive mixing device. A mixing device creates an aqueous fuel emulsion from a source of hydrocarbon fuel, a source of water, and a source of said aqueous fuel emulsifier package by incorporating a small area high velocity-mixing device that produces the appropriate mixing environment for the individual compounds to make an aqueous fuel with relatively homogenous particle sizes of the discontinuous phase. A mixing apparatus is disclosed. The mixing apparatus comprises a mixing device having a constant flow area. The mixing device is configured to create a shearing environment.
The mixing apparatus comprises a disc body having a first face and a second face opposite the first face. The disc body has a disc wall disposed between the first face and the second face. The mixing apparatus also comprises at least one flow passage extending through the disc body from the first face to the second face. The at least one flow passage has a constant flow area. The disc body is configured to shear a fluid flowing through the at least one flow passage.
A method of producing aqueous fuel emulsions with consistently uniform dispersed phase particle sizes using a mixing apparatus is also disclosed. The method comprises disposing aqueous fuel emulsion producing liquids into a mixing device. The mixing device is as above. The method also comprises flowing the aqueous fuel emulsion-producing liquids through a constant flow area of the mixing device.
FIG. 4 illustrates a schematic representation of a manufacturing system 10 for an emulsion. In the preferred embodiment, the manufacturing system operates at ambient conditions. The manufacturing system 10 comprises a series of inlets for the raw materials. For illustration purposes, inlet 12 provides a hydrocarbon fuel inlet 14 provides an emulsifier package, and inlet 16 provides a source of water and can be connected to the specially designed mixing device 32 at an appropriate place. Inlets 12 and 14 provide a hydrocarbon fuel and an emulsifier package, respectively, to a fuel pump 18 disposed at the intersection of inlets 12 and 14 with lead 24. The fuel pump 18 transfers the hydrocarbon fuel and the emulsifier package to a mixing station pump 22 at a selected flow rate [the pumps being fluid pressurization devices]. The hydrocarbon and emulsifier package would flow at a rate of about 0.87 gallons per minute (gpm) in an emulsifying system with a capacity of about 1 gpm. A flow measurement device 30 is adapted to control [meter] the flow of the hydrocarbon fuel and emulsifier package mixture directed from the mixing station pump 22 to the mixing device 32.
Inlet 16 provides a source of water to a water pump 20 through lead 26. The water pump 20 [fluid pressurization device] directs the source of water through a flow measurement device 28. The flow of water is then transferred to the specially designed mixing device 32 at a selected flow rate. The water would flow at a rate of about 0.13 gpm in an emulsifying system with a capacity of about 1 gpm.
After flowing through the flow measurement devices, leads 24 and 26 direct the materials to the specially designed mixing device 32. The materials may be transferred using existing pumps (as illustrated), using additional pumps (not shown), by gravity, or by other methods known in the art.
Following creation of the emulsion, the emulsion can be used immediately after manufacture or directed through a lead 34 to a holding tank 36 for future use.
The above-described blending system is particularly suited for preparing a water blend fuel or aqueous fuel emulsion. Specifically, fuels such as hydrocarbon petroleum fuels, blends of hydrocarbon petroleum fuels, blends of hydrocarbon fuels with derivatives of bio mass, derivatives of bio-mass, and other forms of calorific bearing liquids. The preferred volumetric ratio of calorific bearing liquid to water is about 50% to about 99% of the total volume of the aqueous fuel emulsion. The volumetric ratio of additives is less than about 1% to about 5% of the total volume of the hydrocarbon fuel. The fuel emulsion additives used in the above description can be the following ingredients (or combinations thereof) including surfactants, emulsifiers, detergents, defoamers, lubricants, corrosion inhibitors, anti-freeze inhibitors such as alcohol, and the like.
The mixing device 32 relies on a shearing environment where the amount of mixing energy is about equal at the beginning, middle and end of the mixing geometry. By extending the amount of area in contact with the ingredients, the process has effectively increased the shear force. With no moving parts this consistent mixing rate is ensured so long as the flow rates are maintained constant. It is understood that the velocity profile or shear forces could easily be increased or decreased based on the desired volume output of the aqueous fuel blending system. Similarly, the shear forces could be changed by using any of a range of different environments which provide a consistent environment for mixing such as narrowing the space between the two surfaces or bending the path of flow.
A method for manufacturing an aqueous fuel emulsion is also disclosed. The method comprises blending a flow of a liquid hydrocarbon fuel with a flow of an emulsifier package and a flow of water to form a first mixture. Next, the method comprises directing the first mixture into a mixing vessel and mixing the first mixture to form the aqueous fuel emulsion. The mixing vessel incorporates the specially designed mixing device, which relies on a shearing environment where the amount of mixing energy as defined in the shear rate is about equal at the beginning, middle and end of the mixing process.
FIGS. 6 and 7 illustrate a schematic representation of another exemplary mixing device 32. In the preferred embodiment, the mixing device 32 is a plastic or metal device. The mixing device 32 is preferably a metal material that is chemically inert with respect to (i.e., will not corrode when exposed to) to the liquids encountered when utilizing the mixing device 32. The mixing device 32 preferably operates at ambient conditions. The mixing device 32 illustrated in FIGS. 6 and 7 is composed structurally of a disc body 62 having a first face 64 and a second face 66. Between the first face 64 and the second face 66 is a disc wall 68. The disc body 62 has several flow passages 70 extending through the disc body 62 from the first face 64 to the second face 66 along a substantially straight line. The flow passages 70 have a constant flow area and provide a substantially straight flow path through the disc body 62. As can clearly be seen from an examination of FIGS. 6-7, the flow path is free from structure that would provide an impact surface for the mixture of aqueous fuel emulsion-producing liquids.
The size of the disc body 62 and flow passages 70, and the number of flow passages is dependent upon the flow rate of the liquids to be processed in the disc body 62. For example, at a flow rate of 10 gpm, the disc body 62 can have 110 flow passages 70 having a diameter of about 0.03 inches. The disc body 62 can be about 1 inch thick. The size of the disc body 62 can be extended by making the disc body 62 thicker or by utilizing several disc bodies stacked upon one another, their flow passages aligned with one another.
Referring now to FIG. 8, an embodiment of the invention is illustrated wherein the mixing body 32 is make thicker by stacking two disc bodies together. In the embodiment shown in FIG. 8, disc bodies 62a and 62b are stacked together, first face 64b of disc body 62b is shown abutting second face 66a of disc body 62a. Flow passages 70a in disc body 62a are aligned with flow passages 70b in disc body 62b.
Referring to FIG. 6, the mixing device 32 relies on a shearing environment where the amount of mixing energy as defined in the shear rate is about equal at the beginning (gap 54), middle and end (or the gap 56) of the mixing process. By extending the length of time the ingredients are exposed to a consistent mixing environment, the process has effectively increased the shear force. With no moving parts, this consistent mixing rate is ensured so long as the flow rates are maintained constant.
It is understood that the velocity profile or shear forces could easily be increased or decreased based on the desired volume output of the aqueous fuel blending system. Similarly, the shear forces could be changed by using any of a range of different environments that provide a consistent environment for mixing. For example, multiple tunnels could be introduced rather than a single tunnel. This could increase the capacity as well as the amount of mixing depending on various factors well known to those in the art. Alternatively, the straight tunnels could be bent or curved in a variety of ways to enhance the mixing energy.
The above-described apparatus can be used to create an aqueous fuel emulsions with consistently uniform dispersed phase particle sizes. Aqueous fuel emulsion producing liquids are disposed into the mixing device. The aqueous fuel emulsion-producing liquids are transported through a constant flow area of the mixing device. The flowing of the liquids through the mixing devices creates an aqueous fuel emulsion having consistently uniform dispersed phase particle sizes.
The mixing apparatus of the present invention is less expensive to manufacture and operate. The simplicity of the operation of the mixing apparatus is desirable because there are no moving parts that can result in costly failures of the apparatus. The resulting emulsion is a more cost-effective and stable fuel.
Accordingly, from the above, WALDRON et al. discloses a flow restrictor 32 (Figures 6-8) with a plurality of channels comprising a plurality of tubes 70, 70a, or 70b extending parallel to each other; wherein the plurality of tubes are contained within a housing 62 and are surrounded with a filler material disposed between 64, 66 and between 64a, 66b; wherein passing the pressurized dilute emulsion through the flow restrictor 32 comprises conveying the pressurized dilute emulsion from the fluid pressurization device though an upstream pipe 24 or 26 (Figure 4) having an open cross-sectional area to the flow restrictor, the flow restrictor defines an open cross-sectional area, and a ratio of the open cross-sectional area of the flow restrictor divided by the open cross- sectional area of the upstream pipe ranges from 0.01 to 0.3 - Figures 6-8; wherein a velocity of the pressurized dilute emulsion through the flow restrictor channels is at least 5 times greater than a velocity of the dilute emulsion entering the fluid pressurization device as desired (col. 6, lines 56-65); wherein the flow restrictor 32 defines at least one channel 70, 70a, or 70b having a length ranging from 0.1 mm to 1 meter and an inner diameter ranging from 5 micrometers to 5 millimeters (col. 8, lines 4-13); and wherein the flow restrictor 32 is devoid of mixing elements (Figures 6-8).
It would have been obvious to one skilled in the art before the effective filing date of the invention to have substituted the flow restrictor in HOCH et al. with the flow restrictor of WALDRON et al. for the purposes and advantages of employing a mixing unit [flow restrictor] into a blending system and into a method for producing aqueous fuel emulsions with consistently uniform dispersed phase particle sizes with a relatively inexpensive mixing device; whereby the mixing device [flow restrictor] creates an aqueous fuel emulsion from a source of hydrocarbon fuel, a source of water, and a source of said aqueous fuel emulsifier package by incorporating a small area high velocity-mixing device that produces the appropriate mixing environment for the individual compounds to make an aqueous fuel with relatively homogenous particle sizes of the discontinuous phase; to generate a method of producing aqueous fuel emulsions with consistently uniform dispersed phase particle sizes using a mixing apparatus [flow restrictor] via flowing the aqueous fuel emulsion-producing liquids through a constant flow area of the mixing device [flow restrictor] - col. 4, lines 52-64; col. 5, lines 28-35.
Furthermore, the prior art to HOCH et al. merely differs from the claimed device by the substitution of flow restrictors; the substituted components and their functions were known in the art as evidenced by HOCH et al. and WALDRON et al.; one of ordinary skill in the art could have readily substituted one known flow restrictor chosen from a finite list of flow restrictors for another, and the results of the substitution would have been predictable and obvious since the substitution of one known flow restrictor from the finite list of flow restrictors for another would have yielded predictable results to one of ordinary skill in the art at the time of the invention, i.e., the predictable result of achieving said advantages outlined above such as emulsions with consistently uniform dispersed phase particle sizes with a relatively inexpensive mixing device - KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007) and see MPEP 2143(B). Moreover, “[e]xpress suggestion to substitute one equivalent for another need not be present to render such substitution obvious." In re Fout, 675 F.2d 297, 213 USPQ 532 (CCPA 1982).
Allowable Subject Matter
No claims stand allowed.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
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/CHARLES COOLEY/
Examiner, Art Unit 1774
DATED: 20 FEB 2026