Prosecution Insights
Last updated: April 19, 2026
Application No. 18/949,812

PISTON-DIAPHRAGM PUMP FOR DRILLING OPERATIONS

Non-Final OA §103
Filed
Nov 15, 2024
Examiner
CARROLL, DAVID P.
Art Unit
3674
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
Helmerich & Payne Inc.
OA Round
1 (Non-Final)
80%
Grant Probability
Favorable
1-2
OA Rounds
2y 4m
To Grant
95%
With Interview

Examiner Intelligence

Grants 80% — above average
80%
Career Allow Rate
553 granted / 689 resolved
+28.3% vs TC avg
Moderate +14% lift
Without
With
+14.5%
Interview Lift
resolved cases with interview
Typical timeline
2y 4m
Avg Prosecution
9 currently pending
Career history
698
Total Applications
across all art units

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
36.4%
-3.6% vs TC avg
§102
24.1%
-15.9% vs TC avg
§112
31.3%
-8.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 689 resolved cases

Office Action

§103
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 . Election/Restrictions Applicant’s remarks state claims 9-16, 24-30 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 12/10/2025. Note: The amendment dated 12/10/2025 cancelled claims 9-16, 24-30. Claim Objections Claim 17 is objected to because of the following informalities: Claim 17 appears to contain a scrivener’s error “…the wellbore,;” It is unclear if additional text is missing or if the “,” before the “;” was inadvertently added . Appropriate correction is required. 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. Claim(s) 1-7, 17-19, 22, 31-35 is/are rejected under 35 U.S.C. 103 as being unpatentable over McCaskill (US 20050092523) in view of Giessbach (US 20140248160). Regarding claim 1, McCaskill teaches: A method of drilling a borehole, the method comprising: operating (McCaskill [0026]) a pump (McCaskill 26) to generate a flowrate of the drilling mud through a high-pressure piping system into the borehole; and directing (McCaskill [0026]) the drilling mud through a drill pipe (McCaskill 19) and into the borehole (McCaskill near 24) but does not describe the structure of the pump or expressly state: moving a piston in a cylinder of a piston-diaphragm pump to apply a pressure to a first fluid in the cylinder of the piston-diaphragm pump, the first fluid filling a void inside the cylinder between a head of the piston and a first side of a diaphragm; transferring the pressure from the first fluid across the diaphragm to a drilling mud, wherein the drilling mud is separated from the first fluid by the diaphragm; operating the pump to generate a flowrate of the drilling mud through a valve connected to the cylinder. Giessbach teaches a method of operating a drilling mud pump (Giessbach [0002]) comprising: moving (Giessbach [0047-0053]) a piston in a cylinder of a piston-diaphragm pump (Giessbach comprising 7, 6) to apply a pressure to a first fluid in the cylinder of the piston-diaphragm pump, the first fluid filling a void inside the cylinder between a head of the piston and a first side of a diaphragm; transferring (Giessbach [0047-0053]) the pressure from the first fluid across the diaphragm to a drilling mud, wherein the drilling mud is separated from the first fluid by the diaphragm; operating the pump to generate a flowrate (Giessbach [0050-0053]) of the drilling mud through a valve connected to the cylinder. It would have been considered obvious to one of ordinary skill in the art, before the effective filing date (AIA ) or at the time the invention was made (Pre-AIA ), to have modified McCaskill to have used the known piston-diaphragm pump of Giessbach as the mud pump in the drilling system of McCaskill as McCaskill teaches a generic mud pump and using the known piston-diaphragm pump of Giessbach yields the predictable result of allowing the operator to control circulation of drilling mud during wellbore operations in a known and predictable way. Regarding claim 2, the combination of McCaskill and Giessbach teaches: The method of claim 1, further comprising: forcing (McCaskill [0026]) the drilling mud through one or more nozzles (McCaskill 23) located near a drill bit; drilling (McCaskill [0026]) the borehole by rotating the drill bit; and returning (McCaskill [0026-0029]) the drilling mud from the drill bit through an annulus (McCaskill 24) to a surface (McCaskill near 29) of the borehole. Regarding claim 3, the combination of McCaskill and Giessbach teaches: The method of claim 1, wherein the diaphragm flexes (Giessbach [0023, 0048, 0068, 0073]) to a concave shape at a bottom of a stroke of the piston and the diaphragm flexes to a convex shape at the top of the stroke of the piston. Regarding claim 4, the combination of McCaskill and Giessbach teaches: The method of claim 1, wherein the first fluid is a lubricating oil (Giessbach [0047-0053, 0068]). Regarding claim 5, the combination of McCaskill and Giessbach teaches: The method of claim 1, wherein the diaphragm is of a material (Giessbach [0038, 0057]) suitable to withstand contact with drilling mud for a service lifetime of the pump. Regarding claim 6, the combination of McCaskill and Giessbach teaches: The method of claim 1, wherein the pump operates at a pressure (Giessbach [0002]) of at least 7,000 pounds per square inch (psi). Regarding claim 7, the combination of McCaskill and Giessbach teaches: The method of claim 1, wherein the pump operates at a flowrate (Giessbach [0054-0055]) of at least 200 gallons per minute (gpm). Regarding claim 17, McCaskill teaches: A method of drilling a wellbore, the method comprising: providing (McCaskill [0026]) a drilling fluid for drilling a wellbore; providing (McCaskill [0026]) a pump unit for pumping the drilling fluid into the wellbore,; and operating (McCaskill [0026]) the pump unit to deliver the drilling fluid into the wellbore at a pressure of at least 5,000 psi. but does not describe the structure of the pump or expressly state: operating the pump unit to deliver the drilling fluid into the wellbore at a pressure of at least 5,000 psi. Giessbach teaches a method of operating a drilling mud pump (Giessbach [0002]) comprising: operating (Giessbach [0002]) the pump unit to deliver the drilling fluid into the wellbore at a pressure of at least 5,000 psi. It would have been considered obvious to one of ordinary skill in the art, before the effective filing date (AIA ) or at the time the invention was made (Pre-AIA ), to have modified McCaskill to have used the known piston-diaphragm pump of Giessbach as the mud pump in the drilling system of McCaskill as McCaskill teaches a generic mud pump and using the known piston-diaphragm pump of Giessbach yields the predictable result of allowing the operator to control circulation of drilling mud during wellbore operations in a known and predictable way while also allowing the operator to customize the pump for the specific downhole operation (e.g. drilling) to be performed and the specific environmental characteristics (pressure, depth, mud type, formation type, etc.) where the well is drilled. Regarding claim 18, the combination of McCaskill and Giessbach teaches: The method of claim 17, operating the pump to deliver the drilling fluid into the well bore at a flow rate (Giessbach [0054-0055]) of at least 200 gpm. Regarding claim 19, the combination of McCaskill and Giessbach teaches: The method of claim 17, wherein the drilling fluid is delivered at a pressure (Giessbach [0002]) of at least 7,000 psi and a flow rate (Giessbach [0054-0055]) of at least 250 gpm. Regarding claim 22, the combination of McCaskill and Giessbach teaches: The method of claim 17, wherein the pump unit comprises two piston-diaphragm pumps (Giessbach [0049] 6, 6a, 6a’, Figs. 3-9) for pumping the drilling fluid into the wellbore. Regarding claim 31, the combination of McCaskill and Giessbach teaches: The method of claim 1, wherein the drilling mud has a pressure (Giessbach [0002]) of at least 7,000 psi and a flow rate (Giessbach [0054-0055]) of at least 250 gallons per minute (gpm). Regarding claim 32, the combination of McCaskill and Giessbach teaches: The method of claim 1, wherein the drilling mud has a pressure (Giessbach [0002]) of between 7,000 psi and 8,000 psi and a flow rate (Giessbach [0054-0055]) of between 250 and 350 gpm. Regarding claim 33, the combination of McCaskill and Giessbach teaches: The method of claim 1, wherein the method further includes providing (Giessbach [0049] 6, 6a, 6a’, Figs. 3-9) a second piston-diaphragm pumps for pumping the drilling mud into the borehole. Regarding claim 34, the combination of McCaskill and Giessbach teaches: The method of claim 33, further comprising: moving (Giessbach [0047-0053]) a second piston in a second cylinder of the second piston-diaphragm pump (Giessbach comprising 6a/6a’) to apply a pressure to a second fluid in the second cylinder of the second piston- diaphragm pump, the second fluid filling (Giessbach [0047-0053]) a void inside the second cylinder between a head of the second piston and a first side of a second diaphragm; Regarding claim 35, the combination of McCaskill and Giessbach teaches: The method of claim 34, wherein the first and second pistons are connected (Giessbach [0004, 0054-0055, 0060]) such that when the first piston is retracted the second piston is extended. Claim(s) 8, 23 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of McCaskill and Giessbach in view of Cryer (US 20140010671). Regarding claim 8, the combination of McCaskill and Giessbach teaches: The method of claim 1, but does not expressly state: wherein the pump is operated by a motor of 1,600 horsepower or greater. Cryer teaches operating pumps for drilling mud (Cryer [0002, 0021]) wherein the pump is operated by a motor (Cryer [0034]) of 1,600 horsepower or greater. It would have been considered obvious to one of ordinary skill in the art, before the effective filing date (AIA ) or at the time the invention was made (Pre-AIA ), to have modified the combination to include sizing the pump to be operated by a motor of 1,600 horsepower or greater in order to allow the operator to customize the pump for the specific downhole operation (e.g. drilling) to be performed and the specific environmental characteristics (pressure, depth, mud type, formation type, etc.) where the well is drilled. Regarding claim 23, the combination of McCaskill and Giessbach teaches: The method of claim 22, including a generic system for controlling variable flow rates (Giessbach [0054-0055]) but does not describe the pump/motor control system or expressly state: further comprising adjusting the pressure and/or flow rate by adjusting a variable frequency drive driving one or more motors operating the plurality of piston-diaphragm pumps. Cryer teaches operating pumps for drilling mud (Cryer [0002, 0021]) further comprising adjusting the pressure and/or flow rate by adjusting a variable frequency drive (Cryer [0021, 0031]) driving one or more motors operating the plurality of piston-diaphragm pumps. It would have been considered obvious to one of ordinary skill in the art, before the effective filing date (AIA ) or at the time the invention was made (Pre-AIA ), to have modified the combination to have used the known variable frequency drive of Cryer as the means for adjusting the pump motor in the combination as the combination teaches a generic means for adjusting pressure and/or flow rate and using the known variable frequency drive of Cryer yields the predictable result of allowing the operator customize and control the pump for the specific downhole operation (e.g. drilling) to be performed and the specific environmental characteristics (pressure, depth, mud type, formation type, etc.) where the well is drilled. Claim(s) 20-21 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of McCaskill and Giessbach in view of Hurst (US 20200362975). Regarding claim 20, the combination of McCaskill and Giessbach teaches: The method of claim 17, wherein a flow rate (Giessbach [0054-0055]) is 300 gpm or more. But does not expressly state: wherein the pressure is 7,500 psi or greater Hurst teaches it is common in the art to operate high pressure pumps during wellbore operations (Hurst [0037, 0087, 0094-0095]), including drilling, at pressures between 100 psi and 50,000 psi and flowrates between 1-100 BPM. It would have been considered obvious to one of ordinary skill in the art, before the effective filing date (AIA ) or at the time the invention was made (Pre-AIA ), to have modified the combination to include sizing the pump to be in the desired flow rate and pressure range in order to allow the operator to customize the pump for the specific downhole operation (e.g. drilling) to be performed and the specific environmental characteristics (pressure, depth, mud type, formation type, etc.) where the well is drilled. Regarding claim 21, the combination of McCaskill and Giessbach teaches: The method of claim 17, but does not expressly state wherein the pressure is between 9,500 psi and 10,500 psi and a flow rate is between 250 and 350 gpm. Hurst teaches it is common in the art to operate high pressure pumps during wellbore operations (Hurst [0037, 0087, 0094-0095]), including drilling, at pressures between 100 psi and 50,000 psi and flowrates between 1-100 BPM. It would have been considered obvious to one of ordinary skill in the art, before the effective filing date (AIA ) or at the time the invention was made (Pre-AIA ), to have modified the combination to include sizing the pump to be in the desired flow rate and pressure range in order to allow the operator to customize the pump for the specific downhole operation (e.g. drilling) to be performed and the specific environmental characteristics (pressure, depth, mud type, formation type, etc.) where the well is drilled. Prior Art The following prior art made of record and not relied upon is considered pertinent to Applicant's disclosure. Biggerstaff (US 20180313178) teaches a drilling mud pumping system configured to operate at pressures between 7.500-10,000 psi. Netecke (US 20220065242) teaches a drilling mud pumping system and notes the equivalence of diaphragms, pistons, and plungers for their use in the drilling mud pumping art. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to David Carroll whose telephone number is (571)272-4808. The examiner can normally be reached M-F 2:00-10:00 PM EDT. 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. /David Carroll/ Primary Examiner, Art Unit 3674
Read full office action

Prosecution Timeline

Nov 15, 2024
Application Filed
Feb 07, 2026
Non-Final Rejection — §103 (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

1-2
Expected OA Rounds
80%
Grant Probability
95%
With Interview (+14.5%)
2y 4m
Median Time to Grant
Low
PTA Risk
Based on 689 resolved cases by this examiner. Grant probability derived from career allow rate.

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