Prosecution Insights
Last updated: April 19, 2026
Application No. 18/938,628

METHOD FOR USING DRILLING FLUID IN DRILLING OPERATIONS, DRILLING FLUID AND ITS USE

Non-Final OA §103§112
Filed
Nov 06, 2024
Examiner
AKAKPO, DANY E
Art Unit
3672
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
Petróleo Brasileiro S.A. - Petrobras
OA Round
2 (Non-Final)
87%
Grant Probability
Favorable
2-3
OA Rounds
2y 3m
To Grant
99%
With Interview

Examiner Intelligence

Grants 87% — above average
87%
Career Allow Rate
457 granted / 523 resolved
+35.4% vs TC avg
Moderate +13% lift
Without
With
+13.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 3m
Avg Prosecution
40 currently pending
Career history
563
Total Applications
across all art units

Statute-Specific Performance

§101
2.0%
-38.0% vs TC avg
§103
42.1%
+2.1% vs TC avg
§102
28.2%
-11.8% vs TC avg
§112
23.4%
-16.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 523 resolved cases

Office Action

§103 §112
DETAILED ACTION The amendments filed on 10/14/2025 have been entered. 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. Claims 4 and 7 are 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 applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 4 is a method claim with no positively recited method steps. In claim 7, line 1, the applicant recites “a fluid according…”. It is not clear what fluid the applicant is referring to. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claims 2-4 are rejected under 35 U.S.C. 103 as being unpatentable over Marinho et al. (US 20230104709) alone. Regarding claim 2, Marinho discloses a drilling fluid comprising the following components: a continuous phase, mainly water ([0045], table 1); from 0 to 276.4 g/l (0 to 96.7 lb/bbl) of donor salinity, mainly sodium chloride ([0045], table 1); from 1.43 to 4.29 g/l (0.5 to 1.5 lb/bbl) of calcium and magnesium controller, mainly sodium bicarbonate ([0045], table 1); from 4.29 to 7.15 g/l (1.5 to 2.5 lb/bbl) of viscosifier, mainly xanthan gum ([0045], table 1); a filtrate reducer, mainly polyanionic cellulose ([0045], table 1); from 0.29 to 0.86 g/l (0.1 to 0.3 lb/bbl) of alkalizing agent, mainly caustic soda ([0045], table 1); from 0.29 to 0.86 g/l (0.1 to 0.3 lb/bbl) of bactericide, mainly glutaraldehyde ([0045], table 1); from 0 to 0.86 g/l (0 to 0.3 lb/bbl) antifoaming, mainly silicone antifoaming ([0045], table 1); and from 57 to 257 g/l (20 to 90 lb/bbl) of thickening agent, mainly baryte (([0045], table 1)). Marinho appears to be silent in providing water within the ranges 87.6 to 92.2% v/v and polyanionic cellulose within the ranges of 0 to 2.86 g/l (0 to 1.0 lb/bbl) However, before the effective filling date, it would have been obvious to one of ordinary skill in the art, having the teachings of Marinho before him or her, to modify the apparatus/method disclosed by Marinho to include water between 87.6 to 92.2% v/v and polyanionic cellulose within the ranges of 0 to 2.86 g/l (0 to 1.0 lb/bbl) in order to obtain optimal fluid properties since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 VSPQ 233. Regarding claim 3, Marinho further discloses that the weight of the initial composition varies depending on the initial concentration of the salinity donor, from weights of 10.3 lb/gal (1.23 g/cm3) to 10.5 lb/gal (1.26 g/cm3), and wherein to ensure a calibrated final section with weight in a certain range, the performing of weight control also includes use of saturated and light fluid. ([0023],abstract). Regarding claim 4, Marinho further discloses that the drilling fluid is used for the construction of wells with potential gains in the disciplines of drilling fluids, directional tools and casing and cementing ([0001]-[0003]). Allowable Subject Matter Claims 1 and 5-6 are allowed. Claim 4 would be allowable if rewritten or amended to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action. The following is a statement of reasons for the indication of allowable subject matter: The closest prior art to record is Jamison et al. (US 20120094876) Regarding claim 1 and 4, Jamison discloses A method for employing drilling fluid in drilling operations, the method comprising: (a) receiving details of a salt, with its stratigraphic composition ([0025]); (b) evaluating the upper limit and weight required at an end of a phase ([0006]); (c) based on the well diameter, estimating through a mass balance and desired initial salinity, estimated depth of fluid saturation, and defining initial and final weight after saturation ([0025]); (e) confirming with simulation and the stratigraphic composition provided whether a mass balance prediction is reproduced through temperature balance and salt balance ([0025]); (f) during operation, preparing fluid according to suggested composition and observing salinity and initial weight ([0025]); (g) performing a formation integrity test to assess whether the final weight of the well is within the planned range, and making any necessary adjustments during drilling ([0021]); (h) replacing well fluid and start drilling ([0025]); (i) monitoring the evolution of the weight and salinity of the fluid during drilling, noting the increase in chlorides, sodium, potassium, calcium, and magnesium in the fluid ([0025]); (j) performing weight control with undersaturated fluid and, if necessary to ensuring a calibrated final section with weight in a certain range, use saturated and light fluid ([0025], fig 4); Jamison is silent regarding (d) confirming with a cementing project which final well extension is necessary for the fluid to be close to saturation; (k) temporarily circulating the undersaturated fluid itself, using an undersaturated saline fluid with no viscosity, or even fresh water to release the column; (l) at the end of drilling, using the combination of a low rheology fluid followed by a viscous and low salinity fluid that, when combined, promotes suspension of cuttings when forming a bed in inclined sections and to dissolve during the cleaning flow, in which column rotation to aid in removal can be combined; (m) maneuvering the column and providing a memory profile in LWD during removal, without circulation, to measure the calibrated well extension as specifically called for in the claimed combination. Response to Arguments Applicant's arguments filed 10/14/2025 regarding claim 2 have been fully considered but they are not persuasive. Applicant states that claim 2 depends on allowed claim 1. The Examiner respectfully disagrees. In fact, claim 2 is currently an independent claim. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to DANY E AKAKPO whose telephone number is (469)295-9255. The examiner can normally be reached M-F 9am - 5pm. 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, Nicole Coy can be reached on (571) 272-5405. 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. /DANY E AKAKPO/Examiner, Art Unit 3672 1/29/2026
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Prosecution Timeline

Nov 06, 2024
Application Filed
Jun 12, 2025
Non-Final Rejection — §103, §112
Oct 14, 2025
Response Filed
Jan 29, 2026
Non-Final Rejection — §103, §112 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12601248
SYSTEMS AND METHODS FOR DRILLING
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Patent 12600292
SENSOR AND INDICATOR LIGHT MOUNTING STRUCTURE, AND CARGO HANDLING VEHICLE
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Patent 12590534
SYSTEM AND METHOD FOR DETERMINING PLACEMENT OF A DOWNHOLE DEVICE
2y 5m to grant Granted Mar 31, 2026
Patent 12590526
WELLBORE DRILL DEVIATION HANDLING
2y 5m to grant Granted Mar 31, 2026
Patent 12590527
ROTARY STEERABLE SYSTEM ADVISOR WITH AUTONOMOUS MODE
2y 5m to grant Granted Mar 31, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

2-3
Expected OA Rounds
87%
Grant Probability
99%
With Interview (+13.0%)
2y 3m
Median Time to Grant
Moderate
PTA Risk
Based on 523 resolved cases by this examiner. Grant probability derived from career allow rate.

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