Patent US5128867A successfully refreshed from Google Patents.
US5128867A
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Method and apparatus for determining inclination angle of a borehole while drilling
Assignee: Baker Hughes Oilfield Operations LLC
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Filing: 1990-09-19
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Granted: 1992-07-07
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Expires: 2010-09-19
Abstract
Abstract A method and apparatus is presented for determining the inclination angle of a borehole being drilled, the data for determining the inclination angle being obtained while the drillstring is rotating.
Inventors
- 👤 Walter A. Helm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:13
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/02; E21B47/022
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
134 words
A method for determining the inclination angle of a borehole being drilled by instruments contained downhole in a tool in a drillstring, including the steps of: rotating the drillstring; sensing with accelerometer means while the drillstring is rotating instantaneous acceleration components of gx or gy and gz at a location of the tool wherein the component gz is along an axis of the drillstring and the components gx and gy are orthogonal to gz; determining a rotation rate of the drillstring, said rotation rate being independent of said sensed instantaneous acceleration components; determining inclination angle INC from at least one of the equivalent relationships ##EQU14## where Gx=a magnitude of a first discrete fourier transform coefficient of gx; Gy=a magnitude of a first discrete fourier transform coefficient of gy; and Gz=a time average of gz.
Claim 2
Independent Claim
134 words
A method for determining the inclination angle of a borehole being drilled by instruments contained downhole in a tool in a drillstring, including the steps of: rotating the drillstring; sensing with accelerometer means while the drillstring is rotating instantaneous acceleration components of gx or gy and gz at a location of the tool wherein the component gz is along an axis of the drillstring and the components gx and gy are orthogonal to gz; determining a rotation rate of the drillstring, said rotation rate being independent of said sensed instantaneous acceleration components; determining inclination angle INC from at least one of the equivalent relationships ##EQU14## where Gx=a magnitude of a first discrete fourier transform coefficient of gx; Gy=a magnitude of a first discrete fourier transform coefficient of gy; and Gz=a time average of gz.
Claim 3
Dependent Claim
11 words
The method of claim 1 including the step of: ##EQU15## .
Claim 4
Dependent Claim
61 words
The method of claim 1 wherein said sensing step includes sensing a preselected number of samples and wherein said drillstring is rotated a preselected number of rotations and including the step of: determining Gz from the equation ##EQU16## where K=said preselected number of drillstring rotations; N=said preselected number of samples taken in one rotation; and Tm=period for the m'th tool rotation.
Claim 5
Independent Claim
137 words
An apparatus for determining the inclination angle of a borehole being drilled by instruments contained downhole in a tool in a drillstring, including: means for rotating the drillstring; accelerometer means for sensing while the drillstring is rotating instantaneous acceleration components of gx or gy and gz at a location of the tool wherein the component gz is along an axis of the drillstring and the components gx and gy are orthogonal to gz; means for determining a rotation rate of the drillstring, said rotation rate being independent of said sensed instantaneous acceleration components; means for determining inclination angle INC from at least one of the equivalent relationships ##EQU17## where Gx=a magnitude of a first discrete fourier transform coefficient of gx; Gy=a magnitude of a first discrete fourier transform coefficient of gy; and Gz=a time average of gz.
Claim 6
Independent Claim
137 words
An apparatus for determining the inclination angle of a borehole being drilled by instruments contained downhole in a tool in a drillstring, including: means for rotating the drillstring; accelerometer means for sensing while the drillstring is rotating instantaneous acceleration components of gx or gy and gz at a location of the tool wherein the component gz is along an axis of the drillstring and the components gx and gy are orthogonal to gz; means for determining a rotation rate of the drillstring, said rotation rate being independent of said sensed instantaneous acceleration components; means for determining inclination angle INC from at least one of the equivalent relationships ##EQU17## where Gx=a magnitude of a first discrete fourier transform coefficient of gx; Gy=a magnitude of a first discrete fourier transform coefficient of gy; and Gz=a time average of gz.
Claim 7
Dependent Claim
15 words
The apparatus of claim 4 including: means for determining |Gx| from the equation ##EQU18## .
Claim 8
Dependent Claim
52 words
The apparatus of claim 4 wherein said accelerometer means senses a preselected number of samples and wherein said drillstring is rotated a preselected number of rotations and including: ##EQU19## where Tm=period for the m'th tool rotation. N=said preselected number of samples taken in one rotation; and K=said preselected number of drillstring rotations.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-07-07 | 1996-01-06 | 1996-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-07 | 2000-01-06 | 2000-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-07 | 2004-01-06 | 2004-07-07 | $7700.00 | Window Closed / Lapsed |