Prosecution Insights
Last updated: April 19, 2026
Application No. 18/675,613

HYDRAULIC FRACTURING FLUID COMPRISING MICROPROPPANT COKE PARTICLES, METHOD FOR MAKING SAME, AND HYDRAULIC FRACTURING PROCESSES USING SAME

Final Rejection §103§112
Filed
May 28, 2024
Examiner
SKAIST, AVI T.
Art Unit
3674
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
ExxonMobil
OA Round
2 (Final)
63%
Grant Probability
Moderate
3-4
OA Rounds
2y 4m
To Grant
99%
With Interview

Examiner Intelligence

Grants 63% of resolved cases
63%
Career Allow Rate
241 granted / 380 resolved
+11.4% vs TC avg
Strong +42% interview lift
Without
With
+42.5%
Interview Lift
resolved cases with interview
Typical timeline
2y 4m
Avg Prosecution
17 currently pending
Career history
397
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
57.0%
+17.0% vs TC avg
§102
9.9%
-30.1% vs TC avg
§112
26.1%
-13.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 380 resolved cases

Office Action

§103 §112
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 . Response to Amendment The Amendment filed 3/2/26 has been entered. Claims 1-72 are pending in the application, of which claims 22-68 are withdrawn. Claim 72 is new. As such, the claims being examined are claims 1-21 and 69-72. Claim Objections New claim 72 is objected to under 37 CFR 1.75 as being a substantial duplicate of claim 70. When two claims in an application are duplicates or else are so close in content that they both cover the same thing, despite a slight difference in wording, it is proper after allowing one claim to object to the other as being a substantial duplicate of the allowed claim. See MPEP § 608.01(m). Claim Rejections - 35 USC § 112 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. Claim 14 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention. Claim 14 recites the limitation “a second portion having particle sizes of greater than 105 μm.” The phrase “greater than 105 μm” is a relative phrase which renders the claim indefinite. The term "greater than" is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. It is unclear as to the value of the upper bounds of the range is extended to; “greater than” can include 106 μm or 100 million kilometers. For purposes of examination, the term “greater than 105 μm” will be considered under Broadest Reasonable Interpretation. Claim 19 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention. Claim 19 recites the limitation “substantially free of water.” The term “substantially free” is a relative term which renders the claim indefinite. The term " substantially" is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. It is unclear as to the amount of water required in claim 19 in order to provide for a carrier fluid "substantially free of water” as claimed. For purposes of examination, the term “substantially” will be considered as if removed. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claims 1-21 and 69-72 are rejected under 35 U.S.C. 103 as being unpatentable over Gordon et al. (US 2021/0253944- cited previously). With respect to independent claim 1, Gordon discloses a fracturing fluid comprising a carrier fluid and coke particles (Abstract), wherein: the coke particles comprise microproppant coke particles having a D50 particle size of about 50 μm to about 500 μm ([0008], [0050], and [0060]); the microproppant coke particles have a total concentration of at least about 2 vol % to about 100 vol% based on the total amount of all proppant particulates and comprise at least 5% up to 100% of the total mass of all proppant particulates ([0060], [0062], and [0068]). Regarding claim 1, Gordon discloses wherein the microproppant coke particles have a total concentration of at least about 2 vol % to about 100 vol% based on the total amount of all proppant particulates and comprise at least 5% up to 100% of the total mass (30,000-250,000 pounds) of all proppant particulates ([0062] and [0068]). Although silent to wherein the “microproppant coke particles have a total concentration of at least 3 weight percent” and wherein “the coke particles have a total concentration in the fracturing fluid from 14 kilograms per cubic meter to 480 kilograms per cubic meter,” as instantly claimed, it would have been obvious for a person having ordinary skill in the art before the effective filing date of the claimed invention to provide for the microproppant coke particle and coke particle amounts as claimed insofar as because 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) With respect to depending claims 2 and 3, Gordon discloses wherein the microproppant coke particles comprise at least 5% up to 100% of the total mass (30,000-250,000 pounds) of all proppant particulates ([0062] and [0068]). Although silent to wherein the coke particles have a total concentration in the fracturing fluid “from 18 kilograms per cubic meter to 120 kilograms per cubic meter” or “from 23 kilograms per cubic meter to 96 kilograms per cubic meter,” as instantly claimed, it would have been obvious for a person having ordinary skill in the art before the effective filing date of the claimed invention to provide for the coke particle amounts as claimed insofar as because 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) With respect to depending claims 4, 5, and 69-72, Gordon discloses wherein the microproppant coke particles have a total concentration of at least about 2 vol % to about 100 vol% based on the total amount of all proppant particulates and comprise at least 5% up to 100% of the total mass (30,000-250,000 pounds) of all proppant particulates ([0062] and [0068]). Although silent to wherein the microproppant coke particles have a total concentration of “from about 5 wt% to 100 wt%,” “from about 30 wt% to 80 wt%,” “from about 60 wt% to 100 wt%,” “from about 80 wt% to 100 wt%,” or “from about 90 wt% to 100 wt%,” as instantly claimed, it would have been obvious for a person having ordinary skill in the art before the effective filing date of the claimed invention to provide for the microproppant coke particle amounts as claimed insofar as because 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) With respect to depending claims 6, 7, and 10-13, Gordon discloses wherein the microproppant coke particles may be dry or wet flexicoke (Abstract and [0060]). With regard to the remaining materials of the Markush groups, the Office considers these as obvious variants to those disclosed by the reference, and, therefore, it would have been obvious for a person having ordinary skill in the art before the effective filing date of the claimed invention to alternatively include such materials as the type of coke. With respect to depending claims 8, 9, 12, and 14, Gordon discloses wherein the coke particles comprise microproppant coke particles having a D50 particle size of about 50 μm to about 500 μm ([0008], [0050], and [0060]). Although silent to the specific sizes as instantly claimed, it would have been obvious for a person having ordinary skill in the art before the effective filing date of the claimed invention to provide for the microproppant coke particle sizes as claimed insofar as because 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) With respect to depending claims 15-17, Gordon discloses further comprising third proppant particles differing from the coke particles, wherein the third proppant particles comprise sand ([0059] and [0060]). With regard to the alternative of the third proppant being a lightweight proppant or ultra-lightweight proppant, the Office considers these as obvious variants to those disclosed by the reference, and, therefore, it would have been obvious for a person having ordinary skill in the art before the effective filing date of the claimed invention to alternatively include such materials as the third proppant. With respect to depending claims 18-20, Gordon discloses wherein the carrier fluid may be aqueous based or non-aqueous based, and may further comprise carbon dioxide ([0055]-[0056]). With regard to the remaining materials claimed, the Office considers these as obvious variants to those disclosed by the reference, and, therefore, it would have been obvious for a person having ordinary skill in the art before the effective filing date of the claimed invention to alternatively include such materials as the carrier fluid. With respect to depending claim 21, Gordon discloses further comprising an acid, a biocide, a breaker, a corrosion inhibitor, a crosslinker, a friction reducer, a gel, an oxygen scavenger, a pH control additive, a scale inhibitor, a surfactant, a weighting agent, and inert solid, a fluid loss control agent, an emulsifier, an emulsion thinner, an emulsion thickener, a viscosifying agent, a foaming agent, a stabilizer, a chelating agent, a mutual solvent, an oxidizer, a reducer, and a clay stabilizing agent ([0058]). Response to Arguments Applicant's arguments filed 3/2/26 have been fully considered but they are not persuasive. Applicant argues that “the absence of an explicit upper limit does not render Claim 14 indefinite” and cites case law for support. The Examiner finds the argument unpersuasive. The instance in which the absence of an upper limit would not render a claim indefinite is when the claim recites a percentage of a whole, because “the total percentage must be less than 100%.” In contrast, instant claim 14 recites “a second portion having particle sizes of greater than 105 μm.” The phrase “greater than 105 μm” is indefinite because it can include 106 μm or 100 million kilometers. Applicant argues that the term “substantially” recited in Claim 19 does not render the claim indefinite because “one of ordinary skill in the art would understand what is practically required.” The Examiner finds this argument unpersuasive. The term “substantially free of water” is indefinite because one of ordinary skill in the art would not understand the metes and bounds required in claim 19 in order to provide for a carrier fluid which is "substantially free of water.” Applicant argues that the Examiner is required “to establish that ‘the general conditions of a claim are disclosed in the prior art’ in order to consider an element mere routine experimentation” and “no such primary determination was made as to whether the general conditions of a claimed are disclosed in the prior art.” The Examiner finds this argument unpersuasive. As noted above, Gordon discloses wherein the microproppant coke particles have a total concentration of at least about 2 vol % to about 100 vol% based on the total amount of all proppant particulates and comprise at least 5% up to 100% of the total mass (30,000-250,000 pounds) of all proppant particulates ([0062] and [0068]). As such, the prior art does indeed provide support for the general conditions and criticality of carrier fluid, coke particles, and microproppant coke particles. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to AVI T. SKAIST whose telephone number is (571)272-9348. The examiner can normally be reached M-F 9:30-6. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Doug Hutton can be reached at (571) 272-4137. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /AVI T SKAIST/Examiner, Art Unit 3674 /WILLIAM D HUTTON JR/Supervisory Patent Examiner, Art Unit 3674
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Prosecution Timeline

May 28, 2024
Application Filed
Nov 26, 2025
Non-Final Rejection — §103, §112
Mar 02, 2026
Response Filed
Mar 18, 2026
Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
63%
Grant Probability
99%
With Interview (+42.5%)
2y 4m
Median Time to Grant
Moderate
PTA Risk
Based on 380 resolved cases by this examiner. Grant probability derived from career allow rate.

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