US3815692A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulically enhanced well drilling technique
Assignee: Robert F Varley Co Inc
•
Filing: 1972-10-20
•
Granted: 1974-06-11
•
Expires: 1992-10-20
Abstract
Abstract A method for drilling a well bore hole using a drill string which includes an extensible hydraulic cylinder and piston section located above the drill bit. The drill string is positioned such that the extensible section is in less than a fully extended condition while pressurized fluid is pumped into the extensible section to produce hydraulic forces tending to extend that section. The hydraulic force thus generated within the extensible section influences the effective drill string weight applied to the drill bit and thus controls the force actually exerted between the drill bit and the bottom of the bore hole.
Inventors
- 👤 R Varley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:18
CPC Classifications
E; E21; E21B; E21B44/00; E21B44/005; E21B17/00; E21B17/02; E21B17/04; E21B17/07; E21B21/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
84 words
A method for drilling a well bore hole using a drill string which includes an extensible unanchored hydraulic cylinder and piston section above a drill bit, said method comprising: positioning said extensible section in a less than fully extended condition without anchoring any portion thereof to the bore hole, and pumping pressurized fluid into said extensible section thereby producing hydraulic forces reacting against the drill string weight and tending to extend said extensible section thus influencing the effective force applied to said drill bit.
Claim 2
Independent Claim
84 words
A method for drilling a well bore hole using a drill string which includes an extensible unanchored hydraulic cylinder and piston section above a drill bit, said method comprising: positioning said extensible section in a less than fully extended condition without anchoring any portion thereof to the bore hole, and pumping pressurized fluid into said extensible section thereby producing hydraulic forces reacting against the drill string weight and tending to extend said extensible section thus influencing the effective force applied to said drill bit.
Claim 3
Dependent Claim
38 words
A method as in claim 1 wherein said positioning step comprises: lowering said drill string into said bore hole until indicated drill string weight begins to decrease and then further lowering said drill string by a predetermined amount.
Claim 4
Dependent Claim
20 words
A method as in claim 1 further comprising the step of rotating said drill string simultaneously with said pumping step.
Claim 5
Dependent Claim
35 words
A method as in claim 1 further comprising the step of controlling the pressure of said pressurized fluid to achieve a substantially constant force between said drill bit and the bottom of said bore hole.
Claim 6
Dependent Claim
62 words
A method as in claim 1 wherein said positioning step comprises: lowering said drill string into said bore hole to a first point until said extensible section is substantially retracted, holding the upper portion of said drill string located above said extensible section at said first point while permitting the extensible section to extend, and cyclically repeating said lowering and holding steps.
Claim 7
Dependent Claim
56 words
A method as in claim 1 wherein said positioning and pumping steps comprise: rotating said drill string while fluid pressure is applied to partially extend said extensible section, stopping the rotary motion, slacking off said drill string to completeLy retract said extensible section, and then restarting said rotary motion without further slacking off said drill string.
Claim 8
Dependent Claim
16 words
A method as in claim 6 wherein said stopping, slacking and restarting steps are cyclically repeated.
Claim 9
Independent Claim
141 words
A method for drilling a well bore hole using a drill string which includes an extensible hydraulic cylinder and piston section above a drill bit, said method comprising: positioning said extensible section in a less than fully extended condition, and pumping pressurized fluid into said extensible section thereby producing hydraulic forces tending to extend said extensible section and thus influence the effective force applied to said drill bit, wherein said positioning and pumping steps comprise; pulling the bit free of the bottom of said bore hole, slacking off said drill string until the bit touches the bottom of said bore hole and said extensible section is at least partially closed, holding said drill string, increasing the fluid pressure in said extensible section, rotating said drill string, and then further slacking off said drill string until a desired drilling force is achieved.
Claim 10
Independent Claim
141 words
A method for drilling a well bore hole using a drill string which includes an extensible hydraulic cylinder and piston section above a drill bit, said method comprising: positioning said extensible section in a less than fully extended condition, and pumping pressurized fluid into said extensible section thereby producing hydraulic forces tending to extend said extensible section and thus influence the effective force applied to said drill bit, wherein said positioning and pumping steps comprise; pulling the bit free of the bottom of said bore hole, slacking off said drill string until the bit touches the bottom of said bore hole and said extensible section is at least partially closed, holding said drill string, increasing the fluid pressure in said extensible section, rotating said drill string, and then further slacking off said drill string until a desired drilling force is achieved.
Claim 11
Independent Claim
111 words
A method for drilling a well bore hole using a drill string which includes an extensible hydraulic cylinder and piston section above a drill bit, said method comprising: positioning said extensible section in a less than fully extended condition, and pumping pressurized fluid into said extensible section thereby producing hydraulic forces tending to extend said extensible section and thus influence the effective force applied to said drill bit, wherein said positioning and pumping steps comprise: pulling the bit free of the bore hole bottom, rotating said drill string with sufficient applied fluid pressure to fully extend said extensible section, and slacking off the drill string to partially close said extensible section.
Claim 12
Independent Claim
111 words
A method for drilling a well bore hole using a drill string which includes an extensible hydraulic cylinder and piston section above a drill bit, said method comprising: positioning said extensible section in a less than fully extended condition, and pumping pressurized fluid into said extensible section thereby producing hydraulic forces tending to extend said extensible section and thus influence the effective force applied to said drill bit, wherein said positioning and pumping steps comprise: pulling the bit free of the bore hole bottom, rotating said drill string with sufficient applied fluid pressure to fully extend said extensible section, and slacking off the drill string to partially close said extensible section.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |