US4733733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of controlling the direction of a drill bit in a borehole
Assignee: Baroid Technology Inc
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Filing: 1986-02-11
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Granted: 1988-03-29
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Expires: 2006-02-11
Abstract
Abstract A system for controlling the direction of a drill bit in a borehole utilizes both a drill string model and a bit-rock directional interaction model to compare ideal predicted or expected moments with real time measured moments to arrive at correction data necessary to return the bit to its desired path. The magnitude and direction of moments generated near the bit are measured in a downhole equipment sub, containing a microprocessor and memory, so that the real time data can be collected and acted upon without undue delay thereby minimizing drilling time lost due to deviations from the desired path.
Inventors
- 👤 William B. Bradley
- 👤 John E. Fontenot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:17
CPC Classifications
G; G09; G09B; G09B25/00; G09B25/02; E; E21; E21B; E21B44/00; E21B47/00; E21B47/02; E21B47/022; E21B7/00; E21B7/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
100 words
A method for controlling directional drilling of a bit on the lower end of a drill string, comprising the steps of: measuring bending moments in two orthogonal planes on a portion of said drill string closely adjacent said bit; measuring the inclination and orientation headings of said bit during said bending moment measurements; measuring the penetration rate of said bit into a rock formation; developing a bit-rock directional well interaction model and comparing said measured moments and headings with said model in a downhole microprocessor to derive error signals; and controlling said bit direction in response to said error signals.
Claim 2
Independent Claim
100 words
A method for controlling directional drilling of a bit on the lower end of a drill string, comprising the steps of: measuring bending moments in two orthogonal planes on a portion of said drill string closely adjacent said bit; measuring the inclination and orientation headings of said bit during said bending moment measurements; measuring the penetration rate of said bit into a rock formation; developing a bit-rock directional well interaction model and comparing said measured moments and headings with said model in a downhole microprocessor to derive error signals; and controlling said bit direction in response to said error signals.
Claim 3
Dependent Claim
21 words
A method according to claim 1 further comprising the step of: using said error signal to reformulate said bit-rock interaction model.
Claim 4
Dependent Claim
21 words
A methoc according to claim 1 further comprising the step of: using measuring-while-drilling survey information to reformulate said bit-rock interaction model.
Claim 5
Dependent Claim
26 words
A method according to claim 1 further comprising the step of: using the difference between surface and downhole weight-on-bit measurements to reformulate said bit-rock interaction model.
Claim 6
Dependent Claim
25 words
A method according to claim 1 further comprising the step of: using bit characteristic and assumed rock characteristic information to develop said bit-rock interaction model.
Claim 7
Independent Claim
112 words
A system for controlling directional drilling of a bit on the lower end of a drill string, comprising: means to measure the magnitude and direction of bending moments in two orthogonal planes on a portion of said drill string in close proximity to said bit; means to measure the inclination and orientation headings of said bit during said bending moment measurements; means to measure the penetration rate of said bit into a rock formation; means to develop a bit-rock directional well interaction model and compare said measured moments and headings with said model to develop an error signal; and means responsive to said error signal to control the direction of said bit.
Claim 8
Independent Claim
112 words
A system for controlling directional drilling of a bit on the lower end of a drill string, comprising: means to measure the magnitude and direction of bending moments in two orthogonal planes on a portion of said drill string in close proximity to said bit; means to measure the inclination and orientation headings of said bit during said bending moment measurements; means to measure the penetration rate of said bit into a rock formation; means to develop a bit-rock directional well interaction model and compare said measured moments and headings with said model to develop an error signal; and means responsive to said error signal to control the direction of said bit.
Claim 9
Dependent Claim
28 words
A system according to claim 6 wherein said means to develop a bit-rock directional well interaction model is a microprocessor and memory located downhole on the drill string.
Claim 10
Dependent Claim
42 words
A system according to claim 6 wherein said means to develop a bit-rock directional well interaction model receives measuring-while-drilling information and utilizes it to modify the bit-rock directional well interaction model in accordance with the formation currently being encountered by said bit.
Claim 11
Dependent Claim
41 words
A system according to claim 6 further comprising: means to compare actual bending moment measurements with bending moment measurements derived from said bit-rock directional well interaction model and produce an error signal used to reformulate said bit-rock directional well interaction model.
Claim 12
Dependent Claim
29 words
A system according to claim 6 further comprising: means to feed bit characteristic and assumed rock characteristic data to said means to develop a bit-rock directional well interaction model.
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) | 1991-03-29 | 1991-09-28 | 1992-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-29 | 1995-09-28 | 1996-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-29 | 1999-09-28 | 2000-03-29 | $7700.00 | Window Closed / Lapsed |