US3735337A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Minimizing multiple reflecting
Assignee: AMCO PROD CO
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Filing: 1971-07-22
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Granted: 1973-05-22
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Expires: 1991-07-22
Abstract
Abstract Seismic traces obtained using the common depth point technique are time-corrected first to remove normal moveout corresponding to primary reflections, then further time-corrected to increase the variation of time at which multiple reflections occur on the various traces. The traces are then summed, which decreases the amplitude of multiple reflections relative to those of the primary reflections. Preferably before the second time correction, selection is made of traces such that there is approximately a linear residual normal moveout of multiple reflections on the traces selected. The second time correction does not seriously affect the primary reflections either in amplitude or arrival time. After the second time correction, the selected traces are summed for visual presentation.
Inventors
- 👤 M Widess
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:59
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/28; G01V2210/00; G01V2210/50; G01V2210/56
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
147 words
A process for combining seismic traces representing signals reflected from at least approximately common points in a subsurface formation in which said traces have been obtained using a plurality of spacings from the seismic sources to the detectors, comprising 1. selecting a reference trace and time-correcting the other of said traces with respect to this reference trace to remove the primary reflection normal moveout from at least a common time band of all saiD traces, 2. applying a second timing correction to each of said traces the average value of which is zero and the amount of which applied to each trace is substantially linearly proportional to the effective position of the geophone group from which said trace was obtained, and 3. thereafter adding the second time-corrected traces to provide a single summation trace in which primary reflections have been enhanced in amplitude relative to multiple reflections.
Claim 2
Dependent Claim
147 words
A process for combining seismic traces representing signals reflected from at least approximately common points in a subsurface formation in which said traces have been obtained using a plurality of spacings from the seismic sources to the detectors, comprising 1. selecting a reference trace and time-correcting the other of said traces with respect to this reference trace to remove the primary reflection normal moveout from at least a common time band of all saiD traces, 2. applying a second timing correction to each of said traces the average value of which is zero and the amount of which applied to each trace is substantially linearly proportional to the effective position of the geophone group from which said trace was obtained, and 3. thereafter adding the second time-corrected traces to provide a single summation trace in which primary reflections have been enhanced in amplitude relative to multiple reflections.
Claim 3
Dependent Claim
45 words
applying a second timing correction to each of said traces the average value of which is zero and the amount of which applied to each trace is substantially linearly proportional to the effective position of the geophone group from which said trace was obtained, and
Claim 4
Dependent Claim
45 words
applying a second timing correction to each of said traces the average value of which is zero and the amount of which applied to each trace is substantially linearly proportional to the effective position of the geophone group from which said trace was obtained, and
Claim 5
Dependent Claim
38 words
A process in accordance with claim 1 in which said common time band is essentially the whole record time of each of said traces, and including the step of making a visual presentation of said single summation trace.
Claim 6
Dependent Claim
25 words
thereafter adding the second time-corrected traces to provide a single summation trace in which primary reflections have been enhanced in amplitude relative to multiple reflections.
Claim 7
Dependent Claim
25 words
thereafter adding the second time-corrected traces to provide a single summation trace in which primary reflections have been enhanced in amplitude relative to multiple reflections.
Claim 8
Dependent Claim
41 words
repeating steps (1) and (2) for a plurality of producing and receiving locations chosen to lie substantially symmetrically about the midposition between the initial producing and receiving locations of steps (1) and (2), thereby producing a plurality of said reproducible traces,
Claim 9
Dependent Claim
41 words
repeating steps (1) and (2) for a plurality of producing and receiving locations chosen to lie substantially symmetrically about the midposition between the initial producing and receiving locations of steps (1) and (2), thereby producing a plurality of said reproducible traces,
Claim 10
Dependent Claim
60 words
A process in accordance with claim 2 including the step of selecting from said traces only those having a multiple reflection residual normal moveout which varies approximately linearly with effective trace distance prior to applying said second timing correction, and said second timing correction is zero at least near the center of the effective trace distance of the selected traces.
Claim 11
Dependent Claim
85 words
A process in accordance with claim 3 in which the absolute maximum value of said second timing correction is approximately Delta Te- Delta Tm/2 where Te is the total effective moveout over the total effective source-to-geophone group spacing corresponding to the selected traces, Delta Tm is the effective residual normal moveout of a multiple reflection over said group spacing, and Delta Te/ Tau (where Tau is the predominant period of the wavelet corresponding to said multiple reflection) has a value of at least about 0.6.
Claim 12
Dependent Claim
15 words
time-correcting all of said traces to remove the primary reflection normal moveout from said traces,
Claim 13
Dependent Claim
15 words
time-correcting all of said traces to remove the primary reflection normal moveout from said traces,
Claim 14
Dependent Claim
90 words
A process in accordance with claim 3 in which the absolute maximum value of said second timing correction is approximately Delta Te- Delta Tm/2 where Delta Te is the total effective moveout over the total effective source-to-geophone group spacing corresponding to the selected traces, Delta Tm is the effective residual normal moveout of a multiple reflection over said group spacing, and Delta Te/ Tau (where Tau is the predominant period of the wavelet corresponding to said multiple reflection) has a value in the range of about 0.6 to about 1.2.
Claim 15
Dependent Claim
54 words
applying a second timing correction to each of said traces the average value of which is zero and the amount of which applied to each trace is substantially linearly proportional to the distance from the midpoint of said effective receiving locations to the effective receiving location corresponding to each trace being so corrected, and
Claim 16
Dependent Claim
54 words
applying a second timing correction to each of said traces the average value of which is zero and the amount of which applied to each trace is substantially linearly proportional to the distance from the midpoint of said effective receiving locations to the effective receiving location corresponding to each trace being so corrected, and
Claim 17
Dependent Claim
25 words
producing a visual indication proportional to the summation of the second time-corrected traces to produce a trace in which multiple seismic reflections have been attenuated.
Claim 18
Dependent Claim
25 words
producing a visual indication proportional to the summation of the second time-corrected traces to produce a trace in which multiple seismic reflections have been attenuated.
Claim 19
Dependent Claim
6 words
A process for seismic prospecting comprising
Claim 20
Dependent Claim
6 words
A process for seismic prospecting comprising
Claim 21
Dependent Claim
53 words
A process in accordance with claim 6 including the step of selecting from said traces only those having a multiple reflection residual moveout which varies approximately linearly with effective trace distance prior to applying said second timing correction, and said second timing correction is zero at the midpoint of said effective receiving locations.
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) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |