Patent US4849945A successfully refreshed from Google Patents.
US4849945A
Expired / Lapsed
US
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Seismic processing and imaging with a drill-bit source
Assignee: Western Atlas International Inc
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Filing: 1986-12-08
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Granted: 1989-07-18
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Expires: 2006-12-08
Abstract
Abstract An apparatus (10) for determining while drilling in the earth with a drill bit (12) the positions of seismic wave reflecting geologic formations (15, 17) has seismic wave sensors (A, B) positioned in the earth near its surface (42). The sensors (A, B) are disposed at known positions with respect to the borehole. The drill bit (12) generates the seismic waves. The sensors (A, B) receive the seismic waves both directly and by reflection from the geologic formations (15, 17). Adaptive filters (20, 26) are connected to each of the sensors (A, B). A summing circuit (34) receives outputs from the adaptive filters (20, 26). The converged impulse responses of the adaptive filters provide information about the amplitude of the reflected waves and their arrival times at the surface, thus allowing detection of the reflecting horizons and their location and physical characteristics.
Inventors
- 👤 Bernard Widrow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:37
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/40; G01V1/42; G01V1/28; G01V1/36; G01V1/364; G01V1/368; G01V2210/00; G01V2210/20; G01V2210/27
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
285 words
Apparatus for determining while drilling in the earth with a drill bit the positions of seismic wave reflecting geologic formations in the earth, said drill bit serving to generate the seismic waves, which comprises at least one pair of seismic wave sensors positioned in the earth near the surface thereof, in at least one pair of known positions with respect to said borehole, said seismic wave sensors being adapted to receive first seismic waves generated by said drill bit which travel directly to said sensors and second seismic waves generated by said drill bit which are reflected by the geologic formations, at least one pair of adaptive filtering means each connected to receive sensed signals from one of said at least one pair of seismic wave sensors, and differencing means connected to receive an output from each of said at least one pair of adaptive filtering means to form an error signal, at least one of said at least one pair of adaptive filtering means being connected to receive the sensed signals from one of said at least one pair of seismic wave sensors through a unit delay means and said one of said at least one pair of seismic wave sensors being connected to supply the sensed signals to a summing means, means utilizing an adaptation algorithm to adapt said at least one pair of adaptive filtering means, said differencing means being free of an input other than an input which has been supplied to one of said at least one pair of adaptive filtering means, impulse responses of said at least one pair of adaptive filtering means after convergence yielding arrival times and amplitudes of direct and reflected waves from said drill bit.
Claim 2
Dependent Claim
285 words
Apparatus for determining while drilling in the earth with a drill bit the positions of seismic wave reflecting geologic formations in the earth, said drill bit serving to generate the seismic waves, which comprises at least one pair of seismic wave sensors positioned in the earth near the surface thereof, in at least one pair of known positions with respect to said borehole, said seismic wave sensors being adapted to receive first seismic waves generated by said drill bit which travel directly to said sensors and second seismic waves generated by said drill bit which are reflected by the geologic formations, at least one pair of adaptive filtering means each connected to receive sensed signals from one of said at least one pair of seismic wave sensors, and differencing means connected to receive an output from each of said at least one pair of adaptive filtering means to form an error signal, at least one of said at least one pair of adaptive filtering means being connected to receive the sensed signals from one of said at least one pair of seismic wave sensors through a unit delay means and said one of said at least one pair of seismic wave sensors being connected to supply the sensed signals to a summing means, means utilizing an adaptation algorithm to adapt said at least one pair of adaptive filtering means, said differencing means being free of an input other than an input which has been supplied to one of said at least one pair of adaptive filtering means, impulse responses of said at least one pair of adaptive filtering means after convergence yielding arrival times and amplitudes of direct and reflected waves from said drill bit.
Claim 3
Dependent Claim
59 words
The apparatus for determining the positions of seismic wave reflecting geologic formations in accordance with claim 1 in which said at least one pair of adaptive filtering means is configured and connected to minimize error at an output of said first summing means, thereby balancing the outputs of each of said at least one pair of adaptive filtering means.
Claim 4
Dependent Claim
36 words
The apparatus for determining the positions of seismic wave reflecting geologic formations in accordance with claim 2 in which said at least one pair of adaptive filtering means are adapted by a least mean square algorithm.
Claim 5
Dependent Claim
56 words
The apparatus for determining the positions of seismic wave reflecting geologic formations in accordance with claim 3 in which the sensed signals supplied to said at least one pair of adaptive filtering means are corrupted by white earth noise and the least mean square algorithm is modified to alleviate the effects of the white earth noise.
Claim 6
Dependent Claim
34 words
The apparatus for determining the positions of seismic wave reflecting geologic formations in accordance with claim 1 in which said at least one pair of adaptive filtering means comprise transversal filters with adjustable weights.
Claim 7
Dependent Claim
45 words
The apparatus for determining the positions of seismic wave reflecting geologic formations in accordance with claim 1 in which at least one of said at least one pair of seismic wave sensors is a geophone which detects seismic waves in at least one horizontal direction.
Claim 8
Dependent Claim
50 words
The apparatus for determining the positions of seismic wave reflecting geologic formations in accordance with claim 6 in which the geophone detects seismic waves in a horizontal direction transverse to an axis between the borehole and the geophone or detects seismic waves in a horizontal direction radially of the axis.
Claim 9
Dependent Claim
45 words
The apparatus for determining the positions of seismic wave reflecting geologic formations in accordance with claim 4 in which at least one of said at least one pair of seismic wave sensors is a geophone which detects seismic waes in at least one horizontal direction.
Claim 10
Dependent Claim
35 words
The apparatus for determining the positions of seismic wave reflecting geologic formations in accordance with claim 4 in which said apparatus is configured to provide a three-dimensional image of the seismic wave reflecting geologic formations.
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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) | 1992-07-17 | 1993-01-16 | 1993-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-17 | 1997-01-16 | 1997-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-17 | 2001-01-16 | 2001-07-18 | $7700.00 | Window Closed / Lapsed |