DETAILED ACTION
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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 01/02/26 has been entered.
Drawings
Replacement Fig. 2 was received on 12/01/25. These drawings are accepted.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 2 and 5-10 are rejected under 35 U.S.C. 103 as being unpatentable over Lafitte et al. (US 9,290,689 – cited previously) in view of Ogle et al. (US 2020/0283678 – cited previously).
With respect to independent claim 1, Lafitte et al. discloses a method for monitoring gas production in a subterranean formation (col. 1, l. 25-28) comprising:
introducing at least two polymer composite particles (col. 11, l. 56-col. 12, l. 2) each having a different (col. 10, l. 53-58, wherein the particles of the two subsets are disclosed to have different release profiles; see further explanation below) degradable polymer (col. 7, l. 55-col. 8, l. 30) and a tracer (col. 5, l. 47-col. 6, l. 60) into a stimulation fluid (col. 3, l. 59-61; col. 3, l. 66-col. 4, l. 3; col. 4, l. 4-5), wherein a first polymer composite particle comprises a first degradable polymer selected from the group as claimed (col. 8, l. 41-col. 9, l. 28) and wherein a second polymer composite particle comprises a second degradable polymer (col. 10, l. 53-58, wherein the particles of the two subsets are disclosed to have different release profiles; see further explanation below) that is an organic polymer which undergoes hydrolysis under reservoir conditions and includes block copolymers of polyamides (col. 9, l. 13-15), wherein the tracer has an average particle size (col. 6, l. 66-col. 7, l. 3; col. 11, l. 25-26);
injecting the stimulation fluid comprising the at least two polymer composite particles into the subterranean formation to a treatment stage of a treatment zone comprising at least one opening, wherein the at least two polymer composite particles flow into and remain inside the at least one opening (col. 3, l. 47-58; col. 3, l. 64-col. 4, l. 6; col. 10, l. 55-58);
maintaining the at least two polymer composite particles inside the at least one opening for an amount of time during which the at least two polymer composite particles are exposed to moisture at a downhole temperature, wherein the moisture degrades the degradable polymer (col. 8, l. 34- col. 9, l. 28; col. 20, l. 33-36) of the at least two polymer composite particles at different rates, thereby releasing the tracer at different times (col. 6, l. 66-col. 7, l. 3; col. 10, l. 55-58; col. 13, l. 60-col. 14, l. 25);
recovering produced gas from the subterranean formation, wherein the produced gas comprises a gaseous phase from the treatment stage of the treatment zone of the subterranean formation and the tracer (col. 19, l. 52-55; col. 20, l. 55-56);
determining a presence of the tracer in the produced gas (col. 19, l. 54-55; col. 20, l. 57-58); and
correlating the presence of the tracer to the treatment stage of the treatment zone of the subterranean formation (col. 19, l. 56-58; col. 20, l. 58-61).
Lafitte et al. discloses wherein the tracer may be of small particle size, possibly even of nanoparticle size (col. 7, l. 1-3). The reference further suggests wherein the overall polymer composite particles have first, second and third size ranges, including less than or equal to 10 microns for the first size which enters pores, followed by a size of between 10 and 150 microns for the particles that are retained by a filter cake and greater than 200 microns for the third particles which are retained by proppant (col. 5, l. 1-40). Although silent to the specific size of the tracer particles included within the overall composite particle, given the suggestion by Lafitte et al. to provide for such particles as having a small particle size with the possibility thereof as nanoparticle size, it would have been obvious to one having ordinary skill in the art to provide a tracer with a small particle size that is sized at a size less than the disclosed polymer composite sizes in Lafitte, i.e., less than 10 microns, between 10-150 microns and/or less than 200 microns, so as to allow for the encapsulation thereof within each of the first, second and third particle sets and thereby provide for a particle size within the range as claimed. One of ordinary skill in the art would recognize the optimal tracer particle size to provide for based on the suggestion of a small particle size used therefor by Lafitte, as well as the sizes suggested for the overall polymer composite particle so that the tracer particle can be effectively carried therewithin since it has been held "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). For more recent cases applying this principle, see Merck & Co. Inc. v. Biocraft Lab. Inc., 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir.), cert. denied, 493 U.S. 975 (1989); In re Kulling, 897 F.2d 1147, 14 USPQ2d 1056 (Fed. Cir. 1990); and In re Geisler, 116 F.3d 1465, 43 USPQ2d 1362 (Fed. Cir. 1997); Smith v. Nichols, 88 U.S. 112, 118-19 (1874) (a change in form, proportions, or degree "will not sustain a patent"); In re Williams, 36 F.2d 436, 438 (CCPA 1929) ("It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions."). See also KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007) (identifying "the need for caution in granting a patent based on the combination of elements found in the prior art."). Additionally, the Examiner notes, obviousness can be shown in a predictable art when a difference between the claimed ranges is virtually negligible absent any showing of unexpected results or criticality. In re Brandt, 886 F. 3d 1171, 1177, 126 USPQ2d 1079, 1082 (Fed. Cir. 2018). The instant specification fails to explicitly establish the instantly claimed tracer particle size range as critical and it is unclear if any unexpected results are achieved by providing for such. Since Lafitte et al. teaches wherein the tracer particles are solids and of a small particle size, potentially even nanoparticle size, as well as wherein the overall particles within which they are enclosed are less than 10 microns, between 10-150 microns and greater than 200 microns, it would appear sizes of the tracer particle less than and/or within such ranges would be apparent to one of ordinary skill so that the tracer particle is effectively encapsulated by the overall polymer composite particle for the delayed release thereof. Since such a delayed release of the tracer from the polymer composite is the intent of Applicant, it does not appear that such would be considered an unexpected result of providing for a tracer particle size as claimed, and, as such, the determination of optimal size therefor would be achievable through routine experimentation in the art.
Lafitte et al. suggests a variety of degradable polymers, including a polyester, polyester copolymer and polylactic acid copolymer (col. 8, l. 33-28), thereby providing for a first degradable polymer as claimed; the reference further suggests wherein when two subsets of particles go to the same location, they differ in the tracer substance contained there within, as well as in the release profile (col. 10, l. 53-58), thereby suggesting at least two polymer composite particles each having a different degradable polymer and tracer as claimed. Several examples are provided wherein it is clear that different polymers indeed have different release profiles over time (col. 13, l. 30-62, wherein the release profiles of PLLA, PLDLA and PLGA are shown, as well as col. 14, l. 50-57, wherein the release profiles of different copolymers at the same temperature are shown) and as such, it would have been obvious to one having ordinary skill in the art to use a different degradable polymer for each of the polymer composite particles in order to provide the intended different release profiles for each subset. Further examples of degradable polymers suggested by Lafitte et al. include those that include block copolymers including poly(amides). The reference, however, fails to explicitly identify a poly(amide) as the second degradable polymer of the at least two polymer composite particles. Ogle et al. teaches traceable solid particulates utilized to track production in a formation (abstract) wherein degradable polymers are used therewith; examples thereof include polymers that break down in the presence of water, including some disclosed by Lafitte et al. such as polyesters and polyesteramides, while further suggesting the use of a polyamide for such purposes ([0022]). As such, it would have been obvious to one having ordinary skill in the art to try a polyamide as the second degradable polymer used for the second polymer composite particle of the second subset of particles of Lafitte et al. in order to yield the predictable result of providing a degradable polymer downhole with a release profile for releasing the tracer at an intended time and location upon production of fluids from the formation, wherein such is different from that of the different first degradable polymer. Ogle et al. identifies a polyamide as a degradable polymer from a finite number of identified, predictable solutions used by a person of ordinary skill in the art to degrade upon contact with water so as to release a tracer for the purpose of tracking production from a formation, and, as such, a polyamide would be an obvious alternative to try as a degradable polymer in the method of Lafitte et al. When there is a design need or market pressure to solve a problem and there are a finite number of identified, predictable solutions, a person of ordinary skill has good reason to pursue the known options within his or her technical grasp. If this leads to the anticipated success, it is likely the product not of innovation but of ordinary skill and common sense.
With respect to dependent claim 2, Lafitte et al. discloses wherein the degradable polymer of the at least two polymer composite particles is a polymer comprising hydrolsable bonds (col. 7, l. 61-65; col. 8, l. 41-45; col. 10, l. 24-35; col. 20, l. 33-36).
With respect to dependent claim 5, Lafitte et al. discloses where the tracer is selected from the group as claimed (col. 5, l. 66-col. 6, l. 65).
With respect to dependent claim 6, Lafitte et al. discloses where the amount of time is 1 to 10 days (col. 13, l. 30-50; col. 15, l. 5-22; col. 16, l. 15-25; col. 16, l. 50-55).
With respect to dependent claims 7 and 8, Lafitte et al. discloses wherein the at least two polymer composite particles includes a first polymer composite particle and a second polymer composite particle (col. 10, l. 53-58, wherein a plurality of subsets that differ in release profiles and in tracer substances are suggested, thereby providing for a first and second as claimed). The reference further suggests different release profile times for several different polymers, including a polyester, polyester copolymer and polylactic acid copolymer, used to form the polymer composite particles through example, wherein such show release in 1 day, while others in amounts of time greater than one day, including up to 20 days (col. 13, l. 30-50; col. 15, l. 5-22; col. 16, l. 15-25; col. 16, l. 50-55). Although silent to the specific combination wherein the tracer in the first polymer composite is released in one day and the second polymer composite particle is released in 8-10 days as claimed, given the suggestion by Lafitte et al. to provide for different release profiles for the first and second polymer composite particles, as well as the disclosure therein of some of the same degradable polymers as Applicant, as well as the ability thereof to degrade over time, and, further, the suggestion by Ogle et al. to employ a degradable polymer consisting of polyamide, as set forth above in the rejection of claim 1, it would have been obvious to one having ordinary skill in the art to choose a first and second polymer for each of the first and second polymer composite particles so as to provide a release of tracer therefrom as claimed as based on the desired different release profile to provide for in the fracture. Since Lafitte et al. suggests the intention to provide for different release profiles from the first and second polymer composites, as well as the use of some of the same polymers for forming the first polymer composite as those instantly disclosed and claimed by Applicant, i.e., a polyester, polyester copolymer and polylactic acid copolymer, and, the same polymer for the second polymer composite particle of a polyamide in view of Ogle et al., the polymers used for the first polymer composite particle and the second polymer composite particle of Lafitte et al., in view of Ogle et al., would be expected to act in the manner as claimed, i.e., be capable of releasing the tracer in an amount of time as claimed. If there is any difference between the release of the tracer from the first polymer composite particle of Lafitte et al. and the second polymer composite particle of Lafitte et al. in view of Ogle et al., and that of the instant claims, the difference would have been minor and obvious insofar as because “Products of identical chemical composition cannot have mutually exclusive properties." A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. See MPEP 2112.01(1), In re Best, 562 F2d at 1255, 195 USPQ at 433, Titanium Metals Corp v Banner, 778 F2d 775, 227 USPQ 773 (Fed Cir 1985), In re Ludtke, 441 F2d 660, 169 USPQ 563 (CCPA 1971) and Northam Warren Corp v D F Newfield Co, 1 F Supp 773, 22 USPQ 313 (EDNY 1934). Furthermore, one having ordinary skill in the art would recognize an optimal release profile to provide for the tracer in the first and second polymer composite particles of Lafitte et al. in view of Ogle et al. since it has been held "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). For more recent cases applying this principle, see Merck & Co. Inc. v. Biocraft Lab. Inc., 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir.), cert. denied, 493 U.S. 975 (1989); In re Kulling, 897 F.2d 1147, 14 USPQ2d 1056 (Fed. Cir. 1990); and In re Geisler, 116 F.3d 1465, 43 USPQ2d 1362 (Fed. Cir. 1997); Smith v. Nichols, 88 U.S. 112, 118-19 (1874) (a change in form, proportions, or degree "will not sustain a patent"); In re Williams, 36 F.2d 436, 438 (CCPA 1929) ("It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions."). See also KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007) (identifying "the need for caution in granting a patent based on the combination of elements found in the prior art."). Additionally, the Examiner notes, obviousness can be shown in a predictable art when a difference between the claimed ranges is virtually negligible absent any showing of unexpected results or criticality. In re Brandt, 886 F. 3d 1171, 1177, 126 USPQ2d 1079, 1082 (Fed. Cir. 2018). The instant specification fails to explicitly establish the release time for the tracer in each of the polymer composite particles as critical and it is unclear if any unexpected results are achieved by providing for such. Since Lafitte et al. clearly discloses the desire to provide for different release profiles for different tracers within two subsets placed in the same location, it does not appear such would be an unexpected result of providing for a release of the tracer in each of the first and second polymer composite particles in an amount of time as claimed, and, as such, the determination for the optimal timing for release thereof would be achievable through routine experimentation in the art.
With respect to dependent claim 9, Lafitte et al. discloses wherein the stimulation fluid is selected from the group as claimed (col. 3, l. 59-col. 4, l. 3).
With respect to dependent claim 10, Lafitte et al. discloses wherein the at least one opening is a fracture or a wormhole (col. 3, l. 47-52; col. 3, l. 59-col. 4, l. 3).
Response to Arguments
Applicant’s arguments with respect to the rejections of claims as unpatentable over Lafitte et al. in view of Ogle et al. have been fully considered, but they are not persuasive.
Applicant notes claim 1 has been amended as suggested by the Examiner to specify that the at least two polymer composite particles have a different degradable polymer.
The Examiner notes, this suggestion was presented in the previous office action in response to Applicant’s previous remarks filed 09/16/25 wherein Applicant argued on page 12 “None of the examples include two polymer composite particles with different degradable polymers” since the claims as filed with the 09/16/25 response did not require the two composite particles indeed be different.
Applicant asserts in the instant response neither Lafitte nor Ogle teach a method using two different specific degradable polymers for at least two polymer composite particles as in amended claim 1 and that there is no teaching or motivation to modify the references to use two different specific degradable polymers which achieve the different degradation times.
The Examiner respectfully disagrees.
It is noted, specific degradation times are not explicitly required in independent claim 1.
Furthermore, Lafitte et al. explicitly discloses at column 10, lines 53-58 wherein a set of particles intended to be selectively placed at a subterranean location consist of a plurality of subsets of particles and wherein the particles of the two subsets will be similar in size so that they go to the same location, but they differ both in their release profiles, i.e., degradation times, and in the tracer substances which they contain. Lafitte et al. further discloses a variety of degradable polymers used for such purposes, including a polyester, polyester copolymer and/or polylactic acid copolymer (col. 8, l. 33-28), thereby providing for a first degradable polymer as claimed. Lafitte et al. additionally provides examples wherein it is clear that different polymers indeed have different release profiles over time (col. 13, l. 30-62, wherein the release profiles of PLLA, PLDLA and PLGA are shown, as well as col. 14, l. 50-57, wherein the release profiles of different copolymers at the same temperature are shown). Lafitte et al. therefore suggests providing for different release profiles by using two different polymers for each of the subsets of particles.
The Office admits Lafitte et al. does not explicitly disclose polyamide as a choice for the second polymer composite particle. However, based on the polymers disclosed by Lafitte et al. and Ogle et al.’s teaching of a polyamide as an alternative thereto, it is the position of the Office that the choice to use such as the specific polymer for the second degradable polymer as an alternative to the polymers disclosed by Lafitte et al. would indeed be obvious to one having ordinary skill in the art to try for at least the reasons of record.
Should Applicant consider the first degradable polymer be selected from a group that includes polymers not explicitly disclosed by Lafitte et al., such as polyurethane, polyurethane copolymer or polybutylene terephthalate, further consideration will be given to the prior art.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Angela M DiTrani Leff whose telephone number is (571)272-2182. The examiner can normally be reached Monday-Friday, 9AM-5PM.
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/Angela M DiTrani Leff/Primary Examiner, Art Unit 3674
ADL
02/17/26